Adams, Robert P., and Thomas A. Zanoni. 1979. The distribution, synonomy, and taxonomy of three junipers of southwestern United States and northern Mexico. Sout

Maheshwari, P. and Vimla Vasil. 1961. Gnetum. Botanical Monograph No. 1. New Delhi: Council of Scientific & Industrial Research.

de Laubenfels, David J. 1978. Blumea 24:189-190.

Little, Elbert L. Jr. 1966. Varietal transfers in Cupressus and Chamaecyparis. Madroño 18:161-167.

Maze, J. and W.H. Parker. 1983. A study of population differentiation and variation in Abies procera. Canadian Journal of Botany 61:1094-1104.

Morgenstern, E.K. and J.L. Farrar. 1964. Introgressive Hybridization in Red Spruce and Black Spruce. Toronto: University of Toronto, Fac. Forest., Technical Report 4.

Parish, Roberta; Ray Coupé and Dennis Lloyd. 1996. Plants of southern interior British Columbia. Vancouver, BC: Lone Pine. 463p.

Passini, M-F. 1994. Synonymie entre Pinus discolor et Pinus johannis. Acta Botanica Gallica 141: 387-388.

Pilger, R.K.F. 1903. Taxaceae. V. 18[IV,5] p. 1-124 in H.G.A. Engler, ed., 1900 - 1953. Berlin: Das Pflanzenreich... .

Pilger, R.K.F. 1916. Die Taxales. Mitt. Deutsch. Dendrol. Ges. 25:1-28.

Silba, J. 1981. Revision of Cupressus L. (Cupressaceae). Phytologia 49:390-399.

Stevenson, D.W. 1987. Comments on character distribution, taxonomy and nomenclature of the genus Zamia L. in the West Indies and Mexico. Encephalartos 9:3-7.

Stoltmann, Randy. 1987. Hiking guide to the big trees of southwestern British Columbia. Vancouver, BC: Western Canada Wilderness Committee. 145p.

Vasek, F.C. 1966. The distribution and taxonomy of three western junipers. Brittonia 18: 350-372.

Zavarin, E., K. Snajberk, and J. Fisher. 1975. Geographic variability of monoterpenes from the cortex of Abies concolor. Biochem. Syst. & Ecology 3:191-203.

Zanoni, T.A. 1978. The American junipers of the section Sabina (Juniperus, Cupressaceae)--A century later. Phytologia 38:433-454.

Packee et al. 1981.

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Thompson, J. and L.A.S. Johnson. 1986. Callitris glaucophylla, Australia's 'white cypress pine' -- A new name for an old species. Telopea 2:731-736.

Owens, J.N. and M. Molder. 1975. Pollination, female gametophyte, and embryo and seed development in yellow cedar (Chamaecyparis nootkatensis). Canadian Journal of Botany 53:186-199.

Wright, J.W.; W.A. Lemmien and J.N. Bright. 1971. Genetic variation in southern Rocky Mountain white fir. Silvae Genetica 20:148-150.

Rushforth, K.D. 1989. Two new species of Abies (Pinaceae) from western Mexico. Notes of the Royal Botanic Garden Edinburgh 46 (1): 101-109.

It is estimated the pinyon-juniper woodland type occupies 33 million acres in the western U.S. This vast resource has great potential for social benefits. Our knowledge of the type is summarized in the 12 papers in three areas: Ecology of the type, uses and potentials, and management strategies for the woodland zone.

Allen, R.W., PHYTO-EDAPHIC PARAMETERS OF UTAH JUNIPER PINYON ECOSYSTEMS, Proceedings of the Second Utah Shrub Ecology Workshop, Sept. 1982, p. 3-4.
Evaluation of 3 5 pinyon-juniper stands in Utah for phyto-edaphic characteristics indicating natural site was conducted. Six soil characteristics were sampled over three soil depth classes and correlated with percent presence of juniper-pinyon. Natural juniper pinyon sites appear to be indicated by soil texture, salinity, Ph and permeability characteristics. Neither calcic horizon nor available water holding capacity appear to be significant.


Andersen, A., MAMMALS OF MESA VERDE NATIONAL PARK, COLORADO, University of Kansas Publications, Museum of Natural History No. 14, 1961, p. 29-67.

Andersen, A.E., Walter A. Snyder, and Brown, George W., STOMACH CONTENT ANALYSES RELATED TO CONDITION IN MULE DEER, GUADALUPE MOUNTAINS, NEW MEXICO, Journal of Wildlife Management, vol. 29, 1965, p. 352-366.
An index to the food habits of a nonmigratory mule deer population occupying a juniper-pinyon woodland, succulent-shrub, and shortgrass-shrub compiled in southeastern New Mexico was provided by botanical analyses of 93 stomach content samples. Thirty-nine males and 54 females were obtained by shooting approximately 2 deer per month over a 49-month period. Of the total estimated volume of stomach contents, browse made up about 70 percent; forbs, 26; and grass and unidentified plant material the remainder. The five major food items, comprising about 64 percent of the total, were wavyleaf oak, juniper, hairy cercocarpus, yucca, and unidentified forbs, in order of decreasing percent volume. Juniper was the highest in total frequency with less variability and was the major item during the January-March period. Wavyleaf oak was the major item from April through December. When unusually heavy precipitation increased all forage-especially forb production in 1958-59, forbs exceeded both browse and grass components yearlong. Females of all age-classes collected during and for several months after this period were significantly heavier and presumably in better physical condition.

Anderson, D. F,. and Orrin J. Rongstad, RESPONSE OF NESTING RED-TAILED HAWKS TO HELICOPTER OVERFLIGHTS, The Condor, 1989, p. 296-299.
Low-level helicopter overflights of 35 Red-tailed Hawk nests were conducted at two study areas in southeastern and east-central Colorado in 1984 and 1985. Red-tailed Hawks nesting where low level air traffic was nonexistent prior to 1983 exhibited stronger avoidance behavior than did hawks nesting where helicopter activity had occurred since the late 1950's. Nine (53%) of 17 birds in the first study area flushed from the nest while only one (8%) of 12 birds in the second study area flushed. Age of nestlings at the time an overflight occurred did not influence avoidance behavior, and overflights did not appear to influence nesting success at either study area. Our results are consistent with the hypothesis that Redtailed Hawks habituate to low-level air traffic during the nesting period. However, naive birds may respond negatively to low-level helicopter activity prior to habituation and other species of raptors may respond differently than Red-tailed Hawks.

Within the pinyon-juniper type, trees and understory vegetation are interspersed with open areas forming a mosaic of vegetational patterns. The objective of this research was to define and describe vegetational zones surrounding Rocky Mountain pinyon and oneseed juniper. Transects consisting of contiguous frames were laid out from the base of the tree and continued into the interspace area (outside the canopy) for each cardinal direction. Potential zone boundaries were located by calculating a squared Euclidean distance utilizing basal cover estimates of each frame. Zone boundaries were verified by discriminant analysis. Vegetation associated with both pinyon pine and oneseed juniper exhibited 3 zones. Zone 1 consisted of vegetation associated with the tree bole. Zone 2 was, for the most part, located beneath the tree canopy. Zone 3, consisting primarily of interspace, contained mostly perennial grasses and forbs. Mean basal cover of vegetation surrounding oneseed juniper increased from <1% in zone 1, to approximately 7% in zone 2, to about 12% in zone 3. Mean basal cover estimates of vegetation associated with pinyon pine increased from approximately 4% in zone 1, to 10 and 11% in zones 2 and 3, respectively. Differences in species composition among zones between tree species were apparent.

Pitfall faunal sampling along north-south transects through the Arkansas River watershed in the vicinity of Canyon City, Colorado, was conducted from 1963 to 1965. A total of 721 specimens of insectivores and rodents was obtained, representing 22 species. The altitudinal distribution of these species is detailed and possible factors underlying the ecological distinctiveness of the area are suggested.

Armstrong, D.M., DISTRIBUTIONAL CHECKLISTYLE="OF RODENTS IN CANYONLANDS NATIONAL PARK, UTAH, Texas Technical University Occasional Paper No. 59, 1979, p. 44.

Aro, R.S., PINYON-JUNIPER MANIPULATION WITH MECHANICAL METHODS, In: The Pinyon-juniper Ecosystem: A Symposium. Utah State University, Logan, Utah, 1975, p. 67-73.

Vegetal composition was determined during 1974 and 1984 using 60 permanent 50 meter plots within a mature pinyon-juniper community in northeastern Utah. Results indicated that not only was there little significant change in community composition, but with many species frequency and density remained nearly the same during the decade.

Autenreith, R., W.R. Brigham, W. Molini, P. Shields, J. Slosson, and M. Wickersham, LIVESTOCK AND UPLAND WILDLIFE. ,Univ. of Calif., Agricultural Science Special Publication 3301, Berkeley, California., In: J.W. Menke (ed.), Proceedings: Workshop on Livestock and Wildlife-fisheries Relationships in the Great Basin, 1983, p. 76-86.

Bailey, R.W. and O.L. Copeland Jr., LOW FLOW DISCHARGES AND PLANT COVER RELATIONS ON TWO MOUNTAIN WATERSHEDS IN UTAH, Commission of Surface Waters, 1960, p. 267-278.
Twenty-two years of stream flow records provide a basis for comparing the behavior of low flow discharges from two adjacent watersheds of contrasting use history in Utah. One, the Centerville watershed, has no history of watershed plant cover depletion or floods. The adjacent Parrish watershed produced damaging mud-rock floods in 1930 following destruction of vegetation on the head water lands. Vegetation was restored on the depleted and eroded areas by contour trenching and reseeding prior to the start of streamflow records.
The annual regime of discharge from both watersheds is characterized by a rapid rise shortly 'after the beginning of snowmelt late in March, a brief period of maximum discharge in May, a rapid recession of flow in June, and a more gradual recession of flow through the summer, fall, and winter months. From the Parrish watershed, 73% of the annual discharge occurred in April-June high flow period, about 9% in July-September summer season, and about 2.5% in each of the other low flow months. Lowest discharges from the Centerville watershed in each of the winter months average about 3.5% of annual; that in the 3 summer months about 1.3%, and 62% in the 3 month period of highflow. The maximum discharges during the high flow periods were 14.5 c.s.m. and 10.1 c.s.m. for Parish and Centerville, respectively. Under the impact of several high-intensity summer storms the maximum instantaneous low flow discharges of either stream never exceeded 5 c.s.m. By contrast, summer storm discharges from a nearby area, with plant-soil conditions comparable to those existing on Parish before treatment, exceeded 2,000 c.s.m. The effective control of summer storm floods in the Parrish watershed was accompanied by a decrease of 2.70 inches of annual runoff over the 22 yr. period, 83% of which occurred in the first 11 yrs. Most of the decrease in annual yield occurred during the high flow months of March, April, and May. June yields were slightly increased. Discharge reductions were negligible.

Baker, M.F. and N.C. Frischknecht, SMALL MAMMALS INCREASE ON RECENTLY CLEARED AND SEEDED JUNIPER RANGELAND, Journal of Range Management, Vol. 26, March 1973.
Small mammal numbers were studied by snap trapping on six areas in Utah where juniper range had been cleared and seeded. On one area, which was trapped both before and for the first 3 years after treatment, numbers of deer mice and pocket mice increased greatly in the first 2 years following treatment, then declined sharply to a level which was still above that before treatment. On two areas only the first 2 years after treatment, many more small MAMMALS were caught in the first year. Older seedings had about the same number of small MAMMALS as did untreated juniper. Small MAMMALS showed a clear preference for windrowed slash. This was especially true of deer mice and long-tailed moles.

Baker Jr., M.B., THE DIVERSITY IN STREAMFLOW RESPONSE FROM UPLAND BASINS IN ARIZONA ,USDA Forest Service General Technical Report. RM-149, Ft. Collins, CO, In: Troendle, C.A.M.R. Kaufman, R.H. Hamre, and R.P. Winokur (tech. coord.). Management of Subalpine Forests: Building on 50 Years of Research., 1987, p. 2

Baker, M.B, HYDROLOGIC AND WATER QUALITY EFFECTS OF FIRE., USDA Forest Service General Technical Report. RM-191, Ft. Collins., In: J.S. Krammes (tech. coord.), Effect of Fire Management of Southwestern Natural Resources, 1990, p. 31-42.

Balda, R.P, AVIAN IMPACTS ON PINYON-JUNIPER WOODLANDS, Proceedings-Pinyon-Juniper Conference, Jan. 198 7, p. 525 -533.
The purpose of this paper is to bring together information about the importance of birds in consuming and dispersing pinyon pine and juniper seeds. Four seed caching corvids are responsible for placing hundreds of thousands of pinyon pine seeds in subterranean caches each fall when cone crops are heavy. Three species of thrushes overwinter in juniper woodlands, sometimes in high densities, and consume juniper berries as their stable diet. Both tree species appear to rely heavily on birds to disperse their propagules. With wise and clever management practices, birds may be enticed to obtain our management objectives for us.

Barber, M.J. and R. Josephson, WILDFIRE PATTERNS AND VEGETATION RESPONSE IN EAST- NEVADA, Proceedings-Pinyon Juniper Conference, Jan. 1987, p. 158-160.
Historical mining activity, settlement, heavy grazing, and increased fire suppression activities have led to an increase in number of large (100+ acres) fires over 2.4 million acres of pinyon juniper woodlands. A method of evaluating existing burns is used to make application in predicting vegetation response as part of prescribed burning, escaped fire analysis, or rehabilitation of wildfire burns.

Barnes, F.J. and G.L. Cunningham, WATER RELATIONS AND PRODUCTIVITY IN PINYON-JUNIPER HABITAT TYPES, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 406-411.
Pinyon pine (Pinus edulis) and one seed juniper (Juniperus monosperma ) co-occur in northwestern New Mexico. Relative dominance of the two species varies with elevation along a complex environmental gradient. To determine the ecophysiological parameters contributing to this dominance pattern we have investigated photosynthetic responses to important variables along this gradient. As soil dries, photosynthesis of juniper decreases to zero at a predawn leaf water potential of -4.6 MPa, while in the pinyon the rate decreases to zero at -1.8 MPa. Results indicate that the pattern of species dominance is correlated with the pattern of relative seasonal carbon gain in these species. Wetter sites where pinyon is more dominant support greater carbon gain by that species.

Barney, M.A. and Neil C. Frischknecht, VEGETATION CHANGES FOLLOWING FIRE IN THE PINYON-JUNIPER TYPE OF WEST-CENTRAL UTAH, Journal of Range Management, 1974, p. 91-96.
The stages of succession following fire began with weedy annuals that reached a peak within 3 to 4 years. Juniper woodlands were well developed 85 to 90 years following fire. Intermediate stages of succession varied, but followed a general pattern of perennial grasses, perennial grasses-shrubs, and perennial grasses shrubs-trees. The percentage of dead sagebrush was positively correlated with density of junipers. Thirty-three years was the average minimum age at which Utah juniper produced seed.

Bassett, R.L., SILVICULTURAL SYSTEMS FOR PINYON-JUNIPER, Proceedings-Pinyon-Juniper Conference, Jan. 19 8 7, p. 273 - 2 78.
Silvicultural systems and cutting methods apply to pinyon-juniper stands. Each system and cutting method is described and the advantages and disadvantages compared. It appears that both the even- and uneven-aged silvicultural systems can be used to manage pinyon-juniper stands. The cutting methods that best apply are the single-tree selection and the shelterwood. Regeneration may be more certain with the single-tree selection method. The clearcut method can be used when alligator juniper is in the stand. The land manager must select the appropriate cutting method that fulfills both the land manager's objective and the species silvical requirements.

Henderson, D.E. and M.L. Baughman, WHOLE TREE HARVESTING OF THE PINYON-JUNIPER TYPE: ECONOMIC AND INSTITUTIONAL CONSIDERATIONS, Proceedings- Pinyon-Juniper Conference, Jan. 1987, p.192 -195.
As public land management agencies are faced with tighter fiscal constraints, capabilities to effectively implement desired land management practices may be lessened. Such conditions require innovative partnerships between the public and the private sectors. Such partnerships should seek to accomplish agency objectives while providing adequate economic initiatives to the private sector. Under proper conditions, public land management agency objectives concerning the management of the pinyon-juniper type could be accomplished by private sector. This discussion focuses on the various economic and institutional considerations which may be prerequisite to effective public/private sector relationships. Within this discussion, a model management framework is outlined, necessary institutional relationships defined, and economic benefits assessed.

Woody vegetation was documented over a 12-year period, and rainfall through 10 years of the periods, in 56 climax shrub and woodland communities in the Mojave, Great Basin and transition deserts of the Nevada Test Site in southern Nevada. Line interception data (335 m) were collected in each community in 1963, during a period of below-average rainfall, and again in 1975 along the same sampling lines, by the same method and observer. From summaries of the data for all sites and from data for individual sites, at the end of the 12 years which included periods of unusually high rainfall, there were consistent increases in numbers of shrubs and trees, mean height and percentage cover, and decreases in proportions of dead plants in the lines of nine representative sites. It is evident that most of the shrubs and trees living in 1963 were still present as living plants in 1975 and an average 14% were dead or had disappeared from the lines by 1975; around 20% to 30% of the 1975 plants were new to the lines and of seedling or, in some species, shoot origin. From the data it is predictable that during the recurring dry/moist cycles in desert regions there is a high rate of turnover in the shrub component of the climax vegetation. Plant fluctuations were closely correlated with regional and site rainfall fluctuations of the period. The magnitude of the fluctuations was within the range necessary for continuing stability of all of the communities and populations of woody species in the three desert areas.

Bedell, T.E., REHABILITATION OF WESTERN JUNIPER RANGELAND: A CASE HISTORY, Proceedings-Pinyon-Juniper Conference, Jan. 1987, p. 313-315.
The Bonnieview Ranch in central Oregon (Crook County ) economically increased beef production and drastically improved environmental diversity at the same time. This paper describes why and how it happened.

Bedell, T.E., RANGE MANAGEMENT CONCERNS ON JUNIPER WOODLANDS, Proceedings-Pinyon-Juniper Conference, Jan. 1987, p. 436-439.
Major concerns are the effects of increasingly larger populations of western juniper on watershed stability, forage production, and diversity and thus values of rangelands for various purposes. An allied but perhaps greater concern is that relatively little is done to satisfactorily control and manage existing stands.

Betancourt, J.L., PALEOECOLOGY OF PINYON-JUNIPER WOODLANDS: SUMMARY, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 129-139.
Modern distribution of pinyon and juniper species (arid their associations) should be considered ephemeral over the past 2 million years. Today Pinus edulis and P. monophylla occupy a regional platform with a base level above 1500 m, roughly their lower limit. A late Wisconsin upper limit of ca. 1500 m kept these pinyons south of the platform, where they expanded into desert lowlands. P. edulis immigrated to the Colorado Plateau by 10,000-8000 years B.P. It failed to reach its uppermost sites until 6000-4000 years B.P., possibly due to an expanded ponderosa pine zone. P. monophylla delayed its migration to the Great Basin until after 6500 years B.P., awaiting mid-Holocene climates or dispersal by man. Traditionally attributed to overgrazing and fire suppression, historic invasions could also mark the current progress of continued migration, climatic fluctuation, or recovery from historic and prehistoric woodcutting.

Blackburn, W.H. and Paul T. Tueller, PINYON AND JUNIPER INVASION IN BLACK SAGEBRUSH COMMUNITIES IN EAST-CENTRAL NEVADA, Ecology, Late-Summer 1970, p. 841-848.
As a means of studying inter- and intrazonal invasion in black sagebrush communities, six maturity classes were established for pinyon and juniper in east-central Nevada. Pinyon and juniper invade and increase in black sagebrush communities until the understory, except for a few hardy plants, is eliminated. Juniper invades first and tends to be eventually replaced by pinyon. Accelerated invasion by both species started about 192 1 and is closely related to overgrazing, fire suppression, and climatic change.

Blackburn, W.H. and C.M. Skau, INFILTRATION RATES AND SEDIMENT PRODUCTION OF SELECTED PLANT COMMUNITIES IN NEVADA, Journal of Range Management, Vol. 27, November 1974, p. 476-480.
Infiltration rates and sediment production of 29 plant communities and soils on five rangeland watershed were studied in central and eastern Nevada. Three inches per hour of simulated rainfall applied to initially dry soil and to soil initially at field capacity. Infiltration rates and sediment production for the various plant communities and soils varied considerably within and between watersheds. Highest infiltration rates and lowest sediment production occurred on sites with well-aggregated surface soils free of vesicular porosity.

Blackburn, W.H. and A.D. Bruner, USE OF FIRE IN MANIPULATION OF THE PINYON-JUNIPER ECOSYSTEM, The Pinyon-Juniper Ecosystem: A Symposium, May 1975, p. 91-96.
Benefits from a pinyon-juniper burning are becoming more attractive to land managers. Fire is being regarded as a naturally occurring element in the maintenance of many plant communities and not to be vigorously suppressed. The various types of prescribed pinyon-juniper burnings are categorized into (1) burning slash and debris, (2) burning individual trees, (3) burning grassland or sagebrush/grassland to kill invading trees, and (4) broadcast burning when the fire hazard is low, impact on vegetation is minimized, and in areas with natural firebreaks should be an important and effective method for pinyon-juniper control.

Blackburn, W.H., INFLUENCE OF BRUSH CONTROL ON HYDROLOGIC CHARACTERISTICS OF RANGE WATERSHEDS, Society for Range Management: Proceedings Brush Management Symposium, 1983.
Rangelands of western North America represented a tremendous resource that is producing forage at only about one-half to one-third its potential. The history of degradation of this environment is traced largely from the 18th and 19th centuries with the introduction of livestock, reduction of wildfires and other influences that man exerted on rangelands. Mechanical, chemical and/or prescribed burning are proven effective tools for restoring the forage productivity of shrub-dominated rangelands.

Boeker, E.L., V.E. Scott, and H.G. Reynolds, B.A. Donaldson, SEASONAL FOOD HABITS OF MULE DEER IN SOUTHWESTERN NEW MEXICO, Journal of Wildlife Management, 1973.
Rumen contents from 77 mule deer taken at seasonal intervals on the Fort Bayard Administrative Site, New Mexico, using the period 1964-69 were analyzed by point frame sampling. Woody browse made up approximately 75 percent of the total diet, forbs 16 percent, and grasses 2.2 percent. The most important species, comprising 56 percent, were oaks. For the major shrub species, a significant linear relationship existed between the percent density composition and percent volume in rumen contents for fall and winter, when browse comprised nearly 90 percent of the diet. Forbs were important diet items when available. Nutritional analyses of major forage species revealed adequate protein levels during all seasons. Calcium-phosphorus ratios were slightly higher than desirable in fall and winter, but they produced no visible, detrimental effects on the deer population. Digestibility was highest in spring and fall after periods of greatest precipitation. Generally, food supplies and nutritional quality appear adequate for maintaining mule deer on the Fort Bayard area.

Brackly, G.K., SCS INVENTORY AND CLASSIFICATION PROCEDURES, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 23 1-235.
Under the National cooperative Soil Survey Program, Second and Third Order soft surveys are currently being accomplished about 3.5 million acres of public and privately owned rangeland each year in Nevada. Units of vegetation (range and woodland sites) are correlated to soil taxa identified in these soil surveys. Sites are differentiated by their ability to produce a characteristic natural (climax) plant community. Edaphic, climatic, topographic and other environmental factors such as the potential for periodic wildfire occurring in a pristine situation are evaluated to determine the ability of a site to produce a given climax plant community. A review of concepts, rationalizations, and assumptions used in classifying and correlating units of vegetation to soil taxa inventoried in Nevada is presented.

Broadbent, J.L., DESCRIPTION AND DISCUSSION OF FIELD TOUR SITES, Proceedings of The Second Utah Shrub Ecology Workshop, Sept. 1982, p. 34-36.
The field tour of the 1982 Utah Shrub Ecology Workshop offered its participants an opportunity to examine and evaluate use and management of the pinyon-juniper type in central Utah. Programs and techniques included cabling, chaining, seeding, use of herbicides and prescribed burning together with the effects of post-treatment management.
A majority of the stops were located on the Creek Cooperative Management area located north of Fillmore (see map 1). The Management Area includes federal, state and private lands under cooperative and conjoined management in a practical effort to improve condition and production of natural resources.
Ecological aspects of all sites and treatments were a central part of the discussion, especially those relating to the effects of wildfire and the nature of secondary succession. Discussion leaders were Ron Wilson and Benton Smith (Forest Service), Harvey Gates and Don Burr (Bureau of Land Management), Lee Broadbent and Walt Bleak (Soil Conservation Service), Richard Stevens (Division of Wildlife Resources) and Neil West (Utah State University). A brief description of each site is identified by stop and number located on map 1.

Brotherson, J.D., William E. Evenson, Samuel R. Rushforth, John Fairchild and Jeffrey R. Johansen, SPATIAL PATTERNS OF PLANT COMMUNITIES AND DIFFERENTIAL WEATHERING IN NAVAJO NATIONAL MONUMENT, ARIZONA, The Great Basin Naturalist, 1985, p.1-13.
Vegetation patterns in Navajo National Monument, Arizona, were studied over a five-year period from 1977 to 1981. Twelve distinct plant community types occur within the boundaries of the park. These communities are characterized and the dominant plant species of each are recorded. The relationships of parent material, soils, and moisture to plant communities are also discussed. It appears that discrete communities occupy soils of different characteristics, particularly with respect to amount of weathering of parent material.

Brown, T.C., THE VALUE OF INCREMENTAL WATER FLOW FROM PINYON-JUNIPER LANDS, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 177-182.
Benefit-cost analyses of pinyon-juniper treatments that significantly increase runoff should include the value of the incremental flow. The value depends on the use of those flows, which is affected by the stochastic nature of flows and institutional arrangements for water storage and routing. Under common institutional arrangements, much of the incremental flow from pinyon-juniper manipulation probably would not be consumptively used. This would diminish the at-the-watershed value of incremental flow.

Brown, R.W., ECOPHYSIOLOGY AND WATER RELATIONS RESEARCH IN THE PINYON-JUNIPER VEGETATION TYPE, Proceedings - Pinyon Juniper Conference, Jan. 1987, p. 398-405.
An accelerated program in basic plant water relations research promises to contribute toward refined management of pinyon juniper woodlands. Focus is required on recent technological advances in research methods together with investigations of the morphological and physiological adaptations that influence drought tolerance of plants.

Brown, R.L, EFFECTS OF TIMBER MANAGEMENT PRACTICES ON ELK, USDA Forest Service General Technical Report RM-185, Ft. Collins., In: A. Tecle, W.W. Covington, and R.H. Hamre (tech. coords.), Multiresource Management of Ponderosa Pine Forests, 1989, p. 160-164.

Bruner, A.D. and D.A. Klebenow, PREDICTING SUCCESS OF PRESCRIBED FIRES IN PINYON-JUNIPER WOODLAND IN NEVADA, USDA Forest Service Resource Paper INT-219,1979, p. 11.

Sediment production and infiltration rates were measured in conjunction with an analysis of burning and grazing treatments in a chained pinyon-juniper study in southeastern Utah. While high natural variability was present among sites no significant changes in sediment production were detected following our prescribed burning or grazing treatments. Following treatment, however, both the burned and grazed sites exhibited significantly depressed infiltration rates during certain time intervals in comparison to the "undisturbed, natural" woodland control location.

Buckman, R.E. and G.L. Wolters, MULTI RESOURCE MANAGEMENT OF PINYON-JUNIPER WOODLANDS, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 2-4.
Pinyon-juniper woodlands occupy more than 47 million acres and are the most extensive forest type in many western states. In the past, woodlands were often ignored or converted to grasslands. The Forest Service is involved in the inventory, management, and research of pinyon-juniper woodlands. Forest survey crews are documenting woodland resources on BLM and National Forest lands. An administrative study on the Tonopah Ranger District, in the Great Basin, was one of the first attempts at multiple use management of the woodland. Research is examining the basic ecology of the woodland and developing new and improved management techniques. Woodland response to fire, tree harvesting, and mining activity has been documented. Woodland management strategies are being developed to utilize multiple-cash crops from forage, pine nuts, Christmas trees, and fuelwood while maintaining site quality and productivity for future generations.

Budy, J.D. and R.O. Meeuwig, PINYON-JUNIPER SILVICS AND SILVICULTURE, Proceedings Pinyon-juniper Conference, Jan. 1987, p. 244-248.
The pinyon-juniper type, being more xeric than any other timber type in the United States, has unique silvical characteristics. The demand for products other than wood, particularly forage for livestock and wildlife habitat, may provide an opportunity to practice multiple use silviculture. The development of efficient and appropriate silviculture systems is being facilitated by the increased research conducted in the pinyon-juniper type during the past 10 years.

Bunting, S.C., USE OF PRESCRIBED BURNING IN JUNIPER AND PINYON WOODLANDS, Proceedings Pinyon-juniper Conference, Jan 1987, p. 141-144.
Postfire succession in juniper and pinyon-juniper is primarily dependent upon the potential of the site, the preburn plant community and the characteristics of the fire. The successful use of prescribed burning is dependent upon the appropriate selection of treatment sites. As juniper and pinyon become more dominant on a site, the shrub and herbaceous layers decline in productivity. This reduces the fine fuels on the site making it more difficult to burn. There are also fewer herbaceous perennial plants remaining on the sites with greater tree dominance and the response of this component is less than that of sites burned at an earlier stage of juniper invasion. Treatment sites should be selected that are in stages of succession that can be efficiently burned in an economical and environmentally sound manner.


UNCHAINED PINYON-JUNIPER SITES IN SOUTHEASTERN UTAH, Journal of Range Management, Vol. 34, September 1981, p. 400-405.
This soil test was conducted on sandy loam soils in southeastern Utah during summers of 1971 and 1972. Forage removal and soil compaction had no consistent effect on infiltration rates. However, the clipping and compaction were an instantaneous application of forage removal and soil pressure and thus may not adequately represent long term, accumulative conditions imposed by actual grazing. Areas rested from livestock grazing since 1967 had significantly higher infiltration rates than grazed areas on unchained woodland and chained, debris-in-place sites. Grazed plots had infiltration rates comparable to rates measured in areas protected from grazing since 1969 or 1971. Grazing did not consistently affect infiltration rates it increased on all sites as the period of rest from grazing increased. None of the 21 soils and vegetation variables included in this study were identified by multiple regression models as consistently explaining significant amounts of variation in infiltration rates. Interill or sheet erosion rates were not significantly affected by forage removal subtreatments. No consistent relationship between erosion rates and soil compaction subtreatments or various periods of rest from grazing was found.

Carothers, S.W., and R.R. Johnson, WATER MANAGEMENT PRACTICES AND THEIR EFFECTS ON NONGAME BIRDS IN RANGE HABITATS, USDA Forest Service General Technical Report WO-1, Washington, DC., In: D.R. Smith (tech. coord.), Proceedings of the Symposium on Management of Forest and Range Habitats for Nongame Birds, 1975, p. 210-222.

While it has long been known that localization of litter fall can lead to significant modification of soil chemistry beneath trees and shrub species of arid and semi-arid areas, little has been done to define the detailed structure of these chemical alterations or their significance in terms of general ecosystem function. In recent years, however, there has been a renewal of interest in such plant-induced soil changes and a beginning has been made on the study of such distributional mosaics in relation to nutrient turnover. Early studies were concerned with ions associated with salinity, whereas current emphasis is more towards the configuration of the soil organic regime, particularly the nitrogen pool. Research in saltbrush communities of semi-arid Australia has established that there are marred horizontal and vertical gradients in total soil nitrogen, available phosphorus, organic carbon and nitrogen mineralization capacity. Gradients can be so steep that to be unaware of them, or to ignore them in soil sampling programs, could result in serious errors in estimations of either the nutrient capital or its turnover in the ecosystem. When the present study was initiated, no similar work on nutrient patterning had been undertaken in shrub-dominated rangelands of the western U.S.A. but it was apparent from the data of Garcia-Moya & McKell that some parallels with Australian experience could be expected. Accordingly, a broad survey was undertaken to test the applicability of previous findings and to provide a body of preliminary information on soil nitrogen, carbon and phosphorus levels in support of other research concerned with nutrient cycling.

Chojnacky, D.C, VOLUME AND GROWTH PREDICTION FOR PINYON-JUNIPER, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 207215.
Summarizes the author's work in recent volume and growth prediction for pinyon-juniper trees. Two volume models are compared, volume conversions to different utilization standards are explained, and prediction errors are examined. Three stand growth prediction measures are discussed: (1) current annual growth, (2) mean annual volume growth (mal) for unevened aged stands, and (3) a potential MAI for fully stocked stands. An appendix lists tables of equations developed.

Christensen, K.M. and T.G. Whitham, INDIRECT HERBIVORE MEDIATION OF AVIAN SEED DISPERSAL IN PINYON PINE, Ecological Society of America, vol. 72, 1991, p. 534-542.
During a 4 year study, we examined how an insect herbivore indirectly influenced pinyon pine by affecting its avian seed dispersal agents. Colorado pinyon pine, suffered reduced cone initiation and increased cone mortality primarily from infestation by the stem and cone boring moth. Because avian dispersal agents selectively foraged where cone crops were not highest, individual trees and stands of trees with greater insect abundance were avoided. Even herbivore-resident trees with substantial cone drop did not receive dispersal services if they were surrounded by susceptible trees because the birds often ignored entire stands of trees with artificially reduced crops even though many cones remained. We argue that masting, the production of large cone attractiveness of entire stands of trees to dispersal agents due to infestation may functionally alter the sex expression of uninfested individuals.

Clary, W.P., MULTIPLE USE EFFECTS OF MANIPULATING PINYON JUNIPER, Watershed Management Symposium, August l-975.
Concern about potential water shortages in central Arizona during the mid- 195 O's stimulated interest in watershed management. Different forms of vegetation manipulation were recommended to increase water yield from the surrounding watersheds. Pinyon-juniper was one of the vegetation types recommended for extensive modification. Because the majority of this type occurs on Federal lands, watershed studies were set up by Federal agencies to study the potential impacts of full-scale type modification.

Clary, W.P. and Donald A. Jameson, HERBAGE PRODUCTION FOLLOWING TREE AND SHRUB REMOVAL IN THE PINYON-JUNIPER TYPE OF ARIZONA, Journal of Range and Management, Vol. 34, 1981, p. 109-113.
Herbage production was evaluated after overstory removal from different sites within pinyon-juniper type. Average annual production varied from 43 to 643 Kg/ha before treatment and 715 to 3,703 Kg/ha after treatment. Production variation among sites was related to annual precipitation, pretreatment tree canopy, pretreatment nitrate-nitrogen, and presence or absence of limestone soils. Grasses increased in the composition 46 to 73% on the average, while forbs decreased from 21 to 19%, and half-shrubs and shrubs decreased from 33 to 8%.
The pinyon-juniper vegetation type covers a substantial portion of western and southwestern United States. Recent estimates range from 17.3 million (Forest-Range Task Force 1972) to 32.5 million ha (West et al. 1975), with 3.4 million (Forest-Range Task Force 1972 ) to 5.7 million ha (Folliott and Thorud 2975) in Arizona. The extent of this vegetation type makes it important enough even though the per hectare productivity is low. The diversity of products available from pinyon -juniper woodlands, which gives it some of its appeal, has also resulted in conflicts of use (Gifford and Bushy 1975; Aidon and Loring 1977). Many have suggested that the best use is as range for grazing animals (Springfield 1976). As a result, substantial areas of pinyon and juniper trees have been removed to reduce forage plant competition. Better productivity information is needed so research and management attention can be focused to obtain the best yield of all products and amenities from this vegetation type. The objective of this study was to determine the herbage production after overstory removal from various sites within the pinyon-juniper type of Arizona. Sites with soils developed from different parent rocks were evaluated for their ability to produce native herbaceous vegetation.

Clary, W.P., Sherel Goodrich, and B.M. Smith, RESPONSE TO TEBUTHIURON BY UTAH JUNIPER AND MOUNTAIN BIG SAGEBRUSH COMMUNITIES, Journal of Range Management, vol. 38, 1985, p. 5860.
The herbicide tebuthiuron was applied aerially in replicated parallel strips at rates of O, 1.3, 2.0, and 2.7 kg/ha a.i. (active ingredient) in 40% pellets on a Utah juniper stand, and at rates of O, 0.6, 1.0, and 1.3 kg/ha a.i. in 10% pellets on a mountain big sagebrush stand. Crown kill on Utah juniper was nearly 100% at application rates of 2.0 kg/ha or greater. Control of mountain big sagebrush was obtained at rates of 0.6 kg/ha and above. Antelope bitterbrush, hairy low rabbitbrush, and gray horsebrush responded to the herbicide similarly to Utah juniper. Rubber rabbitbrush was not controlled by tebuthiuron. Total understory production had changed little 3 years after the application, although compensating decreases in production of perennial plants and increases in production of annual grasses occurred.

A variety of techniques were used by the Forest Service and Bureau of Land Management to revegetate major portions of two wildfire burns in central Utah. The techniques included aerial seeding with single chaining, aerial seeding with double chaining, aerial seeding with quadruple chaining, rangeland drilling, and land imprinting. Production of seeded plants, when viewed across the range of seeding techniques and ecological site conditions, varied from 170 to 971 kg/ha. The costs associated with seeding these sites varied from $42 to $84/ha. Economic effectiveness was determined by comparing the value of the forage increase with the cost of seeding.


Clary, W.P., HERBAGE PRODUCTION AND LIVESTOCK GRAZING ON PINYON-JUNIPER WOODLANDS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 440-447.
In the past ten years relatively little new information has become available on herbage production and grazing systems for most areas of the pinyon-juniper ecosystem. Although there are some similarities across the woodlands In herbage production and response to tree removal, the great variety of environmental conditions In which pinyon-juniper woodlands exists reduces the applicability of average values. Broad comparisons of published data suggest that grazed plant communities may have substantially less herbage production than ungrazed plant communities. Continuous season-long grazing at proper stocking rates appears to produce the heaviest calf weights In summer rainfall areas, but no information is available from other parts of the woodlands. New grazing systems are currently being tested.

Clevenger, G.A. and G.W. Workman, THE EFFECT OF CAMPGROUNDS ON SMALL MAMMALS IN CANYONLANDS AND ARCHES NATIONAL PARKS, UTAH, Final Report, Project No. UNWR-013-2, Dept. of Wildlife Science, Utah State University, Logan, Utah, 1977.

Cryptogamic soil crusts in Grand Canyon National Park were trampled by hikers, under controlled conditions, to determine how rapidly they were pulverized and how rapidly they recovered. Only 15 trampling passes were required to destroy the structure of the crusts; visual evidence of bacteria and cryptogam cover was reduced to near zero after 50 passes. Soil crusts redeveloped in just one to three years, and after five years the extensive bacteria and cryptogam cover left little visual evidence of disturbance. Surface irregularity remained low after five years, however, suggesting that recovery was incomplete.

Conner, R.C., J.D. Born, A.W. Green, and R.A. O'Brien, FORESTYLE="RESOURCES OF ARIZONA, USDA Forest Service Res. Bulletin INT-69, Ogden, Utah, 1990.

Covington, W.W. and L.F. DeBano, EFFECTS OF FIRE ON PINYON JUNIPER SOILS, USDA Forest Service General Technical Report RM191, Ft. Collins, In: J.S. Krammes (tech. coord.), Effects of Fire Management of Southwestern Natural Resources, 1990, p. 78-86.

Cramer, K.L. and J.A. Chapman, REPRODUCTION OF THREE SPECIES OF POCKET MICE IN THE BONNEVILLE BASIN, UTAH, Great Basin Naturalist, 1990, p. 361-365.
Data on reproduction of three species of pocket mice occurring in northern Utah are summarized. Perognathus parvus and P. formosus bred in spring but not the remainder of the year. This occurred despite mild fall and winter temperatures and shallow snowcover. Litter sizes for P. parvus and P. formosus were similar to those reported by previous investigators. A small sample of P. longimembris indicated they may have much larger litters (averaging 5.78 young) than previously reported for laboratory populations. Adult body mass was positively correlated with testis mass in all species, and with litter size in P. parvus.

Annual plant populations in northwestern New Mexico were found to be spatially and temporally highly variable. During favorable years annual plant species have patterns of dominance and diversity that are different from those of perennial species. Measurement of perennial plant diversity in plant communities is a poor predictor of productivity. Both perennial and annual components of plant communities should be considered in measurements of diversity and productivity.

Dalen, R.S. and W.R. Snyder, ECONOMIC AND SOCIAL ASPECT OF PINYON-JUNIPER TREATMENT-- THEN AND NOW, Proceedings Pinyon-juniper Conference, Jan. 1987, p. 343-350.
Since 1950, about 550,000 acres of pinyon-juniper woodland on the National Forest in the southwest have been mechanically treated to improve forage production. Management emphasis of pinyon juniper woodland has shifted to fuelwood and wildlife, but if forage production is to be maintained, retreatment is needed. Treated areas are in various stages of regrowth with residual and new trees varying from 10 to over 250/acre. The age of the clearing, forage site productivity, tree density, height distribution, and composition are important factors in selecting retreatment projects. A pinyon-juniper regrowth model was developed to help select the better retreatment sites. Retreatment is most cost efficient on high forage production sites where tree density is between 25-125 trees/acre and 85% of the trees are 6 feet tall or less.

During the late-Pleistocene, pinyon-juniper pollen was abundant in Neotoma middens from the Tinajas Altas Mountains (365-580 m) in the lower Colorado River Valley. At ca. 9000 yr B.P. (radiocarbon years before present) juniper pollen percentages in these middens drop to O; but at the same time juniper pollen percentages increase in three sites above 1300 m elevation on the Colorado Plateau. Juniper percentages are greatest in these high-elevation sites during the late Holocene. At Pecks Lake in central Arizona, juniper pollen percentages increase from ca. 10% at 2630 yr B.P. to ca. 30% at 200 yr B.P. A sudden increase to over 40% ca. 100 yrs ago is preceded by the first occurrence of exotic weeds and indicators of the presence of livestock. Thus, the Pecks Lake pollen diagram clearly shows historic juniper invasion, but the expansion is part of a trend that started over 2600 years earlier.

Davis, J.N. and K.T. Harper, WEEDY ANNUALS AND ESTABLISHMENT OF SEEDED SPECIES ON CHAINED JUNIPER-PINYON WOODLAND IN CENTRAL UTAH, USDA Forest Service General Technical Report INT215, Ogden, Utah., In: E.D. McArthur, E.M. Ronmey, S.D. Smith, and P.T. Tueller (compilers). Proceedings--Symposium on Cheatgrass Invasion, Shrub Die-off, and Other Aspects of Shrub Biology and Management, 1990, p. 72-79.

Curlleaf mountain-mahogany is a widely distributed shrubby tree of western North America. Well-developed stands are most often found on warm, dry, rocky ridges and slopes at high elevations on mostly southern exposures. It can, however, be found on all exposures. The species appears to be indifferent to substrate with soils which are shallow and of low fertility. However, the nitrogen fixing root nodules help overcome soil deficiencies. This highly palatable species is preferred by mountain sheep, mountain goats, deer, and elk. Its nutritive value (about 12% protein) and digestibility ratings (around 50%) in the winter are high when compared with most other associated winter browse species. Early research with curlleaf mountain-mahogany basically dealt with two major management problems: (1) how to increase available forage production on old, even-aged stands too tail for big game to browse, and (2) how to increase fast-growing plants, appears to be a promising management technique providing browse until the younger curlleaf becomes established.

Deacon, J.E., William G. Bradley and Karl M. Larsen, ECOLOGICAL DISTRIBUTION OF THE MAMMALS OF CLARK CANYON, CHARLESTON MOUNTAINS, NEVADA, Journal of Mammalogy, 1964, p. 397-409.
A total of 8,660 trap night and 23 mist net hours were expended in a study of the distribution of small MAMMALS in Clark Canyon, Charleston Mountains (Spring Mountain Range), during June of 1961 and 1962. The MAMMALS are regarded as components of biotic communities which are described in detail. The numbers of species increase with an increase in environmental heterogeneity which is often correlated with a decrease in elevation. Data are presented which indicate that a later reproductive season in 1962 is correlated with the more severe climatic conditions in the winter and the delayed spring of that year.

DeBano, L.F., H.M. Perry and S.T. Overby, EFFECTS OF FUEL WOOD HARVESTING AND SLASH BURNING ON BIOMASS AND NUTRIENT RELATIONSHIPS IN A PINYON-JUNIPER STAND, Proceedings Pinyon-juniper Conference, Jan. 198 7, p. 3 82-3 86.
Fuelwood made up about 3 8% of the tree biomass in a stand of Utah juniper, but contained less than 25% of individual nutrients. Fire acted as a rapid mineralizing agent. Slash burning and tree removal also affected soil mineralization and nitrification.

Debano, L.F. and J.M. Klopatek, EFFECT OF MANAGEMENT ON NUTRIENT DYNAMICS IN SOUTHWESTERN PINYON JUNIPER WOODLANDS, USDA Forest Service General Technical Report RM-149, Ft. Collins, CO. ,in: Troendle, C.A.M.R. Kaufmann, R.H. Hamre, and R.P. Winokur (tech. coords.). Management of Subalpine Forests: Building on 50 years of Research, 1987, p. 157-160.

DeBloois, I.E, D.F. Green and H.G. Wylie, A TESTYLE="OF THE IMPACT OF PINYON-JUNIPER CHAINING ON ARCHAEOLOGICAL SITES, The Pinyon-Juniper Ecosystem: A Symposium, May 1975, p. 153-185.
Clearing of pinyon-juniper forest and sage brushlands with caterpillar tractors and heavy drag chain is a common method of improving grassland grazing habitat in the Western United States. A controlled chaining experiment on a surface lithic site in eastern Utah indicates that the soil disturbance produced by associated uprooting, dragging, and trampling actions can have serious effects on surface and subsurface archaeological remains. These impacts can be quantified and discussed in terms of artifact displacement, loss, breakage, and churning. Some suggestions for mitigating these impacts are considered.

Nearly 22,000 acres of pinyon-juniper woodlands were burned and seeded from 1953 to 1963 on the Hualapai Indian Reservation in northwestern Arizona. Burning was conducted in very hot, dry conditions. Seeded grass species currently dominate these areas and reestablishment of pinyon or juniper trees is largely absent.

Doughty, J.W., THE PROBLEMS WITH CUSTODIAL MANAGEMENT OF PINYON-JUNIPER WOODLANDS, Proceedings-Pinyon-Juniper Conference, Jan. 1987, p. 29-33.
The current lack of management on pinyon-juniper woodlands may result in site degradation; increased soil erosion; depleted understory production; and stagnant, unhealthy overstory. When pinyon and juniper stands become overcrowded from lack of proper management, the trees outcompete the grasses, forbs, and shrubs for moisture and nutrients. Soon the understory is gone and the multiple uses of the resource are diminished. Soil organic matter is reduced and the soil surface is vulnerable to erosive water and wind.
Coordinated resource management and planning can provide a tool for identifying proper management alternatives that will protect resource values and prevent deterioration of pinyon-juniper woodland. There is a demand for fuelwood, fence posts, Christmas trees, pine nuts, foliage and other ornamental material, and chips for processed wood products, as well as forage for livestock and wildlife habitat.

Douglas, C.L., COMPARATIVE ECOLOGY OF PINYON MICE AND DEER MICE IN MESA VERDE NATIONAL PARK, COLORADO, University of Kansas, Museum of Natural History Publications, vol. 18, 1969, p. 42 1-504.

Douglass, R.J., THE USE OF RODENTS IN MONITORING ECOLOGICAL IMPACTS OF OIL SHALE DEVELOPMENT IN THE PICEANCE BASIN, COLORADO, In: R.L. Comer (ed.), Issues and Technology in the Management of Impacted Western Wildlife. Westview Press, Boulder, 1984, p. 70-75.

Douglass, R.J., ASSESSMENT OF THE USE OF SELECTED RODENTS IN ECOLOGICAL MONITORING, Environmental Management, 1989, p. 355-363.
Rodents can be useful in detecting environmental Impacts because they are easy to study (easy to capture and handle), they can occur in densities adequate for statistical analysis, and they are ecologically Important. In this study the usefulness of rodent populations for ecological monitoring was investigated by examining the effect of variation on the possibility of detecting differences in population parameters among grids was also investigated, as was the possibility of inferring population parameters from correlations with habitat data. Statistically significant differences as small as 4.3 Peromyscus maniculature/ha were detected between grids. Of 10 populations, this comprised 12% of the highest-density population and 44% of the lowest-density population. Smaller and more differences among grids were found by examining only animals surviving from previous months. Dispersal confounds detection of direct impacts to populations, especially during the breeding season. Infrequent sampling fails to detect impacts that occur between sampling periods and will indicate impacts when observed changes result from natural variation. Correlations between population parameters and habitat variables exist but should only be used in predicting, not measuring, impacts. It is concluded that some rodent populations can be used in ecological monitoring. However, intensive sampling is required to account for variation and dispersal.

Drivas, E.P. and R.L. Everett, XYLEM WATER POTENTIALS OF SINGLELEAF PINYON SEEDLINGS AND SAGEBRUSH NURSE PLANTS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 423-428.
Encroachment of singleleaf pinyon (Pinus monopylla) into adjacent shrub communities may be related to the trees' ability to maintain a more seasonally stable xylem water potential than associated shrub nurse plants. This study compared xylem water potential of singleleaf pinyon seedlings and shrub nurse plants in low sagebrush (Artemisia arbuscula) and Basin big sagebrush (A. tridentata ssp. tridentata) woodlands ecotones. Predawn shrub xylem water potential (-0.95 Mpa) were less negative than tree seedling xylem water potentials (-1.1 Mpa) in early spring. Sagebrush xylem water potentials became more negative than seedling values in June and remained so for the majority of the 1985 growing season. Predawn water potentials of shrubs declined to the range of -2.1 to -3.9 Mpa during summer drought. Seedling xylem water potentials at this time were -1.6 to -1.8 Mpa. Tree seedlings appear to have a threshold xylem water potential value of -2.0 to -2.5 Mpa that causes stomatal closure and stabilizes xylem water potential the remainder of the day. A threshold value of -5.0 Mpa created the same response in low sagebrush. Pinyon-seedlings maintained dally and seasonal xylem water potentials over a narrower range than sagebrush nurse plants.

Eddleman, L.E., ESTABLISHMENT AND STAND DEVELOPMENT OF WESTERN JUNIPER IN CENTRAL OREGON, Proceedings - Pinyon Juniper Conference, Jan. 1987, p. 255-258.
Establishment and stand development of western juniper were studied in central Oregon. New individuals established primarily beneath the canopies of big sagebrush or juniper. No trees established prior to 1880, but had reached densities greater than 1000 per hectare by 1980. Larger trees made up approximately 10% of the population. Basal area had reached 12.73 m2 by the tenth decade of growth.

Evans, R.A., R.E. Ecert Jr., and J.A. Young, THE ROLE OF HERBICIDES IN MANAGEMENT OF PINYON-JUNIPER WOODLANDS, The Pinyon-juniper Ecosystem: A Symposium, May 1975, p. 83-89.
The pinyon-juniper woodlands comprise diverse plants communities, most of which in the Great Basin are closely allied to sagebrush-grass communities with common problems of weed control and revegetation. Severe ecologic consequences accompany many pinyon-juniper control methods, and the use of herbicides offers alternatives that are less disturbing to the plant communities. Strategies for use of herbicides along with other techniques should lead to more effective and efficient methods for control and revegetation within pinyon-juniper woodlands.

Evans R.A. and J.A. Young, CONTROL, PLANT SUCCESSION, AND REVEGETATION IN WESTERN JUNIPER WOODLANDS, Proceedings -Pinyon-Juniper Conference, Jan. 1987, p. 301-304.
Juniper control methods, successional dynamics of herbaceous vegetation, and revegetation of sites following juniper and sagebrush control have been studied for 10 years on western juniper (Juniperus occidentals, Hook.) woodlands in northeastern California. Juniper trees were controlled by picloram (4 amino-3,5,6,-trichloropicolinic acid), picloram with limbing or removal of trees, mechanical clearing and burning, and wood harvesting. Big sagebrush (Artemisia tridentata, Nutt.) was controlled with 2,4-D and herbaceous weeds by an atrazine-fallow method. Seedings of intermediate wheatgrass [Agropyron intermedium (host) Beauv.l, alfalfa (Medicago sativa L) and sainfoin (Onobrychis viciaefolia L.) were made with a rangeland drill. A multi-faceted weed control-revegetation approach was essential for successful improvement of juniper woodlands for increased cattle production and enhancement of wildlife values.

Evans, R.A., MANAGEMENT OF PINYON-JUNIPER WOODLANDS, USDA Forest Service General Technical Report INT-249, Ogden Utah, 1988.

Everett, R.L. and Susan Koniak, UNDERSTORY VEGETATION IN FULLY STOCKED PINYON-JUNIPER STANDS, The Great Basin Naturalist, 1981, p. 467-475.
Ten fully stocked pinyon-juniper stands contained a total of 73 species in the understory, but the number of understory species in any one stand was moderately low. On each stand, species of at least five different plant groups were present in the understory (shrub, perennial grass, perennial forb, annual grass, or annual forb). A perennial grass, Sandberg bluegrass and a group of annual forbs with relatively high cover and constancy among stands appeared best adapted to coexist with the pinyon-juniper overstory. The proportion of total plant cover was greater on tree-associated microsites (duff and transition) than in the interspace between trees because of the greater surface area of the former in most stands. The transition microsite was the most favorable for understory species and provided understory cover in disproportionately greater amounts than the area it occupied.

Everett, R.L. and Kenneth Ward, EARLY PLANT SUCCESSION ON PINYON-JUNIPER CONTROLLED BURNS, Northwest Science, vol. 58, 1984, p. 58-68.
Pinyon-juniper woodlands are too often burned to increase understory production without sufficient information on probable postfire response. Post-burn vegetation response on six controlled pinyon-juniper burns in eastern Nevada demonstrated multiple entrance points into the standard successional model. Postfire succession was found to be partially explained by both initial and relay floristics successional theories. Species richness increased over time as species turnover rates declined and the proportion of perennial and preburn species increased. Several perennial forb species had maximum cover values during early succession. Predictability of early plant response to burning remains low because of the large species pool adapted to postburn conditions, inadequate detection of fire tolerant forb species, and unpredictable response from soil seed reserves. Once initial postburn plant response occurs, qualitative predictability of midsuccessional stages is thought to increase under the initial floristics successional model.

Everett, R.L., GREAT BASIN PINYON AND JUNIPER COMMUNITIES AND THEIR RESPONSE TO MANAGEMENT, Society for Range Management, Denver Colorado., In: Symposium on the Cultural, Physical and Biological Characteristics of Range Livestock Industry in the Great Basin, 11-14 Feb. 1984, Salt Lake City, UT.

Everett, R.A. and W. Clary, FIRE EFFECTS AND REVEGETATION ON JUNIPER-PINYON WOODLANDS, USDI Bureau of Land Management, Boise, Idaho, In: K. Sanders and J. Durham (eds.), Rangeland Fire Effects: a Symposium, 1985, p. 33-37.

Everett, R.L. PLANT RESPONSE TO FIRE IN THE PINYON JUNIPER ZONE, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 152157.
The understory base in pinyon-juniper woodlands has been depleted by past abuse and suppression by the tree overstory. Wise use of fire provides a means of reestablishing understory species in the successional cycle. Post fire survival of understory plants depends upon physical placement of the plant in the community as well as the physiological characteristics of the species. Understory species demonstrate an array of methods for establishing themselves in postfire successional communities. Succession follows the "initial floristics" successional model where most species are present at the time of disturbance. Plant succession has a strong spatial component. Predicting postfire response is difficult because of several chance factors, but qualitative prediction is possible when we consider aspect, evaluation, and the known response of individual species in the preburn community.

Everett, R.L., ALLELOPATHIC EFFECTS OF PINYON AND JUNIPER LITTER ON EMERGENCE AND GROWTH OF HERBACEOUS SPECIES, USDA-ARS, In: G.W. Frasier and R.A. Evans (eds.). Proceedings of Symposium: Seed and Seedbed Ecology of Rangeland Plants, 1987, p. 62-67.

Everett R.L. and Steven H. Sharrow, UNDERSTORY RESPONSE TO HARVESTING PINYON AND JUNIPER TREES, Proceedings of the Second Utah Shrub Ecology Workshop, Sept. 1982, p. 9-13.
Degree of suppression of understory plant populations and soil seed reserves, and the potential for immigration of shrubs determine the character of understory response to pinyon-juniper harvest. Response is site and soil microsite specific in terms of species composition and potential for growth. thus the standard successional pathway dogma of annual forbs giving way to the grasses that give way to shrubs is invalid and misleading in terms of expected response. Quantity and quality of forage increase following tree harvest can be further increased by broadcasting slash to protect plants from overgrazing.

Fairchild, J., WILDLIFE HABITAT MANAGEMENT ON PINYON-JUNIPER CHAININGS, Proceedings of the Second Utah Shrub Ecology Workshop, Sept. 1982, p. 19-20.
The Utah Division of Wildlife Resources manages big game winter range state wide. Treatment of pinyon-juniper stands to improve habitat, primarily through chaining, has been practiced directly on Division land and cooperatively with land owners. Ecological succession often leads to the reestablishment of pinyon-juniper dominance on treated areas. Hence a continuing need to manage treated areas to maintain or improve wildlife habitat is evident. One useful management tool is prescribed burning, especially spring burning, to increase edge effect and maintain desirable populations of shrubs and herbaceous species.

Floyd, M.E., THE SIGNIFICANCE OF VARIABILITY IN CONE PRODUCTION IN PINUS EDULIS, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 58-64.
Three studies are presented which investigate the relative contribution of exogenous and endogenous variables in reproductive variability in Pinus edulis. Female cone production is reduced on south-facing canyon wails in Utah. The reduction is not correlated with increased internal moisture stress. Endogenous oscilliations in reproductive effort are suggested by tree ring studies. The cost of female cone production is partially, but not entirely, offset by cone photosynthesis.

Ferguson, R.B. and N.C. Frischknecht, SHRUB ESTABLISHMENT ON RECONSTRUCTED SOILS IN SEMIARID AREAS, Wyoming Game and Fish Department, In: L.H. Stelter, E.J. Depuit, and S.A. Mikol (tech. coords.), Shrub Establishment on Disturbed and Semi-arid Lands, 1981, p. 57-63.

Fisher, J.T., A. Fancner and R.W. Neumann, GERMINATION AND FIELD ESTABLISHMENT OF JUNIPER IN THE SOUTHWEST, Proceedings -Pinyon-Juniper Conference, Jan. 1987, p. 293-299.
Studies were conducted to determine reliable methods for germinating and establishing Juniperus monosperma. Poor germination is caused by a germination inhibitor in the seed coat and physiological dormancy. Germination rate and value were significantly improved when seeds were leached 48 hours with H30, or treated with ethephon or H302 plus GA3 before stratification at 4 degrees C.
Establishment studies at three New Mexico sites evaluated the effects of planting date, mulch, drip irrigation, fertilizer and rodent protection on juniper seedling survival. Two best treatment combinations ranged from 70 to 99% among sites. July was the superior planting date for the site near Raton, New Mexico. Plastic mesh was essential and was more effective than animal repellant for rodent protection.

Fisher, H.G., SHRUB ESTABLISHMENT, DOMINANCE, AND ECOLOGY ON THE JUNIPER AND SAGEBRUSH-GRASS TYPES IN WYOMING, In: L.H. Stelter et al., Shrub Establishment on Disturbed Arid and Semi-arid Lands, 1981, p. 213-28.

Floyd, M.E., THE SIGNIFICANCE OF VARIABILITY OF CONE PRODUCTION IN PINUS EDULIS, USDA Forest Service General Technical Report INT-215, Ogden, Utah, In: R.L. Everett (compiler), Proceedings--Pinyon-juniper Conference, Jan. 1987, p. 5 8-64.

Folliott, P.F., OPPORTUNITIES FOR FIRE MANAGEMENT IN THE FUTURE, USDA Forest Service General Technical Report Rm-191, Ft. Collins, CO.: J.S. Krammes (tech. coord.), Effects of Fire Management of Southwestern Natural Resources, 1990, p. 152-167.

U.S. Forest Service- U.S. Department Of Agriculture Intermountain Region-Ogden UT, AN ANALYSIS OF PINYON-JUNIPER CHAINING PROJECTS IN THE INTERMOUNTAIN REGION 1954-1975, Range Improvement Notes, 1977.
The pinyon-juniper type of the west and southwestern portions of the United States occupies about 61,000,000 acres of land ( Barger & Folliot, 1972). Of this total, an estimated 2,300,000 acres occur on the National Forests Region 4. This "pygmy forest" is confined to arid and semiarid regions. In Region 4, it is generally found in areas where annual precipitation ranges from 8 to 17 inches. It has a rather wide elevation level range of 5,000 to 8,000 feet and occurs on all exposures; however, it most commonly occurs on slopes facing south through west. Pinyon-juniper is usually found on shallow, gravelly soils in the 10- to 20-inch depth range, although it does occur on deeper soils. Stand density averages about 400 trees per acre, but ranges from about 50 to well over 1,000 trees per acre.
Since the arrival of the first settlers in the west, the pinyon juniper type has extended its range and dominance by invading millions of acres of contiguous grassland and shrub types. Once established, pinyon-juniper inexorably gains site dominance and eventually replaces most of the vegetation that formerly occupied the invaded site ( Arnold et al 1964). The result of this invasion is loss of forage through decreased type diversity and edge.
Since the mid-1950's, the Forest Service has treated thousand of acres of pinyon-juniper type in Region 4, using various methods to open up old residual stands as well as young invading stands of these trees. The earlier projects were seeded and cabled and slash was generally piled. On several projects, the hula dozer was used to uproot trees not killed by the cabling. Later projects were seeded, then chained with a small chain. The current procedure is to chain either with a smooth or modified chain. The area is chained in one direction and aerial seeded, then the chain is pulled in the opposite direction to cover the seed and increase the kill on the pinyon and juniper trees. Slash has been handled in various way, like disposal by windrowing and burning.
Seed mixtures are comprised largely of grasses. Tree introduced wheatgrasses---crested, intermediate, and pubescent-- are the major components of most mixtures, although other grasses such as Russian wildrye, western wheatgrass, smooth bromegrass, and orchardgrass are used to some extent. Forb species used are alfalfa, yellow sweet clover, and small burnet, while bitterbrush and fourwing saltbrush are the most common shrubs used. Other shrubs used to some extent are mountain mahogany, cliffrose, and serviceberry. Shrubs are generally planted by dribbler, while the forbs are planted aerially with the grasses. Seeding rates range from 6 to 12 pounds per acre with grass making up the bulk of the mixture. Forbs and shrubs together generally comprise less than 2 pounds of the total mixtures.

Fowler J.M. and Jeff M. White, GROWTH CHARACTERISTICS AND THINNING RESPONSE FOR THE PINYON-JUNIPER WOODLAND TYPE IN NEW MEXICO, Proceedings-Pinyon-Juniper Conference, Jan. l987, p. 266-272.
Twelve quarter acre plots were constructed at four sites in New Mexico. Trees were measured and quality rated. There were 4,3 72 trees in this study. The plots were cleared on the basis of O, 33, 67, and 100 % of the net crown cover. Fuelwood volume estimation equations were developed for each site and by species. Thinning treatments were used to determine the trade off between annual forage growth and wood fiber production. Production prices were determined and enabled alternative thinning practices to be analyzed. The results indicate that the 180-year planning horizon currently being used by land management agencies is too short.

Fox, B.E., FUELWOOD OPPORTUNITIES FROM ARIZONA PINYON JUNIPER STANDS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 173-176.
Increasing human population levels and more expensive fossil fuels have stimulated Interests In fuelwood production from pinyon juniper sites. Past research indicates that although more expensive than traditional mechanical conversion treatments herbicide treatments of pinyon-juniper stands to provide fuelwood also increase forage and water production. Given the current cost disadvantage, and ignoring increased water yields, fuelwood prices must increase to a minimum of four times current rates to result in net cost equality between treatments. A review of treatments, costs, and management implications of various treatments to provide fuelwood from pinyon-juniper stands is presented In this paper.

Foxx, T.S. and G.D. Tiemy, ROOTING PATTERNS IN THE PINYON JUNIPER WOODLANDS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 69-79.
An extensive bibliographical study documenting rooting patterns of native and Introduced plants of the western United States resulted in a computerized data base of over 1000 different rooting depth citations. From that data base, average rooting depths and frequencies were determined as related to species, habit, soil type, geographic region, root type, family, root depth to shoot height ratios, and root depth to root lateral ratios. Annual grasses were found to root within 1 rn of the soil surface. Median rooting depth of other life forms was 2.0 m with a maximum rooting depth of 61 m. The various life forms had the following median and maximum rooting depths: annual forbs (median of 0.6 m, maximum of 3.0 m), biennial forms (0.8 m, 1.5 m), perennial grasses (1.1 m, 8.2 m), perennial forbs (1.1 m, 39.0 m ), subshrubs and vines ( 1.2 m, 6.4 m), shrubs (2 m, 17.0 m), and trees (1.6 m, 61 m). In addition to the bibliographic study, 21 species common to the pinyon-juniper woodland were excavated from soils derived from volcanic tuff in northern New Mexico. Rooting patterns and gross morphology were examined. Perennial forbs and grasses occurred within the first 30 cm of the soil surface. Roots of the overstory trees were traced to depths of 6 m and roots of shrubs to depths of 1.8 to 2.6 m.

Frasier, G.W., WATER HARVESTING POTENTIAL AND APPLICATION AS A MEANS OF RANGE WATER SUPPLY, Proceedings - Pinyon Juniper Conference, Jan. 1987, p. 5 18-523.
Water harvesting techniques can provide the necessary quantity and distribution of animal drinking water for the proper management of rangeland resources. Typical water-harvesting systems consist of a catchment area of 700-2500 sq. yds. with storage facilities of 10,000 to 90,000 gallons. Total system costs range from $4,000 to $30,000, depending upon the type of materials used and the availability of labor and equipment.

Fresquez, P.R., G.L. Dennis, and R.E. Francis, SOIL FUNGI: AN ADDITIONAL PARAMETER FOR PHYTO-EDAPHIC COMMUNITY CLASSIFICATION, USDA Forest Service General Technical Report INT-257, Ogden, Utah., In: Proceedings--Land Classifications Based on Vegetation: Applications for Resource Management., 1989, p. 285-287.

The soil fungal community beneath pinyon and one-seeded juniper tree canopies is described and compared with fungi from adjacent interspace soils dominated by blue grama. Significantly higher organic matter contents and fungal propagule levels were found in soils beneath pinyon and juniper trees than in interspace soils. Soils under pinyon and juniper trees contained similar chemical, physical, and biological properties and, consequently, many groups of fungi in common (64% of the species isolated were common to both). In contrast, soil fungi in adjacent interspace soils were vastly different from those collected in soils beneath pinyon and juniper canopies (44% and 48% species in common, respectively). Soil fungi that were isolated more often from pinyon-juniper soils than from interspace soils included Absidia spp., Beauvaria spp, Gliocladium spp, Mucor spp, Penicillium cyclocpium, P, fasciculata, P. frequentarts, P. restrictum, Tharrmidium spp, and Trichoderma spp. Soil fungi that were isolated more often in interspace soils than in pinyon or juniper soils included Aspergillus alutaceus spp, A. fumigatus, some Fusarium spp, Penicillium luteum, and P. talaromyces.

Frischknecht, N., NATIVE FAUNAL RELATIONSHIPS WITHIN THE PINYON-JUNIPER ECOSYSTEM, The Pinyon-juniper Ecosystem: A Symposium, May 1975, p. 55-65.
Of the many species of wildlife that inhabit the pinyon-juniper ecosystem all or part of the year, few species are considered to be obligate. The small MAMMALS most characteristics of the ecosystem are the woodrat and the pinyon mouse. Birds considered to be obligate are the pinyon jay, the titmouse, and the lead-colored bushtit. The peregrine falcon is an endangered species that sometimes uses cliff sites for nesting within pinyon-juniper ecosystem, but does not depend upon the trees. The highly nutritious pinyon nuts and juniper berries are eaten by many species of birds and animals that serve as seed dispersal agents. It can be expected that the pinyon-juniper woodland, which has expanded greatly since settlement at the expense of shrubs and herbaceous plants, will continue to expand. The great challenge facing resource managers is to achieve a desirable balance among trees, shrubs, and herbaceous plant species that will benefit multiple uses, including utilization by wildlife.

Gafney, D.J. and R.M. Lanner, EVOLUTIONARY SORTING OF PINYON JUNIPER TAXA IN ZION NATIONAL PARK, UTAH, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 288-292.
Single-leaf pinyon (Pinus monophylla) grows on the floor of Zion Canyon, while its closely related congener Colorado pinyon (Pinus edulis) grows on the surrounding high plateau. The two species are known to hybridize. Population samples of both species were made along two transects ranging from 1,2 19 m to 2,134 m elevation. Based on percent of monophylly and needle resin canal number, it is concluded that hybrids occur through the elevational ranges of both parents. Distribution of the taxa was closely correlated with bedrock geology. Hybrids of these species occur widely throughout their ranges, including areas of Arizona not heretofore reported. Detailed studies of the site relationships of hybrids are needed in order to predict their behavior under different land management regimens.

Ganey, J.L. and R.P. Balda, DISTRIBUTION AND HABITAT USE OF MEXICAN Spotted OWLS IN ARIZONA, The Condor, 1989, p. 355-361.
Distribution and habitat use of Mexican Spotted Owls in Arizona were studied from 1984-1988. Owls were widely but patchfly distributed throughout the state except for the arid southwestern portion. Distribution of the owl corresponded with distribution of forested mountains and canyonlands within the state. Owls occurred either in rocky canyons or in any of several forest types, and were most common where unlogged closed canopy forests occurred in steep canyons. Several forest types provided these habitat characteristics in southern Arizona, and owls occurred in all of them. Only unlogged mixed-conifer forest provided these characteristics in northern Arizona, and most owls (67%) were found in this forest type in northern Arizona. Many owls in northern Arizona (54%) were located in areas where timber harvest was either occurring now or was planned in the next 5 years. Owls could not be located at 27% of the historic sites resurveyed, indicating that population levels may have declined in Arizona.

Garrett, L.D. EVALUATING MULTI-RESOURCE BENEFITS OF TREATMENTS IN PINYON-JUNIPER WOODLANDS, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 188-191.
Changes in forest policy and law have placed greater emphasis on multi-resource management, and techniques, to ensure its efficiency and effectiveness. Although the lack of multi-resource data has impeded progress in multi-resource modeling, conceptional and prototype models are being developed. The model,"ECOSIM", developed in the Southwest has capability for evaluating multiresource benefits from pinyon-juniper woodlands. For multi-resource models to £red expanded use in land management planning, continued development must be based on sound scientific principles and reflect the needs of management. Managers and analysts using the models must do so within constraints specified in their development.

Garrott, R.A., G.C. White, R.M. Bartman, L.H. Carpenter, and A.W. Alldredge, MOVEMENTS OF FEMALE MULE DEER IN NORTHWESTYLE="COLORADO, Journal of Wildlife Management, vol. 51, 1987, p. 634643.
Seasonal movements of 117 female mule deer were monitored using radio telemetry from November 1980 through October 1984. All deer migrated in October before significant snow accumulated on summer range. During mid-winter, deer usually moved to lower elevations and shifted use from northerly to southerly aspects. Timing of mid-winter movements varied among years and appeared related to weather severity. In spring, deer concentrated around meadows until migrating to summer range. Timing of spring migration varied annually and was related to winter severity. During summer, deer were generally sedentary. However, of 8 animals that made extended movements, 6 were yearlings. We found little evidence of dispersal as all adult deer demonstrated strong fidelity to seasonal movement patterns, returning to essentially the identical locales occupied on summer and winter ranges in previous years. We suggest that the seasonal movements of migratory mule deer in the intermountain west are driven and controlled by seasonal changes in energentic needs of the animals and by the quality not quantity of forage available within the year-round range of the animals.

In this study, we have examined the effect of vegetation structure on the three major vertebrate taxa in Great Basin habitats of southwestern Utah. The effect of increasing vegetation heterogeneity, both horizontal and vertically, on the diversities of lizards, rodents, and postbreeding birds was investigated. We found no statistically significant relationship between diversity of all animal taxa and horizontal vegetation heterogeneity, although lizard diversity tended to decrease with increasing heterogeneity and rodent diversity tended to increase. Bird species diversity was positively correlated with vertical habitat heterogeneity. Abundances were highest for rodents in pinyon/juniper habitat and highest for lizards and bird in areas with the highest grass cover. Species richness was highest in sage brush habitat for rodents but highest for lizards and birds in pinyon/juniper. Evenness values were relatively similar and high for birds and rodents and were relatively high for lizards in all habitats except for pinyon/juniper, which had an evenness value of 0.38. For rodents and lizards, abundance was significantly correlated with the index for horizontal habitat heterogeneity. After logarithmic transformation, abundance of lizards was positively correlated with increasing vegetation complexity. Combined abundance of lizards and rodents was also positively correlated with vegetation complexity. Rodent and lizard abundances, however, were affected by different aspects of the habitat. After logarithmic transformation, lizard abundances increased significantly with increasing grass cover, whereas rodent abundances increased significantly with increasing shrub cover.

Gese, EM., J.R. Orrin, and W.R. Mytton, RELATIONSHIP BETWEEN COYOTE GROUP SIZE AND DIET IN SOUTHEASTERN COLORADO, Journal of Wildlife Management, vol. 52, 1988, p. 647-653.
We investigated the diet of coyotes on the Pinyon Canyon Maneuver Site (PCMS) in southeastern Colorado from February 1983 to June 1986. Based on regression analysis, 71% of the variation in the volume of large prey in coyote scats could be explained by coyote group size; 77% of this could be explained by group size and snow depth. Snow depth alone explained 28% of the variation in the volume of large prey in the scats. Coyote group size explained 19% of the variation in the volume of medium size prey and 38% of the variation in the volume of small prey. Coyote groups were largest in winter and smallest in summer. Most juveniles disappeared before the largest group size were observed. Group foraging and snow depth may influence prey selection by coyotes in southeastern Colorado.

Gese, E.M., J.R. Orrin, and W.R. Mytton, HOME RANGE AND HABITAT USE OF COYOTES IN SOUTHEASTERN COLORADO, Journal of Wildlife Management, vol. 52, 1988, p. 640-646.
We tracked 72 radio-collared coyotes for 13 consecutive biological seasons spanning 4 years. Coyotes displayed 2 behavior modes based on home-range characteristics: resident and transient. Resident and transient coyotes comprised 78 and 22% of the population, respectively. The mean annual home-range size was 11.3 km2 and 106.5 km2 for resident and transient coyotes, respectively. Yearlings and very old coyotes (>8 yrs.) accounted for 68% of the transient cohort. Resident annual home ranges in canyon, hill, pinyon-juniper prairie, and prairie habitats averaged 5.5, 6.6, 11.1, and 16.5 km2, respectively. Coyotes preferred pinyon-juniper woodlands and shrub-grassland but used open grassland habitat less than expected. Regression analysis showed that 65% of the variation in resident home ranges could be explained by the amount of available pinyon-juniper cover. Coyotes with access to little or no pinyon-juniper cover used shrub-grasslands. Similarly, 47% of the variation of home ranges for coyotes inhabiting the prairie could be explained by the amount of available shrub-grassland habitat within an animal's home range.

Gese, E.M.; J.R. Orrin, and W.R. Mytton, CHANGES IN COYOTE MOVEMENT DUE TO MILITARY ACTIVITY, Journal of Wildlife Management, vol. 53, 1989, p. 334-339.
We investigated the response of coyotes to military activity on the Pinon Canyon Maneuver Site (PCMS), Colorado, during 1984-86. Sixteen coyotes responded to military activity by expanding, contracting, abandoning, or not changing their home range during military maneuvers compared to before and after maneuvers. Three coyotes abandoned their home ranges, with 1 animal returning to its original home range 1 week after maneuvers. Most coyotes that expanded from their contracted home range during military maneuvers resumed their original home range after military maneuvers ceased. Response appeared to be related to the amount of available cover, topography, and intensity of military activity in a coyote's home range. Coyote activity patterns during the day increased, while activity at sunrise, sunset, and night remained the same during military activity.

Gese, E.M.; J.R. Orrin, and W.R. Mytton, POPULATION OF COYOTES IN SOUTHEASTERN COLORADO, Journal of Wildlife Management, vol. 53, 1989, p. 174-181.
We captured 96 coyotes on the Pinon Canyon Maneuver Site (PCMS) in southeastern Colorado from March 1983 to December 1986. Of these, 88 (23, 18, and 59% pups, yearlings, and adult, respectively; 146 M: 100 F) were radiocollared and tracked. Home ranges of residents did not overlap whereas transient overlapped resident and other transient home ranges. Annual survival rates for adults, yearlings, and pups

Gifford, G.F., Gerald Williams, and G.B. Coltharp, INFILTRATION AND EROSION STUDIES ON PINYON-JUNIPER CONVERSION SITES IN SOUTHERN UTAH, Journal of Range Management, Vol. 23, November 1970, p. 402-405.
Infiltration and sediment data from small-plot studies (3 25 infiltrometer plots) utilizing high intensity simulated rainfall indicate that areas cleared of pinyon-juniper trees and seeded to grass in southern Utah generally show no consistent decrease or increase in sediment yields or infiltration rates at a given point. Of 14 sites studied, four indicated decreased infiltration and two indicated increased infiltration rates during one or more time intervals at specific points on the treated areas; one site had significantly less sediment yields from points and two sites had significantly higher sediment yields from points on the treated areas. These results nearly parallel those obtained during similar studies of 14 pinyon juniper sites in central Utah.

Gifford, G.F., RUNOFF AND SEDIMENT YIELDS FROM RUNOFF PLOTS ON CHAINED PINYON-JUNIPER SITES IN UTAH, Journal of Range Management, Vol. 26, November 1973, p. 440-443.
Runoff and sediment production from a chained pinyon-juniper site in southwestern Utah was measured from about June 6 to October 1 over a 5 year period (1968-1972) using .04-hectare (0.11 acre) runoff plots. Treatments evaluated included chained-with debris-windrowed, chained-with-debris-in-place, and natural woodland. All treatments were fenced to exclude livestock. Runoff events occurred at both sites during only 2 years (1968, 1970) of the study. Results indicated that chained-with-windrowing plots yield from 1.2 to 5 times more water during a runoff event than respective woodland plots. Runoff from debris-in-place plots was equal to or less than that measured from the natural woodland for all storms. Runoff data and sediment indexes indicate that when runoff exceeds about O. 1 cm from the woodland, from 1.6 to 6 times more sediment can be expected from windrowed sites than from adjacent woodland. Sediment yields from debris-in-place sites were similar to those from adjacent unchained woodland for all storms during this study.

Gifford, G.F., APPROXIMATE ANNUAL WATER BUDGETS OF TWO CHAINED PINYON-JUNIPER SITES, Journal of Range Management, Vol. 28, January 1975, p. 73-74.
Approximate annual water budgets for various pinyon-juniper treatments (chaining-with-windrowing, chaining-with-debris-inplace, and natural woodland) have been compiled for a 3-year period near Milford, Utah, and for a 2-year period near Blanding, Utah. Results of the analysis indicate that most of the annual precipitation falling on each treatment is lost through evapotranspiration, with much of the balance being lost through interception. When runoff did occur, it was greatest from windrowed treatments and least from debris-in-place treatments.

Gifford, G.F., IMPACT OF BURNING PINYON-JUNIPER DEBRIS ON SELECT SOIL PROPERTIES, Journal of Range Management, Vol. 34, September 1981, p. 357-359.
Burning had the greatest impact on soils beneath burned debris piles. Electrical conductivity, phosphorus, potassium, percent nitrogen, and organic carbon increased significantly at all soil depths the first year after burning debris piles. No impact was evident on phosphorus, percent nitrogen, organic carbon by the second year. Impacts on burned interspace areas were generally less pronounced and few impacts were measured the second year. Impact of burning on soil Ph was minor.

Gifford, G.F., IMPACT OF BURNING AND GRAZING ON SOIL WATER PATTERN IN THE PINYON-JUNIPER TYPE, Journal of Range Management, Vol. 35, November 1982, p. 697-699.
Soil water patterns were studied from June 1973 to February 1977 in pinyon-juniper woodland, on pinyon-juniper areas chained and windrowed (grazed and ungrazed), and on pinyon-juniper areas chained with debris-in-place (ungrazed; burned vs. unburned). The pinyon-juniper woodland always had the least soil water, regardless of the season. Grazing did not affect soft water patterns on the chained with windrowing treatment. Burning of debris on the debris in-place treatment had lithe impact on water the first year, but significantly more water was measured on the burned treatment at the beginning of the second year. Soil water patterns previously established between the unburned debris-in-place and ungrazed windrowed treatment changed in August of 1974, and the two treatments were equivalent for the balance of the study. Prior to August of 1974 the unburned debris-in-place treatment had always had more soil water than the ungrazed windrowed treatment. These changes were attributed to possibly milder winters with decreased snowfall.

Gifford, G.F., MYTHS AND FABLES AND THE PINYON-JUNIPER, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 34-37.
During the past ten years much new and interesting information has been derived through a variety of studies within the pinyon juniper type. However, many "facts" associated with the pinyon juniper type are in truth derived from a decade or two of storytelling which relies heavily on personal or agency opinion and often ignores available research results. Some of these myths and fables are briefly examined.

Gifford, G.F., COVER ALLOCATION IN RANGELAND WATERSHED MANAGEMENT, Management of Pinyon-Juniper Woodlands, July 1988.
The importance of cover on rangelands has been recognized for many years. This paper reviews the importance of cover in terms of infiltration and erosion and provides management recommendations where possible. Information gaps are also identified.

Gottfried, J.D., REGENERATION OF PINYON, Proceedings - PINYON JUNIPER Conference, Jan. 1987, p. 249-254.
The current emphasis on management of the pinyon-juniper woodlands has resulted in renewed interests in the regeneration characteristics of Colorado pinyon (Pinus edulis ) and of singleleaf pinyon (P. monophylla). This information is vital for the development of sound silvicultural or range management prescriptions. However, our knowledge is incomplete, and the literature is occasionally contradictory. Most pinyon seedlings are observed in the shade of mature trees, shrubs, or of slash, and not in the spaces between trees, although pinyon is generally considered shade-intolerant. Seedling growth rates are low, but early release from shade can be fatal. The environmental requirements for successful germination and establishment have not been fully evaluated. Corvid birds are primary dispersal agents, but the importance of other seed dispersal pathways is unclear. Ecotypic variations should be anticipated within each of the two pinyon populations. More research is necessary before general management recommendations can be formulated.

Grubb, T.G. and W.L. Ealke, COMPARATIVE MORPHOLOGY OF BALD AND GOLDEN EAGLE NESTS IN ARIZONA, Journal of Wildlife Management, vol. 51, 1987, p. 744-748.
Seventeen bald and 12 golden eagle nests in similar habitat in central Arizona were measured to determine whether unoccupied nests of these 2 species could be differentiated. Measurements included the diameter, length, and weight of nest sticks and overall dimensions of the nests. Sticks comprising bald eagle nests were consistently and significantly thicker and longer than those used by golden eagles (P= 0.001). Although there was much overlap in the sizes of nests and their sticks, the differences were visually evident in the field and can be used for distinguishing unoccupied nests of these 2 specimens.

Gruell, G., S. Bunting, and L. Neuenschwander, INFLUENCE OF FIRE ON CURLLEAF MOUNTAIN MAHOGANY IN THE INTERMOUNTAIN WEST, USDA Forest Service General Technical Report INT-2 15, Ogden, Utah, Ln: J.E. Lotan, and J.K. Brown (compilers), Fire's Effect on Wildlife Habitat--Symposium Proceedings, 1985, p. 58-72.

Gubanich, A.A. and N.R. Panik, AVIAN USE OF WATERHOLES IN PINYON-JUNIPER, Proceedings Pinyon-Juniper Conference, Jan. 198 7, p. 534-540.
Observations at two waterholes in pinyon-juniper woodland indicate that surface water is important to many species of birds during late summer and fall. Water with protective shrub cover was utilized more heavily than water in an open, exposed location. Availability of water may play a role in bird distributions in pinyon juniper woodlands.

W.R. Haase, IMPACTS OF CHAINING ON CULTURAL RESOURCES, Department of Anthropology Washington University (HAND OUT), 1980.
The use of heavy equipment in plant or brush control is an effective and frequently used method of increasing rangeland forage production in the western United States. In particular, large scale "chainings" or conversions of pinyon pine, juniper and big sagebrush to grassland habitat has been a common undertaking for the past 30 years. Chaining can be expected to continue with the USDA Soil Conservation Service providing technical assistance for over 20,000 acres in Utah over the next three years ( Soil Conservation Service 1979), and with the completion of grazing environmental statements by the Bureau of Land Management (BLM) throughout the west.
Specifications for chaining and brush control differ quite markedly among the various federal and state agencies concerned with range management, but it is rare that adequate consideration has been given to the preservation of cultural resources within project areas. Little information is available regarding the effects or impacts of such activities on archaeological of historic sites. Particularly lacking are "How to" materials for use by range management personnel and archaeologists. Of the several chainings within pinyon-juniper woodlands observed by the author over a three year period, most had resources within the project areas.
This paper will attempt to explain both the procedures and purpose of chaining, types of archaeological sites most susceptible to adverse impact and offer documentation of such impacts undertaken in controlled situations. Finally, several recommendations will be offered that are capable of reducing or eliminating the disruptive effects of chaining on cultural resources.

Current strategies for protecting archaeological sites during implementation of brush management practices such as chaining are frequently inadequate. Potentially significant prehistoric remains are sometimes dealt with in a fashion conducive to their destruction. This conflict can be alleviated by developing a chaining program in which there is planned avoidance of cultural resources. This is accomplished through an intensive archaeological, soil, range, and visual assessment of project areas prior to chaining. The development of a chining design by an interdisciplinary planning team and the "buffering" of sites during implementation of the range improvement can enhance all resources. Through careful planning, secondary impacts such as vandalism to prehistoric sites can be reduced as well.

Hagihara, J.S., INVENTORY AND CLASSIFICATION FOR P-J-CHAIRMAN'S SUMMARY, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 197-198.
Current and future multi-resource management of pinyon juniper woodlands requires the collection of necessary information for classification and making management interpretations. Several different inventory and classification systems are currently being used by federal agencies and universities. As a result, it is difficult to develop consistent management interpretations and nomenclature for the pinyon-juniper vegetation associations. The presentations in inventory and classification session should provide an opportunity to resolve some of these problems.

Hartsen, R.M. and B.L. Dearden, WINTER FOODS OF MULE DEER IN PICEANCE BASIN, COLORADO, Journal of Range Management, 1975, p. 298-300.
Fecal samples were examined to estimate the foods of mule deer on winter range in the Piceance Creek Basin on northwestern Colorado. The deer were assumed to be under extreme hardship because of the cold temperatures, the amounts and duration of snow on the ground, and a winter die-off. Pinyon pine and Utah juniper comprised 83% of the total foods eaten between December and March. Big sagebrush, antelope bitterbrush, and Utah serviceberry contributed about 13%. Ten other species of plants occurred in small quantities.

Hartsen, R.M. and L.D. Reid, DIET OVERLAP OF DEER, ELK, AND CATTLE IN SOUTHERN COLORADO, Journal of Range Management, 1975, p. 43-47.
The monthly diets of mule deer and elk were estimated by microscopic analyses of fecal samples from December, 1970, through November, 1971, and from June, 1971, through September, 1971, for cattle. Seasonal preferences for plants were observed for mule deer and elk. Deer diets consisted primarily of browse except in summer and early winter when grasses were taken in significant amounts. Forbs were eaten by deer in small amounts only in the spring and summer. Elk diets were mostly grasses, but a significant percentage of browse was consumed in all seasons except the summer. Cattle diets from June through September were almost entirely grasses or grass-Like plants. Dietary overlap between deer and elk ranged from three percent in winter to 48% in summer; of deer and cattle in summer from 30% to 51%. The diversity of plants in the diets was similar for deer, elk, and cattle.

The effects of area, environmental heterogeneity, and site favorability on plant species diversity and slope of the species-area curves were evaluated at thirty study sites in shrub-dominated communities within the pinyon-juniper zones of central Utah and northern New Mexico. Species diversity, as measured by total number of species per site, varies widely (24-87 species per hectare). Plant species diversity is highly correlated with increasing size of the area at each site. Environmental heterogeneity is also strongly positively correlated with species diversity. In combination, area and environmental herogeneity account for >98% of the variation in species number. Overall site heterogeneity and favorability combine to account for 74% of the observed variation in species number at Utah sites and 84% among New Mexico sites. Species diversity within these communities is largely controlled by two abiotic variables: (1) the amount of available moisture and (2) the number of different soil types within the site. Slope of the species-area curve varies widely among the several study sites. The observed values overlap expected z-values for continental communities. Environmental heterogeneity is shown to be positively associated with z-value. At Utah sites, heterogeneity of site solar irradiation, potential soil moisture, and soil depth explain 66% of the variation in z-values. At New Mexico sites, herogeneity of solar irradiation, soil depth, and surface rock cover account for 90% of the variation in observed z-values.

Harris, J.G., A VASCULAR FLORA OF THE SAN RAFAEL SWELL, UTAH, The Great Basin Naturalist, 1983, p. 79-87.
The vegetation of the San Rafael well in southeastern Utah is examined based on personal field collections and previously collected herbarium specimens in the Brigham Young University Herbarium (BRY). An annotated checklist includes information on frequency of occurrence and habitat preference for each entity. Treated are 491 vascular plant taxa from 5 9 families.

Hassell, W.G. and W.R. Oaks, HERBACEOUS PLANT MATERIALS FOR PINYON-JUNIPER RENOVATION PROJECTS, USDA Forest Service General Technical Report INT-215, Ogden, Utah, In: R.L. Everett (compiler), Proceedings--Pinyon-Juniper Conference, Jan. 1987, p. 335-343.
Thinning or removal of pinyon-juniper (p-J) trees will usually increase grass and forb species for forage production. Reseeding with more desirable and higher producing cultivars will improve renovation projects. The USDA Soil Conservation Service, Forest Service, Agricultural Research Service, and other cooperating state and federal agencies develop plant materials to improve and add new plant cultivars for P-J renovation. Adapted species include Basin wildrye, bluebunch wheatgrass, blue grama, galleta, Indian ricegrass, western wheatgrass, and Lewis flax. Other species have been tested that fit ecological niches in the P-J vegetative zone. High-quality varieties can improve establishment and production on P-J lands.

Hattori, E.M. and M.A. Thompson, EPISODIC, HISTORIC PINYON USE AND DEFORESTATION IN THE CORTEZ MINING DISTRICT, EUREKA COUNTY, NEVADA, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 125-128.
Pinyon stumps and logs at Cortez, Nevada, were crossdated with living trees to determine cutting dates. The chronology reveals distinctive intervals of local pinyon use related to historic mining activity. Living tree ages indicate survival of old-age trees close to mines and mills, and possible expansion at woodlands at lower elevations.

Hawkins, R.H., APPLIED HYDROLOGY IN THE PINYON-JUNIPER TYPE, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 493-504.
The scope of small watershed hydrology in pinyon-juniper areas is described. The limitations imposed by the pinyon-juniper environment are discussed and the need for site-specific data is stressed. Most precipitation goes to soft moisture storage, and ground water recharge is small. Runoff events are rare and usually of small volume, and annual water yields are correspondingly low. Because of this scanty surface water budget and because of inherent climatic and soil factors, on-site erosion and downstream sediment delivery is quite modest. Several operational methodologies are described, and their limitations discussed.

Heede, B.H., THE INFLUENCE OF PINYON-JUNIPER ON MICROTOPOGRAPHY AND SEDIMENT DELIVERY OF AN ARIZONA WATERSHED, USDA Forest Service General Technical Report INT-2 15, Ogden, Utah, In: Troendle, C.A., M.R. Kaufmann, R.H. Hamre, and R.P. Winokur (tech. coords.) Management of Subalpine Forests: Building on 50 Years of Research, 1987, p. 195-198.

Heede, B.W., VEGETATION STRIPS CONTROL EROSION IN WATERSHEDS, USDA Forest Service Res. Note RM-499, Ft. Collins, CO, 1990.

Henderson, D.E. and M.L. Baughman, WHOLE TREE HARVESTING OF THE PINYON-JUNIPER TYPE: ECONOMIC AND INSTITUTIONAL CONSIDERATIONS, USDA Forest Service General Technical Report INT-215, Ogden, Utah. ,In: R.L. Everett (compiler), Proceedings-Pinyon-Juniper Conference, Jan. 1987, p. 192-195.

Hessary, I.K. and G.F. Gifford, PROBABLE IMPACTS OF VARIOUS RANGE IMPROVEMENT PRACTICES ON DIFFUSE SALT, Journal of Range Management, Vol. 32, May 1979, p. 189-193.
In 1976 a study of soil profile salt concentrations and probable salt loading by surface runoff was made on 73 range improvement sites in Utah, Colorado, New Mexico and Arizona. The range improvement practices studied included gully plugs, contour furrowing, pitting, pinyon-juniper chaining and various sagebrush control treatments. The impact of gully plugs and contour furrows on potential diffuse salt production is somewhat variable and may in fact indicate that these treatments have only a minor potential impact, probably because the overland flow route is not a major source of diffuse salt movement, at least on lands sampled in this study. On pinyon-juniper sites and the various sagebrush treatments, the lack of difference in salt concentrations between treated and untreated sites was the only consistent trend. In general the measured salt concentrations in surface soils of either pinyon juniper or sagebrush sites present a problem of little concern as related to salt production within the major river basins.

During 1976 a study of annual production and cover (litter+rock+vegetation) on various range improvement practices was conducted in Utah, Colorado, New Mexico, and Arizona. The range improvement practices studied included gully plugs, contour furrowing, pitting, pinyon-juniper chaining, and various sagebrush control treatments.
Results from studies of annual production on treated vs untreated sites indicated that; (a) about 33% of the contour furrowed sites had significant increases in annual production. Best responses were found on loam soils, while soils of sandy loam or clay texture indicated a poor response to treatment. Soils classified as typical ustifluvents and ustollic haplargids were most favorable in terms of increased productions; (b) annual production on pinyon-juniper chainings was significantly increased across a variety of soil types ( growth of trees excluded). The greatest increases were measured on sites with loam soils classified as typic haplustolls; © Neither of the two pitting on a clay loam site indicated increased annual production; (d) less than 50% of the various sagebrush treatments indicated increased annual production. There appears to be general trend for best response on loam soils, though significant decreases in production were also indicated on this type of soil; (e) plowing was the least successful sagebrush treatment studied.
Best cover responses on the various range improvement practices were found on contour furrowing treatments on sand, clay loam and loam textured soils and on typic torriothent or ustic torriothent soil types. Though significant cover increases due to chaining of pinyon juniper were noted on 57% of the treatments, on a variety of soil textures and soil types, the increases were uniformly small (tree cover included) and no clear pattern emerged with either soil texture or soil type. Only about 20% of the various sagebrush treatments showed significant increase in cover; 10% indicated decrease cover, and there was no impact on cover on the remaining 70% of the treatments. Pitting in this study had no impact on cover.
Age of contour furrow treatments made little difference in either whether there was a significant increase or decrease in either production or cover. Cover data from pinyon-juniper chainings indicate that either that significant increase in cover (if they occur) are slightly more dramatic on more recent treatments, or that treatments approximately 11 years old represent conditions most ideal for enhanced cover. The former interpretation is probably more nearly correct. Production data suggests that pinyon-juniper sites chained since 1964 are not as favorable in terms of increased production as those chained prior to 1964. Age of sagebrush treatment had no impact on significant changes in cover; however, a general trend indicated that production increases are slightly higher for more recent sagebrush chaining treatments than for older ones.

Hironaka, M., CLASSIFICATION OF THE PINYON-JUNIPER VEGETATION TYPE, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 199-201.
For land managers, the purpose of classifying pinyon-juniper land is to identify areas that would respond similarly to the management practices. For identification of areas of similar potential in other vegetation types, climax vegetation has been used as the basis of classification. With pinyon-juniper vegetation, due to the simple species mix of overstory and lack of understory in mature stands, this strategy is unsatisfactory.
Primary succession is visible in many areas in the pinyon-juniper zone. The obvious invasion of juniper into adjacent sagebrush and grassland vegetation and their subsequent displacement in a period of less than a century and a half add to the frustration of developing a baseline classification scheme. Observable changes in soft properties associated with these vegetation changes are also present.
Use of plants alone to classify the pinyon-juniper vegetation type results in large, highly variable classification units because of the simple species mix in mature stand. It will be necessary to complement vegetation information to develop a useful classification of pinyon-juniper land.

The ecological relationships of three cricetine species Peromyscus maniculatus, Perornyscus boyhi, and Neotoma stephensland their utilization of habitat were revealed by species removals from unfenced plots and vegetation tailoring experiments. When N. stephensi, a woodland and shrubland species of woodrat, was removed from a manzanita-oak shrubland and pinyon-juniper woodland, P. boyhi showed few significant changes in its use of the vegetational microhabitats on the grid or in the nature of its arboreal activity. However, when P. boylii, a woodland and shrubland mouse, was removed from a grid in juniper-oak shrubland and juniper grassland, both P. maniculatus, an inhabitant of open habitats such as grassland, and N. stephensi expanded their microhabitat utilization and changed their patterns of aboveground activity. Subsequent removal of both N. stephensi and P. boylii from this plot resulted in further expansion of arboreal activity by P. maniculatus. After crown removal of 0.75 ha of manzanita-oak shrubland, P. boylii, but not N. stephensi, avoided the newly opened area. Habitat selection, differential resource utilization, and interspecific competition all contribute to the coexistence of these species in patchy habitats.

Habitat utilization by Peromyscus-boylii, P. maniculatur, and Neotoma stephensi was studied by live trapping marked animals on grids in a variety of local habitats in east central Arizona. None of the species exhibited clear-cut affinities for specific plant taxa; rather, the types of flora used by each species varied from grid to grid. P. boylii tended to use a wide variety of vegetational microhabitats, but almost always was captured in higher frequencies than expected in the most common type(s) at a locality. P. maniculatus showed much more restricted habitat utilization, but where it did occur, it tended to be captured in the most prevalent vegetation more often than expected. N. stephensi also occurred in a restricted range of microhabitats, and it usually utilized rarer vegetational types. Live trapping on platforms permanently affixed in trees, on logs, and in the canopies of bushes revealed arboreal activity. P. maniculatus spent much less time in above-ground activity than did the other two species. Both N. stephensi and P. boylii climbed in plants of a variety of taxa, shapes, and heights. However, P. boylii tended to use more types of the available aboveground resources and to climb higher than N. stephensi. The amount and nature of each species arboreal activity did not differ significantly between woodland and shrubland habitats.

Honeycurt, R.L., M.P. Moulton, J.R. Roppe, and L. Fifield, THE VEGETATION OF TOPOGRAPHY AND VEGETATION ON THE DISTRIBUTION OF SMALL MAMMALS IN SOUTHWESTERN UTAH, The Southwestern Naturalist, vol. 60, August 1981, p. 295-300.
The distribution of 15 species of small MAMMALS was studied along a 160 km transect on southwestern Utah. The transect followed an elevational gradient and incorporated five community types. Ordination analysis revealed that abundance and distribution of certain small mammal species were influenced by topography features ( Hurricane Cliffs) and vegetational characteristics.

Horton, W.H., K.H. Asay, and F.B. Gomm, NEW GRASSES FOR RANGELAND IMPROVEMENT, USDI Bureau of Land Management, Boise, Idaho, In: K. Sanders and J. Durham (eds.), Rangeland Fire Effects: a Symposium, 1985, p. 109-111.

Howard Jr., V.W., K.M. Cheap, R.H. Heir, T.G. Thompson, and J.A. Dimass, EFFECTS OF CABLING PINYON-JUNIPER ON MULE DEER AND LAGOMORPH USE, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 552-557.
The effect of two-way cabling on seasonal use of pinyon-juniper (Pinus edulis, Juniperus monosperma, J. deppeana) woodland by mule deer (Odocoileus hemionus), desert cottontails (Sylvilagus audubonii), and blacktail jackrabbit (Lepus californicus) was determined at the Fort Stanton Experimental Ranch and adjacent areas of the Lincoln National Forest, NM. Pellet transect data, collected quarterly from September 1976 to June 1982, were used to compare mule deer and lagmorph use of areas cabled in 1954, and 1975 and adjacent undisturbed areas. Each treatment was replicated at four study sites. Mule deer use of cabled areas was higher during spring and summer than during fall and winter. No seasonal trends were evident on untreated areas. Lagomorph use of areas cabled in 1954 showed no seasonality, whereas, a seasonal use pattern that changed from year to year was observed on the areas cabled in 1975. Lagomorphs exhibited a preference for cabled over undisturbed areas in spring, summer, and fall. Use on undisturbed areas was highest in winter, intermediate in fall, and lowest in spring and summer.

Fences constructed to contain livestock and restrict movements of predators, particularly coyotes, may impede movements of deer and other wildlife. A study was designed to determine the effectiveness of 2 electric fences for impeding ingress by coyotes and to evaluate the influence of these fences on movements of mule deer. This paper reports the results of the data gathered on movements of mule deer in relationship to the 2 types of electric fences.

Hubbard, R.E. and R.M. Hansen, DIETS OF WILD HORSES, CATTLE, AN MULE DEER IN THE PICEANCE BASIN, COLORADO, Journal of Range Management, vol. 29, September 1976, p. 389-391.
Diets of free-roaming wild horses, domestic cattle, and mule deer were estimated for three altitudinally different vegetation zones in the Piceance Basin, northwest Colorado. Wild horses and cattle ate mostly grasses and sedges in the each of the vegetation zones. Mule deer diets consisted primarily of browse. Wild horses and cattle diets compared within a vegetation zone were similar to each other than diets of a single herbivore compared between vegetation zones. The percentages of the diets of wild horses and cattle that were identical ranged from 59% to 75% in the three vegetation zones. Diet overlap of wild horses or cattle with mule deer was always less than 11%. The diversities of plants on the diets were lower for mule deer than for cattle or wild horses.

Under rest-rotation grazing heavy emphasis is placed on restoration of vigor to the point where seed can be produced and where conditions are systematically created for establishment of seedlings of desirable forage plants. To obtain reproduction it is necessary to rest the range from grazing at three critical times for three main purposes: first, To restore plant vigor; second, to insure development and ripening of seed; and third, to insure establishment of seedlings. The general form of rest-rotation grazing, therefore, consists of four basic steps in the following sequence: 1. Graze the range for maximum livestock production. 2. Rest the range until plant vigor is restored. 3. Rest the range until seed ripens, then graze for maximum livestock production. 4. Rest the range until reproduction becomes firmly established. The number of years required to apply these steps depends on the growth requirements of the key species on the range, the one species most desired for forage and plant cover.

Hurst, W.D., MANAGEMENT STRATEGIES WITHIN THE PINYON JUNIPER ECOSYSTEM, The Pinyon-Juniper Ecosystem: a Symposium, May 1975, p. 187-194.
The pinyon-juniper ecosystem covers an extensive area within the western states. These are important lands from the standpoint of producing forage, wildlife habitat, water control, and the production of woodland products such as posts, pinyon nuts, fuelwood, and Christmas trees. The density increase in many original pinyon juniper stands and their invasion into grasslands and shrubs vegetative types have led to control projects which are becoming increasingly controversial. Once accepted as a sound range rehabilitation program, the justification of the practice from an economic as well as from an environmental standpoint is now questioned by some segments of the public. Arguments supporting such questions range from wilderness preservation, the recreational and economic importance of pinyon nuts, esthetic values, wildlife habitat needs, and the economics of the practice. There are those who approve of control measures, but there is still a need for a better understanding of this vegetative type and the opportunities it possesses. Its ecology and its potential are not adequately understood or recognized even by the best informed. Depending on the land management objectives sought, there are areas where manipulation of pinyon-juniper can be fully justified in light of ecologic, economic, and multiple use considerations. On the other hand, there are vast areas that would best serve the nation if they were managed as pinyon-juniper.

Jameson, D.A. CLIMAX OR ALTERNATIVE STEADY STATES IN WOODLAND ECOLOGY, Proceedings- Pinyon-Juniper Conference, Jan. 1987, p. 9-13.
Higher elevation areas of the pinyon-juniper woodland are climax forest and the usual concept of (linear) plant succession apply. However, the more interesting ecological questions concern those areas where the time between regeneration events is longer than the life span of the established trees. In either case, there are years of above average precipitation that are not quite adequate for regeneration; these years may become adequate for regeneration if much of the competing vegetation is removed. Rather than linear succession, a more useful concept in pinyon-juniper dynamics seems to be that of alternative steady states. A cusp catastrophe model is suggested as a convenient way of visualizing the effects of fire, grazing, and climatic changes on woodland vegetation.

Jameson, D.A.; J.A. Willams, and E.W. Wilton, VEGETATION AND SOILS OF FISHTAIL MESA, ARIZONA ,Ecology, vol. 43, 1962, p. 403410.
Fishtail Mesa is an island plateau in the Grand Canyon of northwestern Arizona neat. the junction of Kanab Creek and the Colorado River. Although isolated by canyons 1,000-1,000 ft deep it is similar. in elevation, geology, and vegetation to the "mainland" of the Kaibab Plateau. Fishtail Mesa covers about 1,430 acres, and the elevation is 6,000-6,200 ft. Because the mesa has never been grazed by domestic livestock and has been visited by few people, it provides a study area where vegetation and soils have not been altered by man or domestic stock. The mesa was studied to provide management information for similar., but grazed, areas.

Johnsen Jr., T.N., and F.B. Gomm, FORAGE PLANTINGS ON SIX ARIZONA PINYON-JUNIPER SUBTYPES, Journal of Range Management, vol. 34, March, 1981, p. 131-136.
Forty-four species and varieties of forage plants, including 3 shrubs, 6 forbs, and 35 grasses, were planted at each of six sites in four Arizona pinyon-juniper climatic subtypes. Represented were cold-moist and cold-dry climatic subtypes each on medium and fine textured soils; and a warm-dry climatic subtype on medium-textured soil. Sites are described and classified to help identify planting potential and facilitate wider applications of results. Data are given on plant emergence, establishment, survival during 12 growing seasons, and forage production. Agropyron smithii Rydb., A. Intermedium vat'. trichophorum (link) Halac., and Sitamon hystrix (Nutt) J.G. Sm. successfully revegetated swelling clay soils. These three species, Atriplex canescens (Pursh) Nutt. and Bouteloua gracilis (H.B.K.) lag. ex Stued. were the most widely adapted species tested.

Johnsen Jr., T.N., USING HERBICIDES FOR PINYON-JUNIPER CONTROL IN THE SOUTHWEST, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 330-342.
Pelleted picloram or tebuthiuron are being used to kill individual trees, to maintain chained or bulldozed areas, and to restore recently invaded grasslands on southwestern pinyon-juniper ranges. Good control of Utah juniper (Juniperus osteosperma) and pinyon (Pinus edulis), and variable control of one-seed juniper ( J. monosperma) and alligator juniper (J. deppeana) have been obtained. Broadcast applications have been limited to experimental and demonstration trials but both herbicides successfully controlled Utah juniper and pinyon. Tebuthiuron severely damaged cool season grasses; picloram did little damage to grasses. Tebuthiuron controlled understory shrub live oak (Quercus turbinella) and picloram did not.

T.N. Johnsen Jr., SEEDING PINYON-JUNIPER SITES IN THE SOUTHWEST, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 465-472.
Past efforts to reseed southwestern pinyon-juniper sites are briefly reviewed, specific problems unique to this area are discussed, and research needs suggested. Twenty six species adapted to one or more of nine suggested southwestern pinyon-juniper climatic subtypes are tabulated.

Johnsen Jr., T.N. and S.D. Raymond, MANAGING INDIVIDUAL JUNIPER AND PINYON INFESTATIONS WITH PELLETED TEBUTHIURON OR PICLORAM, Journal of Range Management, 1990, vol. 43, p. 249-252.
Junipers and pinyons are reinfesting areas from which they have been removed and are encroaching into other areas. Controlling these trees while they are small would help maintain forage production and protect the soils. Individual trees can be controlled by applications of pelleted picloram and tebuthiuron, but little is known of the comparative effectiveness of these herbicides on junipers and pinyon. We compared pelleted picloram and tebuthiuron on individual alligator juniper, one-seed juniper, and pinyon. Pellets were applied at 0.7 and 1.4 g picloram acid equivalent or tebuthiuron active Ingredient 1 meter of tree height at 3 Arizona and 3 New Mexico locations. Utah juniper and pinyon trees up to 2 m tall were killed with 0.7 g picloram a.e. or tebuthiuron a.i./m of height. One-seed junipers up to 2-m tall were killed by 0.7 g tebuthiuron a.i./m of height, but were not by picloram. Neither herbicide killed alligator juniper consistently. Some understory grasses were damaged more by tebuthiuron than by picloram.

Johnsen Jr., T.N. and H.L. Morton, LONG-TERM TEBUTHIURON CONTENT OF GRASSES AND SHRUBS ON SEMIARID RANGELANDS, Journal of Range Management, 1991, p. 249-253.
Perennial plants collected from 5 north-central Arizona semiarid locations were assayed for tebuthiuron and its metabolites using gas chromatography with flame photometric detection. Tebuthiuron was applied at rates ranging from O.9 to 6.7 kg active ingredient (a.i.)/ha in 1975 through 1979. Plants were harvested in 1980 through 1986, 2 to 11 years after applications. Tebuthiuron was detected in sideoats and blue grama 10 years after application of 6.7 kg/ha. Metabolites of tebuthiuron were detected in blue grama 11 years after applications of 2.2, 4.5, and 6.7 kg/ha. The rations of tebuthiuron to metabolites varied widely. The highest concentrations of tebuthiuron plus metabolites were 25 micrograms/g in blue grama 10 years after application of 45 kg/ha, and 21 and 23 micrograms/g in sideoats grama 9 and 10 years, respectively, after application of 6/7 kg/ha. Only these 3 samples of 120 samples assayed exceeded the legal limit of 20 micrograms/g of tebuthiuron plus metabolites in forage plants. No samples from plots treated with 4.0 or less kg/ha exceeded 10 micrograms/g of tebuthiuron plus metabolites, and only 10% of them exceeded 5 micrograms/g.

Johnson, D.W., ECOLOGY OF SMALL MAMMALS ON TWO ISOLATED Buttes IN CANYONLANDS NATIONAL PARK, UTAH, The Southwestern Nationalist, vol. 26, November, 1981, p. 395-407.
Fewer mammalian species occurred on summits of sheer-walled buttes than occurred in similar "mainland" control sites, but density of small MAMMALS on buttes equaled or exceeded mainland density. Peromyscus crintitus, the only terrestrial mammal on Jug Butte, occupied a larger habitat niche there than in control areas. No such niche expansion was noted for P. crintitus on Junction Butte, where four others species of small MAMMALS and at least one large mammal also occurred. At least 18 species of terrestrial MAMMALS inhabit the control sites. It is hypothesized that the species number remains static on each butte and is a function of the unique dispersal abilities of each species and does not represent an equilibrium between recurrent colonization and extinction.

Johnson, E.J. and P.J. Zwank, FLAMMULATED OWL BIOLOGY ON THE SACRAMENTO UNIT OF THE LINCOLN NATIONAL FOREST, Final Report New Mexico Coop. Fish and Wildlife Reserve Unit, Las Cruces.

Johnston, B.C., WOODLAND CLASSIFICATION: THE PINYON-JUNIPER FORMATION ,USDA Forest Service General Technical Report INT-25 7, Ogden, Utah. ,in: Proceedings--Land Classifications Based on Vegetation: Applications for Resource Management, p. 106-166.

Klebenow, D.A., BIG GAME RESPONSE TO FIRE IN SAGEBRUSH-GRASS RANGELANDS ,USDI Bureau of Land Management, Boise, Idaho. ,in: K. Sanders and J. Durham (eds.), Rangeland Fire Effects: a Symposium, 1985, p. 53-57.

Klopatek, C.C. and J.M. Klopatek, MYCORRHIZAE, MICROBES AND NUTRIENT CYCLING PROCESSES IN PINYON-JUNIPER SYSTEMS, Proceedings -Pinyon-Juniper Conference, Jan., 198 7, p. 3 60-3 64.
Two pinyon-juniper communities, one remnant and one grazed, were examined as to their microbial processing and mycorrhizal status. Nitrifying bacteria were in greater numbers in the interspaces than their corresponding canopies. The interspace of the undisturbed site had the highest concentration of bacteria (213,000 bacteria/g soil) followed by the interspace of the grazed site (96,000 bacteria/g soil), the undisturbed canopy having the lowest number of bacteria (3 5,000 bacteria/g soil). All soils exhibited ammonification and nitrification. Mineralization coefficients of total nitrogen corresponded with the number of nitrifiers. SOILS were also assessed for the presence of vesicular-arbuscular endomycorrhiaze spores. There were greater spore numbers under the canopies than in interspaces at both sites

Klopatek, J.M., NUTRIENT PATTERNS AND SUCCESSION IN PINYON JUNIPER ECOSYSTEMS OF NORTHERN ARIZONA, Proceedings - Pinyon Juniper Conference, Jan, 1987, p. 391-396.
Soil nutrient patterns were evaluated in interspaces of pinyon juniper woodlands. The interspaces and canopies of the mature ecosystem displayed definite differences in both the physical and chemical properties. Nitrogen and organic carbon were 4 and 5.5 times as great, respectively, under canopy then in the interspaces. Soil Ph, texture, and bulk density were also different. The early successional stages following fire showed remarkably less differences. Differences in total phosphorus concentrations indicate that the trees may be mining the interspaces for nutrients. This is substantiated by changes in litter C:N ratios over successional time. Analyses of the soil nutrient levels indicate that, following fire, it may take 200+ years to for the pinyon-juniper ecosystems to regain their prefire nutrient levels.

Klopatek, C.C., L.F. DeBano, and J.M. Klopatek, IMPACT OF FIRE ON THE MICROBIAL PROCESSES IN PINYON-JUNIPER WOODLANDS: MANAGEMENT IMPLICATIONS ,USDA Forest Service General Technical Report RM-191, Ft. Collins ,In: J.S. Krammes (tech. coord.), Effects of Fire Management of Southwestern Natural Resources, 1990, p. 197-205.


Kufeld, R.C., RESPONSE OF ELK, MULE DEER, CATTLE, AND VEGETATION TO BURNING, SPRAYING, AND CHAINING OF GAMBEL OAK RANGELAND, Technical publication/Colorado Division of Wildlife, Colorado Division of Wildlife; No. 34, 1983, p. 47.

Kufeld, R.C., M.L. Stevens, and D.C. Bowden, SITE VARIATION IN FORAGE QUALITIES OF MOUNTAIN MAHOGANY AND SERVICEBERRY, Journal of Range Management, vol. 38, 1985, p. 458-460.
Nutrient and fiber content and in vitro digestible dry matter (IVDDM) were measured in mountain mahogany and serviceberry samples collected during January from 8 geographic areas distributed through-out the western half of Colorado. Coefficients of variation (CV) in dry matter content, cell content, crude protein, soluble carbohydrate, cell walls, holocellulose and IVDDM were 10% or less for both species. Winter variation in these parameters appear to be small enough to permit using a constant value for them in calculating winter nutritional status of big game rangelands.

Lane, L.J. and F.J. Barnes, WATER BALANCE CALCULATIONS IN SOUTHWESTERN WOODLANDS, Proceedings - Pinyon-Juniper Conference, Jan., 1987, p. 480-488.
Water balance calculations are required to compute individual components of the water budget or balance: precipitation, runoff, evapotranspiration, soil moisture recharge and depletion, and seepage below the root zone. Hydrologic models are used to make these calculations, and soil-water-plant relationships are used to identify gaps in knowledge and, thereby, to suggest methods of improving hydrologic models.

Lanner, R.M., TERMINAL MEGASPORANGIATE CONES IN PINYON PINE, Canadian Journal of Botany, vol. 47, 1969, p. 259.
The megasporangiate cone of a pine is normally borne in the axil of a scale leaf. In the case of "uniodal" species the subtending scale leaf is just proximal to the short series of sterile bud of the year's morphogenic activity. Cones are therefore said to be subterminal in their position on the shoot (Shaw 1914).
There have been occasional reports of terminal cones (Doak 1935; Fielding 1960) but not enough data have been given to show that these were actually formed directly through primary apical meristem activity rather than by an axillary apical meristem. Masters (1890) observed that a vigorously growing young conelet could exert dominance over a weakly growing vegetative terminal bud, thereby making the cone appear to be terminal. Several years ago I described such pseudoterminal cones found on Masson pine in Hawaii (Lanner 1966).
This report describes three apparently terminal cones found on a pinyon pine growing on the campus of Utah State University, Logan, Utah. The tree is about 20 years old and 15 ft tall. The cones were borne on branchlets of a first-order branch in a heavily shaded part of the lower crown.
Figure 1 shows one of the cones as it appeared In May, 1968, before spring growth started. The cones had emerged as conelets nearly a year earlier, and would have matured in August or September of 1968. No other development stages were found.
Proximal to each cone was a short series of sterile scales. The most distal of these were closely pressed against the base of the cone. Proximal to the sterile scales was a series of scales subtending short shoots (needle fasicles), and proximal to this was the series of sterile scales normally found at the base of a pine shoot.
Longitudinal sections showed the pith and the xylem to be continuous from the woody stem to the distal end of the cone, with neither external nor Internal evidence of branching between the most distal needle fascicles and the base of the cone. There was no internal evidence of degenerated of necrotic tissue.
The woody stem proximal to the cone contained 1 year's growth of secondary xylem. These observations suggest that the terminal cones were formed by the following sequence of activity in the shoot apical meristem during the summer of 1966: 1) Sterile scale primordia were initiated. 2) Scale primordia were initiated which subsequently subtended short-shoot primodia. 3) A second series of sterile scale primordia was initiated. 4) Ovuliferous scales were initiated, forming a cone.
In spring of 1967 the bud elongated and the conelet emerged and was pollinated. The previously indeterminate vegetative shoot apex had undergone differentiation and become a determinate reproductive apex. Therefore no further apical growth took place.

Lanner, R.M., ORIGIN OF THE SUMMER SHOOT OF PINYON PINES, Canadian Journal of Botany, vol. 48, 1970, p. 1759-1765.
Shaw (1914) used the term "summer-shoot" for the "second flush" of growth that often follows elongation of vigorous pine shoots. He pointed out that such a shoot converts "a uninodal spring-shoot into an imperfect multinodal branchlet."
Other authors have' tended to use the terms "summer-shoot" and "lammas shoot" interchangeably when referring to shoots that result from prompt elongation of a bud formed during the summer. Tepper (1963), for example, recently stated that the summer shoot is the product of elongation of a "summer bud." If the same "does not elongate during the same season, it called a winter bud." Rudolph (1964) described the formation and elongation of a bud in the same summer, and termed its result laminas growth as have many other workers he cites.
Within the subgenus Strobus, however, are species that form summer shoots (in Shaw's sense) without first organizing the shoot components in a bud. Instead, their summer shoots include some units that overwintered In the winter bud, and others that elongated immediately after being formed de novo in the spring.
This reports furnishes some details of the morphology and development of these summer shoots, and shows how their development correlates with that of the spring shoot. In the ensuing discussion the spring shoot plus its summer shoot will be referred to as" the complex shoot."

Lanner, R.M. and Earl R. Hutchison, RELICT STANDS OF PINYON HYBRIDS IN NORTHERN UTAH, Great Basin Naturalist, vol. 32, 1972, p. 171-175.
Relict stands of Pinus edulis and P. monophylla, and of natural hybrids of these species have been found in Cache and Rich counties. The stands and their sites are described. The P. edulis stand in Rich County extends the range of this species northward. Possible means of seed dissemination are discussed and it is speculated that both species formerly migrated into and out of this area during periods of differing climates.

Lanner, R.M. and Thomas R. Devender, MORPHOLOGY OF PINYON PINE NEEDLES FROM FOSSIL PACKRAT MIDDENS IN ARIZONA, Forest Science, vol. 20, 1979, p. 207-211.
Singleleaf pinyon pine needles have been found preserved in packrat middens up to 30,000 years old. Their morphology compares closely to that of singleleaf pinyon needles from modern Arizona stands. Macrofossil associates include species that are associated with modern singleleaf pinyon.

There have been conflicting reports of Pinus quadrifolia needle number since Parry discovered this pine in 1850.
Field studies were made of this species and of nearby populations of P. monophylla to determine their genetic relationship. It is concluded that P. quadrifolia results from natural hybridization between P. monophylla and a heretofore unrecognized 5-needle pinyon pine. Various hybrid segregates have been identified. The new species is described an P. juarezensis Lanner, Sierra Juarez pinyon. This interpretation reconciles conflicting morphological descriptions, and explains the phenotypic variation visible in the field. Characters analyzed are needle number, resin canal number, twig hairiness and stomate position. It is speculated that P. juarezensis may in the future be introgressed out of existence as a distinct entity.

Pinus monophylla Torr. and Frem. is a semi-desert pine typical of the Great Basin but extending southwards across Arizona into Baja California and southeastwards into New Mexico. Its close relative, P. edulis Englem., is a widespread species of the Colorado Plateau and southern Rocky Mountains. Because they produce edible nuts known as pinones in Spanish, they are popularly called "pinyon pines". Outlying populations of these are sympatric in several locations.
Neither species deeply penetrates the range of the other, but the long interface provides an opportunity for gene flow between them. The possibility that these species hybridize in nature has been briefly raised by several authors. Cole compared a population of P. edulis and one of P. monophylla with putative hybrids from central Utah. He showed leaf resin canal number to be intermediate in the presumed hybrids and postulated that hybridization had occurred along a Great Basin ecotone. The trees in Cole's hybrid ecotone were initially identified by the coexistence of 2-needle fascicles and 1 needle fascicles on the same shoots. He assumed the frequencies of these fascicle types to be about equal. Critchfield and Little (1966) stated cautiously that the species "may occasionally intergrade." Mirov ( 196 7 ) speculated that these pinyon pine species "possibly intercross", and urged controlled breeding experiments to settle the question. Mansfield-Jones studied morphological variation in pinyon pines in southwest Utah in an attempt to correlate species distribution with environmental parameters. He referred to intermediate trees as "intergrades" but did not postulate a hybrid origin for them. One feature of the intergrades was the simultaneous occurrence of 1-needle and 2 needle fascicles on the same shoots.
Two recent reports from this laboratory (Lanner 1971; Lanner and Hutchison 1972) have discussed the distribution of putative hybrid pinyon populations in parts of Utah, but the evidence of hybridity has been deferred to this paper. The objective of this study was to define the extent of natural hybridization between P. edulis and P. monophylla.

Lanner, R.M. and T.R. Van Devener, LATE PLEISTOCENE PINON PINES IN THE CHIHUAHUAN DESERT, Quaternary Research, vol. 15, 1981, p. 278-290.
Examination of late Pleistocene packrat middens from the northern and central Chihuahuan Desert disclosed macrofossils of Colorado pinon and Texas pinyon. Radiocarbon dating indicates that Texas pinon was widespread in Trans-Pecos Texas and north-eastern Mexico between 30,000 and 11,000 yr B.P. Today it is found in small refugia east of its edge of the Chihuahuan Desert. Both species occurred in the Hueco Mountains, near El Paso, Texas. No clear evidence was found of the presence of Mexican pinon, though today it is abundant in the Davis and Chisos Mountains. A paleoclimate is postulated that had the following characteristics: increased winter precipitation from Pacific frontal sources, reduced summer temperatures and precipitation, and milder winter temperatures due to a reduced frequency of Arctic airmass incursion. Winter precipitation appears to have decreased from north to south, while winter temperatures, and, possibly, summer precipitation, increased from north to south. During the late Pleistocene, the northern Chihuahuan Desert was dominated by woodlands of pinon pines, junipers, and oaks. The desert-scrub communities that characterize the area today are a Holocene phenomenon.

Lanner, R.M., A SELF-POLLINATED EXPERIMENT IN PINUS EDULIS, Great Basin Naturalist, vol. 40, 1980, p. 265-267.
Controlled pollinations were performed on four pinyons (Pinus edulis Englem.) to compare the results of selling and outcrossing. Final cone size was the same under both treatments. There was no significant difference in number of seeds per cone. Filled-seed yields averaged 14.4% in selfings and 90.5% in outcrossings. Relative self-fertility averaged about 15%, a level comparable with that of other pine species studied.

Larson, M., A MANAGEMENT STRATEGY FOR WOOD PRODUCTION FROM PINYON-JUNIPER WOODLANDS, Proceedings - Pinyon-Juniper Conference, Jan., 1987, p. 279-282.
Applications of principles of forest management is suggested as an appropriate management strategy. Inventory is essential and stratification should include size class, stocking and site quality estimates. Projection or estimates of growth are also needed. Harvest scheduling can then be done using a formula rule or harvest scheduling model. Shelterwood regeneration methods without intermediate cuts appear to be a feasible management strategy.

Lavin, F. and T.N. Johnsen Jr., SPECIES ADAPTED FOR PLANTING ARIZONA PINYON-JUNIPER WOODLAND, Journal of Range Management, 1977, p. 410-414,
Species adaptation trials were observed over periods varying from 21 to 28 years at ten Arizona pinyon-juniper sites. Fifty-nine species and varieties developing fair to excellent stands and persisting five or more years were considered adapted to one or more of the sites. Fifty-four of these were still present at the last rating. Thirty have reproduced themselves and are spreading naturally. Most widely adapted species are Agropyron desertorum, A. intermedium, A. smithii, A. trichophorum, Atriplex canescens, Bothriochloa ischaemum, Bouteloua curtipendula, Muhlenbergia wrightii, and Tridens elongatus. Moisture variation caused some cool season grasses to fluctuate more widely in growth and stand than the other adapted species, especially shrubs. Warm-season growers were generally sensitive to low temperatures and cool-season growers to high temperatures. Complete protection from livestock appeared to have detrimental effects on some species. Sites are described and classified to help identify planting potential and facilitate wide application of results. Guidelines are suggested for shortening the time period needed to evaluate species adaption.

Leonard, S.G., R.L. Miles, and H.A. Summerfield, SOILS OF THE PINYON-JUNIPER WOODLANDS, Proceedings--Pinyon-juniper Conference, Jan., 1987, p. 227-230.
The Soil Resource Information System program on the Fort Collins Computer Center System 2000 was used to evaluate selected soil properties and mapping data for two pinyon and five juniper species in Utah, Nevada, and New Mexico. The soil data indicate two distinct concepts of interpretation between Utah-Nevada and New Mexico. New Mexico provides interpretations for all soils where pinyon or juniper species presently occur while Utah and Nevada provide interpretations only where these species are perceived to be part of the ecological potential or climax situation. Within suitable climatic regimes the range of other soil characteristics indicates a broad ecological amplitude that overlaps several other community types. This suggests associated species and community susceptibility to fire may be an overriding factor to edaphic characteristics in determining the distribution of pinyon-juniper communities.

Leopold, B.D. and P.R. Krausman, DIETS OF 3 PREDATORS IN BIG BEND NATIONAL PARK, TEXAS, Journal of Wildlife Management, vol. 5 2, 1986, p. 664-667.
Mountain lion, bobcat, and coyote scats were collected during 1972-74 and 1980-81. Bobcats consumed lagomorphs as their principal diet during 1972-74 and smaller prey during/-980-81. We believe that the observed changes in the predator diets were due partially to a significant decline in the desert mule deer population between the 2 sampling periods.

Lindzey, F.G., Bruce B. Ackerman, Dan Barnhurst, and Thomas P. Hemker, SURVIVAL RATES OF MOUNTAIN LIONS IN SOUTHERN UTAH, Journal of Wildlife Management, 1988, p. 664-667.
We monitored survival of resident mountain lions during a radio-telemetry study between 1980 and 1986 in southern Utah. Yearly survival of resident adults ranged from 52 to 100%. Causes of death included intraspecific killing, injury related to prey capture, trapping, and starvation. Deaths of dispersing offspring were human-related.

Little Jr., E.L., PINYON TREES (PINUS EDULIS) REMEASURED AFTER 47 YEARS, Proceedings - Pinyon-juniper Conference, Jan. 1987, p. 65-68.
Growth of pinyon (Pinus edulis Englem.) is extremely slow, according to remeasurements by the same person in 1985 of trees in two plots in New Mexico established in 193 8. The 47 yr. study yields information on mortality, regeneration, and management.

Lomolino, M.V., Jame H. Brown, and Russell Davis, ISLAND BIOGEOGRAPHY OF MONTANE FORESTYLE="MAMMALS IN THE AMERICAN SOUTHWEST, Ecology, 1989, p. 180-194.
Information from packrat middens and other paleoenvironmental indicators was used to reconstruct Pleistocene distributions of macrohabitats in the American Southwest (Arizona, New Mexico, southern Utah and Colorado). This revealed a system of southern montane forests that were isolated during the Pleistocene (primarily by woodlands) as well as today (by grasslands, chaparral, and desert scrub). Based on the presence of at least five species of nonvoant forest MAMMALS on these montane islands, we inferred that these MAMMALS immigrated across woodlands during the Pleistocene. Because the great majority of montane forests in the American Southwest are now isolated by woodlands, but not grasslands, chaparral, or desert scrub, we hypothesized that post-Pleistocene immigrations may influence the structure of mammalian communities on these montane islands. This hypothesis was supported by the highly significant correlation of mammalian species richness with current isolation as well as area. When isolation was partitioned into distance to be traveled across woodland vs. grassland-chaparral habitats, species richness was significantly correlated with the latter measure of isolation but not with the former, indicating that woodlands do not represent major barriers to immigration. Seventeen of 26 species considered are reported with at least 10/6 of their record locations in woodlands and other lowelevation habitats. Analyses of pattens of occurrence of seven species of forest MAMMALS inhabiting between 7 and 16 islands revealed that insular distribution was significantly affected by area in two species, by area and isolation in three species, and by isolation alone in the remaining two species. Based on our reconstruction of Pleistocene macrohabitat distributions, analyses of community- and species-level patterns, and evidence on the ability of forest MAMMALS to inhabit and disperse across woodlands and other low-elevation habitats, we conclude that community structure on montane forest MAMMALS in this region of the American Southwest is influenced by post-Pleistocene immigrations as well as extinctions.

Longhurst, W.M., A.L. Lesperance, M. Morse, R.J. Mackie, D.L. Neal, H. Salwasser, D. Swickard, P.T. Tueller, P.J. Urness, and J.D. Yoakum, LIVESTOCK AND WILD UNGULATES, University of California Agriculture Science Special Publication 3 301, Berkeley, California. ,In: J.W. Menke (ed.), Proceedings: Workshop on Livestock and Wildlife-Fisheries Relationships in the Great Basin, 1983, p. 42-64.

Cryptogamic soil crusts on the Colorado Plateau were studied to determine their effect on infiltration rates, potential sediment production, permeability, and several chemical properties of the soil. Six different crust stages were identified. Undisturbed soil cores were used to determine intrinsic permeability under three treatments and disturbed soil samples were analyzed for pH, percent organic matter, soil texture, calcium plus magnesium content and total conductivity. Cryptogamic crust had little effect on soil chemical properties. Analysis of undisturbed soil core data indicated that high cryptogamic cover tended to reduce intrinsic permeability, an effect that was reinforced when cores were irrigated. Sites with any degree of cryptogamic cover had significantly higher infiltration rates than chained areas (no lichen cover) Patterns of sediment production revealed a potential for increased sediment once the crust had been disturbed.

Changes in runoff and yield caused by changing sagebrush cover to grass cover were studied at four small watersheds in western Colorado during a 9 yr. period, from 1965 to 1973. Measurements of runoff and sediment yield from the 4 watersheds were made for 3 yrs. at which time 2 watersheds were plowed and seeded to beardless bluebunch wheatgrass. The same measurements were then continued for an additional 6 yrs. Measurements indicated that conversion to grass caused a reduction in runoff from summer rain storms of about 75%. Runoff from spring snowmelt increased about 12%, and annual runoff from treated watersheds decreased about 20% when compared to control watersheds. Sediment yield from the seeded watersheds reduced by about 80%; most of this reduction is related to the decrease in runoff from summer rainstorms.
The size of barren interspace between plants was reduced on the converted watersheds to about 30/6 of those on the untreated watersheds. Linear regression analysis indicates that a reduction of 3896 in the amount of bare soil resulting from planting grass would result in a decrease of 7396 in sediment concentration.

Lyon, J.L, HABITAT EFFECTIVENESS FOR ELK AS INFLUENCED BY ROADS AND COVER, Journal of Forestry, October 1980, p. 658-660.
Pellet counts conducted over an eight-year period confirmed that elk in western Montana tend to avoid habitat adjacent to open forest roads. The area avoided increases where the density of tree cover is low. Forest roads open to traffic cause available habitat to be less than fully effective. A method for determining the losses of effective habitat is presented.

Lyon, J.L. and Chester E. Jensen, MANAGEMENT IMPLICATIONS OF ELK AND DEER USE OF CLEAR-CUT, Journal of Wildlife Management, vol. 44, 1980, p. 352-362.
Elk, mule deer, and white-deer pelleted-group densities were counted in and adjacent to 87 clear-cuts of various sizes and ages in eastern and western Montana. Pelleted distributions suggest that animals enter clear-cut openings in search of better quality or greater quantities of forage. However, the willingness of animals to enter an opening is influenced by a requirement for security during the feeding period and is locally modified by the past experiences of animals in the available environment. Both elk and deer preferred openings with cover in the opening except where such cover inhibited forage growth. Both preferred openings in which logging slash was not a barrier to movement. Elk preferred smaller openings than deer, but were more tolerant of large openings-particularly where natural openings were already present in the environment. Elk use of clear-cuts was severely depressed by the presence of open roads and inadequate cover at the edge of the opening.

Madany, M.H. and Neil E. West, VEGETATION OF TWO RELICT MESAS IN ZION NATIONAL PARK, Journal of Range Management, vol. 3 7, September 1984, p. 456-461.
Twelve permanent vegetation samplings plots were established on Greatheart and Church mesa in Zion National Park, Utah. Both relict mesas are surrounded by cliffs but contain the same variety of soil conditions as the nearby "mainland". The mesa vegetation was segregated into the following broad community types: mixed conifer forest, ponderosa pine savanna, Gambel oak woodlands, pinyon woodland, snowberry-sagebrush steppe, and oak-sagebrush shrubland. Cover of all species was measured in the plots, in addition to tree stem density. Relationships of each community type to topoedaphic factors and response to fire are noted. The mesa ecosystems can be used as standards to gauge the various effects of resource exploitation on analogous "mainland" areas.

Mason, L.R., H.M. Andrews, James A. Carley, and E. Dwain Haacke, VEGETATION AND SOILS OF NO MAN'S LAND MESA RELICT AREA, UTAH, Journal of Range Management, 1967, p. 45-49.
On No Man's Land Mesa, a relict area in Kane County, Utah, two distinctly different soils were found which produce significantly different kinds and amounts of vegetation. The Upland sand (Pinyon-Juniper) site yielded an average of about 1100 lb/acre air dry comprising 10% grass, 5% forbs and 85% trees and shrubs. The Upland shallow breaks (pinyon-juniper) site yielded an average of nearly 800 lb/acre comprising 5% grass, 5% forbs and 90% trees and shrubs.

Matheny, D.J., AN EVALUATION OF CHAINING AS A PINYON-JUNIPER MANAGEMENT TECHNIQUE, Prepared for a Public Lands class at the J. Ruben Clark Law School, Brigham Young University,
In the United States today over 75,000 square miles of land is covered by a woodland system whose major elements are pinyon pines and junipers. Over 90% of the total pinyon-juniper woodland acreage is in the states of Arizona, Colorado, New Mexico, Nevada, and Utah. Man has found many uses for this woodland type during prehistoric and historic times. in recent times the major use of pinyon-juniper woodland has been and continues to be livestock grazing; of the total acreage of the woodlands, about 80% is grazed. In some areas (principally New Mexico) pinyon-juniper ranges have been grazed for more than 200 years, often with yearlong grazing being practiced. The frequent result of that long use has been overgrazed ranges in poor condition with a low livestock carrying capacity.
There is also evidence that reduced range capacity is sometimes due to the invasion of grasslands by pinyon-juniper woodland which may occur because of overgrazing and the suppression of natural fires. The desire to control and reverse the penetration of trees into the grasslands has led a number of federal and state land management agencies to use several techniques to convert areas of pinyon-juniper woodland into grassland. One of the most widely used of these techniques is mechanical removal of trees by chaining followed by seeding the land to establish grassland species.
After a general definition of the pinyon-juniper ecosystem, a discussion of prehistoric and historic uses of the woodland and an explanation of the theory of historic changes in the extent of the woodland, this paper focuses on chaining as a specific technique for pinyon-juniper management as it has been practiced for the past 30 years. Recent developments involving chaining which, at least in part, result from the passage of NEPA and other statutes, are considered. The effectiveness of chaining on wildlife, the watershed, cultural resources and aesthetic value. The final section of this paper is a critical evaluation of the chaining of pinyon-juniper woodland as a management technique in light of all the factors considered including benefits and costs.

We studied nest-site preferences of Flammulated Owls in the Zuni Mountains of western New Mexico and used multivariate analyses of the nest cavity, nest tree, and surrounding woody vegetation to ask if and then how the birds select nest sites. Significantly reduced variance in used compared to unused sites for both cavity/nest-tree and vegetation data indicates that the used sites are a nonrandom subset of the source pool (i.e., the birds are selective). Preferred cavities are modal in the source pool, but preferred vegetation is characterized by low shrub density, high canopy height, and importance of mature Pinus edulis. Preferred vegetation characteristics appear more limited than preferred cavity/nest-tree characteristics. Nest sites have fewer shrubs in front of than behind the cavity entrance. This is consistent with the species' habit of flying at shrub level upon approaching and leaving the nest. The suggestion that Flammulated Owls have increased in abundance with increasing vegetative density is not supported.

McCulloch, C.Y., SOME EFFECTS OF WILDFIRE ON DEER HABITAT ON PINYON-JUNIPER WOODLAND, Journal of Wildlife Management, 1969, p. 778-784.
Mule deer habitat conditions were observed during 1966-68 on a 50-square mile plateau of pinyon-juniper woodland, half of which was previously burned by crown fires. Deer droppings were abundant in a sampled strip 1/8 mile wide by 11 miles long that included both burned and unburned areas. Accumulation rates of deer pellet groups were greater in the burned than in the unburned parts of the strip. The droppings accumulated at high rates in a burned zone 1/4 to ½ mile from the edge of unburned woodland. Despite the large acreage burned, only 5 percent of it was more than ½ mile from unburned areas. At 13-15 years after fire, the burned area had virtually no cliffrose, a key browse species on nearby unburned range of pinyon-juniper type. Non-browse items including grasses were 85 percent of the contents of deer rumens collected from burned sites in autumn. The increased grass yields on burns benefitted cattle. The plateau and adjacent territory appeared to have a dense population of deer. For the limited purpose of producing both cattle and deer, extensive crown fires seemed acceptable as a range improvement technique in remote woodland near precipitous terrain like that of the Grand Canyon.

McDaniels, K.C. and L. Whitetrefaro, SELECTIVE CONTROL OF PINYON JUNIPER WITH HERBICIDES, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 448-455.
Various rates of tebuthiuron and picloram pellets were applied on pinyon-juniper woodlands in New Mexico to determine effects on the trees and associated shrubs. Pinyon (Pinus edulis) were generally controlled with 1.0 lb active ingredient(a.i.)/ac of tebuthiuron, and O.8 lb a.i./ac of picloram. About 0.8 lb a.i./ac of tebuthiuron pellets controlled one-seed juniper (Juniperus monosperma) growing on sand or loamy sand, whereas 1.5 lb a.i./ac was needed to control the trees on loamy or clay loam soils. Picloram controlled one seed juniper at a 2.1 lb a.i./ac rate on sandy and loam soils, but did not satisfactorily kill the trees on clay loam soils. Wavyleaf oak (Quercus undulata), sand sagebrush (Artemisia filifolia), skunkbrush ( Rhus trilobata) and algerita (Berberis spp.) were controlled by tebuthiuron to 0.8 lb a.i./ac, but were not generally controlled by picloram. Higher rates of tebuthiuron and picloram are needed to control trees and shrubs on deep, fine textured soils than on shallow, coarse textured soils. Trees less than/.0 feet tail were usually more readily controlled than larger trees.

McKell, C.M. and J.R. Goodin, U.S. ARID SHRUBLANDS IN PERSPECTIVE, Society for Range Management, Denver, CO. ,in: D.N. Hyder (ed.), Arid shrublands--Proceedings of the Third Workshop of the United States/Australia Rangelands Panel, 1973, p. 12-18.

McNichols, R.R., MANAGEMENT STRATEGIES IN PINYON-JUNIPER ON THE HUALAPAI INDIAN RESERVATION, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 161-164.
The management of pinyon-juniper woodlands on the Haulapai Reservation has changed from no management, to an emphasis on removal or eradication, to the current strategy of multiple use and sustained yield. While there are still significant pressures from grazing interests for removal of pinyon-juniper the increased value of woodland products has caused the tribe to reevaluate their objectives.

Meeuwig, R.O., PINYON-JUNIPER STAND DYNAMICS AND MANAGEMENT, Proceedings of the Second Utah Shrub Ecology Workshop, SEPT. 1982, p. 5-8.
Product values of most pinyon-juniper stands are presently so low that intensive management is not practical. But where economic conditions permit, some sites can be managed intensively for either forage or wood production. Demands are increasing rapidly for wood from the pinyon-juniper type. Type conversions should be limited to sites where probable benefits gained would exceed lost benefits plus costs of conversion and management.

Mehringer Jr., P.J. and P.E. Wigand, WESTERN JUNIPER IN THE HOLOCENE, Proceedings - Pinyon- Juniper Conference, Jan. 1987, p. 109-119.
Macrofossils from wood rat middens, lake sediments and fossil pollen reveal prehistoric variability in relative importance of grass, sagebrush and western juniper. The spectacular historic expansion of western juniper is matched by similar events of the last 4000 years when episodes of plentiful precipitation favored its spread at lower elevation.

Meinke, R.J., A PRELIMINARY ECOLOGICAL AND HISTORICAL SURVEY OF NORTH AND SOUTH CAINEVILLE MESAS, WAYNE COUNTY, UTAH, Resources Development Internship Program, Western Interstate Council for Higher Education, 1975.

Meyer, S.E. and S.B. Monsen, SEED-SOURCE DIFFERENCES IN INITIAL ESTABLISHMENT FOR BIG SAGEBRUSH AND RUBBER RABBITBRUSH ,USDA Forest Service General Technical Report INT-2 15, Ogden, UT. ,In: E.d. McArhur, E.M. Romney, S.D. Smith, and P.T. Tueller. Proceedings--Symposium on Cheatgrass Invasion, Shrub Die-off and Related Aspects of Shrub Biology Management, 1990, p. 200-208.

Miller, R.F., R.F. Angell and L.E. Eddleman, WATER USE BY WESTERN JUNIPER, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 418422.
A preliminary water use model for western juniper (Juniperus occidentalis) is proposed based on the equation: total water use: leaf conductance x vapor pressure deficit x leaf area x time. Outputs from the model are compared to actual field data.

Moir, W.H. and J.O. Carelton, CLASSIFICATION OF PINYON-JUNIPER (P-J) SITES ON NATIONAL FORESTS IN THE SOUTHWEST, Proceedings -Pinyon-Juniper Conference, Jan. 1987, p. 216-226.
We define woodland plant associations, subseries, ecological sites, all of which are invariant under changing management systems (unless soils are degraded or enriched ).
To date there is no classification of P-J woodlands at the level of plant association or ecological site. Literature from Arizona and New Mexico contains numerous descriptions of P-J vegetation which are generalized over diverse sites and stages of succession and which are not clearly set apart from other kinds of vegetation such as chaparral or Madrean evergreen woodland. Our classification at a subseries level gives an overview of woodland diversity and biotic potentials. This subseries classification relates to patterns of regional climate and provides consistency for applying soil taxonomy. A few, known P-J associations are fitted into this subseries classification.
Based on literature review and field experience, we estimate about 70 plant associations and perhaps 280 ecological sites within the P-J woodland of Arizona and New Mexico.

Monsen, S.B. and N. Shaw (compilers), MANAGING INTERMOUTAIN RANGELANDS-IMPROVEMENT OF RANGE AND WILDLIFE HABITATS, USDA Forest Service General Technical Report INT-157, 1983, p. 194.

Monsen, S.B. and F..D. McArthur, FACTORS INFLUENCING ESTABLISHMENT OF SEEDED BROADLEAF FORBS AND SHRUBS FOLLOWING FIRE, USDI Bureau of Land Management, Boise, ID. ,in: K. Sanders and J. Durham (eds.), Rangeland Fire Effects: a Symposium, 1983, p. 112-124.

Monsen, S.B., SHRUB SELECTIONS FOR THE PINYON-JUNIPER PLANTINGS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 316-329.
Planting limitations of pinyon-juniper woodlands have decidedly influenced shrub seeding success. Species adapted to broadcast seeding have generally excelled. inability to discern site adaptability requirements of individual shrubs has resulted in misplanting, particularly of species with limited distribution. Various subspecies and ecotypes of big sagebrush and rabbitbrush and numerous ecotypes of antelope bitterbrush have proven to be well adapted to pinyon-juniper sites, providing a diverse array of selections with different useful features. Selections of fourwing saltbush, common winter fat, and forage kochia, species naturally occurring in other plant communities, have been developed for pinyon-juniper woodlands. To date, five shrub cultivars with superior vegetative characteristics have been developed for wildlife habitat, including pinyon-juniper sites. These selections, 'Kincon' fourwing saltbush, 'Hatch' winterfat, 'Imigrant' forage kochia, 'Lassen' antelope bitterbrush, and 'Bighorn' skunkbrush sumac have advanced the usefulness of these shrubs.

Murphy, P.M., SPECIALTY WOOD PRODUCTS FROM PINYON-JUNIPER, Proceedings - Pinyon-Juniper Conference, Jan. 19 8 7, p. 16 6-16 7.
Feasibility studies utilizing pinyon-juniper woodlands for providing specialty wood products show mixed promise. Current costs of chipping and hauling proved too high for feasible production of oriented-structure board. A cement board plant proved feasible at one location in eastern Nevada. However, the present slump in the housing market and the high interest rates on money will have a negative effect on this project.


Neese, E., VEGETATION OF THE HENRY MOUNTAINS, Utah Geological Association Pub. No. 8 ,In: M.D. Picard (ed.). Henry Mountains Symposium, 1980, p. 219-136.

Recent invasions by pinyon-juniper woodlands into neighboring ecosystems raise difficult questions for land managers. A complete understanding of the causes of these invasions has remained elusive. However, recent advances in the fields of paleobotany, ecology and climatology allow new syntheses which may hold promise for understanding these difficult problems.

Nix, P.J., G.W. Workman, E.C. Oaks, and L. Henrickx, MAMMALS OF NATURAL BRIDGES NATIONAL MONUMENT, UTAH, Unpublished report prepared for National Park Service, Natural Bridges NM, 1977.

O'Meara, T.E., Jonathan B. Haufler, Lavern H. Stelter, Julius G. Nagy, NONGAME WILDLIFE RESPONSES TO CHAINING OF PINYON-JUNIPER WOODLANDS, Journal of Wildlife Management, 1981, p. 381-389.
Nongame wildlife responses to chaining of pinyon-juniper woodland were studied on 1977 in the Piceance Basin, Colorado. Vegetation and small-mammal populations were sampled on a mature pinyon-juniper woodland (control) and areas chained 1, 8, and 15 years previously. Breeding-bird populations were studied on the areas chained 8 and 15 years previously, the control area, and on the edge between a mature woodland and an area chained 10 years previously. Ten species of breeding birds were observed on the unchained area, whereas only 3 and 4 species were observed on the 8-and 15-year-old chained areas, respectively. Bird densities on the unchained area were more than double those on the chained areas. Five of 17 species breeding on the edge area used both vegetation types. Only 1 species was found exclusively on the edge area. Small MAMMALS were more abundant on chained than unchained areas; species diversity was greatest on the unchained area. Adverse effects on nongame wildlife could be minimized by favoring survival of shrubs and young trees, retaining selected cavity trees, and limiting widths of clearings when chaining pinyon-juniper.

Oakleaf, B., C. Maser, and T. Nappe, LIVESTOCK AND NONGAME WILDLIFE, University of California Agriculture Science Special Publication, h-'x: J.W. Menke (ed.), Proceedings: Workshop on Livestock and Wildlife-Fisheries Relationships in the Great Basin, 1983, p. 95-102.

A simulation model of forage crop, beef production and economic returns of grazing steers on pinyon-juniper woodlands is presented. The model is modified from one developed for steers grazing in the summer on a ponderosa pine site in northern Arizona. The model provides a means for identifying data needs necessary to make reliable management decisions and provides estimates of net economic return to livestock production for scenarios resulting from management decisions and biotic and abiotic parameters.

Orains, G.H. and M.F. Wilson, INTERSPECIFIC TERRITORIES OF BIRDS, Ecology, vol. 45, 1964, p. 736-745.
Territories of birds, usually defended against conspecific individuals, are sometimes defended against individuals of other species. Since such behavior is demanding of both of time and energy, natural selection should favor ecological divergence, the establishment of overlapping territories, and the reduction of aggression. Lack of divergence in modes of exploitation could mean that insufficient time has elapsed for the changes to be completed or that the environment imposed some limitation preventing the evolution of the required degree of divergence. Such environmental limitation can be predicted in (a) structurally simple environments, (b) when feeding sites are strongly stratified in structurally complex vegetation, or © when the presence of other species in the environment prevents divergence in certain directions. The known cases of interspecific territoriality in birds are analyzed and shown to be largely in accordance with these predictions, although several cases of overlapping territories in situations where interspecific has been predicted provide relationships worthy of further study. We suggest that Darwinian selection at the level of the individual permits an understanding of the known structure of avian communities and that there is no need at present to invoke new selective mechanisms at the level of the community or ecosystem.

The U.S. Forest Service in the past 25 yrs. has chained and seeded approximately 31,000 ha of pinyon-juniper (pinus-juniperus) woodlands in Utah. In the past, evaluation of these chainings has been restricted to one or two Intensively studied sites. This project evaluated 20 chained and seeded pinyon-juniper areas and adjacent unchained areas, ranging in age from 1 to 2 5 yrs. and located throughout Utah. The wide ranges of age and geographic distribution of the treated sites allowed comparison of the effects of chaining and seeding on forage production, mule deer (Odocoileus hemionus) usage and watershed conditions. The economic feasibility of chaining and seeding was evaluated using four methods: (1) costs of a 486 ha chaining and seeding project to a private land owner; (2) costs of a 486 ha. chaining and seeding project to the Forest Service, not including administrative costs; (3) costs of the same project to the Forest Service with administrative costs included; and (4) the cost of the project to the Forest Service, using a seed mixture to benefit both livestock and wildfire. Methods and analyses used for this study were designed to be applicable to land management agencies such as the Forest Service and the Bureau of Land Management.
Results indicated forage production is greatly enhanced by chaining and seeding. Crested wheatgrass (Agropyron cristatum) was the most common forage grass seeded and provided the best response on all sites evaluated. Other seeded grasses were site specific in their response. Watershed conditions were separated into distinct problem areas, evaluated individually and then combined for overall evaluation. Most treated sites were either significantly improved or the trend was toward watershed improvement as a result of chaining and seeding.
Mule deer tracks, pellets and browsing signs were higher on approximately half of the chained and seeded areas as compared to the adjacent unchained areas. There was a steady decline in mule deer signs as the distance from an unchained edge into the chaining increased. It is not recommended that chainings be more than 1.800 m in width. Establishment of seeded shrubs has been variable. It appears that the seed selected for a particular site must be suited to that site. If a natural seed source is available in the area prior to treatment then additional shrub seeding appears unnecessary.
Sagebrush (Artemisia tridentata) rapidly becomes established on a treated site and provides a desirable micro-climate for the reestablishment of pinyon and juniper trees. To maximize the Life of a chaining and seeding project, sagebrush controlling would be necessary at eight to ten year intervals.
When crested wheatgrass is the only seed used on a chained site, then based on a 10% borrowing and opportunity cost a 486 ha chaining and seeding project is economically feasible for both private land owners and the Forest Service. When a seed mixture includes several grasses and desirable browse plants and only livestock forage benefits are included in the economic analysis, the chaining becomes economically infeasible. However, it is important to consider that the Forest Service is operating under guidelines established by law to manage public lands for multiple benefits and sustained yield and not necessarily for the highest dollar return. Thus, a chaining project that is economically infeasible might be justified when multiple use values (which cannot be monetarily quantified) are included in the analysis.

Pengelly, L.W., TIMBERLANDS AND DEER IN THE NORTHERN ROCKIES, Journal of Forestry, vol. 61, 1963, p. 734-740.
Since 1880 fires and logging have altered the general aspect of large portions of the virgin coniferous forests of the northern Rockies to diverse admixture of timber remnants, second growth timber reproduction and pole stands, and brushfields of varying sizes. The seral shrubs in the forest understory and clearings in many areas are important as winter range for white-tailed deer and mule deer. Logging is the most effective and least expensive habitat management tool at the disposition of the game manager. The current disparity between the apparent economic values of the timber resource and the indefinite value of game, however, will preclude logging specifically to aid game for some time to come. Temporary increased of good deer forage are produced on Douglas fir - Ponderosa pine sites about 10-15 years after logging and then it gradually declines, with poor forage shrubs and tree reproduction gaining dominance in the understory composition. Current extensive cutting to control insect damage on grand fir sites has limited potential for improving white-tailed deer winter ranges due to a less favorable seral succession and the rigid habitat requirements of this deer. They are subject to heavy periodic winter mortality on the marginal, heavy snowfall ranges where seasonal availability of forage is equally as important as species composition and volume. Cutting alone cannot produce good winter ranges where terrain is unsuited to deer. Excessive timber operations in any one area tend to produce too many roads which increase hunter access to the detriment of quality hunting. Other factors to consider are upset in numbers and distribution of game animals following the profound ecological impact of large cuttings and fines, with the possibility of depredation on adjacent timber reproduction. Experimental habitat manipulation by logging controlled fires, thinnings, and herbicidal sprays is recommended.

Phillips, T.A., AN ANALYSIS OF PINYON-JUNIPER CHAINING PROJECTS IN THE INTERMOUNTAIN REGION 1954-1975, USDA Forest Service Range Improvement Notes (September), 1977.

Phillips, T.A., NORTH CEDARS PINYON-JUNIPER STUDY, USDA Forest Service Range Improvement Notes (November), 1979.

Pieper, R.D. and G.A. Lymbery, INFLUENCE OF TOPOGRAPHIC FEATURES ON PINYON-JUNIPER VEGETATION IN SOUTH-CENTRAL NEW MEXICO, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 53-57.
Pinyon-juniper vegetation occupies all topographic positions in the mountain foothills of the southwest and Great Basin. The pinyon pines tend to be more important at higher elevations than the juniper species, but are often subdominant in other situations. In southcentral New Mexico Juniperus monosperma tends to have higher densities and canopy cover on the northeast exposures and lowest values on the more scenic southwest slopes. Densities of Juniperus monosperma were higher on steep slopes than on gentle slopes. Pinus edulis is somewhat more abundant on north slopes but is not influenced by slope steepness. Understory species appeared to be more sensitive to topographic variables than the tree species. Rhus trilobata exhibited greatest densities and canopy cover on the steepest slopes, but does not respond to aspect. Quercus undulata also has highest densities on slopes above 20%. Opuntia imbricata seems to thrive on gentle south facing slopes.

Pieper, R.D., OVERSTORY-UNDERSTORY RELATIONS IN PINYON JUNIPER WOODLANDS IN NEW MEXICO, Journal of Range Management, vol. 43, 1990, p. 413-415.
Herbage biomass for blue grama (Bouteloua gracilis <H.B.K. Lag>), pinyon ricegrass (Piptichaetium fimbriatum <H.B.K. Hitchc.>), New Mexico muhly (Muhlenbergia pauciflora <Buclkl.>), other grasses and forbs was determined on 25 pinyon-juniper stands of varying overstory cover on the Fort Stanton Experimental Ranch in southcentral New Mexico. Negative 2nd degree polynomial curves were obtained for the relationship between total understory and blue gama biomass overstory canopy cover. Positive polynomial relationships were shown for New Mexico muhly and pinyon ricegrass. Reducing pinyon-juniper canopy cover would likely increase blue gama production and reduce production of New Mexico muhly and pinyon ricegrass.

Pieper, R.D. and R.D. Wittie, FIRE EFFECTS IN SOUTHWESTERN CHAPARRAL AND PINYON-JUNIPER VEGETATION, USDA Forest Service General Technical Report RM-191, Ft. Collins, In: J.S. Krammes (tech. coord. ), Effects of Fire Management of Southwestern Natural Resources, 1990, p. 87-93.

Rasmussen, D.I., BIOTIC COMMUNITIES OF THE KAIBAB PLATEAU, ARIZONA, Ecology Monogram, vol. 11, 1941, p. 229-275.

Renard, K.G., PRESENT AND FUTURE EROSION PREDICTION TOOLS FOR USE IN PINYON- JUNIPER COMMUNITIES, Proceedings - Pinyon Juniper Conference, Jan. 1987, p. 505-5 12.
Although most of the erosion prediction technology currently used in the United States was developed from research on cultivated agriculture, the physics of the process are such that, with appropriate parameter adjustment, the technology can be transferred to other areas and land use types with appropriate caution. The primary erosion process in the pinyon-juniper ecological areas, as in other areas, are those associated with raindrop splash erosion due to the shear of water moving over the land surface. Most models used for most erosion prediction consider erosion in interrill areas, in rills, and in concentrated flow or stream channel areas. Current technology for such prediction involves the Universal Soil Loss Equation, which lumps the processes of rill, interrill erosion, and sediment transport. The paper discusses some recent modifications and improvements to this technology. Also discussed is the effort to develop second generation erosion prediction technology which is physically based, and includes a hydraulic component to provide the runoff estimates required for estimating sediment detachment, transport and deposition at upland sites. The replacement technology is designed to operate on personal computers or small minicomputers, simulates on a storm basis, and aggregates to obtain monthly and annual soil loss values.

Reynolds, H.G., FORT BAYARD HABITAT IMPROVEMENT, New Mexico Wildlife, May-June 1964, p. 10-11.
Pinyon-Juniper woodland of New Mexico serves as important winter, and in some cases, yearlong habitat for several game species. As our human population increases, we demand more usable products from pinyon-juniper. This woodland can be improved, both as game habitat and as livestock range. This article describes a study in southern New Mexico designed to £red out how pinyon-juniper can be treated to increase wildlife.

Reynolds, H.G., IMPROVEMENT OF DEER HABITAT ON SOUTHWESTERN FORESTYLE="LANDS, Journal of Forestry, vol. 67, 1969, p. 803-805.
Tentative suggestions for improving deer habitat include (1) maintaining forest openings and borders, (2) thinning tree practices, (3) minimizing slash cleanup, (4) including forbs and browse in range reseeding practices and (5) allocating forage between deer and cattle.

Ronco Jr., F., STAND STRUCTURE AND FUNCTION OF PINYON-JUNIPER WOODLANDS, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 14-22.
A keynote address, with broad coverage, on pinyon-juniper woodlands discusses factors influencing stand structures. Productivity of woodlands with regard to the overstory, undergrowth, and animal life, and tree and undergrowth relationships are covered, especially with regard to management implications. Productivity is correlated in general terms with stand dynamics and succession.

Rosenstock, S.S., S.B. Monsen, R. Stevens, and K.R. Jorgensen, MULE DEER DIETS ON A CHAINED AND SEEDED CENTRAL UTAH Pinyon juniper RANGE, USDA Forest Service Res. Paper INT-410, Ogden, UT, 1989.

Rostenstock, S.S., HERBIVORE EFFECTS ON SEEDED ALFALFA AT FOUR PINYON-JUNIPER SITES IN CENTRAL UTAH, Journal of Range Management, Vol 46, November 1989.
Effects of rabbits, mule deer, and livestock on seeded alfalfa were studied on 4 sites in central Utah. Sites were dominated by pinyon pine and Utah juniper and were double-chained and seeded with a mixture of grasses, forbs, and shrubs between 1959 and 1962. A 4 way exclosure was built on each site in 1962 which included the following treatments: (1) control (rabbits, deer, and livestock excluded), (2) rabbit access, (3) deer access, and (4) rabbit plus deer access. The fifth treatment (outside the exclosure) was accessible to rabbits, deer, and livestock. Alfalfa density and production were estimated at 1 to 5 year intervals between 1963 and 1986. Alfalfa growth form was measured in 1986. Stand densities declined from 0.5 to 8.5 plants/m2 to 0.5 to 2.5 plants/m2 during the 23-year sampling period. Reproduction by seed was not evident. Alfalfa production fluctuated greatly (4 kg/ha to 4,104 kg/ha) with precipitation and decreased with increased herbivore access. Treatment effects varied. Rabbits had a negative effect on alfalfa density at 2 sites, but no effect on alfalfa production. Deer use had inconsistent effects on alfalfa density, but reduced alfalfa production at 2 sites. The addition of livestock reduced alfalfa density at one site, and alfalfa production at 3 sites. Grazing treatments had a marked effect on alfalfa growth form. Decreases in height and increases in basal cover were associated with increased herbivore access. Results of this study indicate that alfalfa can be an important and persistent component of seeding mixtures used on semiarid pinyon-juniper ranges.

Rumbaugh, M.D. and M.W. Pedersen, SURVIVAL OF ALFALFA IN FIVE SEMIARID RANGE SEEDINGS, Journal of Range Management, vol. 32, 1979, p. 48-51.
Selected cultivars and strains of alfalfa were seeded at five locations in Northern Utah during 1953 and 1954. Average annual precipitation ranged from 20 to 36 cm. Observations and detailed plant counts showed a decline in alfalfa stand densities at four of the five sites. The reduction in plant density at two sites was attributed primarily to livestock grazing and to severe damage by rabbits. Moisture stress was an additional factor at two other sites. Plant density has remained high at the fifth location for 23 years.


Schmidt, L.J., PRESENT AND FUTURE THEMES IN PINYON-JUNIPER HYDROLOGY, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 474-479.
A diverse range of vegetation species, climatic factors, and soil parent materials govern the hydrology of pinyon-juniper ecosystems. Pinyon-juniper covers an estimated 64 million acres (25 million hectares) in the western states. In spite of this, a disproportionally small amount of hydrologic related research has been accomplished. Currently, a gap exists between the available scientific knowledge base and application by land managers. Part of this problem stems from a past tendency to accept hydrologic information supporting eradication of Pinyon-juniper and disregard findings that questioned the watershed benefit ff these practices. This selective body of accepted facts and folklore inhibits support for further research to flesh out concepts and resolve conflicting findings. The failure to synthesize current research facts into a workable strategy for managers also inhibits application. Changes in public demands have resulted in a reassessment of management goals for pinyon-juniper. However, managers lack adequate knowledge on inventory methods, silvicultural systems, and productivity in relation to runoff processes. An indicated need exists for a soil-vegetation classification to enable transport of hydrologic knowledge gained from research or practice. Further long-term small-watershed studies are needed to fill knowledge gaps and provides a framework for plot studies.

Schott, M.R. and R.D. Pieper, SUCCESSION IN PINYON-JUNIPER VEGETATION IN NEW MEXICO, Rangelands, 1986, p. 126-128.
Pinyon-juniper is a major vegetation complex of the southwestern United States. One-seed juniper and pinyon are the major species of the complex in central New Mexico. Since settlement of the Southwest by Europeans, this vegetation type has increased in distribution and density of individual trees. A decline in forb and grass production accompanied these increases. Because of the decline in forage production, land managers have attempted various types of pinyon-juniper control, often without an understanding of the ecology of the complex or an idea of how the vegetation will respond to the treatment. For example, cabling has been used extensively in the Sacramento Mountains of southcentral New Mexico as a form of pinyon-juniper control. Larger trees are pulled out of the ground, but many smaller trees and shrubs survive the cabling. The successional pattern following cabling and other types of disturbance is not understood for many areas in New Mexico. Research concerned with secondary succession of pinyon juniper communities where one-seed juniper and pinyon are the dominants has not been extensive. This article presents the result of several studies on pinyon-juniper succession in the Sacramento Mountains in south central New Mexico.

Predawn potentials of Quercus undulata, Pinus edulis, and Juniperus monosperma were estimated on three areas, each consisting of three different seral communities. Two areas had similar seral communities: one cabled in 1975 for pinyon-juniper control; one cabled in 1954; and an uncabled site. Seral communities of the third area were a 1964 push where the trees were removed by bulldozing, a late-seral community, and a near-climate community. Oak appeared to be a mid-seral species because it exhibited the most negative water potentials on the 1954 cablings and late seral communities. Juniper appeared to be a late seral species because it is the most water stressed in climax communities. Water potential of pinyon was relatively constant over the growing season and among seral communities. Pinyon had different age classes as understory and appeared to be the climax species in these associations. Pinyon does not appear to compete for soil water with other species. However, oak and juniper seem to compete, especially on areas with shallow soils.

Schott, M.R. and R.D. Pieper, OVERSTORY-UNDERSTORY INTERACTIONS IN SOUTHWESTERN PINYON-JUNIPER VEGETATION, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 461-464.
Pinyon-juniper overstory has pronounced influence on understory vegetation. This influence is reflected in reduced understory biomass and shifts in species composition. The overstory may restrict understory production by limitations in soil water, influence of pinyon-juniper litter, light reductions, or a combination of factors. Considerable efforts have been expended in the Southwest to control pinyon-juniper trees to increase herbaceous production for livestock. Studies in Arizona and New Mexico revealed distinct zonation patterns around individual juniper trees. In most cases there is a gradient from relatively high herbaceous cover near the edge of the canopy to low values near the trunk. Some species such as Piptochaetum fimbriatum and Muhlenbergia pauciflora appear to be adapted to conditions under juniper canopies.

Principal component analysis (PCA) was used to interpret secondary succession of pinyon-juniper stands after cabling or bulldozing. Soil types were used to separate 93 sample units into 3 groupings. A PCA was run on 2 of the groupings. Groups of sample units were defined as community types for each ordination. Stepwise discriminant analysis using environmental variables was used to assist in delineation of community types. Species that contributed the most to the first 3 principal components were compared among community types for each ordination using an analysis of variance and a comparison of the least squares means. Grasses on the deeper soils usually increased after cabling, but after 25 years they had declined to near pretreatment levels. Wavyleaf oak increased after cabling, and on the older cablings it had reached higher cover values than on the other community types. Pinyon and juniper response appeared to be dependent on density and size of trees before cabling. If the stand was near climax before cabling, pinyons rapidly became dominant on the site. The successional pattern following cabling on relatively deep soils is similar to what was found after fire, but it occurs faster. Cover of grasses and shrubs increased more on rock-free soils compared to sites treated similarly but with rock. The ordinations indicated that succession in pinyon juniper communities is directional and leads towards climax with a decrease in variability among sites.

Schreyer, R. and L.E. Royer, IMPACTS OF PINYON-JUNIPER MANIPULATION ON RECREATION AND AESTHETICS, The Pinyon Juniper Ecosystem: a Symposium, May 1975, p. 143-15 1.
Increasing public concern for environmental quality has led to support for including aesthetic considerations in the resource allocation decision-making process. This paper reviews research relevant to identifying aesthetic factors in natural environments and their relations to resource management operations. The practice of pinyon-juniper chaining is examined in Light of its impact on the aesthetic resource of pinyon-juniper ecosystem. Two questions are addressed: When should aesthetic considerations cause chaining not to be employed, and assuming chaining is necessary, how can it be performed to minimize visual impacts? Guidelines are suggested for making these decisions.

Sedgewick, J.A., AVIAN HABITAT RELATIONSHIPS IN PINYON JUNIPER WOODLAND, Wilson Bulletin, 1987, p. 413-43 1.
Habitat relationships of breeding birds were examined in northwestern Colorado in pinyon-juniper woodland and in openings where most overs tory trees had been knocked down by anchor chaining. Vegetation characteristics and physical habitat features were measured in 233 O.04-ha circular plots around singing males of 13 species of birds from 15 May to 15 July 1980. Thirteen-group discriminant function analysis ordinated bird species along three habitat dimensions described by (1) canopy height; (2) slope, shrub size, and shrub species diversity; and (3) percentage canopy cover. Woodland, open-area, and intermediate edge species were clearly segregated along the first discriminant axis, and species' associations with shrubs, inclination, ground cover, and edges were revealed by the ordinations along the second and third discriminant axes. Two group discriminant analyses comparing occupied and available plots identified additional and more specific habitat associations. For example, Hermit Thrushes were associated with mature forested habitats and forest interiors, Virginia's Warblers favored steep, oakcovered draws, Rock Wrens selected areas where percentage log cover and small tree density were high, and Dusky Flycatchers preferred shrubby slopes with scattered large trees near woodland edges.

Sedgwick, J.A. and R.A. Ryder, EFFECTS OF CHAINING PINYON-JUNIPER ON NONGAME WILDLIFE, Proceedings - Pinyon-Juniper Conference, Jan. 1987, 541-551.
The effects of chaining pinyon-juniper on nongame wildlife were studied from 1976-1980 in Piceance Basin, Colorado. Small MAMMALS and breeding birds were sampled in 1976 before treatment and for 4 years (birds) and three years (small MAMMALS) following chaining. Seven of the 16 most common species of birds used the control plot more (P< 0.05) while only one used the chained more. Foliage-and timber searchers, aerial foragers, foliage nesters, and cavity nesters rarely used the chained plot, whereas some species in the ground searching and nesting guilds regularly foraged or nested in the treatment plot. Small mammal species richness was greater on the chained plot than on the control plot, as was the total number of captures of all species combined. However, deer mice (Peromyscus maniculatus) comprised 85% of the total catch, and appeared to be the only small mammal species that benefited from chaining. Pinyon mice were captured only on the control. Varied responses by birds and small MAMMALS to chaining suggest strategies for minimizing its negative effects.

U.S. Forest Service, VEGETATION STRIPS CONTROL EROSION IN WATERSHEDS, Research Note RM-499, June 1990.
Natural vegetation buffer strips were found to act as barriers for reducing soil movement. In ponderosa pine in Arizona, buffer strips up to 20 m wide withheld practically all of the sediment delivered from non-wooded areas that had slope of lengths of up to 130 m. While the buffer strip delivered an average of 0.85 kg ha yr of sediment, similar non-wooded areas without buffer strips averaged 51.60 kg/ha/yr, or 61 times more sediment. Buffer strips in other southwestern vegetation types similarly restrained sediment delivery, as did buffer strips of willows and poplars on a large disturbed site in the Idaho batholith. Erosion control efforts in mountain areas should thus utilize vegetation buffer strips for relatively fast stabilization of disturbed hillslopes and for gaining time for large-area control applications. Furthermore, timber and other vegetation could be harvested in a manner that would leave appropriately located buffer strips.

Severson, K.E., WOODY PLANT REESTABLISHMENT IN MODIFIED PINYON-JUNIPER WOODLANDS, NEW MEXICO, Journal of Range Management, 1986, vol. 39, p. 438-442.
Pinyon, one-seed juniper, and alligator juniper woodlands in southwestern New Mexico were thinned, were pushed with bulldozers leaving slash in place, and were pushed and then slash piled and burned. There was no significant differences (P>O.05) in densities of these trees 13 and 18 years later between untreated (379 trees/ha) and thinned (489 trees/ha) plots or between pushed/left (67 trees/ha) and pushed/piled/burned/untreated/ thinning treatments were significant (P>O.05). Total shrubs, 75% of which were gray oak and hairy mountain mahogany, were significantly more abundant in untreated areas ( 67 2 shrubs/ha), than in any of the treatments (493,393,329, shrubs/ha for thinned, pushed/left, and pushed/piled/burned, respectively). Rates of pinyon re-establishment increased slowly up to the mid- 1960's (from 1.1 to 1.3 trees/ha/year) then accelerated to 10 to 13 trees/ha/year. Pinyon and juniper densities were about 120 trees/ha when re-establishment rates increased.

Severson, K.E., SMALL MAMMALS IN MODIFIED PINYON-JUNIPER WOODLANDS, NEW MEXICO, Journal of Range Management, 1986, vol. 39, p. 32-34.
The effects of pinyon-juniper treatments on rodent abundance, 13 to 18 years after treatment, were studied in southwestern New Mexico from 198 1 to 1983. Treatments included bulldozing, bulldozing/piling/burning, thinning, and untreated woodland. The area had not been grazed by livestock since time of treatment but was subjected to light and irregular use by wild ungulates. Total rodent numbers were significantly greater (P greater than or equal to 0.05) on all treated areas compared to untreated woodlands but individual species and groups responded differently. Woodrats and brush mice increased in abundance as slash accumulations increased, regardless of condition of overstory. Pinyon mice and rock mice numbers were also greater where slash was present, but only ff the pinyon-juniper overstory was relatively intact. Grassland rodents, as a group, were more abundant on areas where the pinyon-juniper overstory and slash had been removed (bulldozed and bulldozed/ piled/burned), but reduced numbers on bulldozed plots where slash was left suggested slash accumulations may have detrimental effects on numbers of these species. Treatments did not influence number of different rodent species. Data indicated that numbers of individuals and proportions of rodent species can be affected by manipulation of pinyon-juniper overstory and method of slash disposal.

Shelly, J., FIELD TESTING OF THE POINT SAMPLING METHOD IN PINYON-JUNIPER WOODLANDS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, 283-287.
Utilizing a point sampling volume estimation method for pinyon juniper woodlands by means of a slope-compensating stick type angle gauge is an efficient, accurate technique. This paper deals with field testing of the method in northwest Colorado.

Short, H.L. and C.Y. McCulloch, MANAGING PINYON-JUNIPER RANGES FOR WILDLIFE, General Technical Report RM-47, 1977.
Reviews, in a general way, the distribution and composition of pinyon-juniper woodlands in the occupying woodlands. Describes procedures for managing the woodlands in a manner advantageous to wildlife.

Short, H.L.; W. Evans, and E.L. Boeker, THE USE OF NATURAL AND MODIFIED PINYON PINE-JUNIPER WOODLANDS BY DEER AND ELK, Journal of Wildlife Management, 1977, vol. 41, p. 543-559.
Pinyon pine-juniper woodlands are important deer and elk habitats and occupy about 243,000 km2 of the western United States. In the study area at Fort Bayard, New Mexico, mule deer and elk ate evergreen browse extensively during winter. Mule deer ate more forbs during spring and summer, less browse during spring and less grass at all seasons than did elk. When woodland canopy was dense, production of midstory browse and understory herbage was reduced and deer and elk use diminished. Small clearings within the woodlands (<0.5 kin) were readily used by both deer and elk. Extensive clearings of pinyon pines and junipers increased herbage production but may have been sufficiently detrimental to wildlife to negate any additional grazing values for range cattle. Although small patch cuttings within woodlands increased usefulness for deer and elk, large cuttings in themselves and those that isolated undisturbed woodland from contiguous protective cover were unacceptable wildlife habitat.

Short, H.L., WILDLIFE GUILDS IN ARIZONA DESERT HABITATS, USDI Bureau of Land Management Technical Note No. 362, Washington, D.C., 1983.

Shultz, L.M., E.E. Neely, and J.S. Tuhy, FLORA OF THE ORANGE CLIFFS OF UTAH, Great Basin Naturalist, 1987, vol. 47, p. 287-298.
The vascular flora of the Orange Cliffs area, defined here as part of the Colorado Plateau floristic province, harbors approximately 209 species in 123 genera and 49 families. A species checklist is provided with a discussion of physical and floristic aspects of the region. The flora is compared statistically to the San Rafael Swell flora, which is also a subset of the Colorado Plateau. We define six vegetation types and three edaphic communities; these are described and mapped. Of eleven endemic plant species in the Orange Cliffs, three are local and rare. Sites for Astragalus nidularius, A. moencoppensis, and Xylorhiza glabriuscula var. linearifolia are discussed and mapped.

Two adjacent mechanically treated pinyon-juniper big game winter range sites in central Utah were sampled in 198 1 to estimate vegetational differences and tree mortality from the two treatments. One site was treated by selectively bulldozing in 1957 and the other was double chained in 1965. Both treatments significantly reduced tree and litter cover, whereas significant increases were found for native grasses and shrubs compared to a nearby untreated site. Juniper cover for the untreated site was 35.5% compared to only 1.4% for the bulldozed area and 4.1% for the two-way chained area. Browse species densities were increased by the mechanical treatments. The use of different mechanical treatments on separate smaller portions of critical areas of big game winter range would help provide: (1) for both long-term and short-term use of a critical wintering area, (2) greater overall productivity and carrying capacity, and (3) greater diversity by creating more edge effect between the differently treated and untreated areas.

Skousen, J.G., J.N. Davis, and J.D. Brotherson, PINYON-JUNIPER CHAINING AND SEEDING FOR BIG GAME IN CENTRAL UTAH, Journal of Range Management, 1989, vol. 42, p. 98-104.
Vegetation and soils were evaluated on 5 different-aged, mechanically treated and seeded pinyon-juniper sites and compared to adjacent untreated areas. Plant cover was significantly changed after treatment: trees were reduced from 26 to 6% total ground cover; shrubs were increased from 2 to 8% ground cover; and herbaceous plants increased from 2 to 13% ground cover. Annuals and perennial forbs were 75% of the total plant cover on the 2-year old site, perennial grasses and shrubs dominated the plant cover (52 to 83%) on three, 14- to 20-year-old sites, while shrubs and trees combined for 84% of the plant cover on the 24-year-old site. Two Agropyron grass species showed good establishment and persistence after seeding. Seeded forbs contributed about 5% of the total plant cover on the 2-year-old treated site and they declined on the older treated sites. Seeding of shrubs was only successful on sites where the shrub species was already present in the understory naturally. Seeding of nonactive shrub seed did not produce stands. Even though tree cover was reduced after treatment, total tree density was not. Shrub density increased from an average of 800 plants/ha on untreated areas to 2,750 plants/ha on treated areas. Juniper mortality during mechanical treatment, varied from 60 to 91% and was related to the percentage of trees estimated to be 60+ years old (r--0.97) and with the number of trees greater than 5 cm in stem diameter (r--0.71) on the adjacent untreated sites. Big game pellet group counts were not different between untreated and treated sites, suggesting that big game make use of these treated areas because of increased forage and browse and in spite of reduced security cover.

Smith, F.W. and T. Schuler, ASSESSMENT OF SITE QUALITY IN PINYON-JUNIPER WOODLANDS, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 260.
Various site quality estimators for southwestern pinyon-juniper woodlands were evaluated using data from sixty temporary plots. Anamorphic height-age site index curves were found to be useful in predicting volume when used in conjunction with stand density. Results indicated that regional growth equations for the species could be developed.

Home range use and activity patterns of black-tailed jackrabbits in northern Utah were studied using telemetry. Home range sizes ranged from <1 km to 3 km and did not differ between sexes or among seasons. Jackrabbits were inactive during daylight, became active at dusk, and remained active throughout the night. Animals often traversed their home ranges in a few hours. During the breeding season, males were more active than females. Jackrabbits were most active during well-lit nights, and high winds decreased jackrabbit activity.

Smith, S.D. and D.J.M. Bradney, MOJAVE DESERT FIELD TRIP, USDA Forest Service General Technical Report INT-276, Ogden, UT. ,In: E.D. McArthur, E.D. Romney, S.D. Smith, and P.T. Tueller (compilers). Proceedings--Symposium on Cheatgrass Invasion, Shrub Die-off and Other Aspects of Shrub Biology and Management, 1990, p. 350-35 1.

The specific goals and processes to be followed in the implementation of the woodland management program are: (1) develop and maintain an extensive inventory and classification of public woodlands; (2 ) manage available woodlands under the principle of sustained yield, maintaining an allowable harvest to provide a permanent source of wood products for future generations; (3) receive fair market value from the sale of wood products; (4) manage woodlands to achieve a positive benefit/cost ratio, including development of analysis procedures which ensure that associated values (watershed protection, improved habitat and forage for wildlife and livestock, reduced dependency on fossil fuels for home heating, and other values received from wood product harvest) are considered; and (5 ) facilitate the management of other resources through wood product sales. Specific examples of the latter include selling pinyon-juniper instead of chaining to improve livestock forage or using commercial woodcutting to make the desirable openings in forest cover to improve wildlife openings on forest cover to improve wildlife habitat.

Sparks, S.R., Neil E. West, and E.B. Alien, CHANGES IN VEGETATION AND LAND USE AT TWO TOWNSHIPS IN SKULL VALLEY, WESTERN UTAH, General Technical Report, 1990, p. 26-36.
Historical changes in plant dominance, in two townships of Skull Valley, UT, were assessed by repeating the earlier descriptions made by surveyors from the General Land Office. Massive conversions to cheatgrass and other annuals of former sagebrush- and shadscale dominated vegetation on bench, foothill, and bajada sites were found. In addition to unrestricted livestock grazing, wild fires were identified as the probable triggering factors for these changes. Both forces were probably required for conversion to dominance by annuals. Juniper at high elevations, lesser grazed areas at midelevations, and greasewood, and pickleweed-dominated areas at lower elevations have undergone much less change.

Spencer, A.C., NUT CROPS FROM UTAH RANGELANDS: THE PINYON TREES, Proceedings of the Second Utah Shrub Ecology Workshop, SEPT. 1982, p. 15-17.
Pinyon pine trees often produce good crops of seeds (nuts), although yields are affected by several factors operating over the 2 year production cycle. It is likely that management of suitable stands through use of pesticides, pruning, selective cutting and even irrigation could increase yields greatly. Nut production alternatives should be considered before brush management practices involving removal of pinyon trees are implemented. Through management it may be possible to achieve both pinyon nut and forage production. The ideas should be considered in planning and perhaps tested in practices.

Springer, E.P., ASSESSING RANGE MANAGEMENT ALTERNATIVES USING SIMULATION MODELS, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 5 13-5 17.
A methodology is proposed to assist land managers in decision making using simulation models as a tool. Two modes of analysis, point in time and time series, are presented, but all examples use the point in time technique. Examples use the EPIC model as the simulation model. The methodology allows managers to use current technology in the decision making process.


Stager, D.W. and D.A. Klebenow, MULE DEER RESPONSE TO WILDFIRE IN THE GREAT BASIN PINYON-JUNIPER WOODLAND, Proceedings -Pinyon-Juniper Conference, Jan. 1987, p. 572-581.
Mule deer (Odocoileus hemionus) habitat use, as indicated by pellet tracking counts, varied with successional stage following burning of pinyon-juniper woodlands. In early years following burning, forbs were abundant and mule deer pellets and tracks were most dense near the edge in unburned cover. Shrub cover and density increased to dominate sites by 16 years after fires and mule deer use on the burned areas became more general. Deer use was greater than on unburned areas and widespread throughout the 24 year-old burns. Mule deer use was greater in burned areas versus unburned sites 115 years following fire. Grasses, shrub, and tree response to fire was still evident 115 years following

Stahlecker, D.W., Patricia L. Kennedy, Anne C. Cully, and C.B. Kuykendall, BREEDING BIRD ASSEMBLAGES IN THE RIO GRANDE WILD AND SCENIC RIVER RECREATION AREA, NEW MEXICO, The Southwestern Naturalist, vol. 34, December 1989, p. 487-498.
Breeding bird assemblages were quantified on a 7,600-ha study area in northern New Mexico. Birds were censused on spot-mapping grids within six of eight habitats during the spring and summer of 1985. Population estimates were made for 43 species in at least one habitat while 113 confirmed and potential breeding species were dominated in the study area. The riparian habitat had the highest density (75 pairs/40 ha) while sagebrush-grasslands had the lowest canyon benches had the highest species richness. The greatest similarity in breeding bird species occurred in adjacent and structurally similar habitats.


Steuter, A.A. and H.A. Wright, SPRING BURNING EFFECTS ON REDBERRY JUNIPER MIXED GRASS HABITATS, Journal of Range Management, 1983, p. 161-164.
Habitat and plant species parameters were compared among untreated, chained/burned, burned/chained and burned/chained/reburned treatments on redberry juniper-mixed grass rangeland. Chaining followed by burning with a standardized fire plan in mid-March drastically decreased shrub and debris cover, while increasing percentage bare ground. Perennial grass yields were maintained or increased compared to previously chained or untreated areas following burning in a year of above-normal rainfall. Burning in a dry year reduced grass yields by 50% of that on areas chained only, but yields were only slightly less than on untreated areas. Grass species density was reduced for 2 growing seasons following burning. Burning greatly reduced annual forbs from March through June of a moist spring. Total forb densities on burned areas were generally similar to or higher than, those on unburned by July because of extended growth of perennial forbs. March burns appeared to have the most severe impact on the least desirable shrub (redberry juniper), grass, and forb (common broomweed) species.

Stevens, R., B.C. Giunta, and A.P. Plummer, SOME ASPECTS IN THE BIOLOGICAL CONTROL OF JUNIPER AND PINYON, The Pinyon Juniper Ecosystem: A Symposium, May 1975, p. 77-82.
Indications are that a competitive grass, forb, and shrub community in combination with browsing pressure is the key to preventing juniper and pinyon from regaining dominance on chained and seeded areas in central Utah.
Little research has been done on the potential of insects and diseases for the control of juniper and pinyon; however, potential exists.

Stevens, R., PINYON-JUNIPER, Habitat Express, May 1982, p. 11.
Pinyon-juniper woodlands are found scattered over about 60 million acres in western North America as shown in low precipitation zones (10-18 inches) and on course, slightly alkaline soils which are low in organic matter (Barrett 1962; Fowells 1965; Short and McCullough 1977). As the name suggests, the dominant plant species in P-J vegetative communities are pinyons and junipers. Pinyon are small, bush-like conifers with needle-shaped leaves that occur either singly P. monophylla or in pairs P. edulis (Barrett 1962). They grow 15 to 3 5 feet tail. Junipers are evergreen trees and shrubs with small, scale-like leaves that are closely appressed against the twigs. Often, but erroneously called cedars, junipers grow up to about 40 feet in height. The most important juniper species within the P-J woodland are Rocky Mountain juniper, Utah juniper, one-seed juniper, and alligator juniper. Pinyons, being more moisture demanding, occupy the higher elevational sites within P-J woodlands (Wright et al. 1979). Conversely, junipers are more drought resistant and dominate the lower zones. A pinyon-juniper mix is typical of mid-elevational sites, and it is within this strata where the highest densities are normally found (West et al. 1979). The understory vegetation in P-J communities varies considerably. Several grass species, including prairie June grass, needle-thread, Indian rice grass, blue bunch wheatgrass, western wheatgrass, sandberg bluegrass, Idaho rescue, and cheatgrass grow in the P-J zone.

Stevens, R., SPECIES ADAPTED FOR SEEDING MOUNTAIN BRUSH, BIG, BLACK, AND LOW SAGEBRUSH AND PINYON-JUNIPER COMMUNITIES, USDA Forest Service General Technical Report INT-2 15, Ogden, UT., In: S.B. Monsen, and N. Shaw (compilers), Managing Intermountain Rangelands--Improvement of Range and Wildlife Habitats, 1983, p. 78-82.

Stevens, R., POPULATION DYNAMICS OF BASIN BIG SAGEBRUSH, BLACK SAGEBRUSH, AND WHITE RUBBER RABBITBRUSH AS INFLUENCED BY MULE DEER, BLACKTAIL. JACKRABBIT, AND CATTLE USE OVER 22 YEARS AFTER SEEDING IN A PINYON-JUNIPER SITE, USDA Forest Service General Technical Report INT-. ,In: E.D. McArthur, and B.L. Welch (compilers), Proceedings--Symposium on the Biology of Artemisia and Chrysothamnus, 1984, p. 278-285.

Stevens, R., THIRTY YEARS OF PINYON-JUNIPER BIG GAME HABITAT IMPROVEMENT PROJECTS: WHAT HAVE WE LEARNED ?, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 558-571.
A majority of the fall, winter, and spring big game and livestock ranges in the Great Basin are located in the pinyon-juniper type. During the past three to four decades many of these rangelands have been treated mechanically and seeded. Techniques, procedures, equipment, and plant materials have changed, improved, and increased over the years. Modern methods and materials, when applied, can result in improved wildlife value compared to the values that have been derived from older pinyon-juniper improvement projects. With time, major vegetational changes have occurred in all pinyon-juniper improvement project areas. Vegetational changes within combined seeded and native communities have been influenced by community makeup, use, management practices, and the adaptability of the seeded species to site characteristics. Cattle can be used as a tool for improving wildlife values on pinyon-juniper improvement project areas. Juniper and pinyon trees on chained and seeded areas are more a result of poor kill during chaining than they are of reinvasion.

Stoecker, R.E., A MOVING TRANSECT LINE FOR ESTIMATING RELATIVE ABUNDANCE OF SMALL MAMMALS, In: R.L. Comer (ed), Issues and Technology in the Management of Impacted Western Wildlife Westview Press, Boulder, CO., 1984, p. 66-69.

Strelke, W.K. and James G. Dickson, EFFECT OF FORESTYLE="CLEAR-CUT EDGE ON BREEDING BIRDS IN EASTYLE="TEXAS, Journal of Wildlife Management, vol. 44, 1980, p. 559-567.
Breeding birds in 2 pine-hardwood stands (>30 years old) and adjacent clear-cuts (>3 years old) in East Texas were censused from transects from 1 May to 26 June 1978 to determine if differences appeared in bird populations between woods edge and interior and between clear-cut edge and interior. Number of bird species (S), species diversity (H'), and abundance (A) were higher (P<O.01) in the first 25 m of the woods edge than in other sections of the woods and clear-cut. The S, H', and A indices were similar in woods interior and in clear-cut edge and interior. Concentrations of woods-associated species singing posts, and some species were found mostly in the edge. This prevalence probably resulted from the greater number of foliage layers at the edge from simultaneous access by birds to more than 1 habitat type at the woods clear-cut juncture.

Summerfield, H.B.; R.L. Miles, S.G. Leonard, and R.L. Everett, EDAPHIC RELATIONSHIPS IN CLIMAX SINGLELEAF PINYON STANDS OF WESTERN NEVADA, Research Note INT-364, 1986.
We examined soil series and soil properties that are associated with climax singleleaf pinyon stands in western Nevada. This information is useful in inventorying woodland and range resources and in land use planning. We used the Soil Resource Information System Program to evaluate and test soil properties associated with singleleaf pinyon. Soils supporting singleleaf pinyon stands commonly had mollic epipedons, argillic horizons, shallow depth to bedrock, mesic temperature regimes, and low available water capacities. The 11 soil stands occur on 7% of the land surface (approximately 188,000 acres) in western Nevada. These soils have low potential for forage production and are best suited for producing wood products.

Sverson, K.E. and J.N. Rinne, INCREASING HABITAT DIVERSITY IN SOUTHWESTERN FORESTS AND WOODLANDS VIA PRESCRIBED FIRE, USDA Forest Service General Technical Report RM-191, Ft. Collins., In: J.S. Krammes (tech. coord.), Effects of Fire Management of Southwestern Natural Resources, 1990, p. 94-104.


This study was undertaken to determine some of the longterm effects of secondary succession on tree control in pinyon juniper woodlands by cabling and chaining with "debris in place," a technique used for about two decades. Plant species representative of all the successional stages we observed following treatment exist simultaneously from treatment. These observed changes were primarily changes in relative abundance resulting from differences in the growth rates and competitive abilities of the species concerned. Competitive ability appears directly related to the length of time following treatment that a species is able to maintain an increased growth rate. The trees maintain this increased growth for two to three time as long as many understory species studied. The result is a steady reduction of understory cover and production beyond the fifth to eight year following treatment, depending on site.

R.J. ;. Tausch, West Neil E.; and Nabi, A.A., TREE AGE AND DOMINANCE PATTERNS IN GREAT BASIN PINYON-JUNIPER WOODLANDS, Journal of Range Management, vol. 34, July 1981, p. 259-264.
Prior studies of pinyon-juniper woodlands at a few locations have indicated considerable historical expansion of the trees and loss of understory. Whether these changes are a widespread phenomenon and related to pervasive, rather than local, influences was the question asked by this research. An objective sampling of 18 randomly selected mountain ranges in the Great Basin was undertaken. Tree age and dominance in the pinyon-juniper woodlands showed definite geographical, elevational, and historical trends. The oldest, most tree-dominated woodlands were located in areas of intermediate topography where disturbances may have been less frequent. Populations of both tree species and were progressively younger and less dominant in both upslope and downslope directions from the intermediate elevations. Tree densities have also historically increased within the oldest woodlands. Pinyon density has increased faster than that of juniper. Approximately 40 percent of the sampled plots had their trees establishing during the last 150 years. These changes generally coincide with introduction of heavy livestock grazing, tree utilization by the mining industry, and fire suppression that followed settlement of the region. Associated climatic trends were also investigated. The relative importance of these influences on the changes in tree age and dominance cannot be determined without further research. The loss of understory, coincident with increasing tree dominance, has reduced forage production and made the woodlands progressively less susceptible to fire. Barring some major environmental change or management action, this forage reduction and decreased frequency of burning will continue until trees dominate much more area.


Tausch, R.J. and P.T. Tuller, EVALUATION OF PINYON SAPWOOD TO PHYTOMASS RELATIONSHIPS OVER DIFFERENT SITE CONDITIONS, Journal of Range Management, vol. 42, 1989, p. 209-2 12.
Detailed studies of competitive interactions in the pinyon/ juniper ecosystem require accurate estimates of biomass from physical measurements of the plant species involved. Relationships between green leaf biomass and trunk sapwood area were evaluated on 6 plots on a western Nevada mountain range. Four of the plots covered a range of environmental conditions from the lower to the upper edge of the woodland belt in 100-m elevation increments. The remaining 2 covered canyon and mountain top environments. The sapwood area to phytomass relationship was first individually analyzed for each of the 6 plots and the results compared. The ratio for grams of phytomass per cm 2 of sapwood area for the tree in each plot with the highest value ranged from 1.5 to over 2 times the tree with the lowest value. The highest average plot ratio was only 10% greater than the lowest average plot ratio. Individual regression slopes for the 6 plots did not significantly differ and the data were combined for the remaining analyses. The regression relationship for trees with less than 40-cm2 sapwood area differed from the overall relationship. The slope values for the sapwood area to foliage biomass relationship for the western Nevada data averaged about 2/3 the slope values for a data set from a mountain range in southwestern Utah. These differences were significant between a subset of young trees from each site with up to 40-cm2 sapwood area (P greater than of equal to 0.01) and for an analysis between all the sampled trees from each site (P greater than or equal to 0.10).

Woodlands dominated by Singleleaf Pinyon and Utah juniper cover extensive areas In the Great Basin and Southwest. Both species are aggressive and can nearly eliminate the previous shrub dominated community. Successional pathways from shrub dominated communities before tree establishment to the tree dominated communities that follow are only known for a few specific sites. How site growing conditions affect successional patterns needs further study. We compared the relationship of foliage biomass and percentage of cover between paired shrub-dominated and tree dominated plots over several sites. Sites studied are from different elevation and topographic conditions on one mountain range. Foliage biomass in shrub-dominated plots had about a three-to one variation over the range of site conditions sampled. Tree-dominated plots varied by about two to one. Cover in shrub-dominated plots had a four to one variation; cover in the tree dominated plots varied about one to two. Total foliage biomass in both tree- and shrub-dominated plots correlated best with the site index of height at 200 years of age. Variations in percentage of cover in both tree- and shrub-dominated plots correlated best with elevation. Foliage biomass variation in shrub dominated plots was proportional to the variation in the paired tree-dominated plots. A similar proportional relationship was present for percentage of cover between paired tree- and shrub dominated plots. Foliage biomass was more sensitive to topographic differences than to cover. Variations in plant species sampled in the shrub-dominated plots correlated with total foliage biomass of the same plots. Species sampled also correlated with pinyon height at 200 years of age and total foliage biomass in the paired tree dominated plots.

Terrel, T.L. and J.J. Spillett, PINYON-JUNIPER CONVERSION: ITS IMPACT ON MULE DEER AND OTHER WILDLIFE, The Pinyon-Juniper Ecosystem: A Symposium., May 1975, p. 105-141.
The impact of pinyon-juniper woodland (P-J) type conversion on wildlife is very poorly documented. Published literature is restricted, apparently, to mule deer (Odocoileus herinonus), rodents, and rabbits. Six major projects concerning mule deer are available from Arizona, Colorado, Nevada, New Mexico and Utah. At least three minor reports come from Colorado, Nevada and the Great Basin Region of California. The general consensus of research to date is that P-J rehabilitation could be quite beneficial to mule deer (and by inference to Cervus canadensis, Bison, and Ovis canadensis). However, projects to the present have not been generally beneficial. A summary conclusion for the several million acres of treated P-J is one of no overall impact--either positive or negative. Rehabilitation projects which contained certain attributes resulted in increased deer use. The most important factors were: 1) creation of a mid-successional vegetation matrix having high species diversity, 2) small projects close to escape cover, 3 ) treatments restricted to areas with a prior history of moderate to heavy deer use, and 4) location of the plots in areas protected from the brunt of severe weather, i.e., south exposures at relatively low elevations. p-J conversion projects on most mule deer ranges receive little winter use, although spring use may be high. P-J rehabilitation projects frequently receive heavy winter use. The rehabilitation projects also support the best rodent and rabbit populations. One could therefore infer that such would be most desirable for carnivorous species. We remain in near total ignorance of the impact of P-J conversions on the hundreds of vertebrate species influenced by this large ecosystem.

Terry, R.E. and S.J. Burns, NITROGEN FIXATION IN CRYPTOGAMIC SOIL CRUSTS AFFECTED BY DISTURBANCE, Proceedings - Pinyon Juniper Conference, Jan. 1987, p. 369-372.
Cryptogamic soil crusts are major constituents of the desert ecosystem, effectively stabilizing the soil surface against wind and water erosion. Significant amounts of nitrogen are also fixed by the blue-green algal component. The objective of this study was to determine the effects of grazing and burning disturbances on nitrogen fixation by crust organism. Research sites were located at Camp Floyd State Park and at Rush Valley in central Utah. In April and May of 1981, at the Camp Floyd site, nitrogen fixation in the ungrazed portion was greater than in either the burned or grazed sites. However, there were no significant differences in nitrogen fixation rates in annual spring samples collected from the disturbed and undisturbed Camp Floyd sites between 1982 and 1984. In April 1985 nitrogen fixation rates were significantly higher at the two disturbed Camp Floyd sites. A partial explanation for this reversal is related to the fact that the cryptogamic crusts of the grazed and burned Camp Floyd sites had recovered significantly due to the higher than average precipitation from 1981-1.984. There were also significant differences in nitrogen fixation rates between the undisturbed, grazed, and tilled areas at the Rush Valley site. The rates were generally higher in the undisturbed area. Nitrogen fixation in crusted soils increased significantly with increasing soil moisture. Nitrogen fixation also decreased with increasing time following wetting of the crusts.

Thatcher, A.P. and H.L. Virgil, SPY MESA YIELDS BETTER UNDERSTANDING OF PINYON-JUNIPER IN RANGE ECOSYSTEM, Journal of Range Management, Vol. 27, September 1.974, p. 354-357.
A 2-year study on the Spy Mesa relict of the Arizona Strip provides information concerning the natural occurrence of pinyon-juniper in range ecosystems of this area. The 40-acre relict is unique because there is a wide variety of soils and natural fires have occurred over the past 50 years. The plants have been grazed by rodents and mule deer and yet they have been inaccessible to livestock. This study reveals that, following natural fires, grass became significant in the plant community only on soils that had sandy surface textures. Pinyon-juniper was the dominant species in the absence of fire, regardless of the kind of soil. Those soils having a vesicular, massive, or platy surface layer did not produce significant quantities of grass at any stage of plant succession.

Thran, D.F. and R.L. Everett, IMPACT OF TREE HARVESTYLE="ON SOIL NUTRIENTS ACCUMULATED UNDER SINGLELEAF PINYON, Proceedings -Pinyon-Juniper Conference, Jan. 1987, p. 387-390.
This study was undertaken to document the distribution of soil nutrients in undisturbed woodlands and changes in surface mineral soil nutrients following tree harvest. Samples from profiles were analyzed to define available nutrient distribution in undisturbed woodlands. Iron, manganese, zinc, copper, nitrogen, and phosphorus are concentrated in the A horizons. Calcium, magnesium, sodium, and nitrogen reached maximum concentrations in the B horizons. Most nutrients decline with distance from under a tree canopy to into the interspace. Surface soil was sampled in the area once covered by the canopy and in the former interspace between trees 5 years after tree harvest. Surface soils from under the canopy of harvested plots were significant (p=.05) higher in nitrate, calcium, magnesium, zinc, copper, and potassium than surface soils of control plots. In the former interspace areas, only zinc and manganese increased following tree harvest.

Tidwell, T.L., USE OF BRUSH BEATING, CHAINING, FIRE, AND AERIAL APPLICATION OF ATRAZINE IN CONTROL OF SAGEBRUSH AND CHEATGRASS, Abstract Paper Presented at the Annual Meeting of the American Society of Range Management. Portland, Oregon, 1980, p. 38.

Pinyon-juniper woodland occupies about 60 mill. acres in the western United States. In the past 3 decades agencies focused a great deal of attention on converting areas of pinyon-juniper woodland to more productive sites for increased livestock forage, improved big game habitat, and improved watershed conditions. Several methods to accomplish the restoration were used with varying degrees of success, i.e., manipulation of livestock grazing, mechanical removal of trees, and chemical treatment. The most common and effective, was mechanical treatment accompanied by the introduction of grasses or a mixture of grass, forbs, and shrubs. In the 1970's, environmentalists challenged the use of mechanical treatment because of its drastic effect on the environment. Costs became restrictive. More recently, greater attention has been directed to production of woodland products such as firewood, Christmas trees and pinyon nuts. There is a continuing need to selectively restore depleted pinyon-juniper woodlands to more productive sites. However, we must consider all resource values produced on the site. The land manager is encouraged to look at innovative ways to achieve these objectives.

Pinyon and juniper trees function similarly to other shrubs and trees in their capacity to accumulate nutrients from adjacent openings and enrich the area beneath their canopies. This accumulation may occur at the expense of the nutrient capital of areas away from the influence of tree canopies. Invasion of pinyon and juniper trees into areas previously occupied by shrubs, grasses, and forbs may result in substantial shifts in the distribution of nutrients among biotic and abiotic ecosystems compartments. Incorporation of a greater proportion of the total site nutrient capital into above-ground biomass has important implications for the management of these stands from the perspective of future site productivity.

Tohill, A. and J. Dollerschell, "LIVESTOCK" THE KEY TO RESOURCE IMPROVEMENT ON PUBLIC LANDS, Rangelands, 1990, p. 329-336.
Since the Taylor Grazing Act was set in motion in the mid 1930's, improving public rangelands has been perceived as a need to eliminate overgrazing by reducing livestock numbers. After 50 years of livestock reductions, along with the development of high dollar rangeland improvements and implementation of elaborate academic grazing systems, there continues to be undesirable plant encroachment (annual and perennial), lack of perennial grass seedlings, and absence of plant and animal complexity and diversity. This fuels a concerted effort by the environmental community to promote the complete removal of livestock from public lands. The Mountain Island Ranch and Bureau of Land Management (BLM) offices in Grand Junction, Colorado, and Moab, Utah, have initiated a management process to improve the rangeland condition using techniques that are economically and environmentally sound. The management process involves both human interaction and collaboration coupled with non-traditional tools of grazing and animal impact. Livestock are recognized as a necessary component of the ecosystem rather than a deterrent to range improvement

Five pinyon-juniper woodland communities representing different successional stages were studied in north central Arizona. The postfire successional communities ranged from 7-90 years in age, while the mature community was greater than 300 years old. This paper documents the changes in community structure associated with this sere, including density-diameter distributions, diversity (H', J', and species richness) and crown cover. An estimate of successional rate, based upon community similarity indices and a computer simulation of pinyon-juniper succession is presented.

Tueller, P.T.; C.D. Beeson, R.J. Tausch, N.E. West, and K.H. Rea, PINYON-JUNIPER WOODLANDS OF THE GREAT BASIN: DISTRIBUTION, FLORA, VEGETAL COVER, Research Paper INT-229, 1979.
The distribution of pinyon-juniper woodlands of the Great Basin has been mapped from LANDSAT-1 satellite photography. Dot grid analysis of this map indicates that about 17.6 mill. acres (7.1 mill. ha) of this woodland are found in the Great Basin. The distribution was field checked and floristic data were systematically taken at 482 stands on 66 of the approximately 200 mountain ranges in the study area.
A list of 240 positively identified species of vascular plants is provided to help other workers initiate studies in the pinyon-juniper vegetation type.
In this study, variations in total vegetal cover are related to latitude, longitude, and elevation. Vegetal cover increases strongly with elevation and slightly with latitude Longitudinal patterns are related to increase in average elevation. The greatest average vegetal cover is found in the higher, central portion of the Great Basin. Sorting of the trees species is due more to elevation than latitude or longitude. Junipers occupy the lower, drier elevations, whereas pinyons increase at higher elevations. Double-needle pinyon is found more frequently in the southeastern Great Basin where more of the rainfall comes during the summer.

Tueller, P.T., VEGETATION AND LAND USE IN NEVADA, Rangelands, 1979, p. 204-2 10.
The majority of Nevada is range land. The Soil Conservation Service, USDA has described some 45 3 ecological sites or unique soil-vegetation-landform units that form the basis for management recommendations. These sites are found mostly in areas of average and higher forage productivity. Many more ecological sites and their plant communities have yet to be described, particularly at the highest elevations and some of the lower salt desert or Mojave desert sites. Areas dominated by sagebrush or salt desert shrubs constitute the two most common kinds of vegetation. This article discusses Nevada's vegetation and land use.

Tueller, P.T. and J.E. Clark, AUTECOLOGY OF PINYON-JUNIPER SPECIES OF THE GREAT BASIN AND COLORADO PLATEAU, The Pinyon Ecosystem: A Symposium, May 1975, p. 27-40.
The literature was reviewed for autecological material concerning three pinyon pines and six junipers occurring on the east side of the Sierra Nevada, the Great Basin, the foothills of the Rocky Mountains and the Colorado Plateau. Descriptions are given and some information on reproduction, developmental history, habitat relationships (climatic, edaphic, and biotic) and physiological relationships. Pinus monophylla, Pinus edulis, Juniperus osteosperma, and Juniperus deppeana seem to have been studied more than other species. Little physiological data is available for any species.

Tueller, P.T. and J.D. Tower, VEGETATION STAGNATION IN THREEPHASE BIG GAME EXCLOSURES, Journal of Range Management, vol. 32, July 1979, p. 258-263.
The allocation of range forage for deer and livestock is an important range management problem. Utilization of the three-phase exclosure technique for such evaluations is complicated by the response of plants to nonuse. Protection from browsing can cause "stagnation" to occur as early as the second year after the exclosure is established. Nonuse of bitterbush resulted in an average reduction in production of 70%. Temporary exclosures moved each year are required for accurately determining annual forage production.

Tueller, P.T., REMOTE SENSING APPLICATIONS FOR THE Pinyon juniper WOODLAND, Proceedings - Pinyon-Juniper Conference, Jan. 1987, p. 236-242.
The pinyon-juniper woodland resource in western United States can be managed if suitable techniques are available for inventory and monitoring. Remote sensing procedures offer considerable potential for these applications. The pinyon-juniper woodland in the Great Basin was mapped from Landsat color composites. Lowelevation woodland boundaries were easily mapped on any imagery while winter scenes were required before upper ecotones could be mapped. Continuous areas of pinyon-juniper were mapped with tree densities as low as 41 trees/ha while isolated stands as small as 25 ha require at least 73 trees/ha. Large-scale imagery (1:1000 or larger) has proven successful for tree inventories, erosion evaluations, etc. Now there are many newer systems that await evaluation for use in pinyon-juniper woodland. These include the Thematic Mapper, SPOT, AIS, and radar systems. Computer assisted mapping techniques will become commonplace as we learn more about basic radiometric characteristics of the integrated pinyon juniper pixels.

Tuhy, J.S. and J.A. MacMahon, VEGETATION AND RELICT COMMUNITIES OF GLEN CANYON NATIONAL RECREATION AREA, Final Report to National Park Service contract CX-12OO-6-B076, 1988.

Turkowski, F.J. and Hudson G. Reynolds, RESPONSE OF SOME RODENT POPULATIONS TO PINYON-JUNIPER REDUCTION ON THE KAIBAB PLATEAU, ARIZONA, The Southwestern Naturalist, vol. 15, June 1970, p. 23-27.
Uprooting pinyon and juniper with a bulldozer for rangeland improvement changed habitat conditions enough to affect populations of several species of small rodents. In general, numbers of resident rodents increased and additional species invaded the treatment site areas. Brush and pinon mouse populations were exceptions; they decreased. Additional herbaceous cover and dead trees on the ground were the gross habitat changes associated with population differences.

USDA, SCS, Temple, Texas, EFFECT ON WATER YIELD AND SUPPLY, Grass Land Restoration, 1967.
Water has been one of Texas' most valuable and least abundant resources, particularly 'in the western part of the state. As population and industries grow, it will become even more valuable.
Many organizations are studying and developing plans for conserving water resources, usually involving immense and costly projects. Often overlooked as an important possible source of saving water is the water wasted by the non-economic plants, weeds, and woody invaders. These silent thieves are stealing more water in Texas every year than is consumed by all the towns, factories, and all the agricultural plants m-crops, orchards, grasses and commercial timber trees.
It will shock most Texans to learn that scientists estimate about one hundred thirty eight million acre-feet of water-almost 3 8% of the average annual precipitation- are consumed by non-economical plants. The brush survey made by the Soil Conservation Service in 1964 found that eighty-eight million acres, 82% of Texas' grasslands were infested with brush, fifty-four million acres so dense that most of the moisture that entered the soil was consumed by the brush.
Grass is a more efficient user of water than most woody plants, requiring less water to produce a pound of dry matter. There is less water used on an acre of grass than on an acre covered with woody plants or weeds. A grassland restoration program, involving the control of undesirable plants and replacing them with grass, would result in a saving of water, most of which would be available for deep percolation into underground aquifers and as return flow to Streams.
Just how much could be saved is somewhat difficult to estimate since there is so little research available from Texas on moisture consumption by non-economic plants. Using all available information including research data and studies and experiences of Soil Conservation Service hydrologists, engineers, and soil plant scientists, it is estimated that about ten million acre-feet of water could be saved annually by brush control as part of a state wide grassland improvement program. Others may not agree with this estimate but all must recognize that such a program will save large quantities of needed water.
Landowners are presently treating about two million acres of brush annually, often with financial assistance through the Agricultural Conservation Program or the Great Plains Conservation Program. However, this amount is hardly keeping up with the rapid increase in density of brush on Texas grassland and the reinfestation within a few years of acres treated.
The importance of water conservation is so widespread that a concentrated effort and the support of all interests are needed to accomplish the job. Grassland restoration as a means of saving water is apparently one of the cheapest means of saving water, less costly than, but not a substitute for, de-salinization of sea water or transportation of water for hundreds of miles to thirsty lands. A grassland restoration program would not only save water, but the improved grass cover would provide more grass for a more stable livestock industry. Increased wildlife, recreation, and beautification purposes would be important additional benefits. Every Texan will benefit from such a program.

USDA Intermountain Region Forest Service, PINYON-JUNIPER CHAINING PROGRAM ON NATIONAL FORESTYLE="LANDS ON THE STATE OF UTAH, U.S.D.A. Forest Service Environmental Statement, 1973
The National Environmental Policy Act of 1969 and guidelines issued by the Council on Environmental quality in 1971 require environmental statements on major Federal actions which, in themselves or in a series of cumulative actions, could significantly affect the quality of the human environment. Statements are also required for actions which are likely to be highly controversial. National Forests in Utah have for several years been chaining areas of pinyon-juniper trees making it possible to seed plant species for improved forage production and to improve watershed conditions.
This environmental statement covers the required components for a pinyon-juniper control program. It provides an analysis of the pinyon-juniper control program and environmental consideration on a statewide basis. It does not deal with individual projects.
An environmental analysis is required for individual projects. Project environmental analysis covers objectives, protected areas, treatment, management cost benefits, and environmental impacts that are unique to the specific projects. Instructions for preparation of the environmental analysis for specific projects contain provisions for recognizing whether or not the requirement of the Environmental Policy Act have fully been met.

Ancient packrat middens record thriving Late Wisconsin pinyon-juniper-oak woodlands in the present Chihuahaun desert. The range of Pinus remota was from the southern Chihuahuan desert, Mexico (25 degrees 56'N). At 610-680 m elevation In Big Bend National Park (29 degrees 13'N ), P. remota was common in the Late Wisconsin (11,000-22,000 B.P.) but declined or disappeared in the Middle Wisconsin (22,000->36,000 B.P.) with a modest increase in its lower elevational limit. Both P. remota and P. edulis were identified in the Hueco Mountains midden sequence which documents pinyon juniper-oak woodland from 42,000-10,720 B.P. in the northern Chihauhuan Desert. In the Holocene, the range of P. remota first retreated from the Chihauhuan Desert proper soon after 11,000 B.P. to the southern Edwards Plateau, and later was fragmented into its modern relict stands. At the same time Pinus cembroides probably expanded to dominate modern woodlands In the Chisos and Davis mountains. The Late Wisconsin range of Pinus edulis was probably restricted to a small area in south-central New Mexico and adjacent Texas (32-33 degrees N). In the Holocene, P. edulis expanded from this Ice Age refugium into the Colorado Plateaus and into the Rocky Mountains finally reaching its northern limit in Colorado (40 degrees 50'N) in the last few centuries. The composition of the pinyon juniper-oak woodlands has varied continuously as individual dominants responded differentially to climate changes.

Van Hooser, D.D. and O.E. Casey, P-J--A COMMERCIAL RESOURCE?, Proceedings Pinyon-Juniper Conference, Jan. 1987, p. 202-206.
Pinyon and juniper are species of questionable character. During the frontier and mother lode era they were used extensively as fuel to convert ore to precious metals. From the turn of the century until recently pinyon-juniper woodlands were abused extensively, primarily by anchor chains and D8 "Cats." Now, use for fuel, Christmas trees, and pine nuts makes them once again valuable, if not commercial, species. Also the current historic distribution of the species is presented, and some contemporary examples are given to establish that pinyon and juniper are a commercial resource.

Van Pelt, N.S.; R.Stevens, and N.E. West, SURVIVAL AND GROWTH OF IMMATURE JUNIPERUS AND PINUS EDULlS FOLLOWING WOODLAND CHAINING IN CENTRAL UTAH, The Southwestern Naturalist, vol. 3 5, September 1990, p. 322-328.
Post disturbance survival, seedling recruitment, and height growth rates of 3 31 mapped Juniperus osteosperma and Pinus edulis were studied for 26 years within chained woodlands of central Utah. Size-specific attrition primarily occurred in the first 4 years (1962 to 1966) after chaining. Juniperus osteosperma was subsequently twice as prolific but showed a 10% net loss in numbers between 1962 and 1988, whereas P. edulis grew faster and apparently more uniformly in height while sustaining a 27% loss in density. Growth and survival of the two species were least in the seedling stage, apparently a key influence on population size and compositional ratios in the first decades of stand redevelopment.

Small-plot trials of effective herbicides for manual woody weed treatments should be validated on large tracts where rapidity, thoroughness, and efficiency of application are integral to operational-scale recommendations. A 7.9 ha woodland chaining in Utah, with 248 Juniperus osteosperma Torr. (Little) and Pinus monophylla (Torr. & Frem.) saplings per ha, was divided into nine 25-m by 350-m strips for timed tebuthiuron manual application trials in fall 1986 and summer 1987. About 1 ha was treated per hour, and 6 to 15% of the trees were missed. Three application methods differed in total and aggregate time outlays, accuracy, and tediousness, but were highly similar in formulated tebuthiuron expenditures of 1.5 to 2.0 kg/ha. Time expenditures were moderately predictable from treated tree density and mean tree height, whereas percent trees missed was unrelated to density or method. Placing herbicide particles at the stem base and basing dosages on stem height are preferable to dripline applications and crown-volume based dosage estimations.

  1. Introduction (129)

    A bibliography containing over 2,500 references to the literature concerning fossil and Recent species of bivalves in the genus Corbicula is presented for the period 1774 ‑ 2005.
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    A bibliography containing over 2,500 references to the literature concerning fossil and Recent species of bivalves in the genus Corbicula is presented for the period 1774 2005.

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