Download or read book Western Juniper in Eastern Oregon written by and published by . This book was released on 1999 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Western Juniper in Eastern Oregon written by and published by . This book was released on 1999 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings Western Juniper Forum 97 written by Scott A. Leavengood and published by . This book was released on 1998 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Western Juniper Resource of Eastern Oregon written by David L. Azuma and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Western Juniper Resource of Eastern Oregon written by David L. Azuma and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the Western Juniper Ecology and Management Workshop Bend Oregon January 1977 written by and published by . This book was released on 1978 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Western juniper (Juniperus occidentalis subsp. occidentalis) is an important invader of range lands in central and eastern Oregon. Many people have asked questions about its control, effect on range productivity, and its benefits. The papers in this proceedings resulted from a conference held in Bend, Oregon, January 1977, to summarize our knowledge of western juniper and to evaluate research needs.

Download or read book Vegetation and Small Mammal Responses to Western Juniper Juniperus Occidentalis Control in Eastern Oregon written by Corinne N. Morozumi and published by . This book was released on 2015 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock grazing, active fire suppression, conversion to agriculture, and urbanization of the west. Since the late 1800s woody encroachment of piñon-juniper species has also contributed to the loss of shrub-steppe habitat. Presently, land managers remove woody tree species in order to recover shrub-steppe although it is unclear how responses to these management activities differ due to site-specific conditions and existing woodland development. I studied post juniper-thinning responses in eastern Oregon at a wildlife area important as winter range for mule deer (Odocoileus hemionus). I investigated vegetative responses to western juniper (Juniperus occidentalis) thinning across a woodland development gradient and tested for interactive effects of juniper cutting and cattle exclusion. In addition, I explored plant and small mammal successional dynamics after juniper thinning and examined plant community responses within microhabitats created by the felled trees. I compared vegetative responses to juniper thinning as well as cattle exclusion among sites where juniper were subordinate (Phase I), co-dominant (Phase II), and dominant to shrubs and grasses (Phase III, sensu Miller et al. 2005). At the Phase I site, thinning did not increase herbaceous biomass while thinned plots at the Phase II site had 2.71 times more median herbaceous biomass (99.17% CI: 1.37 to 5.37 times more biomass) than unthinned plots. Conversely, herbaceous biomass at the Phase III juniper woodland site was 0.36 times lower in thinned plots when compared to unthinned plots (99.17% CI: 0.17 to 0.78 times less biomass). Unfortunately, many of the responses were driven by exotic species release. Where juniper were subordinate (Phase I), mean percent cover by exotic grass increased by 24.58 percentage points in thinned plots as compared to unthinned plots (98.30% CI: 0.27 to 48.90 percentage points higher). Thinning at the Phase II site increased mean exotic grass cover by an estimated 28.47 percentage points as compared to mean exotic cover in the same plots before treatment (98.30% CI: 4.15 to 52.79 percentage points higher cover). Median native bunchgrass cover at this site was 5.06 times greater after juniper treatment (99.7% CI: 1.78 to 14.35 times higher percent cover). I found few main or interactive effects of cattle exclosure after one year of treatment. Responses to grazing exclosure may take longer to develop. These results indicate that sites within the wildlife area respond differently to juniper management and that exotic grass control will be key to successful shrub-steppe recovery. In addition, I used a time-since-juniper thinning chronoseries consisting of plots cut in 2008, 2009, 2010, 2012, and an adjacent uncut control to explore how shrub-steppe flora and fauna are responding to juniper treatment through time. Shrub cover and seedling density were low in each plot. I recorded the highest seedling abundance (mean of 0.25 seedlings) in the uncut control plot. Median grass cover in the uncut control was 9.50% while in the most recently treated plot (2012) it was 26.75%. Small mammal relative abundance and diversity was low across all time-since-treatment plots though highest in the plot with the greatest time-since-treatment. Deer mouse (Peromyscus maniculatus) was the most abundant species in all plots and accounted for 70-95% of all unique captures. Least chipmunk (Tamias minimus) were present in the plot with greatest time-since-treatment indicating the potential recovery of key native shrubs since these small mammals perform an important seed dispersal role. I also investigated how potential microhabitats created by the felled juniper might support different plant communities. I assessed plant responses within zones created by 1) the felled tree (canopy zone), 2) the original duff zone, and 3) the between - tree interspace zone. The three zones had different plant community compositions as analyzed multivariately with non-metric multidimensional scaling (NMS). Canopy and duff zones were forb - dominated and had less exotic grass invasion while interspace zones were heavily invested with medusahead (Taeniatherum caput-medusae) and ventenata (Ventenata dubia). Exotic herbaceous productivity was lowest under the standing trees of the control plot and high in the interspace of all plots with juniper thinning. In the 2012 cut plot, grass cover was 27.90 percentage points less in the canopy zone compared to the interspace zone (98.75% CI: 17.64 to 38.16 percentage points less grass cover). In the uncut control, median native biomass was 2.08 times greater under the standing trees compared to the interspace (96.25% CI: 1.09 to 3.97 times more biomass). Results from the time-since-treatment chronoseries indicated that exotic grass dominance might be limiting shrub-steppe recovery. Active restoration of shrubs and native grasses may be necessary to address the dominance of exotic grass after juniper thinning. Positive signs of habitat recovery included small mammal responses though I was unable to calculate population estimates due to plot size.

Download or read book Biology Ecology and Management of Western Juniper Juniperus Occidentalis written by and published by . This book was released on 2005 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial and Temporal Distributions of Western Juniper in John Day Fossil Beds National Monument Oregon written by Ya-Chian Chen and published by . This book was released on 1996 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Post-settlement juniper expansion in the western states has been reported for decades, including western juniper (Juniperus occidentalis Hook ssp. occidentalis) woodlands in the northwestern states. A 15 km2 study area in the Sheep Rock Unit of John Day Fossil Beds National Monument in eastern Oregon was selected to study spatial and temporal distribution patterns of western junipers, and build statistical models for the patterns. Environmental characteristic data are from soil, vegetation and contour maps. Western juniper data are from aerial photos. Image processing techniques and geographical information system (GIS) were used to process data. Nonparametric statistical methods, including Kruskal-Wallis one-way analysis of variance by ranks, Spearman rank correlation coefficient, chi-square test and chi-square partitioning, and classification and regression tree (CART) were used for data analysis and building statistical models. The results show a clustering spatial distribution pattern. Western juniper is more abundant above elevations of about 900 to 1,000 meters MSL, on sites with soil type 15f- Gwin-Rock outcrop complex or 43f- Simas-Badlanci association, and on medium slopes, but probabilities of juniper occurrence on less steep slopes are higher at lower elevations. Northeastern aspects have significantly lower juniper abundances than other aspects. Junipers prefer sites with higher surface flow accumulation, except extremely high flow accumulation supporting only low juniper abundances. The CART spatial model shows three density classes classified by four out of five environmental characteristics with a misclassification rate of 0.27. Temporally, juniper density in the study area has increased from 37 junipers/ km2 to 1,404 junipers/ km2 during the last century. However, relationships of this expanding pattern to environmental characteristics are obscure. There is no conspicuous difference between habitats of young and old jumpers, except perhaps soil types. The likelihood for finding mature or old junipers is higher in sites with soil type 41e- Simas very stony clay loani, 43f- Simas-Badland association or 46f- Snell-Anatone complex. The spatioteniporal distribution pattern of western juniper in the study area could be described as a clustering pattern with chronologically increased abundances. Juniper may continue to increase its abundance and expand from high density areas to low density or non-juniper areas. Unless juniper density is controlled, it seems likely that junipers will dominate most of the monument's landscape in the future.

Download or read book Forests of Eastern Oregon written by Sally J. Campbell and published by . This book was released on 2003 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication provides highlights of forest inventories and surveys from 1993 to 2001. About 35 percent of eastern Oregon is forested. The amount of forest land in eastern Oregon has increased by about 650,000 acres from the 1930s, with increases in juniper forest land accounting for most of the change. Thirty-one tree species were tallied in forest inventories during the 1990s, with ponderosa pine the predominant species in all ecological provinces in eastern Oregon. The Forest Service, Bureau of Land Management, and other federal agencies manage about 71 percent of eastern Oregon forests; about 27 percent is privately owned; and the remaining 2 percent is managed by the Oregon Department of Forestry and other nonfederal public agencies. The volume of wood in eastern Oregon forests is about 25.7 billion cubic feet, of which about 312 million cubic feet per year were harvested between 1987 and 1999. In the same time period, annual mortality and removals exceeded annual growth for all ownerships. Down wood is an important forest component and shows increases with forest age. Insect defoliators, bark beetles, root diseases, and dwarf mistletoes are present on over 72 percent of forest land in eastern Oregon. Year-to-year defoliation or mortality trends can be detected with aerial surveys. Introduced plant species are present on over 50 percent of private and other public forest land. Diversity of lichens (indicators of air pollution, climate, and forest age and structure) is greatest in the Blue Mountains Province and lowest in the Intermountain Province. No ozone injury has been detected on sensitive forest trees and plant species in eastern Oregon.

Download or read book Silvical Characteristics of Western Juniper written by James E. Sowder and published by . This book was released on 1958 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Western Juniper written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characteristics of Western Juniper Encroachment Into Sagebrush Communities in Central Oregon written by Mary M. Rowland and published by . This book was released on 2008 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Climate growth Relationships of Western Juniper and Ponderosa Pine at the Pine woodland Ecotone in Southern Oregon written by Kevin C. Knutson and published by . This book was released on 2006 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pinyon-juniper woodlands throughout the western U.S. have expanded rapidly following European settlement during the late 19th century. In central and eastern Oregon, western juniper (Juniperus occidentalis var. occidentalis Hook.) encroachment has been previously documented in the sagebrush steppe and upper elevation aspen communities. While these vegetation changes and dynamics have been extensively studied, the ability to accurately predict future effects on vegetation structure in response to climatic effects requires the identification of climatic factors that most directly regulate growth across variations in spatial features, particularly when future climate change is likely. I sought to address this problem at the pine-woodland ecotone using tree-ring data for western juniper and ponderosa pine (Pinus ponderosa Dougl. Ex Loud.) from the Fremont National Forest of central Oregon. Site and soil-derived growth chronologies for the period 1950 to 2000 were developed for both species using standard dendrochronological techniques at 17 sites within the Fremont National Forest stratified by elevation (1584 and 1865 meters). Analysis of the climatic relationship with site and soil-derived chronologies using correlation and linear regression revealed that, similar to previous studies in Oregon, radial growth in both species is highly dependent on winter-spring precipitation events that recharge growing-season soil water. Ordinations of site- and soil-derived chronology principal components (PCA) scores for both species identified distinct gradients in growth patterns related to elevation, slope, and soil infiltration class. Low elevation sites had reduced growth in the nine driest years during 1950-2000 compared to high elevation sites. Slope was also positively associated with the ratio of standardized growth in wet years to dry years (W:D), a measure of climate sensitivity. Tree growth of both species on coarse-textured soils with rapid infiltration rates was more climate-sensitive (higher values of W:D) and was also reduced during drought years when compared to other infiltration classes. These findings suggest potentially significant variation in growth responses to future climate changes across distinct local features at the pine-woodland ecotone. Juniper and pine radial growth at sites that feature poor water-holding capacities (i.e., low elevation, steep slopes, and coarse-textured soils) can be expected to be most sensitive to future drought and climate fluctuations in southern Oregon.

Download or read book Western Juniper Control Studies written by Tony J. Svejcar and published by . This book was released on 2007 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Western Juniper on Understory Herbage Production in Central Oregon written by Milda R. Vaitkus and published by . This book was released on 1986 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence suggests that western juniper (Juniperus occidentalis) in Central Oregon affects understory production and composition. As trees increase in size and density, understory production is reduced and composition changes. This study was designed to identify the relationship between production and composition of understory vegetation and various tree canopy sizes of western juniper, and to describe the responses of understory vegetation to removal of western juniper. Understory production was sampled in 1983 and 1984 by clipping plots on an individual trees basis from areas with trees present and areas from which trees had been removed in 1982. Biomass production was determined from trees within three canopy diameter size classes and from two zones, beneath the canopy and in the interspace. Production was examined on two sites, a lower slope, shallow soil site and an upper slope, moderately deep soil site. Some year-to-year differences in production of individual species and specific tree sizes may be explained by variation in precipitation during critical growth periods the two years of the study. Sandberg bluegrass and, possibly, Idaho fescue production may have been greater in 1983 than 1984 due to variation in late spring precipitation, especially on shallow soils associated with small trees. Differences in patterns of production of individual species were most clearly developed associated with large, rather than small and intermediate trees. Cheatgrass, squirreltail, bluebunch wheatgrass, and Idaho fescue were common beneath the canopy, while Sandberg bluegrass was common in the interspaces. Cheatgrass and perennial forb production beneath the canopy increased with tree size. Production of other species, such as Sandberg bluegrass, was apparently not affected by tree size. Canopy removal resulted in species-specific increases in biomass production both years. Production increases were greater beneath the canopy than in the interspaces. Perennial grasses provided small variable production increases beneath the canopy of large trees. Annual grasses, primarily cheatgrass, and annual forbs, primarily Epilobium paniculatum, contributed most to elevated productivity the first two years following juniper removal. Cheatgrass response was mainly associated with large trees, while annual forb response was independent of tree size. Sandberg bluegrass production seemed more closely tied to growing season precipitation than to canopy removal, regardless of tree size.

Download or read book Spatial and Age Class Analysis of Managed Western Juniper Juniperus Occidentalis Woodlands in Central Oregon written by Kelley T. Zophy and published by . This book was released on 2006 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Juniper is a native species to Oregon and confers ecological benefits to wildlife when it is at savannah and transitional densities. Its range and extent have fluctuated with climatic change, but the current range expansion is unprecedented in its extent. The range expansion has been associated with the degradation of the sagebrush steppe ecosystem in central Oregon. In the past, attempts to restore the sagebrush-steppe from western juniper aforestation were motivated by the desire to improve forage quality. Currently western juniper management is wider in scope, encompassing social, ecological, and environmental objectives. Past research in the area of western juniper management focused extensively on the causes of western juniper aforestation, its impact on understory plant communities, soil and the water budget. Researchers have also explored multiple mechanisms for removing western juniper and have quantified resulting amelioration of ecosystem function. However little work has been done identifying topographical features or environmental conditions that may influence the density of western juniper woodlands and seedling reestablishment following the application of treatment regimes. This study used spatial modeling to explore the influence that elevation and direct incident radiance have on western juniper density and multivariate, nonparametric tools to identify relationships between topography, understory plant community and seedling reestablishment on managed sites. The study findings indicate that western juniper densities in central Oregon are influenced by topographical features in the landscape. The multivariate analysis revealed that seedling reestablishment is positively associated with the diversity of the understory plant community. The study also revealed that on almost all of the sites included in the study, western juniper seedling are reestablishing after treatment application. With the information generated in the study, managers have tools with which to assess the risk a region has to be dominated by western juniper woodlands. Managers can then efficiently allocate western juniper management resources by choosing to treat that sites that have both the greatest risk and the greatest capacity to meet their objectives.