Juniper Woodlands of the June 1998 Great Basin

This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. where he has been located since 1964. He attended Oregon State University where he received a bachelor's degree in general science and a Ph.D, degree in plant ecology. He has served as a National Science Foundation postdoctoral fellow at the University of Georgia and visiting professor and holds a bachelor's degree in wildlife management, a masters degree in range management, and a Ph.D. degree in range ecology. He was a member of the faculty in the He holds a bachelor's degree from Idaho State University in wildlife conservation, an M.S. degree from the University of Nevada, Reno in range management, and a Ph.D. degree from Oregon State University in range ecology. During his 35 year career he has taught range and forest ecology and remote sensing and traveled extensively, lecturing on rangeland remote sensing. Research Summary Pinyon-juniper woodlands cover about 7.1 million ha (17.6 million acres), constituting about 18 percent of the land area of the Great Basin, yet no comprehensive ecological classification of them has been attempted before. To begin a classification, we sampled a random set of 66 of the approximately 110 mountain ranges within the Great Basin. Macroplots were systematically placed at 200 m elevation intervals up and down cardinal slopes. ~ a t a on tree age, vegetational cover, soils, and land form were collected from 1972 to 1975 within 463 stands used to either develop or test the classification presented here. We used the already delineated National Hierarchical Frameworkof Ecological Units (ECOMAP 1993) down to the Section level to frame our classification to an intermediate coarseness. This subdivided the Great Basin into nine relatively environmentally homogenous Sections. Observable vegetational characteristics were used at lower layers because ECOMAP delineations are not yet available. Nine categories were recognized at the Series level based on variation in the relative cover contributions by the various junipers and pinyons. Subdividing the nine Sections by the nine possible Series gave 45 actual geographically distributed Series. The next lower level of the vegetation-based classification is the Association, identified by the dominant shrub species. Twenty-six species of dominant shrubs, combined with the Sections and Series, gave 183 Associations. The Sub-association level was based primarily on the 23 dominant native perennial grasses. When, rarely, a native, perennial grass was not present, the …