• Perennial Grasses and Their Response to a Wildfire in South-central Washington

      Uresk, D. W.; Rickard, W. H.; Cline, J. F. (Society for Range Management, 1980-03-01)
      Three years of past burning responses of three perennial grasses were evaluated by comparing a burned area with an adjacent control (unburned) area. The average leaf length of Cusick bluegrass and Thurber needlegrass was shortened by burning in all 3 years, but leaf shortening was inconsistent for bluebunch wheatgrass. Burning increased the number of flowering culms per clump for Cusick bluegrass during the second year of postburning and for Thurber needlegrass during the third year. The average number of flowering culms per clump in bluebunch wheatgrass was greater in the burned area for all 3 years of postburning. Culm and spike lengths of bluebunch wheatgrass were increased by burning for the first 2 years. Cusick bluegrass and Thurber needlegrass generally responded to burning with shortened culms and spikes. The basal area of Cusick bluegrass and Thurber needlegrass was reduced by burning. Phytomass production of bluebunch wheatgrass showed an increase during the 3 years of postburning, whereas Cusick bluegrass and Thurber needlegrass showed a reduction in phytomass production. No single measurement provided a way to evaluate overall plant responses.
    • Plant-soil Relationships on Bentonite Mine Spoils and Sagebrush-grassland in the Northern High Plains

      Sieg, C. H.; Uresk, D. W.; Hansen, R. M. (Society for Range Management, 1983-05-01)
      Plant canopy cover, standing crop, and soils were sampled on (1) old (unreclaimed), (2) reclaimed, (3) semireclaimed (newly mined) bentonite mine spoils and (4) native sagebrush-grass rangelands in southeastern Montana. Plant cover and standing crop were higher on sagebrush-grass rangelands than on all bentonite spoils. Scurfless saltbush (Atriplex suckleyi) was the most successful and abundant plant on bentonite spoils. Soil chemical analyses indicated that low pH, excessive salinity and sodium, plus soil compaction were limiting for plant growth and establishment on bentonite spoils.
    • Protocol for monitoring standing crop in grasslands using visual obstruction

      Benkobi, L.; Uresk, D. W.; Schenbeck, G.; King, R. M. (Society for Range Management, 2000-11-01)
      Assessment of standing crop on grasslands using a visual obstruction technique provides valuable information to help plan livestock grazing management and indicate the status of wildlife habitat. The objectives of this study were to: (1) develop a simple regression model using easily measured visual obstruction to estimate standing crop on sandy lowland range sites in the Nebraska Sandhills, (2) provide sampling and monitoring suggestions in the use of visual obstruction on this grassland type, and (3) compare the visual obstruction technique to the standard clip and weigh procedure. Visual obstruction precisely predicted average standing crop dry weights for the sandy lowland range sites (r2=0.88). A prediction accuracy of ± 295 kg ha-1was found using a test data set. Two sampling options (A and B) were evaluated using a 2-stage sampling protocol. Option A (1 transect/quarter section) provided more precise estimates applicable to extensive grasslands than option B. However, option A was not applicable to a section (259 ha) or a few sections. Option B (3 transects/section) provided estimates applicable to each section and to the entire area, but it required more intensive sampling than option A to attain the same precision. The visual obstruction technique provided more precise estimates of standing crop than the standard clip and weigh technique when clipping and weighing up to 6 plots per transect. When 7 or more clipped and weighed plots per transect were sampled, standing crop estimates were more precise than using visual obstruction readings. However, since 20 visual obstruction readings/transect (25 minutes) can be sampled in about half the time spent clipping and weighing 6 plots/transect (45 minutes), visual obstruction in combination with a previously estimated regression model provides a simple, reliable, and cost effective alternative to the clip and weigh technique. Regression models should be developed for other grassland types following the methodology described in this paper.
    • Sampling Big Sagebrush for Phytomass

      Uresk, D. W.; Gilbert, R. O.; Rickard, W. H. (Society for Range Management, 1977-07-01)
      A double sampling procedure was employed for obtaining more reliable weight estimates for leaves, flowering stalks, live wood, dead wood, various combinations of the preceding, and total phytomass of sagebrush shrubs. Easily obtained dimension measurements were related to harvest categories using regression analyses. Volume (length × width × height) and length measurements were the most highly correlated to phytomass. Double sampling reduced the variance of the mean phytomass estimates ranging from 33% to 80% for the various categories assuming optimum allocation. The precision achieved by combining dimension measurements with harvesting is significantly higher than by harvests without supporting dimensional measurements.
    • Spring burning Japanese brome in a western wheatgrass community

      Whisenant, S. G.; Uresk, D. W. (Society for Range Management, 1990-05-01)
      Plots dominated by Japanese brome (Bromus japonicus) and western wheatgrass (Agropyron smithii) were burned in Badlands National Park, South Dakota, in April 1983 and/or 1984. Standing crop of all species and tiller densities of the 2 dominate species were determined for 4 years. Burning favored western wheatgrass and reduced Japanese brome tiller density and standing crop for at least 1 growing season. In years where no burning occurred, Japanese brome standing crop and tiller density were dependent on the presence of litter on the soil surface. Burning in April killed Japanese brome seedlings for 1 growing season and reduced subsequent generations by reducing surface litter accumulations, with the effect being greatest when autumn precipitation was below average. April burning reduced the standing crop of green needlegrass (Stipa viridula) for at least 3 growing seasons after burning but increased standing crop of buffalograss (Buchloe dactyloides) and sand dropseed (Sporobolus cryptandrus) for 3 to 4 years after burning. Threadleaf sedge (Carex filifolia) standing crop was not significantly affected by burning.
    • Substrate relations for rillscale [Atriplex suckleyi] on bentonite mine spoil

      Voorhees, M. E.; Uresk, D. W.; Trlica, M. J. (Society for Range Management, 1991-01-01)
      Rillscale (Atriplex suckleyi), the dominant native invader of bentonite mine spoil in northern Wyoming, is apparently uniquely adapted to this extremely harsh plant growth substrate. The objective of this study was to determine which chemical properties of spoil influence growth of rillscale. Plant production, foliar and spoil chemistry on spoils were treated as a factorial arrangement of treatments, each of 3 spoil amendments (gypsum, fertilizer, sawdust). Regression analyses with analysis of covariance and factorial analysis of variance model were used to control for effects of amendments on plant production. Calcium and nitrogen were growth-limiting nutrients for this plant. The species was very sensitive to an increase in the level of spoil molybdenum and in the ratio of copper to molybdenum, but was very tolerant of high levels of soluble sodium. Rillscale acted as a molybdenum accumulator.
    • Summer Food Habits of Domestic Sheep in Southeastern Montana

      Alexander, L. E.; Uresk, D. W.; Hansen, R. M. (Society for Range Management, 1983-05-01)
      The summer food habits of sheep were investigated in a sagebrush-grass rangeland in southeastern Montana. Grasses and sedges made up 96% of the diets. Prairie sandreed (40%), needleleaf sedge (28%), and western wheatgrass (20%) were the most important foods. Forbs and shrubs made up less than 1 and 3% of sheep diets, respectively.
    • Using multivariate techniques to quantitatively estimate ecological stages in a mixed grass prairie

      Uresk, D. W. (Society for Range Management, 1990-07-01)
      Cluster analysis followed by stepwise discriminant analysis was used to delineate ecological stages on a mixed grass prairie in western South Dakota. Forty-seven variables were analyzed for 48 sites ranging from potential vegetatlon to early seral stages. A cover-frequency index for western wheatgrass (Agropyron smithii), blue grama (Bouteloua gracilis), and buffalograss (Buchloe dactyloides) was the most valuable in identifying 4 different (P<0.0001) ecological stages. Ecological stage classification was estimated to be 95% accurate. The methods presented are quantitative, precise, easy, time-efficient, and meet the goals of resource managers with a minimum of bias.