Habitat management guidelines for greater sage-grouse, Centrocercus urophasianus, have been formulated, in part, based on studies of nest site selection. However, these guidelines may not represent conditions when the female initiates nesting because sampling occurs posthatch (> 30 days after nest initiation) to avoid disturbing incubating females. In 2002, we investigated differences in 22 habitat variables at initiation and hatch. Sampling was at 30 randomly selected active nests marked in 2001. There was no significant difference in structural or cover data (P > 0.05). Grass height and percent grass cover differed (P < 0.05) based on timing of sampling. Grass heights at the nest bowl and at 1 m from the edge of the nest bowl were 10 and 9 cm at initiation and 16 and 13 cm at hatch, respectively. Percent grass cover increased from 4% to 6% cover from initiation to hatch. Sampling occurred in a dry year; differences in grass heights and percent cover may be more pronounced in years of normal precipitation. Preliminary results indicated current habitat sampling techniques conducted posthatching adequately described selection of structural components of shrub height, visual obstruction, and percent cover of shrubs, bare ground, litter, and forbs at the nest site at initiation. Data need to be verified for other study areas and under different climatic conditions.  

Western juniper (Juniperus occidentalis spp. occidentalis Hook.) expansion into sagebrush steppe plant communities in the northern Great Basin has diminished shrub-steppe productivity and diversity. Chainsaw cutting of western juniper woodlands is a commonly applied practice for removing tree interference and restoring understory composition. Studies reporting understory response following juniper cutting have been limited to early successional stages. This study assessed successional dynamics spanning 13 years following tree cutting. Total herbaceous standing crop and cover increased significantly in the CUT. Total standing crop was 10 times greater in the CUT vs. WOODLAND. Herbaceous standing crop and cover, and densities of perennial grasses in the CUT did not change between 1996 and 2004 indicating that by the 5th year after cutting, remaining open areas had been occupied. In the early successional stages, perennial bunchgrasses and Sandberg’s bluegrass were dominant. By the 5th year after treatment, cheatgrass had supplanted Sandberg’s bluegrass and was codominant with perennial bunchgrasses. In 2003 and 2004, perennial bunchgrasses dominated herbaceous productivity in the CUT, representing nearly 90% of total herbaceous standing crop. A pretreatment density of 2-3 perennial bunchgrasses m-2 appeared to be sufficient to permit natural recovery after juniper control. Perennial bunchgrass density peaked in the 6th year after treatment and the results suggested that 10-12 plants m-2 were sufficient to fully occupy the site and dominate herbaceous composition in subsequent years. In the CUT, juniper rapidly reestablished from seed and from the presence of seedlings not controlled in the initial treatment. The shifts in herbaceous composition across years suggests that long term monitoring is important for evaluating plant community response to juniper control and to develop appropriate post treatment management to promote continued site improvement.  

The University of California Cooperative Extension surveyed rangeland owners and managers who attended California’s Ranch Water Quality Planning (RWQP) Short Course in 1995-2002. The survey evaluated the effectiveness of this industry-supported voluntary program by evaluating indicators for short course impacts, including 1) rancher participation in the short courses, 2) completion of nonpoint source self-assessments, 3) completion of ranch water quality plans, and 4) implementation of best management practices (BMPs). This report describes the RWQP short course and ranch water quality plan content including the nonpoint source pollution self-assessment and monitoring. Questionnaires were mailed to 777 short course participants on 5 August 2002 (Round 1). A second survey (Round 2) was mailed to nonrespondents on 7 April 2003. Round 1 and 2 surveys resulted in a 52.9% total adjusted response rate. Citing privacy issues, 28 respondents refused to complete the survey. Round 1 respondents had a significantly higher rate of BMP implementation, but Round 2 respondents invested more personal funds in BMPs. There was a significant relationship (P < 0.001) between plan completion and implementation of BMPs. While the majority of the respondents completed ranch water quality plans and self-assessments, and implemented BMPs, less than 50% of the respondents implemented a monitoring program. Fifty percent of the respondents raised beef cattle, and the majority managed ranches less than 5 000 acres in size. The results of this survey suggest that industry-initiated, voluntary programs supported by education are effective in helping rangeland owners and managers address nonpoint source pollution on their properties. In addition, social surveys are a viable method for landowners to confidentially self-document identified pollution sources and BMP implementation, and to avoid formal reporting to regulatory agencies.  

Integrating use of seeded perennial cool-season grass pastures with native rangeland can increase available forage and provide a high plane of nutrition for grazing livestock. Our objective was to compare performance of yearling beef heifers grazing native rangeland with those grazing an integrated system that included seeded forages. Twice-replicated, 3-ha pastures seeded to either ‘Rosana’ western wheatgrass (Pascopyron smithii [Rydb.] A. Love), ‘Luna’ pubescent wheatgrass (Elytrigia intermedia [Host] Nevski), or ‘Hycrest’ crested wheatgrass (Agropyron cristatum [L.] Gaertn. ssp. desertorum [Fisch. ex Link] A. Love) were grazed in spring, whereas twice-replicated, 3.24-ha pastures seeded to either ‘Alkar’ tall wheatgrass (Thinopyrum ponticum [Podp.] ZW Liu RC Wang), ‘NewHy’ hybrid wheatgrass (Elymus hoffmannii KB Jensen KH Asay), ‘Bozoisky’ Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski.), or ‘Prairieland’ Altai wildrye (Leymus angustus [Trin.] Pilger) were grazed in autumn. Native rangeland was grazed during summer in the integrated system and spring, summer, and autumn in the rangeland treatment. Heifers exhibited greater weight gains on seeded pastures than on native rangeland in spring and autumn of most years. In 2 out of 3 years, heifers that grazed native rangeland during spring gained more (P = 0.012 for gain head-1 and P = 0.021 for gain head-1 day-1) while grazing native rangeland during summer than heifers that grazed seeded pastures in spring. Spring + summer gains averaged (mean +/- SE) 0.56 +/- 0.01 kg head-1 d-1 and 73.1 +/- 1.6 kg head-1. Livestock managers need to consider their livestock marketing and management strategies when using seeded pastures for seasonal grazing.  

Enhancing desired species establishment and persistence is central to rehabilitating invasive plant-infested rangeland. We hypothesized that nonnative desired species (alfalfa [Medicago sativa L., var. Arrow], intermediate wheatgrass [Thinopyrum intermedium fHostg Barkworth D.R. Dewey], and crested wheatgrass [Agropyron cristatum fL.g Gaertn., var. Hycrest]) increase as desired species richness within seeding mixture increases, and spotted knapweed (Centaurea maculosa Lam.) decrease as desirable species richness increases. We simultaneously tested the degree of niche differentiation among desired species. Experiments consisted of 7 seeding monocultures and combinations. Treatments were monocultures of each desired species (3 plots), all combinations of 2 desirable species (2 250 seeds m-2 per species; 3 plots), and 1 plot containing all 3 desirable species (1 500 seeds m-2 per species). Monocultures or mixtures were replicated 4 times by seeding each treatment with four background densities of spotted knapweed (1 250, 2 500, 3 750, and 7 500 seeds m-2; 7 treatments X 4 background densities = 28 plots). Analysis included regression with the 7 desired species monocultures or mixtures as a fixed effect and spotted knapweed sowing density as a continuous effect. All desired species established had either low or no negative influence on their neighbor, and differed in niche after 7 years of growing in association. Increasing richness of desired species led to increased productivity. Spotted knapweed density and biomass were low across all monocultures and mixtures at the productive site because shade and litter of desired species reduced light availability to the rosette-forming invasive weed. Combining crested wheatgrass and alfalfa provided lower spotted knapweed density and biomass more than did monocultures or grass mixtures because these 2 species appeared to occupy complementary niches. Increased niche occupation by nonnative desirable species may increase resource use and productivity, thus minimizing establishment and dominance of unwanted invasive plants during rehabilitation on arid, marginally productive rangeland sites.  

The cover of Festuca gracillima (coirón fueguino), a native tussock grass that dominates grass steppes of Southern Patagonia and Tierra del Fuego, has diminished under continuous sheep grazing. This loss is a concern, because it also reduces forage availability in winter, biodiversity, and soil stability. In the present study, the hypothesis that tussock grass birth and mortality rates are balanced only under moderate-grazing or exclusion regimes was tested with two 5-year records of demographic data obtained from 3 sheep grazing regimes: exclosure (no grazing), low (0.0348 AU ha-1 y-1, where AU represents animal units equivalent to the consumption of a 450-kg cow), and high (0.1043 AU ha-1 y-1). Tussocks were outlined in photographs and marked in the field at two 5-year intervals. The initial total number of plants for the 3 grazing regimes (n = 358) increased to 384 plants at the end of the 10-year period. No recruitment from seed was observed; plant number changed as a balance of yearly rates of tussock mortality (1.48%), amalgamation (0.75%), and subdivision (2.04%). Intensely grazed populations showed greater (2.13%) mortality rates than ungrazed (1.20%) or moderately grazed (0.78%) populations. Tussocks in intensely grazed populations were smaller (167 cm2 plant-1) than those in moderately grazed (197 cm2 plant-1) or ungrazed (300 cm2 plant-1) populations. Transition matrices showed eigenvalues of 0.701 (high grazing), 0.794 (exclosure), and 0.876 (low grazing). All growth rates of demographic models were negative; the largest rate of population decrease was found under high-intensity grazing, for which projections show that half the tussocks would be lost in 37 years. Under low-intensity grazing and exclosure, a similar tussock loss would take place in 87 and 74 years, respectively. Results show 1) the importance of vegetative processes for tussock demography, 2) the extremely slow dynamics of population changes, and 3) that tussocks may suffer increased mortality as a consequence of subdivision or fragmentation, a process that can be viewed as a small-scale example of the generalized effect of patch subdivision under grazing.  

Hyperspectral 1-m-resolution remote sensing has the potential to reduce the time spent sampling and reduce spatial sampling errors found in traditional forage nutritive analysis over large areas. The objective of this study was to investigate if 1-m-resolution hyperspectral techniques are useful tools to provide reliable estimates of forage nitrogen (N), phosphorus (P) and neutral detergent fiber (NDF) in Yellowstone National Park. The vegetative communities investigated varied in the amount of canopy coverage and species diversity, and ranged from xeric, semiarid environments to mesic, wetland/riparian environments. A large number of simple ratio-type vegetation indices (SRTVI) and normalized difference-type vegetation indices (NDTVI) were developed with the hyperspectral dataset. These indices were regressed against N, P, and NDF values from ground collections. We found that 1) there were strong linear relationships between selected SRTVI and N (R2 = 0.7), P (R2 = 0.65), and NDF (R2 = 0.87) nutritive values on an area basis (g m-2); and 2) there were no strong linear relationships (R2 < 0.3) between a variety of SRTVI and NDTVI and N, P, and NDF on a dry matter basis (g g-1 X 100). The lack of relationship is related to 1) the highly variable relationship between the dry matter biochemical signal and total plant biomass and water content and 2) the weakening of the biochemical signal from exposed soil in low-canopy situations, from nonphotosynthetic vegetation (bark, stems, and litter), and from different plant species.