Barry L. Perryman

Vegetation Change After 65 Years of Grazing and Grazing Exclusion

Abstract The Nevada Plots exclosure system was constructed in 1937 following passage of the Taylor Grazing Act to assess long-term effects of livestock grazing on Nevada rangelands. A comparison of vegetation characteristics inside and outside exclosures was conducted during 2001 and 2002 at 16 sites. Data analysis was performed with a paired t test. Out of 238 cover and density comparisons between inside and outside exclosures at each site, 34 (14% of total) were different (P < 0.05). Generally, where differences occurred, basal and canopy cover were greater inside exclosures and density was greater outside. Shrubs were taller inside exclosures at 3 sites grazed by sheep (Ovis aries). Perennial grasses showed no vertical height difference. Aboveground plant biomass production was different at only 1 site. Plant community diversity inside and outside exclosures were equal at 11 of 16 sites. Species richness was similar at all sites and never varied > 4 species at any site. Few changes in species composition, cover, density, and production inside and outside exclosures have occurred in 65 years, indicating that recovery rates since pre-Taylor Grazing Act conditions were similar under moderate grazing and grazing exclusion on these exclosure sites.

Brome Control and Microbial Inoculation Effects in Reclaimed Cool-Season Grasslands

Abstract Introduction and subsequent invasion of smooth brome (Bromus inermis Leyss.) into native cool- and warm-season grassland communities has become problematic where presence of native species is important or mandated. The objectives of this study were to examine the efficacy of burning, grazing, and herbicide to reduce smooth brome production and cover while minimizing coincident detrimental effects on cool-season grasses in a reclaimed surface coal mine site. Concurrently, the project also investigated effects of microbial inoculation on respread topsoil subjected to long-term storage and associated effects on seeded cool-season grasses subjected to brome control treatments. Results indicated that grazing and burning were most effective after 2 years of treatment. Smooth brome biomass was lowest in reburned cells (mean ± SE, 189 ± 77 kg·ha−1) followed by regrazed (294 ± 129) compared to untreated cells (824 ± 42) (P < 0.0001). Native grass production was highest in grazed cells (141 ± 67 kg·ha−1) followed by burning (104 ± 41), herbicide (72 ± 30), and untreated (30 ± 27). Foliar cover response patterns were similar. Inoculation had little effect on microbial biomass and mycorrhizal infection. Retreated cells did show differences among months (P = 0.013) in 2000, and microbial carbon ranged from 0.07± 0.01 mg/g in June to 0.12 ± 0.01 in July and 0.12 ± 0.01 in August, averaged across treatments. Root infection decreased as soil moisture declined. Results indicate grazing offers the greatest potential for controlling smooth brome without harming native, seeded grasses on reclaimed lands in northern mixed-prarie communities, and inoculation was unnecessary for enhancing seeded, cool-season grass growth.

CASE STUDY: Reducing cheatgrass (Bromus tectorum L.) fuel loads using fall cattle grazing

Wildfire is a major concern in the Intermountain West. Fuels management can lower the potential for negative wildfire effects. Cheatgrass (Bromus tectorum L.), a nonnative annual grass, invasion has resulted in a buildup of highly flammable fine fuels that promote frequent wildfire. Removal of cheatgrass standing crop through targeted, prescriptive grazing should provide a reduction in fire intensity and possibly frequency on a local basis. Spring cattle-grazing prescriptions have provided critical reductions in cheatgrass standing crop and seed production. However, annual fluctuations in timing of readiness and standing crop production pose planning difficulties for both producers and land managers. With fall grazing, the uncertainties are no longer planning obstacles. We examined the effects of pasture-scale fall grazing of cheatgrass by cattle on standing crop (fuel reduction), the perennial vegetation community, and cattle performance. Fall grazing removed significant amounts of cheatgrass standing crop during 2006 to 2009: 79, 80, 79, and 58%, respectively. Cumulatively, 675 kg/ha were removed from the fuel base, significantly reducing carryover fuels. With protein supplementation, cattle increased BCS and gained BW in all 3 yr of the assessment (0.17, 0.35, and 0.29 kg/d in 2007 to 2009, respectively). Cheatgrass seed bank decreased by 6-fold in the grazed treatment and a little more than 2-fold in the ungrazed area 2007 to 2009. Perennial plants increased standing crop production at the expense of cheatgrass production. Fall grazing of cheatgrass can remove significant amounts of fine fuel with beneficial effects to grazing animals and the perennial plant community.

SITE AND AGE CLASS VARIATION OF HEMATOLOGIC PARAMETERS FOR FEMALE GREATER SAGE GROUSE (CENTROCERCUS UROPHASIANUS) OF NORTHERN NEVADA

Decreases in Greater Sage Grouse (Centrocercus urophasianus) numbers throughout the western United States have been attributed to declining habitat quantity and quality. Improving our understanding of how interannual ecologic site variability affects nutritional status and fitness of different bird age classes will lead to improved land management and conservation strategies. Greater Sage Grouse were sampled from two Population Management Units located in northern Nevada, United States: Tuscarora (TU) and Lone Willow (LW) during 15 March–11 April 2004 and 14–20 March 2005. Twenty (16 yearlings, four adults) and 17 (7 yearlings, 10 adults) female Sage Grouse were captured and bled during 2004, and 12 (four yearlings, eight adults) and 14 (10 yearlings, four adults) were sampled during 2005 in TU and LW, respectively. Samples were evaluated to examine the effect of site, age, and year on specific hematologic and serum chemistry parameters. Several differences between age classes, sites, and years were detected for a number of fitness indicators; however, actual values fell within normal ranges of variation for Sage Grouse or other avian species. Differences were also detected for several parameters more closely related to reproductive fitness, including total plasma and serum proteins, and serum calcium and phosphorus. Yearlings had lower plasma protein (P<0.0001) and lower serum protein than did adults (P=0.0003). In 2004, TU yearlings had lower serum calcium levels than the adults, and in 2005, LW yearlings had lower levels than adults (P=0.008). Females on the TU site had lower serum phosphorus than the LW females (P<0.0001). Overall, adult females weighed more than yearlings (P=0.0004). Lower values found in yearlings, and on the TU management unit, indicate a lower production potential, particularly in unfavorable years. A lower intrinsic ability of yearlings to reproduce, combined with lower nutrition potentials and associated annual variations on certain types of habitat combinations, indicate that conservation measures must be flexible and based on local prescriptions. Fitness parameters of Sage Grouse should be used to assess effects of land management practices and conservation on Sage Grouse populations in order to provide more certainty of the outcome, whether positive, neutral, or deleterious.

Fitness and nutritional assessment of greater sage grouse (Centrocercus urophasianus) using hematologic and serum chemistry parameters through a cycle of seasonal habitats in northern Nevada.

Abstract Bird health can significantly affect spring reproductive fitness. A better understanding of how female sage grouse health varies with seasonal nutrition changes provides insight for determining if specific nutritional habitats are limiting bird productivity. In 2004, greater sage grouse adult and yearling hens were captured, and blood samples collected, during breeding (MARCH: March 15 to April 11; n = 22), early brood rearing (MAY: May 20 to June 22; n = 21), and on summer range (JULY: July 7 to August 17; n = 19) in two distinct but similar northern Nevada population management units (Tuscarora [TU] and Lone Willow [LW]). In TU, yearlings weighed less (P < 0.043) than adults at all sampling periods. No age-related differences were observed for LW birds. Serum blood chemistry values were influenced by site, bird age, and season. Adults had more plasma protein and albumin than yearlings during MARCH (P < 0.005) followed by a decrease by MAY (P ≤ 0.0001). Lone Willow females had higher albumin levels (P = 0.0005). Higher serum phosphorus levels were detected for LW females during MARCH (P < 0.0001), and no site differences were detected for MAY or JULY. Tuscarora yearlings had lower serum calcium levels than adults during MARCH (P < 0.0001); LW yearlings had lower levels than adults during MAY (P = 0.030). Both TU yearlings (MARCH P < 0.0001) and adults (MARCH P < 0.0001; MAY P = 0.040) had lower values than LW counterparts. Tuscarora adults and LW yearlings and adults showed decreases between MARCH and MAY (P < 0.0001). The combination of lower yearling weight, plasma protein, and serum calcium and phosphorus in the TU birds indicates a lower nesting and re-nesting potential. Leading to the conclusion that TU yearlings contributed less to the population production than LW yearlings for that particular year.

Explaining patterns of species dominance in the shrub steppe systems of the Junggar Basin （China） and Great Basin （USA）

Natural scientists have long recognized that regions with similar climate tend to have similar vegetation. Preliminary observations suggest that shrub steppe communities of the western US and western China may be two such regions with similar annual precipitation, temperature, land use, and vegetation. These cold dry shrub steppes have traditionally been grazed. Despite these similarities, patterns of species dominance are different. Annual species that are rare in China become dominant when introduced to the United States. The objective of this study was to investigate how climate, land use and community structure may explain these patterns of species dominance. Community structure and grazing intensity were measured at 5 sites in each region. This information was combined with a broader review of the literature describing the history of grazing in both basins. Climate was analyzed based on a spatially-gridded, interpolated weather time series (monthly records) and climatological summary (1961–1990 mean conditions) data set from the Climate Research Unit. We found that differences in summer precipitation and winter minimum temperature, land use intensity, and shrub size may all contribute to the dominance of annual species in the Great Basin, particularly Bromus tectorum. In particular, previous work indicates that summer precipitation and winter temperature drive the distribution of Bromus tectorum in the Great Basin. As a result, sites with wet summers and cold springs, similar to the Chinese sites, would not be expected to be dominated by Bromus tectorum. A history of more intense grazing of the Chinese sites, as described in the literature, also is likely to decrease fire frequency, and decreases litter and shrub dominance, all of which have been demonstrated to be important in Bromus tectorum establishment and ultimate dominance. Further research is necessary to determine if other annuals that follow the same pattern of scarcity in the Junggar Basin and dominance in the Great Basin are responding to the same influences.

Range readiness is an obsolete management tool.

Range readiness is an outdated practice forcing rangeland managers into management situations that are detrimental to the natural resource base. DO:10.2458/azu_rangelands_v27i2_perryman

Plant Age and Growing Season Nutritional Content Relationships of Three Artemisia tridentata Subspecies

Abstract The effect of plant age on growing season chemical compositions and rumen fermentation characteristics was determined for three subspecies of big sagebrush: basin (Artemisia tridentata [Nutt.] subsp. tridentata), mountain (A. tridentata subsp. vaseyana [Rybd.] Beetle), and Wyoming (A. tridentata subsp. wyomingensis [Beetle and Young]). In vitro dry matter (IVDMD) and organic matter (IVOMD) disappearance, ammonia nitrogen (NH3N), and volatile fatty acid (VFA) content were determined at the end of two fermentation periods (24 h and 48 h) by combining rumen inocula with age-classified vegetative samples from each sagebrush subspecies. An additional one-way analysis of variance was performed to investigate potential differences among subspecies in IVDMD, IVOMD, total VFA, and NH3N following a 48-h fermentation period. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) components were also compared among sagebrush subspecies. Age class responses were variable across the spectrum of sagebrush subspecies and response variables. Where plant age effects were indicated, the small numeric differences probably have little biological or ecological significance. Mountain sagebrush was lower in IVOMD and total VFA concentrations (P < 0.0001) than basin and Wyoming. NH3N concentration and CP were higher (P < 0.0001) in basin sagebrush than the other two subspecies, while Wyoming sagebrush was higher in NDF, ADF, and ADL than basin and mountain subspecies (P < 0.0001). NH3N concentration for all three subspecies was lower than the minimum level (20 mg · 100 mL−1) required for uninhibited rumen activity. Overall, this research questions the contention that older sagebrush plants offer less nutritional value than younger ones, at least for growing season conditions. The results also provide information that can be utilized in designing supplementation strategies for domestic animals on diets with characteristically high utilization of big sagebrush.

Forum: A Framework for Resetting Wild Horse and Burro Management

On the Ground There are now over 130,000 head of wild horses and burros in the Bureau of Land Management program. Management tools in the original authorizations (Wild Horse and Burro Act; Public Rangelands Improvement Act) have been inhibited or banned by subsequent appropriation riders. The original framework for horse and burro management has been undermined, leading to on-range populations in excess of legally mandated levels. New, creative approaches to horse and burro management are required to bring populations back to legally mandated and ecologically appropriate levels.

Viewpoint: An Alternative Management Paradigm for Plant Communities Affected by Invasive Annual Grass in the Intermountain West

On the Ground Over 400,000 km2 of the Intermountain West is colonized by cheatgrass and other annual grasses. Planning and management actions designed to foster perennial grass health throughout the region have never addressed how annual grasses would respond. For decades, the most significant landscape-level management approach toward invasive annual grasses has been to complain. We now know how to begin the process of taking the Intermountain West back from the domination of invasive annual grasses: through the management of standing dead litter. Sustaining perennial bunchgrasses at landscape scales will require an integrated ecological approach to fuels management.