Location: Rangeland Resources Research2010 Annual Report
1a. Objectives (from AD-416)
Evaluate how management practices (e.g., grazing) and disturbance processes (e.g., fire and prairie dogs) interact to influence: (1) plant communities (specifically transitions and thresholds); (2) heterogeneity of plant communities and nesting habitat for grassland birds; (3) mechanisms and risks of weed invasions; and (4) spatial and temporal dynamics of ecological indicators of rangeland health.
1b. Approach (from AD-416)
Livestock weight gains will be compared from pastures with: (1) differing acreage; (2) differing management (e.g., stocking rates, season of use); (3) differing disturbance processes (e.g., patch fire, prairie dogs); (4) abundance of shrubs; and (5) relative contribution of upland/lowland topography. In addition, additional data (livestock behavior, grazing patterns, wildlife habitat structure, soil nutrient dynamics, forage quality/quantity and abundance of cactus) will be used to assist in the assessment of management and disturbance effects on ecosystem function/structure/production. Additional experiments will be designed to investigate the larger scale effects of adaptive management for addressing the interface of contemporary livestock production and conservation goals. Techniques such as remote sensing will be utilized to characterize spatial and temporal dynamics of ecological indicators of rangeland health as well as shrub abundance. Long-term livestock gains (from 1939) from light, moderate and heavy grazing intensities will be evaluated to determine if relationships exist between intra-annual and inter-annual variability in precipitation and gains to assess potential influences of climate change on livestock production in shortgrass steppe.
3. Progress Report
The objective of this cooperative work is to more fully characterize the ability of state-and-transition models to classify and predict vegetation change, and learn how grazing (intensity and season of use) and plant resources (carbon, nitrogen and water) influence vegetation change in shortgrass steppe; and to utilize techniques like very large-scale aerial and ground photography methods to accurately monitor bare ground, plant cover and plant communities in shortgrass steppe. In FY 2010, efforts continued on evaluating ecosystem responses to a gradient of management practices and disturbance interactions (no grazing, light summer grazing, moderate summer grazing, moderate summer grazing with ¼ of the pasture area burned, heavy summer grazing, very heavy summer grazing, very heavy spring grazing, moderate summer grazing with prairie dogs). These responses include soil moisture, plant growth, animal movement and distribution patterns, animal weight gains, plant productivity, plant composition and diversity, vegetation structure, grassland bird nesting patterns, bare ground and plant cover (both from ground and remotely sensed platforms), nitrogen cycling, grasshopper abundance and composition, and use patterns by pronghorn antelope. Work by this project will ultimately result in the development of grazing management strategies that are desirable for enhancing habitat for grassland bird species that are currently experiencing population declines, while also providing needed ecological information regarding how this rangeland ecosystem responds to grazing intensities previously not experimentally evaluated. This information will be used by land managers to increase their management options to achieve desired vegetation structure and composition for a suite of needs. To ensure accountability in the mutual expectations of this collaboration, ADODR meets on a monthly basis with the Board of Directors and members of the Crow Valley Livestock Cooperative, Inc., to discuss research findings. In addition, ADODR presents a summary of the research highlights to the entire membership of the Crow Valley Livestock Cooperative, Inc., at their annual meeting in January.