1a. Objectives (from AD-416):
1) Evaluate the effects of fire, mechanical treatments, livestock grazing, introduced invasive weeds, western juniper expansion, and climate on the vegetation and watershed function of sagebrush steppe rangelands. 2) Improve our understanding of livestock behavior and livestock/environment interactions. Improve tools to manipulate livestock behavior and grazing patterns. 3) Understand mechanisms of weed invasion and develop management strategies that can be used to restore rangelands that have been degraded by weeds or other disturbances.
1b. Approach (from AD-416):
The mission of the Burns unit is to provide the science for sound land and livestock management. This five-year plan builds on a rich history of research at this location, in some cases reaching back to the 1940's. Rangelands of the Great Basin are spatially variable and land ownership patterns are a complex mix of public and private land. Annual weather variation is high, and can obscure vegetation responses to management treatments. Ranching forms the basis of the regional economy, underscoring the importance of forage production, and the large percentage of public land in the region translates into public scrutiny of management actions, and a focus on environmental impacts and biodiversity. Invasive species and expanding juniper populations represent major threats to existing land uses and values. Our research program has evolved with substantial public input and addresses questions raised by our customers. Land managers in this region are faced with information gaps in basic sagebrush steppe ecology, vegetation responses to management actions, plant community restoration, seedling establishment and livestock grazing management. Our research program will fill some of those gaps while expanding and enhancing current ecological theory and building on our long-term data sets. The unit also has a commitment to synthesizing research information and developing management tools. Formerly 5360-11630-005-00D (1/08).
3. Progress Report:
This is the final report for Project 5360-11630-006-00D, terminated in September of 2012, and replaced with project 5360-21630-001-00D. For additional information, please see the new project report. All work was completed prior to the start of FY2013. Progress was made on all three objectives and their sub objectives during the past 5 years. All the objectives covered in this report fall under National Program 215, Component 1, Problem A. Under Objective 1.A we continue to collect data on the hydrologic inputs and outflows from four small watersheds (< 100ha) near Jordan Valley, Oregon in far southeastern Oregon. This research is cooperative with the ARS unit in Boise, Idaho. The initial research conducted under Objective 1.B has been published and shows that deferment of grazing after prescribed fire had little impact on vegetation composition or productivity. Long-term measurements of both productivity and composition are being continued on the site. We continue to measure both climate and vegetation composition in and outside of our 13 grazing enclosures at the experimental range. This past year we also worked on summarizing and analyzing 70 years of climate data from the experimental range. The climate summarization is complete and we added several adjacent weather stations to the analysis. Vegetation analysis is in progress. The focus this past year under Objective 2 has been to summarize and analyze the large data sets associated with the livestock behavior using global positioning system (GPS) research. The data relates to grazing behavior of different classes of cows, and factors influencing grazing distribution in very large pastures (> 25,000 ha). For objective 3.A, several manuscripts have been submitted. Results associated with objective 3.B have been published and results from objective 3.C have been published and additional publications are in progress. Objective 3.D is focused on long-term vegetation trends after juniper management; initial response data has been published and the vegetation measurements are ongoing.
Davies, K.W., Bates, J.D., Nafus, A.M. 2012. Mowing Wyoming big sagebrush communities with degraded herbaceous understories: has a threshold been crossed?. Rangeland Ecology and Management. 65(5):498-505.