2012 Annual Report 1a.Objectives (from AD-416): To conduct collaborative research on population dynamics, biogeochemical dynamics, soil ecology, and land-atmosphere interactions at the USDA-ARS Central Plains Experimental Range, to use knowledge from these investigations to elucidate the long-term ecological functioning of the shortgrass steppe, to develop and evaluate conservation/production practices for semi-arid rangelands, and to conduct workshops and outreach activities to disseminate knowledge gained from this research to the public. 1b.Approach (from AD-416): Unlike intensively-managed agro-ecosystems, the functioning of native grasslands requires experiments of sufficient duration to incorporate important temporal dynamics that underlie their structure and function. Since decades or even centuries are sometimes required to fully capture the effects of management and environmental disturbances on some ecosystem components, experiments and monitoring of critical system components must be of sufficient duration for elucidating response mechanisms. The emergence of climate change as one of the central environmental problems of the 21st century places increased importance on long-term ecological research such as we propose here for monitoring long-term ecosystem responses. Under this proposed agreement, the Rangeland Resources Research Unit (RRRU) will collaborate with scientists from primarily Colorado State University (CSU) to conduct long-term experiments that will evaluate population dynamics of key animal and plant species; biogeochemical cycling of primarily C and N; ecology and genetics of key soil microbial communities; and land-atmosphere exchange of primarily water, C, and energy. The results of these investigations will provide the basis for formulating new sustainable management practices that address both conservation and agricultural production goals, as well as evaluating the state and condition of semi-arid rangelands. 3.Progress Report: The purpose of this Shortgrass Steppe Long Term Ecological Research (SGS LTER) Project is to conduct long-term experiments that will evaluate population dynamics of key animal and plant species; land-atmosphere exchanges of primarily water, C, and energy; and biogeochemical cycling of primarily C and N. The SGS LTER Project is currently winding down with termination in 2013 following only one more year of renewed funding. Research is focused on wrapping up long-term experiments with final sampling harvests and a dedicated effort to systematically sample the existing grazing exclosures with ARS. To ensure accountability in the mutual expectations of this collaboration, ADODR meets on at least a quarterly basis with lead Colorado State University collaborator and other co-PIs on the SGS LTER Project to discuss research findings and ramping down this research for priorities of final sampling harvests. ARS scientists attend monthly SGS LTER seminars during the academic school year, and regularly present to the group.