International

Science and technology needs for global rangeland assessment. (Keynote address) International Grassland-Rangeland Congress, Hohot China, July 2008.

Texas warming and rainfall manipulation (T-WaRM) project: growth form contrasts in oak savanna. Joint U.S.-European Union Global Change Workshop sponsored by TERACC and NSF, Elsinore, Denmark. May, 2006.

Vegetation responses to grazing: have unifying principles emerged? Symposium presentation at the 59th Annual Meeting of the Society for Range Management, Vancouver, British Columbia, Canada. February, 2006.

Increasing precision in describing ecological thresholds, drivers and indicators.  Annual Meeting of the Ecological Society of America, Montreal, Canada. August 2005.

Ramet dynamics and clonal organization: a grassland perspective. VI International Workshop on Clonal Plant Ecology, Obergurgul, Austria. August 2000.

Plant traits determining grazing resistance: why have they proven so elusive? VI International Rangeland Congress, Townsville Australia. July 1999.

Plant responses to grazing: a comparative evaluation of annual and perennial grasses. International workshop sponsored by the European Commission on the Environment, Thessaloniki, Greece. October, 1997.

Clonal biology of caespitose grasses: A case study with Schizachyrium scoparium. Plant Ecology and Physiology Center, University of Buenos Aries, Buenos Aries, Argentina. October 1993.

Plant demography and grassland community balance: the contribution of population regulation mechanisms. XVII International Grassland Congress, Palmerston North, New Zealand. February 1993.

Current status of individual plant responses to defoliation. Volcani Center, Israel Ministry of Agriculture, Bet Dagan Israel. January 1992.

National

Grass and juniper responses to modified precipitation seasonality and warming.   Annual Meeting of the Society for Range Management, Louisville KY, February 2008.

State-and-transition models: recommendations for resilience-based application.  Annual Meeting of the Society for Range Management, Louisville KY, February 2008.

The detection of catastrophic thresholds: perspectives, definitions and methods-Synthesis and conclusions. Ecological Society of America Meeting, Memphis TN, August 2006.

State-and-transition models and ecological thresholds; bridging theory and application. State-and-transition model theory workshop, Oregon State University, Corvallis OR, August, 2006.

Impact of altered precipitation distribution and warming on tree and grass life forms in oak savanna. Principal Investigator Workshop, National Institute for Global Environmental Change-Department of Energy, Tulane University, New Orleans LA, June 2005.  

State-and-transition models and ecological thresholds: bridging theory and application. Leu Distinguished Seminar Series, Center for Grassland Studies, University of Nebraska-Lincoln. October, 2005.

Forage and range professions: distinct, similar, or irrelevant. Annual meeting of the Society for Range Management, Omaha, Nebraska. February 1999.

Demography and clonal biology of caespitose grasses. Annual meeting of the American Institute of Biological Sciences, San Diego, CA. August, 1995.

Individual plant response to grazing: current status and ecological significance. Kling Anderson Lecture, Department of Agronomy, Kansas State University, Manhattan, Kansas. December 1992.

Physiological responses of individual plants to grazing: Current status and ecological significance. Annual meeting of the American Institute of Biological Sciences, San Antonio, Texas. August 1991.

Editor-in-Chief Rangeland Ecology and Management, 2008 – present: This position is responsible for all academic aspects of publishing the premier international journal addressing global rangeland issues. Activities include management of the editorial board (26 members with a strong international presence), coordination with the managing and production editors at Allen Press, and numerous aspects of Journal promotion. The Journal receives over 200 submissions from authors world-wide and publishes 720 pages per year.

Academic Coordinator for USDA Rangeland CEAP, 2007-present: Nominated to serve as academic coordinator to the Conservation Effects Assessment Program (CEAP) of the USDA-NRCS Resource Inventory and Assessment Division. The goal of this national program is to provide an evidence-based assessment of the ecological effectiveness of major rangeland conservation practices. The current program involves nine academic teams, totaling 36 scientists, to conduct a science-based assessment of current conservation practices implemented on rangelands. The recommendations of this initiative will inform policy makers of science-based priorities to effectively allocate funds to rangeland conservation systems in the current and subsequent Farm Bills.

Participation in NSF NEON Initiative, 2006-present: Elected to serve as coordinator of the Executive Committee for the Southern Plains Domain (domain 11 of the 20 domain network) for the National Ecological Observatory Network (NEON) sponsored by NSF. This involves coordination of a five member steering committee to identify ecological sites that best represent the eco-regions of Texas and Oklahoma for inclusion as one of 20 monitoring sites that will span the entire US. Upon completion of the national infrastructure, NSF will prioritize funding to support NEON research activities in each of the respective domains. NEON represents a program of unprecedented scope and cost for the U.S. ecological community.

Member of the Rangeland Ecology and Management editorial board, 2005-07: Supervised peer review of 31 manuscripts and 19 revisions and worked with the editor-in-Chief to enhance Journal format and academic impact.