Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 12/1/2005
Publication Date: 7/26/2006
Citation: Derner, J.D., Andales, A.A., Morgan, J.A. 2006. Tactical and strategic difficulties in managing water-limited rangelands of the Western Great Plains. In: Soil and Water Conservation Society Proceedings, Rocky Mountain Rendezvous II. p. 10. Interpretive Summary:
Technical Abstract: Water is the primary driver affecting ecosystem responses in semi-arid rangelands of the western Great Plains. Because intra- and interannual variability in precipitation is high, it is problematic for land managers to properly adjust management strategies between and within years to achieve sustainable use of these lands. Growing season precipitation has been used for coarse-level decisions as this metric is often highly correlated with forage and livestock production in these rangelands. In addition, mechanistic models have been developed as decision support tools. For example, the USDA-Agricultural Research Service Great Plains Framework for Agricultural Resource Management (GPFARM) forage growth model has functional utility as a strategic (between years) planning tool for simulating forage and livestock production in semi-arid rangelands. There is little tactical (within-year) utility of forage productivity information based simply on early-to-mid growing season precipitation, however. Therefore, land managers often are relegated to making reactionary management decisions during the growing season. Further development and subsequent testing of the GPFARM forage growth model using current soil water availability and predictions of future weather is needed to assess its capacity to adequately function as a tactical management tool for making earlier season estimates of forage production. In addition, advances in simulating ecosystem-level CO2 and water fluxes and responses to management and weather would provide insights into managing for net carbon uptake as well as for maintaining healthy ecosystems. We will provide suggestions for increasing the flexibility in livestock classes and numbers for land managers to assist in tactical and strategic management decisions.