|Milchunas, Daniel - COLORADO STATE UNIVERSITY|
|Pendall, Elise - UNIVERSITY OF WYOMING|
Submitted to: Rangelands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 24, 2008
Publication Date: June 2, 2008
Citation: Morgan, J.A., Derner, J.D., Milchunas, D., Pendall, E. 2008. Management implications of global change for Great Plains rangelands. Rangelands 30(3):18-22. Interpretive Summary: Climate change is accepted by most not only as a potential phenomenon with numerous important implications for Earth and its inhabitants, but as a present-day reality that is underway and already affecting the face of American agriculture. The rangeland community is acutely aware of the need for understanding how management and climate affect the ecology and agricultural utility of rangelands, but remains largely unconcerned or at least undecided on how to deal with the advent of climate change. In this synthesis of the recent literature, we make the case that climate change is already transforming rangelands of the Great Plains, and that we need to improve our understanding of this phenomenon if we hope to develop intelligent policy and management practices for dealing with this critical issue.
Technical Abstract: Just as water and temperature drive the ecology of Great Plains rangelands, we predict that the impacts of global change on this region will be experienced largely through changes in these two important environmental variables. A third global change factor which will impact rangelands is increasing levels of atmospheric CO2, which has direct effects on plant growth and physiology, and also is a major driver of climate change. In northern Great Plains and high altitude rangelands, combined warming and higher CO2 may continue to enhance plant production, at least for the next few decades or so. However, in the southern Great Plains, production may be little affected or may eventually decline in some regions due to increased water stress expected at warmer temperatures. Plant species changes are likely already underway in response to global changes, and are expected to continue in a future CO2-enriched and warmer world, favoring those plant species which prefer those conditions. The long-term responses of Great Plains rangelands will depend, in part, on how combined changes in climate, CO2, and vegetation affect the available plant nutrients in the soil. Forage quality is expected to change in response to altered nutrient cycling and species change; research to date suggests rising atmospheric CO2 is leading to lower forage quality. We argue that scientists and land managers need to include these current notions of climate change impacts on rangeland plants and soils in management models to more accurately reflect current and future environments.