|Miglietta, Franco - INSTITUTE OF BIOMETEROLOG|
|Parton, William - COLORADO STATE UNIVERSITY|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: September 30, 2003
Publication Date: May 5, 2004
Citation: Morgan, J.A., Blumenthal, D.M., Reeder, S.J., Lecain, D.R., Miglietta, F., Mosier, A.R., Parton, W., Schuman, G.E. 2004. CO2 enrichment in great plains grasslands: past findings and future research direction. FACE workshop, Ascona, Switzerland. March 2004. No proceedings were published. Technical Abstract: Two similarly designed open-top chamber CO2 enrichment experiments have been completed in native Great Plains grasslands, the Kansas tallgrass prairie and the Colorado shortgrass steppe. Although mean annual precipitation differs almost 3-fold between these two grasslands, findings from these two studies were similar in that they demonstrated the importance of soil/plant water relations in driving ecosystem responses to elevated CO2. Elevated CO2 often led to large increases in plant community aboveground biomass, especially in the semi-arid shortgrass steppe, although aboveground production of only a small number of plant species was affected by CO2. Soil nitrogen appeared to be an important driver in several attribute responses to CO2, but many questions remain concerning the role of soil N cycling in affecting the long-term CO2 responses of these grasslands. A new FACE CO2 enrichment study is being planned for a northern mixed-grass prairie (NMP) in southeastern Wyoming to extend our understanding of how Great Plains grasslands respond to CO2, and to gain additional insights on N and weed interactions. Several weed and legume species will be seeded into the NMP under variable CO2 concentrations to evaluate weed and N interactions with CO2 on system responses.