TY - JOUR
T1 - Ecosystem Water-Use Efficiency of Annual Corn and Perennial Grasslands
T2 - Contributions from Land-Use History and Species Composition
AU - Abraha, Michael
AU - Gelfand, Ilya
AU - Hamilton, Stephen K.
AU - Shao, Changliang
AU - Su, Yahn Jauh
AU - Robertson, G. Philip
AU - Chen, Jiquan
N1 - Funding Information:
This work was supported by the US Department of Energy’s Great Lakes Bioenergy Research Center (DOE Office of Science, DE-FC02-07ER64494 and DOE Office of Energy Efficiency and Renewable Energy, DE-AC05-76RL01830), the US National Science Foundation LTER Program (DEB 1027253), and MSU AgBioResearch. We thank T. Zenone, H. Chu, M. Deal, R. John, J. Xu and K. Kahmark for tower-related works, S. Bohm and S. Sippel for data management and S. Vanderwulp, P. Jasrotia, J. Bronson, and J. Simmons for field-related work. We also thank the subject-matter editor Dr. Peter Groffman and the two anonymous reviewers for their constructive comments.
Publisher Copyright:
© 2016, Springer Science+Business Media New York.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Carbon and water exchanges between vegetated land surfaces and the atmosphere reveal the ecosystem-scale water-use efficiency (WUE) of primary production. We examined the interacting influence of dominant plant functional groups (C3 and C4) and land-use history on WUEs of annual corn and perennial (restored prairie, switchgrass and smooth brome grass) grasslands in the US Midwest from 2010 through 2013. To this end, we determined ecosystem-level (eWUE) and intrinsic (iWUE) WUEs using eddy covariance and plant carbon isotope ratios, respectively. Corn, switchgrass, and restored prairie were each planted on lands previously managed as grasslands under the USDA Conservation Reserve Program (CRP), or as corn/soybean rotation under conventional agriculture (AGR), while a field of smooth brome grass remained in CRP management. The iWUEs of individual C3 plant species varied little across years. Corn had the highest (4.1) and smooth brome grass the lowest (2.3) overall eWUEs (g C kg−1 H2O) over the 4 years. Corn and switchgrass did not consistently show a significant difference in seasonal eWUE between former CRP and AGR lands, whereas restored prairie had significantly higher seasonal eWUE on former AGR than on former CRP land due to a greater shift from C3 to C4 species on the former AGR land following a drought in 2012. Thus, differences in grassland eWUE were largely determined by the relative dominance of C3 and C4 species within the plant communities. In this humid temperate climate with common short-term and occasional long-term droughts, it is likely that mixed grasslands will become increasingly dominated by C4 grasses over time, with higher yields and eWUE than C3 plants. These results inform models of the interaction between carbon and water cycles in grassland ecosystems under current and future climate and management scenarios.
AB - Carbon and water exchanges between vegetated land surfaces and the atmosphere reveal the ecosystem-scale water-use efficiency (WUE) of primary production. We examined the interacting influence of dominant plant functional groups (C3 and C4) and land-use history on WUEs of annual corn and perennial (restored prairie, switchgrass and smooth brome grass) grasslands in the US Midwest from 2010 through 2013. To this end, we determined ecosystem-level (eWUE) and intrinsic (iWUE) WUEs using eddy covariance and plant carbon isotope ratios, respectively. Corn, switchgrass, and restored prairie were each planted on lands previously managed as grasslands under the USDA Conservation Reserve Program (CRP), or as corn/soybean rotation under conventional agriculture (AGR), while a field of smooth brome grass remained in CRP management. The iWUEs of individual C3 plant species varied little across years. Corn had the highest (4.1) and smooth brome grass the lowest (2.3) overall eWUEs (g C kg−1 H2O) over the 4 years. Corn and switchgrass did not consistently show a significant difference in seasonal eWUE between former CRP and AGR lands, whereas restored prairie had significantly higher seasonal eWUE on former AGR than on former CRP land due to a greater shift from C3 to C4 species on the former AGR land following a drought in 2012. Thus, differences in grassland eWUE were largely determined by the relative dominance of C3 and C4 species within the plant communities. In this humid temperate climate with common short-term and occasional long-term droughts, it is likely that mixed grasslands will become increasingly dominated by C4 grasses over time, with higher yields and eWUE than C3 plants. These results inform models of the interaction between carbon and water cycles in grassland ecosystems under current and future climate and management scenarios.
KW - C
KW - C
KW - carbon isotope ratio
KW - ecosystem WUE
KW - eddy covariance
KW - evapotranspiration
KW - gross primary production
KW - intrinsic WUE
KW - restored prairie
KW - switchgrass
UR - http://www.scopus.com/inward/record.url?scp=84964344075&partnerID=8YFLogxK
U2 - 10.1007/s10021-016-9981-2
DO - 10.1007/s10021-016-9981-2
M3 - Article
AN - SCOPUS:84964344075
SN - 1432-9840
VL - 19
SP - 1001
EP - 1012
JO - Ecosystems
JF - Ecosystems
IS - 6
ER -
