TY - JOUR
T1 - Ecosystem Carbon Fluxes in Response to Warming and Clipping in a Tallgrass Prairie
AU - Niu, Shuli
AU - Sherry, Rebecca A.
AU - Zhou, Xuhui
AU - Luo, Yiqi
N1 - Funding Information:
This study was financially supported by the US National Science Foundation (NSF) Grant DEB 0743778, DEB 0840964, DBI 0850290, EPS 0919466, and by the United States Department of Energy, Biological Systems Research on the Role of Microbial Communities in Carbon Cycling Program (DE-SC0004601) and Oklahoma Bioenergy Center (OBC).
PY - 2013/9
Y1 - 2013/9
N2 - Global warming and land-use change could have profound impacts on ecosystem carbon (C) fluxes, with consequent changes in C sequestration and its feedback to climate change. However, it is not well understood how net ecosystem C exchange (NEE) and its components respond to warming and mowing in tallgrass prairie. We conducted two warming experiments, one long term with a 1.7°C increase in a C4-dominated grassland (Experiment 1), and one short term with a 2.8°C increase in a C3-dominated grassland (Experiment 2), to investigate main and interactive effects of warming and clipping on ecosystem C fluxes in the Great Plains of North America during 2009-2011. An infrared radiator was used to simulate climate warming and clipping once a year mimicked mowing in both experiments. The results showed that warming significantly increased ecosystem respiration (ER), slightly increased GPP, with the net outcome (NEE) being little changed in Experiment 1. In contrast, warming significantly suppressed GPP and ER in both years, with the net outcome being enhanced in NEE (more C sequestration) in 2009-2010 in Experiment 2. The C4-dominated grassland showed a much higher optimum temperature for C fluxes than the C3-dominated grassland, which may partly contribute to the different warming effects in the two experiments. Clipping significantly enhanced GPP, ER, and NEE in both experiments but did not significantly interact with warming in impacting C fluxes in either experiment. The warming-induced changes in ecosystem C fluxes correlated significantly with C4 biomass proportion but not with warming-induced changes in either soil temperature or soil moisture across the plots in the experiments. Our results demonstrate that carbon fluxes in the tallgrass prairie are highly sensitive to climate warming and clipping, and C3/C4 plant functional types may be important factor in determining ecosystem response to climate change.
AB - Global warming and land-use change could have profound impacts on ecosystem carbon (C) fluxes, with consequent changes in C sequestration and its feedback to climate change. However, it is not well understood how net ecosystem C exchange (NEE) and its components respond to warming and mowing in tallgrass prairie. We conducted two warming experiments, one long term with a 1.7°C increase in a C4-dominated grassland (Experiment 1), and one short term with a 2.8°C increase in a C3-dominated grassland (Experiment 2), to investigate main and interactive effects of warming and clipping on ecosystem C fluxes in the Great Plains of North America during 2009-2011. An infrared radiator was used to simulate climate warming and clipping once a year mimicked mowing in both experiments. The results showed that warming significantly increased ecosystem respiration (ER), slightly increased GPP, with the net outcome (NEE) being little changed in Experiment 1. In contrast, warming significantly suppressed GPP and ER in both years, with the net outcome being enhanced in NEE (more C sequestration) in 2009-2010 in Experiment 2. The C4-dominated grassland showed a much higher optimum temperature for C fluxes than the C3-dominated grassland, which may partly contribute to the different warming effects in the two experiments. Clipping significantly enhanced GPP, ER, and NEE in both experiments but did not significantly interact with warming in impacting C fluxes in either experiment. The warming-induced changes in ecosystem C fluxes correlated significantly with C4 biomass proportion but not with warming-induced changes in either soil temperature or soil moisture across the plots in the experiments. Our results demonstrate that carbon fluxes in the tallgrass prairie are highly sensitive to climate warming and clipping, and C3/C4 plant functional types may be important factor in determining ecosystem response to climate change.
KW - C
KW - C
KW - biofuel harvest
KW - carbon fluxes
KW - carbon sequestration
KW - climate warming
KW - feedback
KW - optimum temperature
KW - plant functional types
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U2 - 10.1007/s10021-013-9661-4
DO - 10.1007/s10021-013-9661-4
M3 - Article
AN - SCOPUS:84881543832
SN - 1432-9840
VL - 16
SP - 948
EP - 961
JO - Ecosystems
JF - Ecosystems
IS - 6
ER -