TY - JOUR
T1 - Biotic and climatic controls on interannual variability in carbon fluxes across terrestrial ecosystems
AU - Shao, Junjiong
AU - Zhou, Xuhui
AU - Luo, Yiqi
AU - Li, Bo
AU - Aurela, Mika
AU - Billesbach, David
AU - Blanken, Peter D.
AU - Bracho, Rosvel
AU - Chen, Jiquan
AU - Fischer, Marc
AU - Fu, Yuling
AU - Gu, Lianhong
AU - Han, Shijie
AU - He, Yongtao
AU - Kolb, Thomas
AU - Li, Yingnian
AU - Nagy, Zoltan
AU - Niu, Shuli
AU - Oechel, Walter C.
AU - Pinter, Krisztina
AU - Shi, Peili
AU - Suyker, Andrew
AU - Torn, Margaret
AU - Varlagin, Andrej
AU - Wang, Huimin
AU - Yan, Junhua
AU - Yu, Guirui
AU - Zhang, Junhui
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - Interannual variability (IAV, represented by standard deviation) in net ecosystem exchange of CO2 (NEE) is mainly driven by climatic drivers and biotic variations (i.e., the changes in photosynthetic and respiratory responses to climate), the effects of which are referred to as climatic (CE) and biotic effects (BE), respectively. Evaluating the relative contributions of CE and BE to the IAV in carbon (C) fluxes and understanding their controlling mechanisms are critical in projecting ecosystem changes in the future climate. In this study, we applied statistical methods with flux data from 65 sites located in the Northern Hemisphere to address this issue. Our results showed that the relative contribution of BE (CnBE) and CE (CnCE) to the IAV in NEE was 57%±14% and 43%±14%, respectively. The discrepancy in the CnBE among sites could be largely explained by water balance index (WBI). Across water-stressed ecosystems, the CnBE decreased with increasing aridity (slope=0.18%mm-1). In addition, the CnBE tended to increase and the uncertainty reduced as timespan of available data increased from 5 to 15 years. Inter-site variation of the IAV in NEE mainly resulted from the IAV in BE (72%) compared to that in CE (37%). Interestingly, positive correlations between BE and CE occurred in grasslands and dry ecosystems (r>0.45, P<0.05) but not in other ecosystems. These results highlighted the importance of BE in determining the IAV in NEE and the ability of ecosystems to regulate C fluxes under climate change might decline when the ecosystems experience more severe water stress in the future.
AB - Interannual variability (IAV, represented by standard deviation) in net ecosystem exchange of CO2 (NEE) is mainly driven by climatic drivers and biotic variations (i.e., the changes in photosynthetic and respiratory responses to climate), the effects of which are referred to as climatic (CE) and biotic effects (BE), respectively. Evaluating the relative contributions of CE and BE to the IAV in carbon (C) fluxes and understanding their controlling mechanisms are critical in projecting ecosystem changes in the future climate. In this study, we applied statistical methods with flux data from 65 sites located in the Northern Hemisphere to address this issue. Our results showed that the relative contribution of BE (CnBE) and CE (CnCE) to the IAV in NEE was 57%±14% and 43%±14%, respectively. The discrepancy in the CnBE among sites could be largely explained by water balance index (WBI). Across water-stressed ecosystems, the CnBE decreased with increasing aridity (slope=0.18%mm-1). In addition, the CnBE tended to increase and the uncertainty reduced as timespan of available data increased from 5 to 15 years. Inter-site variation of the IAV in NEE mainly resulted from the IAV in BE (72%) compared to that in CE (37%). Interestingly, positive correlations between BE and CE occurred in grasslands and dry ecosystems (r>0.45, P<0.05) but not in other ecosystems. These results highlighted the importance of BE in determining the IAV in NEE and the ability of ecosystems to regulate C fluxes under climate change might decline when the ecosystems experience more severe water stress in the future.
KW - Biotic effect
KW - Climatic effect
KW - Climatic stress
KW - Interannual variability
KW - Net ecosystem exchange
KW - Relative importance
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U2 - 10.1016/j.agrformet.2015.02.007
DO - 10.1016/j.agrformet.2015.02.007
M3 - Article
AN - SCOPUS:84922981901
SN - 0168-1923
VL - 205
SP - 11
EP - 22
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
ER -