[Seasonal characteristics of CO2 fluxes from the paddy ecosystem in subtropical region].
CO2 fluxes from paddy ecosystem in subtropical hilly region were measured continuously using eddy covariance technique. Based on data rejecting, correcting and filling, the daily and annual CO2 fluxes were calculated from the instantaneous values, respectively. The objectives were to investigate the variation of CO2 fluxes on seasonal temporal scale, analyze the relationship between CO2 fluxes and environmental factors, and to quantify the annual net ecosystem exchange (NEE) from the paddy ecosystem. Results show the values of GPP, R(eco) and NEE are higher from Jun. to Sep. and lower in the other months. The NEE from May to Sep. accounted for above 80% of the annual value and is crucial to the whole annual value. Photosynthetically active radiation (PAR) and mean daily air temperature (T(a)) were two main influential factors for controlling the seasonal trend of GPP and NEE and could be described by binary linear functions, respectively. The annual NEE in paddy ecosystem was 2 475.6 g/(m2 x a). This is showed that paddy ecosystem was a carbon sink for the atmosphere in subtropical region.
Zhu
Yong-Li
YL
Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China. zhuyongli76@126.com
Tong
Cheng-Li
CL
Wu
Jin-Shui
JS
Wang
Ke-Lin
KL
Wang
Qin-Xue
QX
Ren
Xiu-E
XE
D002245:Carbon Dioxide / Q000378:metabolism*; D017753:Ecosystem; D012275:Oryza / Q000254:growth & development / Q000378:metabolism*; D012621:Seasons; D014329:Tropical Climate
D002245:Carbon Dioxide