Inland water bodies,being the most active biogeochemical cycle reactors,play a pivotal role in the global carbon cycle and CO_(2) budget.This study integrates existing observation dataset of CO_(2) flux(fCO_(2))in riv...Inland water bodies,being the most active biogeochemical cycle reactors,play a pivotal role in the global carbon cycle and CO_(2) budget.This study integrates existing observation dataset of CO_(2) flux(fCO_(2))in rivers,lakes and reservoirs in China,to elucidate their spatial-temporal patterns and key influencing factors and to reappraise the significance for regional carbon balance.It showed that,the fCO_(2) in rivers,lakes and reservoirs in China presented significant variability with large range of-379.3-4947.6,-160.1-785.0 and -74.0-1603.1 mg CO_(2)m-2h^(-1),respectively.The median of the fCO_(2) in rivers was of 228.5 mg CO_(2)m^(-2)h^(-1),observably higher than these in lakes and reservoirs(26.0 and 28.3 mg CO_(2)m^(-2)h^(-1),respectively).The fCO_(2)in rivers and reservoirs exhibited similar decreasing trend from south to north as a result of universal climate restraint,the averaged fCO_(2) in Pearl River and Yangtze River basins showed much higher than that in Northeastern rivers.While,the averaged fCO_(2) in the Mongolia-Xinjiang lake district and the Northeast lake district were higher than other lake districts,followed by the Qinghai-Xizang lake district,and the Eastern and Yungui lake district were generally low,contradicting the climatic restriction.The water primary production enhancement resulting from human activities was the main driver of spatial variation in the fCO_(2) in lakes.Meanwhile,the fCO_(2) in rivers presented seasonal pattern with higher wet season than dry season,while opposite patterns were found in lakes and reservoirs.Seasonal temperature,precipitation and water primary production were main factors.Furthermore,it showed pH was a key factor indicating the variability of the fCO_(2) levels either in rivers,lakes or in reservoirs.In lakes,the fCO_(2) is closely linked to chlorophyll a(Chl-a)and dissolved oxygen(DO),whereas,the fCO_(2) in rivers is primarily associated with organic carbon(OC)and total nitrogen(TN),highlighting the diverse controlling mechanisms of fCO_(2) in various展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32371680,41807321)the Natural Science Foundation of Chongqing(Grant No.2022NSCQMSX2598)the Science and Technology Project of Chongqing Education Commission(Grant Nos.KJQN202200536,KJZD-K202000502)。
文摘Inland water bodies,being the most active biogeochemical cycle reactors,play a pivotal role in the global carbon cycle and CO_(2) budget.This study integrates existing observation dataset of CO_(2) flux(fCO_(2))in rivers,lakes and reservoirs in China,to elucidate their spatial-temporal patterns and key influencing factors and to reappraise the significance for regional carbon balance.It showed that,the fCO_(2) in rivers,lakes and reservoirs in China presented significant variability with large range of-379.3-4947.6,-160.1-785.0 and -74.0-1603.1 mg CO_(2)m-2h^(-1),respectively.The median of the fCO_(2) in rivers was of 228.5 mg CO_(2)m^(-2)h^(-1),observably higher than these in lakes and reservoirs(26.0 and 28.3 mg CO_(2)m^(-2)h^(-1),respectively).The fCO_(2)in rivers and reservoirs exhibited similar decreasing trend from south to north as a result of universal climate restraint,the averaged fCO_(2) in Pearl River and Yangtze River basins showed much higher than that in Northeastern rivers.While,the averaged fCO_(2) in the Mongolia-Xinjiang lake district and the Northeast lake district were higher than other lake districts,followed by the Qinghai-Xizang lake district,and the Eastern and Yungui lake district were generally low,contradicting the climatic restriction.The water primary production enhancement resulting from human activities was the main driver of spatial variation in the fCO_(2) in lakes.Meanwhile,the fCO_(2) in rivers presented seasonal pattern with higher wet season than dry season,while opposite patterns were found in lakes and reservoirs.Seasonal temperature,precipitation and water primary production were main factors.Furthermore,it showed pH was a key factor indicating the variability of the fCO_(2) levels either in rivers,lakes or in reservoirs.In lakes,the fCO_(2) is closely linked to chlorophyll a(Chl-a)and dissolved oxygen(DO),whereas,the fCO_(2) in rivers is primarily associated with organic carbon(OC)and total nitrogen(TN),highlighting the diverse controlling mechanisms of fCO_(2) in various
