This paper aims to provide an overview of regional carbon fluxes and budgets in the marginal seas adjacent to China.The "China Seas" includes primarily the South China Sea, East China Sea, Yellow Sea, and th...This paper aims to provide an overview of regional carbon fluxes and budgets in the marginal seas adjacent to China.The "China Seas" includes primarily the South China Sea, East China Sea, Yellow Sea, and the Bohai Sea. Emphasis is given to CO_2 fluxes across the air-sea interface and their controls. The net flux of CO_2 degassing from the China Seas is estimated to be9.5±53 Tg C yr^(-1). The total riverine carbon flux through estuaries to the China Seas is estimated as 59.6±6.4 Tg C yr^(-1). Chinese estuaries annually emit 0.74±0.02 Tg C as CO_2 to the atmosphere. Additionally, there is a very large net carbon influx from the Western Pacific to the China Seas, amounting to ～2.5 Pg C yr^(-1). As a first-order estimate, the total export flux of particulate organic carbon from the upper ocean of the China Seas is 240±80 Tg C yr^(-1). This review also attempts to examine current knowledge gaps to promote a better understanding of the carbon cycle in this important region.展开更多
Using dark enclosed chamber technique, CO2 fluxes from meadow, Leymus chinensis grasslandand Stipa grandis grassland and major environmental factors were measured in Xilin RiverBasin of Inner Mongolia under abnormally...Using dark enclosed chamber technique, CO2 fluxes from meadow, Leymus chinensis grasslandand Stipa grandis grassland and major environmental factors were measured in Xilin RiverBasin of Inner Mongolia under abnormally dry circumstances during June to September2001, when rainfall was less than 1/6 of that in normal years. Results showed the diurnalvariation of CO2 flux was significantly positively correlated with the earths surfacetemperature and air temperature. As to the response of the fluxes of CO2 to annualprecipitation, the average CO2 emission decreased from 268.7, 211.6 to 181.4 mg m-2 h-1 inmeadow, Leymus chinensis grassland and Stipa grandis grassland, respectively, with adecrease in annual precipitation. Therefore precipitation was an important environmentalfactor influencing CO2 flux from grassland. We also found close positively correlationbetween CO2 emissions and soil water content, organic content and total nitrogen contentin different soil layers. However, there was little correlation between the monthlyfluctuation of CO2 emissions with air temperature, topsoil temperature and soil temperaturesat 5 and 10cm soil depth.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.91328202 & 91428308)the Major Scientific Research Program of the Ministry of Science and Technology (Grant No. 2015CB954001)+1 种基金the Marine Public Welfare Project of the State Oceanic Administration (Grant No. 201505003-3)the Global Change Program (Grant No. GASI-0301-02-02)
文摘This paper aims to provide an overview of regional carbon fluxes and budgets in the marginal seas adjacent to China.The "China Seas" includes primarily the South China Sea, East China Sea, Yellow Sea, and the Bohai Sea. Emphasis is given to CO_2 fluxes across the air-sea interface and their controls. The net flux of CO_2 degassing from the China Seas is estimated to be9.5±53 Tg C yr^(-1). The total riverine carbon flux through estuaries to the China Seas is estimated as 59.6±6.4 Tg C yr^(-1). Chinese estuaries annually emit 0.74±0.02 Tg C as CO_2 to the atmosphere. Additionally, there is a very large net carbon influx from the Western Pacific to the China Seas, amounting to ～2.5 Pg C yr^(-1). As a first-order estimate, the total export flux of particulate organic carbon from the upper ocean of the China Seas is 240±80 Tg C yr^(-1). This review also attempts to examine current knowledge gaps to promote a better understanding of the carbon cycle in this important region.
基金supported by the Project of Carbon Cycle and Driving Mechanisms in Chinese Terrestria1 Ecosvstem(2002CB412503)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX1-SW-01-04)the Innovationa1 Proj ect of the Institute of Geoqraphical Sciences and Natural Resources Research of Chinese Academy of Sciences(CXIOG-E01-03-01).
文摘Using dark enclosed chamber technique, CO2 fluxes from meadow, Leymus chinensis grasslandand Stipa grandis grassland and major environmental factors were measured in Xilin RiverBasin of Inner Mongolia under abnormally dry circumstances during June to September2001, when rainfall was less than 1/6 of that in normal years. Results showed the diurnalvariation of CO2 flux was significantly positively correlated with the earths surfacetemperature and air temperature. As to the response of the fluxes of CO2 to annualprecipitation, the average CO2 emission decreased from 268.7, 211.6 to 181.4 mg m-2 h-1 inmeadow, Leymus chinensis grassland and Stipa grandis grassland, respectively, with adecrease in annual precipitation. Therefore precipitation was an important environmentalfactor influencing CO2 flux from grassland. We also found close positively correlationbetween CO2 emissions and soil water content, organic content and total nitrogen contentin different soil layers. However, there was little correlation between the monthlyfluctuation of CO2 emissions with air temperature, topsoil temperature and soil temperaturesat 5 and 10cm soil depth.
