Response of terrestrial carbon uptake to climate interannual variability in China
Response of terrestrial carbon uptake to climate interannual variability in China
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DOI：
10.1046/j.1365-2486.2003.00617.x
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发表时间：
2003-04-01
影响因子：
11.6
通讯作者：
Shao, XM
中科院分区：
文献类型：
--
作者：
Cao, MK;Prince, SD;Shao, XM
由于《京都议定书》将一些陆地碳汇纳入了控制温室气体排放的具有法律约束力的框架，各国对陆地生态系统碳预算的兴趣一直在增加。陆地碳汇的准确量化必须考虑到与气候变率和变化有关的年际变化。利用基于过程的生物地球化学模型和基于遥感的生产效率模型，估算了1981—2000年气候变率和大气CO2增加对中国净初级生产量（NPP）、土壤异养呼吸（HR）和净生态系统生产量（NEP）的影响。结果表明：1981—1998年，中国陆地NPP变化在2.86 ~ 3.37 Gt C yr（-1）之间，年增长率为0.32% (-1)；HR变化在2.89 ~ 3.21 Gt C yr（-1）之间，年增长率为0.40%（-1）。HR的增加主要与变暖有关，而NPP的增加则归因于降水和大气CO2的增加。净生态系统产量（NEP）在-0.32 ~ 0.25 Gt C /年（-1）之间变化，平均值为0.07 Gt C /年（-1），导致植被碳积累为0.79 Gt，土壤碳积累为0.43 Gt。对于NEP的年际变化，干旱的华北地区NPP的贡献大于HR，而湿润的华南地区NPP的贡献较小。新经济政策在统计上没有显著的变化趋势，但90年代的年平均新经济政策低于80年代，因为南方新经济政策的增加被北方新经济政策的减少所抵消。这些估计表明，中国陆地生态系统正在吸收碳，但持续的气候变化削弱了这种能力。估算的与气候变化和大气CO2增加相关的NEP可能占中国陆地碳汇总量的40% ~ 80%。
The interest in national terrestrial ecosystem carbon budgets has been increasing because the Kyoto Protocol has included some terrestrial carbon sinks in a legally binding framework for controlling greenhouse gases emissions. Accurate quantification of the terrestrial carbon sink must account the interannual variations associated with climate variability and change. This study used a process-based biogeochemical model and a remote sensing-based production efficiency model to estimate the variations in net primary production (NPP), soil heterotrophic respiration (HR), and net ecosystem production (NEP) caused by climate variability and atmospheric CO2 increases in China during the period 1981-2000. The results show that China's terrestrial NPP varied between 2.86 and 3.37 Gt C yr(-1) with a growth rate of 0.32% year(-1) and HR varied between 2.89 and 3.21 Gt C yr(-1) with a growth rate of 0.40% year(-1) in the period 1981-1998. Whereas the increases in HR were related mainly to warming, the increases in NPP were attributed to increases in precipitation and atmospheric CO2 . Net ecosystem production (NEP) varied between -0.32 and 0.25 Gt C yr(-1) with a mean value of 0.07 Gt C yr(-1), leading to carbon accumulation of 0.79 Gt in vegetation and 0.43 Gt in soils during the period. To the interannual variations in NEP changes in NPP contributed more than HR in arid northern China but less in moist southern China. NEP had no a statistically significant trend, but the mean annual NEP for the 1990s was lower than for the 1980s as the increases in NEP in southern China were offset by the decreases in northern China. These estimates indicate that China's terrestrial ecosystems were taking up carbon but the capacity was undermined by the ongoing climate change. The estimated NEP related to climate variation and atmospheric CO2 increases may account for from 40 to 80% to the total terrestrial carbon sink in China.