Quantifying ecosystem-atmosphere carbon exchange with a 14C label
Quantifying ecosystem-atmosphere carbon exchange with a 14C label
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使用 14C 标签量化生态系统-大气碳交换
DOI：
10.1029/2002eo000187
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
J. Southon
中科院分区：
文献类型：
--
作者：
S. Trumbore;J. Gaudinski;P. Hanson;J. Southon
陆地生态系统作为大气碳源或汇的作用及其对大气CO2年际变化的贡献一直是人们争论的热点。碳通过光合作用这一单一过程进入陆地生态系统，但通过植物、动物和微生物的综合代谢活动返回大气层（图1）。在我们对陆地碳循环的理解中，最大的不确定性在于这些返回过程，特别是生态系统中的CO2损失如何在活植物的呼吸（称为自养呼吸）与微生物和动物对植物残体的分解（称为异养呼吸）之间分配（图1）;以及改变植物生理状态和土壤条件的季节和气候因素如何影响这种分配。
The role of terrestrial ecosystems as sources or sinks for carbon to the atmosphere and their contribution to inter-annual variations in atmospheric CO2 remain hotly-debated topics. Carbon enters terrestrial ecosystems through a single process, photosynthesis, but it is returned to the atmosphere by the combined metabolic activity of plants, animals, and microbes (Figure l). The largest uncertainties in our understanding of terrestrial carbon cycling are in these return processes, especially how CO2 losses from ecosystems are divided among respiration by living plants—termed autotrophic respiration—versus microbial and faunal decomposition of plant residues—termed heterotrophic respiration (Figure 1); and how seasonal and climatic factors that change plant physiological status and soil conditions influence that partitioning.