Climate Sensitivities of Carbon Turnover Times in Soil and Vegetation: Understanding Their Effects on Forest Carbon Sequestration
Climate Sensitivities of Carbon Turnover Times in Soil and Vegetation: Understanding Their Effects on Forest Carbon Sequestration
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土壤和植被碳周转时间的气候敏感性：理解其对森林碳固定的影响
DOI：
10.1029/2020jg005880
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
R. Ge;Honglin He;Li Zhang;X. Ren;M. Williams;Guirui Yu;T. Luke Smallman;Tao Zhou;Pan Li;Zongqiang Xie;Silong Wang;Huimin Wang;Guoyi Zhou;Qibin Zhang;An-zhi Wang;Z. Fan;Yiping Zhang;W. Shen;H. Yin;Luxiang Lin
中科院分区：
文献类型：
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作者：
R. Ge;Honglin He;Li Zhang;X. Ren;M. Williams;Guirui Yu;T. Luke Smallman;Tao Zhou;Pan Li;Zongqiang Xie;Silong Wang;Huimin Wang;Guoyi Zhou;Qibin Zhang;An-zhi Wang;Z. Fan;Yiping Zhang;W. Shen;H. Yin;Luxiang Lin
陆地碳循环对气候响应的高度不确定性主要由生态系统碳周转时间（τeco）决定。尽管τeco与气候的关系已被广泛研究，但在主要生物量库（τveg）和土壤库（τsoil）周转时间的气候敏感性差异方面仍存在重大知识空白，气候变化下它们对植被和土壤固碳的影响也知之甚少。在这里，我们从中国10个森林的永久样地收集了土壤和植被C的多个时间序列观测数据，并使用模型-数据融合来检索调节τsoil和τveg的关键C循环过程参数。分析表明，τveg和τsoil均随温度和降水量的增加而减小，τsoil的敏感性（1.27年/℃，1.70年/100 mm）是τveg（0.53年/℃，0.40年/100 mm）的两倍多。τ土的气候敏感性较高，在温暖湿润条件下，τ土的下降速度快于τveg，从而显著减小了τ土与τveg之间的差异（τdiff）。τdiff是反映土壤碳输入和输出之间平衡的指标，对土壤固碳量的变化（超过50%）有很大的影响。因此，在温暖和潮湿的条件下，较小的τdiff表明土壤固碳的贡献相对较低。这些信息对于理解森林碳气候反馈、预测气候变化下森林碳汇在土壤和植被中的分布以及在森林种植或土壤保护中实施碳减排政策具有重要意义。
The high uncertainty associated with the response of terrestrial carbon (C) cycle to climate is dominated by ecosystem C turnover time (τeco). Although the relationship between τeco and climate has been extensively studied, significant knowledge gaps remain regarding the differential climate sensitivities of turnover time in major biomass (τveg) and soil (τsoil) pools, and their effects on vegetation and soil C sequestration under climate change are poorly understood. Here, we collected multiple time series observations on soil and vegetation C from permanent plots in 10 Chinese forests and used model‐data fusion to retrieve key C cycle process parameters that regulate τsoil and τveg. Our analysis showed that τveg and τsoil both decreased with increasing temperature and precipitation, and τsoil was more than twice as sensitive (1.27 years/°C, 1.70 years/100 mm) than τveg (0.53 years/°C, 0.40 years/100 mm). The higher climate sensitivity of τsoil caused a more rapid decrease in τsoil than in τveg with increasing temperature and precipitation, thereby significantly reducing the difference between τsoil and τveg (τdiff) under warm and humid conditions. τdiff, an indicator of the balance between the soil C input and exit rate, was strongly responsible for the variation (more than 50%) in soil C sequestration. Therefore, a smaller τdiff under warm and humid conditions suggests a relatively lower contribution from soil C sequestration. This information has strong implications for understanding forest C‐climate feedback, predicting forest C sink distributions in soil and vegetation under climate change, and implementing C mitigation policies in forest plantations or soil conservation.