Effects of aridification on soil total carbon pools in China's drylands
Effects of aridification on soil total carbon pools in China's drylands
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DOI：
10.1111/gcb.17091
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发表时间：
2024-01-01
影响因子：
11.6
通讯作者：
Stringer，Lindsay C.
中科院分区：
文献类型：
--
作者：
Ren，Zhuobing;Li，Changjia;Stringer，Lindsay C.
旱地是重要的碳库，极易受到气候变化的影响，特别是在干旱日益严重的情况下。然而，干旱化对土壤全碳（包括有机碳和无机碳）的影响研究较少，这阻碍了对旱地土壤碳动态的全面认识和预测。为确定土壤全碳对干旱化的响应，以及干旱化如何通过不同生态系统属性驱动土壤全碳沿着干旱度梯度的变化，测定了中国北方干旱区4000 km干旱度梯度上土壤有机碳、无机碳和全碳的含量。分析了有机碳、无机碳和全碳在沿着干旱梯度不同位置的分布格局。结果表明，土壤有机碳和无机碳之间存在互补关系，即半干旱-超干旱区土壤无机碳的增加正补偿了有机碳的减少。土壤全碳随干旱度的增加呈非线性变化，在0.71的干旱度水平上，土壤全碳受干旱度的影响由负向正转变。在不太干旱的地区，干旱化导致总碳减少，主要是通过减少有机碳，而在更干旱的地区，干旱化促进无机碳的增加，从而增加总碳。我们的研究强调了土壤无机碳对总碳的重要性以及干旱对旱地土壤碳库的不同影响。在制定保护陆地碳汇的措施时，需要考虑土壤总碳。
Drylands are important carbon pools and are highly vulnerable to climate change, particularly in the context of increasing aridity. However, there has been limited research on the effects of aridification on soil total carbon including soil organic carbon and soil inorganic carbon, which hinders comprehensive understanding and projection of soil carbon dynamics in drylands. To determine the response of soil total carbon to aridification, and to understand how aridification drives soil total carbon variation along the aridity gradient through different ecosystem attributes, we measured soil organic carbon, inorganic carbon and total carbon across a ~4000 km aridity gradient in the drylands of northern China. Distribution patterns of organic carbon, inorganic carbon, and total carbon at different sites along the aridity gradient were analyzed. Results showed that soil organic carbon and inorganic carbon had a complementary relationship, that is, an increase in soil inorganic carbon positively compensated for the decrease in organic carbon in semiarid to hyperarid regions. Soil total carbon exhibited a nonlinear change with increasing aridity, and the effect of aridity on total carbon shifted from negative to positive at an aridity level of 0.71. In less arid regions, aridification leads to a decrease in total carbon, mainly through a decrease in organic carbon, whereas in more arid regions, aridification promotes an increase in inorganic carbon and thus an increase in total carbon. Our study highlights the importance of soil inorganic carbon to total carbon and the different effects of aridity on soil carbon pools in drylands. Soil total carbon needs to be considered when developing measures to conserve the terrestrial carbon sink.