Priming effect and its regulating factors for fast and slow soil organic carbon pools:A meta-analysis
Priming effect and its regulating factors for fast and slow soil organic carbon pools:A meta-analysis
复制标题
快、慢土壤有机碳库启动效应及其调控因素的荟萃分析
DOI：
10.1016/s1002-0160(21)60064-4
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发表时间：
2022
期刊：
影响因子：
5.7
通讯作者：
Cheng Weixin
中科院分区：
文献类型：
--
作者：
Huo Changfu;Liang Junyi;Zhang Weidong;Wang Peng;Cheng Weixin
启动效应（PE）在控制土壤碳循环中起着重要作用，并影响着新鲜碳输入对土壤有机碳分解的影响。然而，由于个体研究的结果不同，快速和慢速SOC池的PE驱动因素仍不清楚。使用荟萃分析与提升回归树（BRT）分析相结合，我们评估了PE与底物的多个驱动因素及其模式在每个驱动因素梯度中的相对贡献。结果表明，快SOC库的PE变异性大于慢SOC库。BRT分析的基础上，67%和34%的PE的变化解释了快速和慢速SOC池，分别。影响土壤有机碳快速库的PE因子有7个，其中土壤全氮含量最重要，其次依次为基质碳氮比、土壤水分、土壤粘粒含量、土壤pH、基质添加率和有机碳含量。当土壤全氮含量低于2g kg-1和基质C：N比低于20时，PE的方向为负，但随着这两个因子水平的增加，PE的方向由负向正转变。具有最佳含水量（持水量的50%-70%）或适度低pH值（5-6）的土壤易于产生更大的PE。对于慢SOC库，土壤pH和土壤全N含量基本上解释了PE的变化。PE的幅度可能会随着土壤pH值的增加而降低，为缓慢的SOC库。此外，PE的幅度略有波动与土壤氮含量的缓慢SOC库。总体而言，这项荟萃分析为不同SOC池的独特PE提供了新的见解，并指出了慢SOC池的PE及其调节因素之间的知识差距。
The priming effect (PE) plays a critical role in the control of soil carbon (C) cycling and influences the alteration of soil organic C (SOC) decomposition by fresh C input. However, drivers of PE for the fast and slow SOC pools remain unclear because of the varying results from individual studies. Using meta-analysis in combination with boosted regression tree (BRT) analysis, we evaluated the relative contribution of multiple drivers of PE with substrate and their patterns across each driver gradient. The results showed that the variability of PE was larger for the fast SOC pool than for the slow SOC pool. Based on the BRT analysis, 67% and 34% of the variation in PE were explained for the fast and slow SOC pools, respectively. There were seven determinants of PE for the fast SOC pool, with soil total nitrogen (N) content being the most important, followed by, in a descending order, substrate C:N ratio, soil moisture, soil clay content, soil pH, substrate addition rate, and SOC content. The directions of PE were negative when soil total N content and substrate C:N ratio were below 2 g kg~(-1) and 20, respectively, but the directions changed from negative to positive with increasing levels of this two factors. Soils with optimal water content (50%-70% of the water-holding capacity) or moderately low pH (5-6) were prone to producing a greater PE. For the slow SOC pool, soil pH and soil total N content substantially explained the variation in PE. The magnitude of PE was likely to decrease with increasing soil pH for the slow SOC pool. In addition, the magnitude of PE slightly fluctuated with soil N content for the slow SOC pool. Overall, this meta-analysis provided new insights into the distinctive PEs for different SOC pools and indicated knowledge gaps between PE and its regulating factors for the slow SOC pool.