Reconciling multiple impacts of nitrogen enrichment on soil carbon: plant, microbial and geochemical controls
Reconciling multiple impacts of nitrogen enrichment on soil carbon: plant, microbial and geochemical controls
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协调氮富集对土壤碳的多重影响：植物、微生物和地球化学控制
DOI：
10.1111/ele.13083
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发表时间：
2018
期刊：
影响因子：
8.8
通讯作者：
Hu Shuijin
中科院分区：
文献类型：
--
作者：
Ye Chenglong;Chen Dima;Hall Steven J.;Pan Shang;Yan Xuebin;Bai Tongshuo;Guo Hui;Zhang Yi;Bai Yongfei;Hu Shuijin
活性氮（N）输入对生态系统碳（C）动态的影响是高度可变的，其内在机制尚不清楚。在这里，我们提出了一个新的概念框架，整合植物，微生物和地球化学机制，以协调不同的和对比的影响，N对土壤C。在蒙古草原草原上，使用长期的N富集和酸添加实验对该框架进行了测试。不同的机制可以解释N对颗粒和矿物相关的土壤C库的影响，可能解释以前的N添加研究之间的差异。虽然植物生产主导了颗粒碳的变化，但氮诱导的土壤酸化通过减少微生物生长以及铁和铝矿物与碳之间的pH敏感性关系，强烈影响矿物相关碳。我们的研究结果表明，氮诱导酸化对微生物呼吸和地球化学性质的影响应包括在地球系统模型中，预测未来氮沉降/输入情景下的生态系统C预算。
Impacts of reactive nitrogen (N) inputs on ecosystem carbon (C) dynamics are highly variable, and the underlying mechanisms remain unclear. Here, we proposed a new conceptual framework that integrates plant, microbial and geochemical mechanisms to reconcile diverse and contrasting impacts of N on soil C. This framework was tested using long‐term N enrichment and acid addition experiments in a Mongolian steppe grassland. Distinct mechanisms could explain effects of N on particulate and mineral‐associated soil C pools, potentially explaining discrepancies among previous N addition studies. While plant production predominated particulate C changes, N‐induced soil acidification strongly affected mineral‐associated C through decreased microbial growth and pH‐sensitive associations between iron and aluminium minerals and C. Our findings suggest that effects of N‐induced acidification on microbial respiration and geochemical properties should be included in Earth system models that predict ecosystem C budgets under future N deposition/input scenarios.