植物生态学报 ›› 2015, Vol. 39 ›› Issue (10): 1012-1020.DOI: 10.17521/cjpe.2015.0098

所属专题: 生态化学计量

• • 上一篇    下一篇

土壤有机碳对外源氮添加的响应及其机制

李嵘1,2, 常瑞英1,*()   

  1. 1中国科学院水利部成都山地灾害与环境研究所山地表生过程与生态调控重点实验室, 成都 610041
    2中国科学院大学, 北京 100049
  • 出版日期:2015-10-01 发布日期:2015-10-24
  • 通讯作者: 常瑞英
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学青年基金(41301219)和中国科学院“西部之光”人才培养计划西部博士资助项目

Effects of external nitrogen additions on soil organic carbon dynamics and the mechanism

LI Rong1,2, CHANG Rui-Ying1,*()   

  1. 1Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2015-10-01 Published:2015-10-24
  • Contact: Rui-Ying CHANG
  • About author:

    # Co-first authors

摘要:

土壤有机碳库是陆地生态系统碳库的重要组成, 在全球碳循环中发挥着重要的作用。受元素化学计量平衡调控作用, 氮输入的增加将会对土壤有机碳库产生重要影响。然而, 目前关于陆地生态系统碳库对氮添加的响应主要集中在植被碳库, 对土壤碳库研究较少, 且研究结论争议较大, 尤其对其响应机制缺少系统梳理。该文作者通过对已有文献进行梳理, 认为生态系统类型、土壤碳变化的检测方法、土壤深度, 以及土壤稳定性碳和易变碳含量的差异可能是造成当前研究土壤碳汇增量(每克氮输入所增加的碳)差异的重要原因。氮添加条件下土壤有机碳的积累机制可能包括3个方面: 1)氮添加增加了凋落物输入, 促进了碳积累; 2)氮添加减少土壤碳输出, 尤其是抑制了稳定性碳的分解; 3)促进土壤腐殖质及稳定性碳的形成。此外, 该文结合当前研究中存在的不足, 提出今后需加强对深层土壤碳、土壤可溶性有机碳的淋溶及吸附, 以及不同土壤碳组分对氮添加的响应研究, 并通过改进检测方法减少氮添加条件下碳储量的测量误差。

关键词: 外源氮添加, 易变碳, 稳定性碳, 土壤固碳, 化学计量平衡

Abstract:

What would be the impact of external nitrogen additions on soil carbon, an issue still under debating, as reported experimental results were either positive, negtive or neutral. Several factors may be related to these seemingly controversial results: differences in ecosystem types and soil properties, soil carbon detection methods, soil depths, and contents of soil labile and recalcitrant carbon that affect the responses to nitrogen additions, all could cause discrepancies and variations in carbon sequestration. The several processes that contribute to enhance soil organic carbon storage include increasing litter input, decresing soil carbon output, particularly, by supressed decomposition of recalcitrant carbon, promoting soil humifiction and formation of recalcitrant carbon storage. However, there are still many uncertainties associated with these issues. To improve our understanding, the research about carbon in deep soil layers, dissolved organic carbon leaching and accumulation, and the effect of labile and recalcitrant soil C ratios on N addition responses, should be further investigated in the future studies.

Key words: external nitrogen addition, labile carbon, recalcitrant carbon, soil organic carbon sequestration, stoichemical balance