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目前,由人类活动造成的陆地生态系统氮输入量已经远远超过了其自身的生物固氮,外源氮输入的增多已经并将继续对土壤有机碳矿化和凋落物分解产生影响。本文分析了国内外有关氮输入增多对土壤有机碳矿化和凋落物分解的影响及其机理:由于研究点环境状况不同,凋落物性质的差异和分解阶段的不同等原因,氮输入对土壤有机碳矿化的结果主要表现为抑制或促进作用;对凋落物分解的影响表现为促进、无影响和抑制三种效果,有关其作用机理还有待进一步深入研究。着重指出对于作为大气CO2“汇”的沼泽湿地,氮输入的增多能够对其碳“汇”功能产生影响,因此进行氮输入对湿地土壤有机碳矿化和凋落物分解方面的研究,对于探讨湿地碳循环对外源氮输入的响应及其机理非常重要。
At present, the input of nitrogen to terrestrial ecosystems caused by human activities has far exceeded its own biological nitrogen fixation. The increase of input of exogenous nitrogen has and will continue to affect the mineralization of soil organic carbon and litter decomposition. In this paper, the effects of nitrogen input on soil organic carbon mineralization and litter decomposition are analyzed both at home and abroad. Due to different environmental conditions at the research site, differences in litter properties and decomposition stages, the effect of nitrogen input on soil organic The main results of carbon mineralization are inhibition or promotion. The effects on litter decomposition are promoted, unaffected and inhibited. The mechanism of action is yet to be further studied. Emphatically pointed out that for the marsh wetland that is atmospheric CO 2 “sink ”, the increase of nitrogen input can affect its carbon sink function. Therefore, the study of nitrogen input for organic carbon mineralization and litter decomposition in wetland , It is very important to explore the response of wetland carbon cycle to the input of exogenous nitrogen and its mechanism.