氮沉降对凋落物分解的影响研究进展

过去几十年的人类活动增加了陆地生态系统的氮输入量,对凋落物分解的影响有促进、抑制和没有影响3种情况。凋落物的基质质量影响凋落物的分解,其中木质素、纤维素、酚类物质、N浓度、P浓度、C/N比、C/P比、木质素/N比具有重要作用。人类活动引起的全球变化,如CO2增加、温度上升和降水变化,影响了氮沉降的速率和凋落物分解。未来氮沉降对凋落物分解的研究热点包括加强氮沉降对热带与亚热带森林凋落物和阔叶树种凋落物分解影响的研究,氮沉降对凋落物分解影响研究的长期化,采用13C同位素研究凋落物分解,注重凋落物分解对氮沉降与大气CO2浓度升高、气候变暖、降水变化、紫外线辐射增强、P沉降交互作用响应的研究。

Research Progress in the Effect of Nitrogen Deposition on Litter Decomposition

Human activities in the past decades have increased the nitrogen input in terrestrial ecosystem, which has created 3 kinds of effect on litter decomposition, including promoting effect, restraining effect and no effect. Litter decomposition is affected by the substrate quality of the litter, including lignin, cellulose, phenolics, N concentration, P concentration, C/N ratio, C/P ratio and lignin/N ratio. The global changes (such as elevated CO₂, global warming, changes in precipitation) resulted from anthropogenic activities have affected the rate of N deposition and litter decomposition. The future research hotspots in the regard include the effect of N deposition on litter decomposition in the tropical forests and subtropical forests and on the decomposition of litter of broad-leaf species, a long-term effect of nitrogen deposition on litter decomposition, using¹³C isotope to study litter decomposition, and the interactions between N deposition and elevated atmospheric CO₂, global warming, changes in precipitation, elevated ultraviolet, phosphorus sedimentation.