西藏地区C·N·P生态化学计量学研究进展

Research Progress of Ecological Stoichiometry of C,N,P in Xizang

生态化学计量学是从生态系统能量和元素平衡的角度,揭示元素在生物地球化学循环以及生态系统对环境变化的调控机制。总结近年来在我国西藏地区针对植物、凋落物、土壤和土壤微生物量C、N、P生态化学计量及其对环境变化的响应方面的研究成果,并对未来的研究方向进行展望。相关研究表明,植物-凋落物-土壤-土壤微生物系统C、N、P化学计量具有较强相关性,并受生物因子、非生物因子和人类活动的显著影响。植物生长主要受N元素的限制,C、P极度下降时N含量升高,植物通过自我调节能力表现出较强的竞争力和较高的内稳性;土壤养分表现出一定的“表聚性”效应;受海拔高度和温度的影响,微生物对凋落物的分解速率下降,可在一定程度上解释高海拔地区土壤肥力较贫瘠的原因。关于植物-凋落物-土壤-土壤微生物系统生态化学计量学的研究,今后可在多尺度、不同生态系统下进行长期的、多因子交互控制试验的研究。

From the point of view of ecosystem energy and elemental balance,eco-chemometrics reveals the biogeochemical cycle of elements and the mechanism by which ecosystems regulate environmental change.This paper summarizes the recent achievements in ecological chemistry measurement of plants,litter,soil and soil microorganisms C,N,P and their response to environmental change in Xizang,and puts forward the future research direction.The results show that the plant-litter-soil-microbe system C,N and P in plant litter has a strong correlation and is significantly influenced by biological factors,abiotic factors and human activities.Plant growth is mainly restricted by N element,N content is higher when C and P are in extreme decline,and plants show strong competitiveness and high internal stability through self-regulating ability.Soil nutrients show a certain“surface aggregation”effect.Under the influence of altitude and temperature,microbial decomposition rate of litter decreases,which may explain the poor soil fertility in high elevation areas.The research on ecological stoichiometry of plant litter soil microbial system can be conducted in long-term,multi factor interactive control experiments at multiple scales and different ecosystems in the future.