氮添加对森林生态系统植物–土壤–微生物化学计量比影响的研究进展

Effects of Nitrogen Addition on Plant-Soil-Microorganism Stoichiometry Ratio of Forest Ecosystem: A Review

摘要: 人类活动引起大气氮沉降速率增加的问题虽有所改善，但仍影响着森林生态系统的物质循环。模拟施氮对中国森林生态系统化学计量比的影响多集中于植物、土壤和微生物的单一分析，对植物–土壤–微生物碳(C)、氮(N)和磷(P)化学计量特征及其耦合关系的研究较少。本文通过整合先前的研究结果，总结了外源氮输入后植物–土壤–微生物C、N和P化学计量特征的响应，结果发现，低浓度施氮有利于土壤主要养分和微生物量的积累，促进植物和微生物养分的吸收利用，高浓度施氮则相反。但对于C和P元素，则表现出不同的结果，C元素随着外源氮的输入而增加或不发生变化，而P元素则充满不确定性，表现为增加、不变或减少等3种结果，这主要是由于养分元素的限制和环境因素的变化所致。通过本文系统的整合，补充了森林生态系统中植物–土壤–微生物C、N、P化学计量特征耦合领域的知识缺失，可为深入认识和理解未来氮沉降对生态系统生物地球化学循环的影响提供理论依据。

Abstract: Although the problem of increasing atmospheric nitrogen deposition rate caused by human activities has been improved, it still affects the material cycle of forest ecosystems. The effects of simulated nitrogen application on the stoichiometric ratio of forest ecosystems in China are mostly focused on the single analysis of plants, soil and microorganisms, and there are few studies on the stoichiometric characteristics and coupling relationship of plant-soil-microbial carbon (C), nitrogen (N) and phosphorus (P). In this paper, we summarized the response of plant-soil-microorganism C, N and P stoichiometry characteristics after exogenous nitrogen input by integrating previous research results. The results showed that low concentration of nitrogen application was beneficial to the accumulation of soil main nutrients and microbial biomass, and promoted the absorption and utilization of plant and microbial nutrients, while high concentration of nitrogen application was the opposite. However, for C and P elements, different results are shown. C element increases or does not change with the input of exogenous nitrogen, while P element is full of uncertainty, showing three results of increase, constant or decrease, which is mainly due to the limitation of nutrient elements and the change of environmental factors. Through the systematic integration of this paper, the lack of knowledge in the field of plant-soil-microbial C, N and P stoichiometric characteristics coupling in forest ecosystems is supplemented, which can provide a theoretical basis for further understanding and understanding the impact of nitrogen deposition on ecosystem biogeochemical cycles in the future.