土壤呼吸主要影响因素的研究进展

SOME ADVANCE IN THE MAIN FACTORS CONTROLLING SOIL RESPIRATION

影响土壤呼吸的因子有很多,在不同时间空间的不同生态系统其影响因子各不相同。综述了土壤呼吸主要影响因子的研究进展,主要从土壤温度、土壤湿度、降水、土壤C/N等非生物因子,植被类型、生物量、叶面积指数、植被凋落物等生物因子以及人类活动等方面阐述对土壤呼吸产生的影响。在此基础上对土壤呼吸的Q10值、关键影响因子及各种生态环境因子的综合影响进行了讨论。从众多研究中发现土壤温度、湿度是影响土壤呼吸的主要因子,建立土壤温度及湿度影响下的土壤呼吸模型更有助于对土壤呼吸进行定量的描述。但是在土壤温度及湿度过高或过低的情况下会出现较大的误差,为了尽量减少土壤呼吸的误差,给出了如下建议:①加强土壤呼吸和生态系统自动碳通量的结合研究;②加强对不同生物和非生物生态环境因子的同步测定,特别重视生物因子对非生物因子的调节和影响;③加强典型物候期和不同季节典型天气土壤呼吸的测定;④加强模拟试验研究和模式研究。总之,土壤呼吸是一个比较复杂的过程,虽然有规律可循,但是,很多时候由于因子间交互作用而表现偏离,对其准确估算需要找出关键因子,并综合分析其它因子的影响。

Soil respiration is influenced by many factors, which are different in a variety of spatio-temporal ecosystems. The objective of this paper is to review the main factors including abiotic factors such as the soil temperature, soil moisture, rainfall, soil C/N,biotic factors such as vegetation types, biomass, leaf area index, litter, and human activities as well. Based on the summarization, the Q10 of soil respiration, key controlling factors and interaction among different factors were discussed. Soil temperature, soil moisture are the key factors controlling soil respiration. So it is helpful to estimate the amount of soil respiration on the basis of modeling by these factors. However, the prediction has a limitation of underestimation and overestimation at low and high temperature or moisture conditions respectively. In order to acquire accurate estimation of soil respiration, main suggestions for further study are to: combine measurement of soil respiration by chamber with carbon flux of ecosystem by eddy covariance, measure synchronously the biotic and abiotic factors, especially pay more attention to the role of modification of biotic factors on the performance of abiotic controllers, make more measurement in typical plant phenology phase and different weather conditions, and strengthen experimental manipulation and modeling. In conclusion, soil respiration is a complex biochemical process, which is controlled by certain models although regulated by interactions among multi-factors. In order to get accurate modeling and prediction, key factors need to be sought and estimate synthetic influence of interactive factors.