植物根系分解及其对生物和非生物因素的响应机理研究进展

Plant root decomposition and its responses to biotic and abiotic factors

植物根系在生态系统物质循环和能量流动过程中具有重要意义,其分解是固定于植物体内的物质返回土壤和大气环境的重要过程,受生物和非生物等多重因子影响。其中:生物因素方面,根系化学特征是影响根分解的主要因素,根系寿命、直径、菌根及物种差异等生物因素主要是通过改变根系化学性质产生作用,根系分泌物、土壤微生物等主要通过改变分解者的数量和活性影响根系分解。非生物因素方面,水热因子是影响根分解的关键。另外,在全球变化背景下,大气氮沉降、CO_2浓度增加等因素也对植物根系分解产生影响。本文从植物根系分解过程和影响根分解的因素两方面,综述了植物根系分解过程中物质释放规律,总结和归纳了主要生物和非生物因素对植物根系分解的影响机理,并对根系分解的研究进行展望。

The plant root system plays an important role in ecosystem matter exchange and energy flux,and root decomposition is one of the main contributors to these processes.Matter accumulates in roots and is then released back into the roots＇ surroundings,including the atmosphere and soil,via the decomposition process.Root decomposition is affected by multiple biotic and abiotic factors.In terms of biotic factors,the chemical characteristics of roots are among the main factors affecting their decomposition.Other factors such as root lifespan,size/diameter,and the abundance and types of fungi and other microbes in soil also affect plant root decomposition,and their effects can be explained by their ability to alter the chemical characteristics of plant roots.Root exudates and changes in the abundance and activities of soil microorganisms that degrade plant roots affect the root decomposition rate.In terms of abiotic factors,water and temperature are the main factors affecting root decomposition.Other factors related to climate change,for example,nitrogen deposition and carbon dioxide concentrations,will affect the root decomposition rate to different degrees,the extent of which is currently unknown.In this study,we reviewed the process of matter release during plant root decomposition,and summarized the current knowledge on how different biotic and abiotic factors affect plant root decomposition.Finally,we proposed some related perspectives based on the current status of plant root decomposition research.