叶片凋落物分解的主场优势研究进展

Research progress on home-field advantage of leaf litter decomposition

凋落物在原生生境(“主场”)中比在非原生生境(“客场”)中分解得更快的现象被称为凋落物分解的“主场优势”。探究凋落物分解的主场优势的主要影响因素及驱动机制对预测植物养分的归还过程和生态系统碳收支有重要意义。该文主要从主场优势的计算方法、影响因素及驱动机制出发,综述了近年来凋落物分解的主场优势的研究进展,并对未来的研究方向进行了展望。度量凋落物分解的主场优势有4种常见的计算方法,其中采用线性模型计算主场优势在当前最为合适。凋落物质量(化学成分等)、土壤微生物群落结构是影响凋落物分解的主场优势的主要因素,土壤动物、气候条件、分解时间、植物生活型及生长型也能改变主场优势的强度。凋落物之间质量差异越大,产生的主场优势越大。土壤微生物群落驱动着凋落物分解的主场优势,但其作用时常受到动物的干扰及气候的制约。此外,带有叶际微生物的凋落物比去除了叶际微生物的凋落物有更强的主场优势。凋落物化学性质趋同假说、分解者控制假说及凋落物质量与环境相互作用假说是解释主场优势产生的主要假说,但它们均有不足之处。该文认为凋落物和土壤微生物的协同作用可能是产生和驱动主场优势的主要机制。当前的研究存在着各因素对主场优势的影响探究不够深入、关注的生态系统类型较为单一等问题,在未来的研究中需要进一步深入探究各因素对主场优势效应的影响及其相对贡献,关注更多不同的生态系统类型,从而增强对主场优势相关机制的理解。

Litter often decomposes more rapidly in its native habitat(“home”)than in non-native habitats(“away”),a phenomenon called the“home-field advantage”.To explore the driving mechanism of home-field advantage of litter decomposition is important to predict the process of plant nutrient return and ecosystem carbon budget.This study reviewed the research progress on the home-field advantage of litter decomposition in recent years by discussing the quantification of home-field advantage,the controlling factors,and related driving mechanisms.There are four common metrics to describe home-field advantage in litter decomposition,and the use of linear model analysis to calculate home-field advantage is more appropriate.Litter quality(chemical composition,etc.)and soil microbial community structure are the main factors influencing the home-field advantage of litter decomposition,and soil fauna,climatic conditions,decomposition time,plant life form and growth form can also influence the intensity of the home-field advantage.Greater differences in litter quality usually generate stronger home-field advantage.Microbial taxa in the soil drive the home-field advantage of litter decomposition,but the role of soil microbes is often mediated by animal and climatic disturbances.In addition,the existence of phyllosphere microbes makes the home-field advantage of litter decomposition stronger.The litter chemical convergence hypothesis,decomposer control hypothesis and substrate quality-matrix quality interaction hypothesis are major hypotheses explaining the home-field advantage in litter decomposition,but they are not impeccable.We believe that the association between litter and soil microbial community is the driving force behind home-field advantage.The current researches on the factors and relative contribution of home-field advantage are not deep enough and usually focusing on a single ecosystem.Future investigations should explore deeper on the factors and their relative contributions of home-field advantage,and focus on more ecosystem types to improve the understandings of the mechanism of home-field advantage.