植物功能多样性及其与生态系统功能关系研究进展

Research Advances in Plant Functional Diversity and Its Relationship with Ecosystem Functions

生物多样性影响生态系统的多种功能。生物多样性的急剧丧失使得对其影响评定尤为重要和紧迫,因此,生物多样性与生态系统功能关系成为生态学研究的热点问题之一,其中功能多样性与生态系统功能关系的研究成为近十年该领域研究的重点。文章首先概括了植物功能多样性的多种定义,并详细介绍了目前被广泛接受的定义"功能多样性是某一群落内物种间功能特征的变化范围或指特定生态系统中所有物种功能特征的数值和范围"。其次重点阐述了围绕植物功能多样性开展的5个重要研究论题:(1)分别从功能丰富度、功能均匀度、功能离散度3个方面介绍了功能多样性算法,并强调要注重多指数相结合以综合描述功能多样性;(2)植物功能性状间主要体现为权衡关系,植物功能性状受到了气候、土壤、海拔、地形地貌、放牧、土地利用方式等一系列因素的影响;(3)基于植物功能性状更有利于探讨环境过滤和相似性限制对群落构建的驱动作用;(4)功能多样性与物种多样性间呈现正相关、负相关和饱和曲线等一系列关系,之所以呈现不同关系与资源状况和外界干扰密切相关;(5)尽管很多研究都证明了功能多样性对生态系统功能具有正效应,但依然存在两个主要的争议,一方面是物种多样性、功能多样性在生态系统功能维持中的相对重要性,另一方面是选择效应与互补效应在功能多样性与生态系统功能关系中的适用性。最后,提出了该领域需要进一步深入开展的4个研究方向:开展多尺度研究、重视多营养级研究,加强野外观测与受控实验相结合的研究、深化生态系统多功能性的研究。

Biodiversity affects a variety of ecosystem functions.With the unprecedented loss of biodiversity it is urgent to evaluate its consequences for ecosystem functions.Thus,the relationship between biodiversity and ecosystem function has been a hot topic in ecology.Plant functional diversity,being an important component of biodiversity,has received great attention in the past 10 years.This paper reviews various definitions of functional diversity and focuses on the widely accepted one defining it as the range of inter-species functional traits of a community or functional traits of all species in a particular ecosystem.We highlight five key issues of functional diversity as follows.（1） Functional diversity can be divided into three aspects-functional richness,functional evenness,and functional divergence.It is most valuable to evaluate functional diversity by combining assessments of these three aspects.（2） Relationships between functional traits are dominated by trade-offs.Plant functional traits are influenced by such factors as climate,soil,elevation,topography,grazing,and land use patterns.（3） It is advantageous to explore the role of environment filtering and similar limitations on community assembly through the lenses of plant functional traits.（4） Relationships between plant functional diversity and species diversity can be either positive or negative,and it may exhibit a saturation curve pattern.These patterns are largely reflective of differences in resource conditions and disturbances.（5） Many experimental studies have proved the positive effects of functional biodiversity on ecosystem function.Nevertheless,controversial issues regarding the relative importance of functional and species diversities in maintaining ecosystem function still remain.The applicability of selection and complementary effects in explaining the relationship between functional diversity and ecosystem function still remains to be explored.This paper discusses four research directions to improve our understanding of this topic：（1） conduct multi-scale research;（2） analyze multi-trophic levels;（3） better integration of field observations with controlled experimentation;（4） ecosystem multi-functionality research.