生物多样性是生态学的核心问题。传统的多样性指数仅包含物种数和相对多度的信息,这类基于分类学的多样性指数并不能很好地帮助理解群落构建和生态系统功能。不同物种对群落构建和生态系统功能所起到的作用类型和贡献也不完全相同,且物种在生态过程中的作用和贡献往往与性状密切相关,因此功能多样性已经成为反映物种群落构建、干扰以及环境因素对群落影响的重要指标。同时,由于亲缘关系相近的物种往往具有相似的性状,系统发育多样性也可以作为功能多样性的一个替代。功能多样性和系统发育多样性各自具有优缺点,但二者均比分类多样性更能揭示群落和生态系统的构建、维持与功能。
Understanding biodiversity is the central goal of ecology. Taxonomic diversity indices are not the only features of biodiversity, and they are hardly useful in revealing the ecological processes (i.e. species assemblage, disturbance and environmental gradients). Community assembly and ecosystem functioning were deterministic with respect to species traits, thus trait-based functional diversity has been the indicators of ecological processes. Closely related species often share similar traits through common ancestor, so phylogenetic diversity could often be a proxy of functional diversity. Both functional and phylogenetic diversity have their own advantages and limitations in revealing the community assembly and ecosystem functioning, despite that they both are superior to taxonomic diversity.