Trends and advances in researches on plant functional diversity and functional groups

The paper reviewed the advances of studies on plant functional diversity and functional group related to ecosystem processes, function and stability. Classification of functional groups is mainly dependent upon physiology, morphology, life history, or other traits relevant to controls on an ecosystem process. Most functional classification schemes have their goals in predicting patterns in species distributions rather than in predicting the effects of diversity on the provision or maintenance of ecosystem function. In this sense, these schemes are more correctly labeled plant-ecology-strategy schemes than plant-function-strategy schemes. Although functional groups are not always clear-cut, they help to elucidate mechanisms by which plant species influence ecosystem processes, generalize such mechanisms across species, and simplify studies in systems with a high diversity of plant species. The links between plant diversity and ecosystem function remain highly controversial. There is a growing consensus, however, that functional diversity, rather than species numbers per se, strongly determines ecosystem function. Despite its importance, functional diversity has been studied in relatively few cases. Approaches based on both species richness and functional traits and types have been extremely productive in recent years, but attempts to connect their findings have been rare. Major advances have been made in describing the relationship between species diversity and ecosystem processes and functions, in identifying functionally important species, and in revealing the underlying mechanisms. Differences in plant composition explained more of the variation in production and nitrogen dynamics than did the number of species at present. It is possible to identify and differentiate among potential mechanisms underlying patterns of ecosystem response to variation in plant diversity with implications for resource management. Perhaps the most substantial contribution of the plant functional trait approach to ecosystem and community studies is that it would provide a much stronger insight into the links between community structure and ecosystem function than did the consideration of species richness alone. An integration of these two approaches is a promising way to gain mechanistic insight into the links between plant diversity and ecosystem processes and to contributing to practical management for the conservation of diversity and ecosystem services.