Effects of Long-Term Variability of Plant Species and Functional Groups on Stability of a Leymus chinensis Community in the Xilin River Basin, Inner Mongolia
Abstract:The long-term variability of plant species, functional groups and compensatory effects between functional groups within a Leymus chinensis community were studied during 1980-1999 in the Xilin River Basin of Inner Mongolia. The results showed that long-term variability of aboveground biomass decreased from the plant species level to the functional group and community levels. Plant species and functional composition were the principal factors explaining the long-term variation in production of the community. There were obvious compensatory effects in the dynamics of biomass between perennial bunch grasses and perennial rhizome grasses and forbs, between xerads and intermediate xerads, and between intermediate mesophytes and mesophytes. Longterm variability in the biomass of populations seems to depend on the sensitivity of species to environmental fluctuations and amplification of environmental fluctuations by interactions among species. Biodiversity may increase community stability by promoting diversity among species due to their differentiated responses to environmental fluctuations, and by compensatory effects among plant functional groups.