The Relationship Between Plant Functional Diversity And Primary Productivity In Desert Steppe Of Inner Mongolia

The relationship between biodiversity and ecosystem function is one of the hot topics of ecological research in recent years. Traditional research was generally studied by focusing on species diversity, but there is a growing considerable interest in exploring the biodiversity-ecosystem function relationship by using the concept of functional traits and functional diversity at present. Natural ecosystem is effected by the biotic and environmental filters that constraining species diversity of natural ecosystems and have a long-time scale, which play an important role in the study of biodiversity-ecosystem functions. Temperate grassland and forest ecosystems have been carried out related researches. In this paper, took the desert steppe in Inner Mongolia for example, studied the impact of plant functional diversity on the community primary productivity.In this thesis, established54plots and obtained the community productivity (aboveground biomass) data by vegetation inverstigation at the peak of vegetation biomass. Meanwhile, plant functional traits of plant height, aboveground weight, leaf size and leaf dry weight were measured, and calculated the specific leaf area and specific leaf weight, then obtained the plant functional traits data. We caculated the mean trait value and plant functional diversity, aiming at exploring the relationship between plant functional traits, plant functional diversity and community primary productivity through regression analysis.The main results are as follows:(1) The plant in desert steppe is dwarf, and it’s indicators about aboveground weight, leaf size, leaf dry weight, specific leaf area were lower.(2) Plant height, aboveground weight, leaf size and leaf dry weight were significant positive correlated with community primary productivity; there were no signidicant correlation between specific leaf area, specific leaf weight and community primary productivity.(3) Functioanl evenness was significant negative correlated with community primary productivity; Functional richness、 Fucntional divergence were not significant correlated with community primary productivity, supported the"mass ratio" hypothesis.(4) Plant functional diversity, based on single trait and muitiple traits, were not significant correlated with community primary productivity.(5) In summary, desert steppe in Inner Mongolia, the impact of functional diversity on communities primary productivity was small; functional traits had a greater impact on primary productivity, and the functional traits of dominant species determine the productivity of communities.Drought climate, low community productivity and fragile ecological environment are the obvious characteristics in desert steppe of Inner Mongolia, which make it more sensitive to the diveristy changes. The functional traits of dominant species control the community primary productivity in desert steppe. Therefore, in order to maintain the ecosystem primary productivity in desert steppe, should pay more attention to the dominant species in management strategies.