What determines community stability in the Inner Mongolia typical grassland?

Relationship of diversity and ecosystem stability and its maintenance mechanism has been one of the hotspots in ecology. There are mainly three relationships between the diversity and stability: positive correlation, negative correlation and nonlinear relationshiphttp://www.cusabio.com/. Many hypothesized mechanisms of maintaining diversity and ecosystem function have been proposed, such as diversity-stability hypothesis, rivet-popping hypothesis, species redundancy hypothesis, idiosyncratic hypothesis, and keystone species hypothesis, etc. Among these, the redundancy hypothesis proposed by Walker has increasingly become an important concept in understanding the ecological values of biodiversity. This hypothesis believes that in a functional group which containing many species, the species often manifest functional redundancy, that is, some species present similar or identical features and these species show asynchronous response to environmental changes, or display a phenomenon of time niche differentiation, playing a role as insurance in maintaining system stability during interference. However, some scholars doubted the accuracy of the redundancy hypothesis, thus this hypothesis is not widely accepted. Although some studies on a large scale investigated the relationship between diversity and ecosystem functions in Inner Mongolia grassland, more studies focused on productivity, carbon sequestration and other functions, and there is a lack of description on ecosystem stability of this region. On the other hand, there are rare studies on small-scale landscape, while topography is the most important environmental factor of landscape scale, leading to re-distribution of resource in space and thereby affecting the diversity and ecosystem functions. Therefore, taking the example of Inner Mongolia typical steppe, this study analyzes changes of diversity and community stability as well as their relationship under different resource supply rate caused by micro-topography, and plans to solve the following scientific issues: (1) The type of relationship between the diversity and ecosystem stability in Inner Mongolia typical steppe. (2) To verify the usefulness of the redundancy hypothesis in this region and further investigate the relative importance of species redundancy and functional redundancy in maintaining the stability. It aims to provide scientific basis for rational restoration of degraded grassland and range management at the same time of enriching the theoretical studies of diversity and stability. The results are as following: The soil total N, total P, available N, and organic C in seven transacts showed increasing trend with decreasing slope position from the top to the base of hills, except the available phosphorus does not showed obvious change with decreasing slope position. Therefore, it was considered that overall soil resource supplement gradually increased with transacts. The Shannon-weaver species diversity index (SD) and reciprocal of variation coefficient of aboveground biomass (S) increased with decreasing slope position, representing that the species diversity and community stability increased with the resource supplement. Meanwhile, the regression analysis displayed the positive relationship between diversity and stability (R2=0.550，P > 0.05). The regression analysis of species redundancy and functional redundancy revealed the non-significant causal effect of species redundancy to functional redundancy (R2=0.223， P > 0.05). The regression analysis for species redundancy and functional redundancy with stability showed that both community redundancy indices were positively related with stability, and the functional redundancy presented significant causal relationship with stability (R2=0.893，P ˂ 0.01), while the species redundancy was displayed lower R2 value (R2=0.146，P > 0.05). In conclusion, Species redundancy and functional redundancy are two different features of community redundancy. Species redundancy and functional redundancy are two different features of community redundancy. Functional redundancy is more important in maintaining stability compared with the species redundancy. You may like to read this:http://www.cusabio.com/Polyclonal-Antibody/ATL3-Antibody-FITC-conjugated--11098195.html