Influences of alpine meadow degradation on species diversity and abundance distribution of plant functional groups in Gannan

Abstract

[Objective] To investigate the response of species diversity and richness distribution of plant functional groups to degradation in the Gannan alpine meadow, we analyzed the community construction mechanism and resource utilization of different plant functional groups with the deepening of degradation. [Methods] We took the Gannan alpine meadow as the research object, collected the data by sample survey method, fitted the model of species multiplicity, and classified the community species by two-way cluster analysis. [Results] With the deepening of degradation, the vegetation species were dominated by gramineae and saxifragaceae, which were gradually changed to the domination of miscellaneous grasses. The functional group of the miscellaneous grasses played a dominant role in the distribution of the diversity of the community. The multidimensional distribution of all the species was changed with the deepening of degradation, in which the optimal fitting model for the non-degraded meadows was VOLKOV, for the mildly degraded meadows was GEO, and for the moderately and severely degraded meadows were BRO, where the resource allocation mode shifted from random to fixed allocation. The ecological niche model dominated the optimal fitting model for the grass functional group, and the resource allocation mode was dominated by both fixed and random allocation. The optimal fitting model for the legume functional group was BRO, and the resource allocation mode was dominated by fixed allocation. The optimal fitting model for the miscellaneous grass functional group shifted from neutral to neutral allocation mode. The optimal fitting model of the weed functional group shifted from neutral model to ecological niche model, consistent with the optimal model of the multidimensional distribution of all species. The resource allocation shifted from the random allocation to fixed allocation. [Conclusion] The weed functional group is the main reason influencing the multidimensional distribution of the community species. However, the contribution of the graminoid and legume functional groups should not be neglected.

Keywords

• alpine meadows
• degradation
• species abundance distribution
• plant functional groups
• ecological niche theory
• neutrality theory