| The alpine zone is a harsh environment and significantly affected by climate change.Exploring the geographic distribution patterns of plant community diversity in the alpine zone and its influencing factors is of great significance for the conservation and utilization of species diversity.In this paper,we analyzed the species composition and community structure of plant communities in the alpine zones of China based on 223 field plant community samples along the elevation gradient,and analyzed the distribution patterns of diversity and their relationships with environmental factors in terms of species diversity,functional diversity and phylogenetic diversity.The main study findings are as follows:1.Based on the field plant community survey,we found that there are 48 families,157 genera and 322 species of plants in the region,with the dominant species being Cyperaceae,Polygonaceae,Fabaceae,Poaceae,Rosaceae and Salicaceae.In terms of different alpine distribution characteristics,the families with a global distribution are Poaceae,Asteraceae,Polygonaceae,Gentianaceae,and Rosaceae.2.The altitudinal distribution patterns of species richness in different high mountains were different,and most of them showed a decreasing trend.Overall,species richness showed a decreasing trend followed by an increasing trend.Species α-diversity showed a significant increasing trend with both annual mean temperature and annual precipitation,and the speciesα-diversity index showed a significant decreasing trend on the latitudinal gradient.The β-diversity of plant communities in different alpine zones showed different trends with increasing altitude.Climate,soil fertility and topography factors explained more than 49% of the species diversity indices,and hydrothermal conditions were the most important factors shaping the species diversity distribution patterns in the alpine zones of China.3.The distribution pattern of functional diversity of plant communities in the alpine zones of China shows a significant decreasing trend in functional richness and functional diversity with increasing altitude,and a single-peaked trend in functional evenness,with a distinct vertical pattern.In the hydrothermal gradient,both functional richness index and functional evenness showed a significant decreasing trend as the mean annual temperature increased,and functional evenness showed a significant decreasing trend as the annual precipitation increased;there were significant differences in plant traits among different alpine zones;climatic factors and topographic factors mainly influenced the functional diversity of plant communities in the Chinese alpine zones through soil fertility factors,explaining 69% of the functional richness and only 27% of the functional evenness,and soil fertility conditions were the most important factors in shaping the functional diversity of plant communities in the Chinese alpine zones.Soil fertility conditions are the most important factors shaping the functional diversity of plant communities in the alpine zones of China.4.The phylogenetic structure of plant communities in the Chinese alpine zone is complex,and the overall phylogenetic structure shows an aggregated state;phylogenetic diversity shows a significant upward trend with increasing mean annual temperature and annual precipitation,a significant downward trend with increasing latitude,and a significant downward trend along the elevation;climate factors,soil fertility factors and topographic factors explain 59% of the PD index,and hydrothermal conditions are the main influencing factors shaping the distribution pattern of phylogenetic diversity in the Chinese alpine zones.5.The distribution pattern of plant community diversity in the alpine zones of China is determined by environmental filtering factors rather than evolutionary history.Water and temperature conditions and soil nutrient conditions are the main limiting factors.This paper aims to elucidate the species composition,community structure and diversity distribution patterns of plant communities in the alpine zones of China and their influencing factors,identify priority areas for plant community diversity conservation,and understand the drivers of plant community diversity,so as to provide a theoretical basis for the conservation of wild plant resources in the alpine zones of China. |
