南岭自然保护区不同海拔梯度植物多样性分布格局OA北大核心CSTPCD

Studying the distribution patterns of plant diversity along altitudinal gradients is crucial for the successful restoration of forest vegetation and the conservation of species.To reveal the vertical distribution characteristics of plant diversity in mountainous areas,eight elevations(800,900,1000,1100,1200,1300,1400,and 1500 m)in Nanling Nature Reserve were studied.The distribution pattern of plant diversity at different elevations was analyzed,and the logarithmic Cauchy model was used to fit plant abundance at different elevations.The results showed that 1)there were 290 species belonging to 148 genera and 81 families in eight altitudinal gradient plots in Nanling.2)The species diversity of Nanling showed a"unimodal"trend along the altitude gradient,and the species diversity index(species richness index 157,Shannon-Wiener index 4.142,Pielou's evenness index 0.459)was highest at middle altitudes(1000-1300 m).The high-altitude areas(1300-1500 m)had the lowest species richness index(69),Shannon-Wiener index(2.317),and Pielou evenness index(0.197).3)The phylogenetic diversity of the tree layer(-2.918 to 0.762)differed from species diversity,and phylogenetic diversity showed a discrete structure in general.The environmental filtering effect played an important role in the construction of the Nanling forest community,and the competitive exclusion effect gradually appeared in the high-altitude forests.4)Habitat restriction and interspecific competition in the middle-and high-altitude communities may weaken the formation potential of dominant species in the tree layer but increase the coexistence probability of rare species in the community.In terms of species protection,humans severely disturb low altitudes,and it is recommended that an ecological red line be set at low altitudes(800-1000 m).High-altitude areas(1300-1500 m)of forest habitats are relatively poor,but are important habitats for many rare and endangered plants.Good growth conditions,such as reduced intensity of interspecific competition and an improved microclimate,should be created for these species.The results of this study deepen our understanding of the changes in plant community biodiversity in Nanling evergreen broad-leaved forests and contribute to the formulation of biodiversity conservation strategies in this region.