Abstract: Laoshifuhai wetland is one of the alpine lakes in Shanxi Province. Understanding plant species composition, diversity, and their relationships with environmental factors is the prerequisite for indepth study of wetland communities. Based on the data of 28 plots (with a size of 1 m×1 m) of Laoshifuhai wetland, we analyzed species composition of plant communities in this area. We used cluster analysis, ordination analysis and diversity indices to explore the classification, characteristics and species diversity of wetland associations, as well as the relationship between plant community and environmental factors. The plant community in Laoshifuhai wetland could be classified into Polygonum tenellum+Heleocharis dulcis association, Hippuris vulgaris+Nymphoides peltatum association, Hippuris vulgaris+Polygonum hydropiper association,Hippuris vulgaris+Scirpus validus association and Polygonum hydropiper+Nymphoides peltatum association. Ass.Polygonum tenellum+Heleocharis dulcis had the highest Simpson diversity and the lowest evenness, while the Ass. Polygonum hydropiper+Nymphoides peltatum had the lowest Simpson diversitybut the highest evenness. The results of DCA ordination were consistent with the clustering results, with the first axis interpretation being the largest (53.29%), which reflected the change trend of plant associations’ water level from low to high. The PCA results showed that chemical oxygen demand  and water depth were the key environmental factors affecting the distribution of plant communities. Our results can provide scientific basis for the protection and restoration of Laoshifuhai wetlands.

Key words: plant community, environmental factor, ecological relationship, diversity.