Research on plant community characteristics and biodiversity in the whole section of the main stream of Baihe River in the upper reaches of the Yellow River

Recently, the lateral migration of curved rivers in the Zoige Plateau has become more and more prominent, with the formation of more and more band-shaped formed silt bodies (point-side beaches) on both banks of the river. As a result, the erosion of farmers and herdsmen’s grassland resources has become increasingly severe. Regional water conservation function has been significantly affected, threatening the ecological security, biodiversity protection, and economic development of animal husbandry in the upper reaches of the Yellow River. Thus, there is an urgent need to develop a treatment scheme for point-side beaches. This study takes the vegetation community along the whole section of the main stream of Baihe River in the upper reaches of the Yellow River as the research object. Using the typical sample plot method, typical sample plots were set along the concave and convex banks of the main stream of Baihe River to evaluate the characteristics and biodiversity of the plant community in the whole section of the main stream of Baihe River. Changes were identified in plant community characteristics along the section of the main stream of Baihe River, as well as the key role of vegetation factors in the formation of point-side beaches. The results showed that 1) spatial scale of trunk line: the vegetation community of the entire coastline of the main stream of the Baihe River has a total of 88 species of shrubs, grasses and vines, 70 genera, and 26 families, including 6 families, 8 genera, and 10 species of shrubs; 21 families, 62 genera, and 77 species of herbs; 1 family, 1 genus, and 1 species of Lianas. The herbaceous layer was the main body of species composition of the alpine shrub community on the shoreline of the main stream of the Baihe River. The plant population comprises mesophytes and wet mesophytes as the constructive species or dominant species. The community species, average height and coverage, and aboveground biomass of the herbaceous layer generally showed a gradual increase, and the species diversity showed a gradual decline; 2) spatial characteristics of concave and convex banks: the heterogeneity of the vegetation community in the riparian zone was marked. The vegetation types and species diversity index of the shrub layer were higher than those of the concave bank. Aboveground biomass and species diversity were higher in concave banks than in convex banks, and the heterogeneity of concave and convex banks in the middle and lower reaches was higher than that in the upstream. Therefore, different management measures should be employed for different river sections in the regulation of riparian beaches in the upper reaches of the Yellow River. In particular, the reasonable control of human activities, such as grazing, sand mining, and urban construction, and the interaction of riparian vegetation in the evolution of curved rivers should be reasonably managed. Lastly, attention should be paid to the two key areas of concave and convex banks.