SPATIAL DISTRIBUTION PATTERN OF FISH MULTIFACETED BIODIVERSITY IN THE LONGYANGXIA RESERVOIR

To understand the status and the spatial distribution pattern of fish multidimensional biodiversity, we conducted a survey on fish resources in Longyangxia Reservoir in June 2022. Three types of data, including the presence or absence of fish species, the number and biomass of individuals, were used to analyze the status and spatial distribution of species diversity, phylogenetic and functional diversity of fish in Longyangxia Reservoir. A total of 2416 specimens weighing 94.24 kg belonging to 4 orders, 7 families, 17 genera and 19 species were collected. Among these, 8 species were native, while 11 species were exotic. Compared to historical research, the native species in Longyangxia Reservoir decreased, while the number of exotic species increased significantly. There are differences in the distribution of species diversity, phylogenetic diversity, and functional diversity calculated based on the three data types. Specifically, the species richness was the highest in the head region of the reservoir, followed by the tail region and the middle region, while the number of individuals and biomass gradually decreased from the tail region to the head region. The phylogenetic diversity based on the three data types was the highest in the middle region. The functional diversity calculated based on the presence or absence of species and the number of individuals was the highest in the tail region, while the functional diversity calculated based on biomass data was the highest in the head region. The regression analysis showed that the phylogenetic diversity of fish in Longyangxia Reservoir was significantly affected by exotic species, while the changes in species diversity and functional diversity were not correlated with the distance from the dam and the number of exotic species.