[Niche and Interspecific Association of Phytoplankton Dominant Species at Different Hydrological Periods in Xiaoche River, Guizhou Province].

To understand the niche and interspecific association of phytoplankton in different hydrological periods of the Xiaoche River in Guizhou Province, phytoplankton samples were collected in two different hydrological periods （dry period and wet period） from 2020 to 2022. The niche width （），niche overlap（），variance ratio method（VR），chisquare test（）, AC test, and Jaccard index （JI） were used to analyze the niche and interspecific association of phytoplankton dominant species. The results showed that a total of 7 phyla and 50 species of phytoplankton were identified in the Xiaoche River, with 4 phyla and 12 species being the dominant species.