Analysis of ecological niche and interspecific associations among dominant zooplankton species in the major lakes of Yinchuan City, China

Zooplankton are crucial primary consumers in lake ecosystems, and clarifying their niche characteristics and interspecific relationships is vital for comprehending species interactions and improving community stability. We conducted a seasonal study in 2020 on zooplankton and associated physicochemical parameters in representative lakes of Yinchuan City. Using niche width, niche overlap, variance ratio, Chi-square test, and association coefficient, we mainly analyzed the ecological niches of dominant species and their interspecific associations. The findings indicated 46 zooplankton species across four main phyla, with the dominant species counts in January, April, July, and October being 7, 20, 20, and 18, respectively. The primary factors fluctuated during the months. In total, five factors demonstrated the most significant explanatory capacity: DO, EC, NO₂^--N, F^-, and Cl^-. The niche breadth and overlap of the dominating species suggested that populations were less restricted and more environmentally adaptive across spatiotemporal resource dimensions than within a single dimension. A substantial nonlinear positive connection existed between niche overlap and the association coefficient. Twelve environmental parameters contributed to 38.1%, 6.6%, 37.5%, and 47.5% of the overall change in the abundance of dominating species in January, April, July, and October, respectively. This work serves as a fundamental reference for multidimensional niche research and for trend analysis of community succession.