照壁山水库浮游生物群落结构特征及其驱动因素研究OA

[Objective]Reservoir ecosystems in arid and semi-arid regions are highly sensitive to hydrological variability and nutrient loading.As key biological indicators of water quality,plankton communities reflect ecosystem responses to environmental change;however,the mechanisms underlying their assembly and environmental relationships remain insufficiently understood.This study aimed to characterize plankton community structure and elucidate its relationships with key water environmental factors in Zhaobishan Reservoir,Ningxia,China.[Method]Three field surveys were conducted in spring,summer,and autumn of 2023.Pearson correlation analysis,Mantel tests,and redundancy analysis(RDA)were applied to quantitatively assess the relationships between plankton communities and environmental factors.[Result]A total of 27 phytoplankton taxa belonging to 7 phyla were identified.Phytoplankton density exhibited significant seasonal variation,reaching a maximum in summer(62.75×104 ind./L),with Chlorophyta(40.74%)and Bacillariophyta(29.63%)as dominant groups.Thirteen zooplankton species were recorded,with an average density of 130.17×104 ind./L and a seasonal pattern of autumn＞spring＞summer.Rotifers dominated zooplankton abundance(54.61%),whereas copepods contributed the highest biomass(63.83%),indicating a clear community succession from small-sized rotifers to larger copepods and cladocerans.RDA results showed that environmental factors explained 71.86%and 64.22%of the variation in phytoplankton and zooplankton communities,respectively.[Conclusion]Plankton communities in Zhaobishan Reservoir exhibit pronounced spatiotemporal heterogeneity and ecological functional differentiation.Nitrite and total nitrogen were identified as the primary drivers of summer phytoplankton blooms,while dissolved oxygen and permanganate index significantly influenced zooplankton distribution patterns and community succession.These findings provide theoretical support and methodological reference for ecological assessment and water quality management of reservoirs in arid and semi-arid regions.