渤海兴城-觉华岛海域海草床典型生物群落特征及其关键环境因子识别

海草床是近海重要、高产的生态系统，发挥着净化水质、维持生物多样性等多种生态功能．本文以渤海辽东湾觉华岛海域海草床为研究对象，分别于2020年8月和10月开展了海草床夏、秋两季的典型生物群落调查，阐明了该区域海草（鳗草（Zostera marina L.））、浮游植物、浮游动物、底栖生物等群落结构特征及时空差异，揭示了海草床典型生物群落特征与环境因子的响应关系．研究结果显示:觉华岛海域鳗草在夏季的茎枝长度、茎枝密度、生物量均显著高于秋季(P<0.05)；海草床内典型生物群落夏秋两季的Shannon-Wiener指数（H′）、Margalef丰富度指数（D′）、Pielou均匀度指数（J）分别在1.09~1.77、0.46~1.17、0.65~0.88间波动；其中浮游植物的H'在夏季低于秋季，而浮游动物和底栖动物均呈现相反趋势．RDA分析表明:沉积物沙含量、水体无机氮和pH是该区域海草生态学指标变化的主要环境因子；而水体总磷、无机氮和溶解氧是海草床内浮游生物和底栖生物群落特征变化的主要环境因子． 

Characteristics of typical biological communities and identification of key environmental factors in the seagrass bed of Xingcheng-Juehua Island,Bohai Sea

Seagrass bed is one of the most crucial and productive coastal ecosystems, with multiple ecological functions such as water purification and biodiversity maintenance．We surveyed typical biological communities, including Zostera marina L., phytoplankton, zooplankton and zoobenthos, in seagrass beds in August and October 2020 in Juehua Island, Liaodong Bay, to analyze seasonal and spatial difference, and key environmental factors．The length, density, and biomass of Zostera marina L.．in summer were found to be significantly higher than in autumn (P < 0.05)．Shannon-Wiener index (H'), Margalef index (D'), Pielou index (J) of communities in the seagrass bed fluctuated from 1.09 to 1.77, 0.46 to 1.17, and 0.65 to 0.88, respectively．Shannon-Wiener index (H') of phytoplankton, zooplankton and zoobenthos were found to be lower, higher and significantly higher in summer than in autumn．RDA analysis found that sediment sand content, water inorganic nitrogen, and pH were significant factors for seagrass, but total phosphorus, inorganic nitrogen, and dissolved oxygen in seawater were significant for phytoplankton, zooplankton and zoobenthos in seagrass bed．