筑坝蓄水对不同水深浮游微生物群落结构和种间互作模式的影响

微生物群落之间通过直接或间接的关系相互作用，在生态过程中发挥重要作用，然而目前对于水库微生物种间互作模式的关注仍然较少.选择江苏省横山水库为研究区域，分别采集表层及深层水样，探究浮游微生物群落结构和分子生态网络对水深变化的响应规律，并辨识不同水深处浮游微生物群落的关键物种.结果发现，表层浮游微生物丰富度及均匀度均高于深层，且不同深度浮游微生物群落结构具有显著差异.水深通过改变环境异质性间接对浮游微生物群落产生影响，其中总有机碳（TOC）、硝酸盐（NO^-₃）、铵盐（NH⁺₄）和磷酸盐(PO₄^3-)等指标对浮游微生物群落结构影响最为显著.此外，深层浮游微生物分子生态网络的节点数和边数均显著高于表层，且深层浮游微生物群落中关键物种数目和种类均显著高于表层，表明深层浮游微生物群落网络规模更大，但表层浮游微生物群落种间协同合作关系和网络连通性更强.上述结果将为水库微生物群落种间相互作用研究提供科学依据，对预测水库生态系统中微生物的生态规律及全球物质循环影响具有重要意...

Effects of Damming and Impoundment on Planktonic Microbial Community Structure and Interspecific Interaction Patterns in Different Water Depths

Microbial communities play an important role in ecological processes through direct or indirect interactions. However, the interspecific interaction pattern of reservoir microorganisms has still received little attention. The Hengshan Reservoir in Jiangsu province was selected as the research area. Surface and deep water samples were collected to respectively explore the response of planktonic microbial community structure and the molecular ecological network to water depth changes, as well as to identify the key species of planktonic microbial communities in different water depths. The results showed that the richness and evenness of planktonic microorganisms in the surface layer were higher than those in the deep layer, and there were significant differences in the community structure of planktonic microorganisms in different depths. Water depth indirectly affected the planktonic microbial community by changing the environmental heterogeneity, among which the indicators such as TOC, NO₃^-, NH₄⁺, and PO₄^3- had the most significant impact on the planktonic microbial community structure. In addition, the number of nodes and edges of the deep planktonic microbial molecular ecological network were significantly higher than those on the surface, and the type and number of key species in the deep planktonic microbial community were significantly higher than those on the surface, indicating that the network scale of the deep planktonic microbial community was larger; however, the interspecific cooperative relationship and network connectivity of the surface planktonic microbial community were stronger. These results will provide a scientific basis for the study of interspecific interactions of reservoir microbial communities and are of great significance for predicting the ecological law of microorganisms in reservoir ecosystems and the impact of global material cycles.