Response mechanism of bacterial community and physicochemical factors evolution to ecological restoration in sediment and water dual medium of Baiyangdian Lake

Abstract

Deciphering the response of lake planktonic bacterial and sedimentary bacteria to ecological restoration is essential for providing multi-habitat shallow lake governance. The dynamic changes of plankton, sedimentary bacteria, and environmental indicators were investigated from 2019 to 2023 in Baiyangdian Lake. The results indicate that ecological restoration in Baiyangdian Lake can effectively improve the quality of water environment. The alpha diversity of planktonic bacteria and sedimentary bacteria increased, with the highest values being 879.56 ± 125.09 and 2725.40 ± 238.09, respectively. With ecological restoration, there was no significant difference in bacterial community composition, but significant temporal heterogeneity (P < 0.05). The proportion of Norank_f_Anaerolineaceae gradually increases (1.70 %, 3.92 %, and 4.43 %), leading to a decrease in nitrogen in sediments. The environmental driving factors exhibited heterogeneity, while dissolved oxygen (DO) and weak acid extractable form nitrogen (WAEF-N) mainly played roles for the microbial community variation of water and sediment. The symbiotic network further showed that the planktonic bacterial network in 2021 and the sedimentary bacterial network in 2019 were the most complex and stable, with key taxa being the drivers of microbial community junction stability. There are significant similarities among bacterial subcommunities, and rare taxa (RT) are important components to maintain the stability and complexity of bacterial communities. Finally, with the implementation of ecological restoration, the similarity between planktonic and sedimentary bacterial communities increases, and the ecosystem is more stable. The results of this study enhance our understanding of the microbial changes and physicochemical factors evolution during ecological remediation processes.