Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China.
Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, 650500, China; Southwest United Graduate School, Kunming, 650500, Yunnan, China.
Environ Res. 2024 Sep 15;257:119410. doi: 10.1016/j.envres.2024.119410. Epub 2024 Jun 11.
Microorganisms are crucial components of freshwater ecosystems. Understanding the microbial community assembly processes and niche characteristics in freshwater ecosystems, which are poorly understood, is crucial for evaluating microbial ecological roles. The Yunnan Plateau lakes in China represent a freshwater ecosystem that is experiencing eutrophication due to anthropogenic activities. Here, variation in the assembly and niche characteristics of both prokaryotic and microeukaryotic communities was explored in Yunnan Plateau lakes across two seasons (dry season and rainy season) to determine the impacts of rainfall and environmental conditions on the microbial community and niche. The results showed that the environmental heterogeneity of the lakes decreased in the rainy season compared to the dry season. The microbial (bacterial and microeukaryotic) α-diversity significantly decreased during the rainy season. Deterministic processes were found to dominate microbial community assembly in both seasons. β-Diversity decomposition analysis revealed that microbial community compositional dissimilarities were dominated by species replacement processes. The co-occurrence networks indicated reduced species complexity for microbes and a destabilized network for prokaryotes prior to rainfall, while the opposite was found for microeukaryotes following rainfall. Microbial niche breadth decreased significantly in the rainy season. In addition, lower prokaryotic niche overlap, but greater microeukaryotic niche overlap, was observed after rainfall. Rainfall and environmental conditions significantly affected the microbial community assembly and niche characteristics. It can be concluded that rainfall and external pollutant input during the seasonal transition alter the lake environment, thereby regulating the microbial community and niche in these lakes. Our findings offer new insight into microbiota assembly and niche patterns in plateau lakes, further deepening the understanding of freshwater ecosystem functioning.
微生物是淡水生态系统的重要组成部分。了解淡水生态系统中微生物群落组装过程和生态位特征至关重要，因为这些过程和特征目前了解甚少，而这对于评估微生物的生态作用至关重要。中国云南高原湖泊是一个受到人为活动影响而富营养化的淡水生态系统。本研究以云南高原湖泊为研究对象，在两个季节（旱季和雨季）探索了原核生物和微型真核生物群落的组装和生态位特征的变化，以确定降雨和环境条件对微生物群落和生态位的影响。结果表明，与旱季相比，雨季湖泊的环境异质性降低。雨季微生物（细菌和微型真核生物）α多样性显著降低。在两个季节中，确定性过程都主导着微生物群落的组装。β多样性分解分析表明，微生物群落组成差异主要由物种替代过程驱动。共生网络分析表明，降雨前微生物的物种复杂性降低，原核生物网络不稳定，而降雨后微型真核生物则相反。雨季微生物生态位宽度显著降低。此外，雨季观测到原核生物生态位重叠降低，而微型真核生物生态位重叠增加。降雨和环境条件显著影响了微生物群落的组装和生态位特征。综上所述，季节性过渡期间的降雨和外部污染物输入改变了湖泊环境，从而调节了这些湖泊中的微生物群落和生态位。本研究结果为高原湖泊中的微生物群落组装和生态位模式提供了新的见解，进一步深化了对淡水生态系统功能的理解。
