金泽水库库区细菌群落构建过程与关键驱动因子分析

为探究微污染水生态系统中细菌群落对人为干扰响应所依赖的生态机制,基于生态零模型(ecological null model),应用拟合分析(fitting analysis)研究了环境因子与金泽水库来水及库区不同区域间细菌群落构建过程的关系.结果表明,细菌群落在系统发育上的聚类比预期要分散得多(SES.MNTD的单样本t检验95%置信下限为9.79).温度是影响群落系统发育的重要因子.随机性过程(stochastic processes)和确定性过程(deterministic processes)在不同样品细菌群落演替中的相对重要性呈明显的季节性特征.春、夏和秋季样品细菌群落演替由随机性过程主导,冬季则由随机性过程和确定性过程共同主导.NH~+_4-N是影响随机性过程和确定性过程相对重要性的主要环境因子.NH~+_4-N浓度为0.06～0.40 mg·L~(-1)时,由随机性过程主导;NH~+_4-N浓度为0.40～0.80 mg·L~(-1)时,则由随机性过程和确定性过程共同主导.分散限制(61.68%)和异质选择(26.65%)在研究区域中不同采样点之间细菌群落变化中起到重要作用.

Phylogenetic Processes and Key Driving Factors of Bacterial Communities in Jinze Reservoir

To investigate the ecological mechanisms of the bacterial response to human disturbance in micro-polluted water ecosystems, we studied the relationship between the environmental factors and bacterial community development in the incoming water and various areas of a reservoir based on an ecological null model. The results showed that the phylogenetic clustering of bacterial communities was more dispersed than expected (the single-sample t-test of SES.MNTD has a 95% lower confidence limit of 9.79). Temperature is an important environmental factor affecting community phylogeny. The relative importance of stochastic and deterministic processes in the bacterial community succession of different samples showed seasonal characteristics. The bacterial community succession in spring, summer, and autumn samples was dominated by random and deterministic processes. NH₄⁺-N is the main environmental factor affecting the relative importance of random and deterministic processes. When the concentration of NH₄⁺-N is 0.06-0.40 mg ·L^-1, the bacterial community succession is dominated by random processes; when the concentration is 0.40-0.80 mg ·L^-1, it is dominated by both random and deterministic processes. Dispersal limitation (61.68%) and heterogeneous selection (26.65%) played important roles in bacterial community changes at different sampling points in the study area.