Data for: Key bacterial groups maintain stream multifunctionality in response to episodic drying

Microbial biodiversity is fundamental to maintain ecosystem functioning in seasonally variable ecosystems. However, it remains unclear how alterations in water availability caused by seasonal drying compromise the ability of stream microbes to maintain multiple functions simultaneously (i.e., multifunctionality). Using data from 32 streams, we investigated how the phenology of seasonal drying influences stream microbial biodiversity and their capacity to sustain multifunctionality. Our results showed that stream multifunctionality and most bacteria did not respond to changes in drying phenology. Only two bacterial groups, the drying-resistant Sphingobacteriia and the drying-sensitive Acidobacteria_Gp7, exhibited positive associations with multifunctionality, whereas bacterial diversity showed a negative correlation with functions. Among these biodiversity aspects, Sphingobacteriia showed the strongest capacity to maintain multifunctionality at low and moderate performance levels. Our findings will help to better understand the mechanisms through which biodiversity sustains the functioning of seasonally variable streams and their responses to global change.

微生物生物多样性（microbial biodiversity）是维持季节性波动生态系统功能运转的核心基础。然而，目前学界尚未明确，季节性干旱引发的可利用水量变化，会如何削弱溪流微生物同时维持多种生态功能，即多功能性（multifunctionality）的能力。本研究依托32条溪流的观测数据，探究了季节性干旱的物候（phenology）特征如何影响溪流微生物生物多样性及其维持多功能性的能力。研究结果显示，溪流多功能性与多数细菌类群均未随干旱物候的变化产生显著响应。仅两类细菌类群——抗干旱的鞘脂杆菌纲（Sphingobacteriia）与干旱敏感型的酸杆菌Gp7群（Acidobacteria_Gp7）——与多功能性呈显著正相关，而细菌多样性则与生态功能呈负相关。在上述生物多样性维度中，鞘脂杆菌纲在低、中等功能水平下，展现出最强的维持多功能性的能力。本研究结果有助于更深入地阐明生物多样性维持季节性波动溪流生态功能的内在机制，以及溪流生态系统对全球变化的响应模式。