Genomic signatures of life-history traits and structural attributes in prokaryotic communities

Global change due to human activities causes an increasing number of disturbed ecosystems and poses a challenge to humanity because human life on earth depends on the stability of ecosystem services. Microorganisms are main drivers of element cycling, they contribute largely to the global organic carbon budget and are therefore a fundament for all biological processes and relevant for ecosystem services. They furthermore represent model organisms to test ecological theory, as they are small and have short generation times what facilitates the generation of comprehensive datasets for statistical evaluation. Earlier research points to the following mechanisms that support stability of community functioning in fluctuating environments: first, the tolerance of individual community members against environmental change impacts also the community-level robustness and the classification of individual community members along the generalist-specialist continuum may be a valuable tool to evaluate the vulnerability of a whole community in a disturbed environment. Secondly, there has been a long debate about the link of community structures, such as diversity patterns but also the architecture of species interactions to the vulnerability of these communities to environmental change. The genomic material of microbial communities represents a blueprint of their functioning and should contain the information about the tolerance of individual community members and concerning the above mentioned community structures.We use metagenome data from two aquatic sites that are contrasting concerning their environmental variability and their trophic status to explore parameters that can be delineated from metagenome data to characterize the community performance in response to environmental change.

人类活动引发的全球变化正导致受干扰生态系统的数量持续攀升，这对人类社会构成严峻挑战——因为地球上的人类生存依赖于生态系统服务的稳定性。微生物是元素地球化学循环的核心驱动者，它们对全球有机碳收支贡献巨大，因此是所有生物过程的基础，且与生态系统服务密切相关。此外，微生物体型微小、世代周期短，便于生成可用于统计评估的全面数据集，因此是检验生态学理论的理想模式生物。早期研究已揭示以下可维持波动环境中群落功能稳定性的机制：其一，群落内单个成员对环境变化扰动的耐受能力同样会影响群落层面的稳定性；而根据泛化-特化连续体（generalist-specialist continuum）对群落成员进行分类，或可成为评估受干扰环境中整个群落脆弱性的有效工具。其二，关于群落结构（如多样性模式）乃至物种互作网络结构与群落应对环境变化的脆弱性之间的关联，学界已展开长期讨论。微生物群落的基因组物质是其功能运作的蓝图，理应包含单个群落成员的耐受信息，以及与上述群落结构相关的信息。本研究使用来自两类环境变异性与营养状态均存在显著差异的水生生境的宏基因组（metagenome）数据，旨在探索可从宏基因组数据中解析得到的参数，用以表征群落应对环境变化的功能表现。