Ecology of microbial communities in lake ecosystems in transition

微生物在分类、系统发育和新陈代谢方面具有高度的多样性，在湖泊的功能和营养结构中发挥着重要作用。由于气候变化，湖泊生态系统的结构、完整性以及与周围景观的连通性正在经历快速和重大的扰动。然而，对于这些变化如何以及在多大程度上改变这些社区的多样性和功能，我们仍然知之甚少。因此，确定影响湖泊微生物群(分类群和功能的微生物网络)的机制对于了解微生物群落在预测湖泊生态系统将如何对新的或不断变化的选择力量作出反应方面的作用至关重要。我未来五年的研究计划的主要目标是调查微生物群落在塑造湖泊对环境变化的反应中所起的作用。在这里，考虑到许多北方湖泊最近的增加及其对细菌过程和湖泊功能的重要性，这项研究将使用溶解有机物(DOM)的变化作为环境变化的替代。我将通过解决三个短期目标来实现这一NSERC-Discovery目标：1)识别和比较不同DOM含量的北部湖泊典型的核心微生物群；2)评估DOM来源对湖泊核心微生物群组成和功能的影响；以及3)评估群落组成对湖泊微生物群对DOM变化的功能响应的作用。为此，我将制定一个概念框架，以便能够确定湖泊中的核心微生物群，并在实证研究和实地调查中结合使用下一代测序和单细胞技术。针对这些目标的研究计划将被组织为四个不同的HQP项目(2个PhD，2个MSc)，以评估DOM变化对微生物群落组成和新陈代谢以及湖泊功能的影响，从而为预测微生物群落和生态系统对气候和景观变化的响应提供信息。该研究项目的多学科性质将提供一个向所有人开放的工作和研究环境，这将促进多样性和公平性，鼓励女性和其他代表性不足的群体参与，并将为学生提供广泛的技能，使他们在毕业后获得广泛的理科就业选择。这项计划代表着对环境变化如何不仅扰乱水生微生物群落结构，而且扰乱湖泊生态系统功能的综合理解迈出的关键一步。

Microbes are highly diverse taxonomically, phylogenetically, and metabolically and play a major role in the functioning and trophic structure in lakes. Lake ecosystems are undergoing rapid and major perturbations in their structure, integrity and connectivity with their surrounding landscape as a result of climate change. Yet, we still know very little on how and to what extent these changes may alter the diversity and functioning of these communities. Identifying the mechanisms affecting lake microbiomes (microbial networks of taxa and functions) is therefore pivotal for understanding the role of microbial communities in predicting how lake ecosystems will respond to novel or changing selective forces. The primary goal of my research program for the next five years is to investigate the role of microbial communities in shaping the response of lakes to environmental change. Here, the research will use changes in dissolved organic matter (DOM) as a proxy for environmental change given recent increase in many northern lakes and its importance for bacterial processes and lakes functioning. I will meet this NSERC-Discovery goal by addressing three short-term objectives: 1) Identify and compare the core microbiomes typical of northern lake of varying DOM content 2) Assess the influence of DOM source on lake core microbiomes composition and functioning, and 3) Assess the role of community composition on lake microbiome functional response to change in DOM. To this end, I will develop a conceptual framework that allow the identification of core microbiome in lakes and combine the use of next generation sequencing and single-cell technologies in empirical studies and field-based surveys. The research program targeting these objectives will be organized as four distinct HQP projects (2 PhD, 2 MSc) to evaluate the influence of changes in DOM on microbial community composition and metabolism as well as lake functioning, therefore providing information to forecast the response of microbial communities and ecosystems to changing climate and landscapes. The multidisciplinary nature of this research program will provide a work and research environment open to all that will promote diversity and equity and encourage the participation of women and other underrepresented groups and will provide students with broad skills for a wide range of science employment options after they graduate. This program represents a crucial step towards an integrative understanding of how environmental change may disrupt not only the structure of aquatic microbial communities, but also the functioning of lake ecosystems.