Dimensions: Collaborative research: Community genomic drivers of moss microbiome assembly and function in rapidly changing Alaskan ecosystems

苔藓及其相关微生物是北极生态系统营养循环的重要组成部分，但这些社区的许多方面知之甚少。苔藓相关微生物是北方和苔原生态系统中支持植物生长的氮的主要来源，这意味着植物生长的速率可能对苔藓及其微生物的活性高度敏感，苔藓及其微生物将大气中的氮“固定”为对植物生长有用的形式。重要的是，固氮速率以复杂的方式取决于苔藓的遗传多样性及其相关的微生物群落（微生物组）。然而，我们不知道哪些物种（苔藓或微生物）负责在这一关键的固氮地球化学过程中的速率变化，也不知道这些群落将如何应对气候变暖。这项工作将检验遗传变异与固氮作用之间的联系，以便模拟北方高纬度生物多样性和生态系统功能对气候变化的反应。这项研究将提供有关环境变化将如何影响北极生态系统的工具信息，并有助于深入了解苔藓及其相关微生物的弹性，拟议工作的目标是确定苔藓遗传多样性对两种广泛和丰富的苔藓在北方森林和北极苔原生态系统中的群落组装和固氮微生物功能的影响。研究人员将采用人口基因组学，功能基因测序和氮固定率的稳定同位素分析沿着阿拉斯加的大规模气候梯度，包括北极和北方长期生态研究（LTER）和国家环境观测网络（氖）网站。这种跨学科的方法将使研究人员能够确定这个快速变化的生态系统的社区组装和功能变化的历史和当代驱动因素，并预测在温暖的气候中，与硼镁石相关的固氮将如何变化。因此，研究人员将使用高纬度系统中的苔藓-微生物相互作用作为模型，为我们更广泛地了解生物多样性如何在气候变化的背景下与生态系统功能相互作用提供信息。

Mosses and their associated microbes are critical components of nutrient cycling in arctic ecosystems, yet many aspects of these communities are poorly understood. Moss-associated microbes are the major source of nitrogen to support plant growth in boreal and tundra ecosystems, meaning that rates of plant growth may be highly sensitive to the activity of mosses and their microbes, which "fix" nitrogen from the atmosphere into a form useful for plant growth. Importantly, the rates of nitrogen fixation depend in complex ways upon both the genetic diversity of the mosses and their associated microbial communities (microbiomes). However, we do not know which species (moss or microbial) are responsible for rate variation in this key biogeochemical process of nitrogen fixation, nor how these communities will function respond to a warming climate. This work will test for associations between genetic variation and nitrogen fixation in order to model the response of high northern latitude biodiversity and ecosystem function to climate change. The research will provide instrumental information about how environmental change will affect Arctic ecosystems and contribute insight into the resiliency of mosses and their associated microbiomes.The goal of the proposed work is to determine the effect of moss genetic diversity on the community assembly and function of the N-fixing microbiomes of two widespread and abundant mosses in boreal forest and arctic tundra ecosystems. The researchers will employ population genomics, functional gene sequencing, and stable isotope assays of N fixation rates along a large-scale climate gradient in Alaska that includes arctic and boreal Long-term Ecological Research (LTER) and National Environmental Observatory Network (NEON) sites. This interdisciplinary approach will enable the researchers to determine both the historical and contemporary drivers of variation in community assembly and function of this rapidly changing ecosystem, and predict how bryophyte-associated nitrogen fixation will change in a warmer climate. Thus the researchers will use moss-microbe interactions in high latitude systems as a model to inform our broader understanding of how biodiversity interacts with ecosystem function in the context of a changing climate.