Tackling microbial biodiversity to create ecological strategies relevant to soil carbon cycling

土壤是地球上第二大碳库。随着气候变化的持续，温度和降水量的变化可能会影响土壤微生物，改变土壤中碳的循环，从而可能缓解或加剧气候变化。科学家预测这种反馈的能力仍然很差，至少部分原因是对土壤中微生物的生态和功能还没有很好的了解。此外，土壤碳是从简单的糖到复杂的植物和微生物碎片的混合物。这项研究将确定哪些微生物消耗关键类型的土壤碳。实验工作将考虑来自不同地区，气候和土壤类型的一系列土壤，以提供广泛适用的知识。该项目将测试一个假设，即描述分解和消耗土壤碳的不同成分的微生物种群将改善土壤碳模型。准确预测生态系统对全球变化的反馈有利于社会，使决策者能够为未来做好准备。这项工作的其他更广泛的影响，包括体验学习的机会，超过100名高中学生在农村和经济萧条地区的西弗吉尼亚州。该项目将为早期大学课程和STEM学院提供实践科学学习活动，以提高一个只有不到10%的成年人拥有学士学位的县的风险，经济弱势，服务不足的青年的科学素养。一克土壤含有数千种微生物“物种”，使土壤成为地球上生物多样性最丰富的栖息地之一。也许正是由于这种生物多样性，微生物群落的组成与功能之间的联系一直存在。这项研究将通过量化碳同化和生长的分类特异性速率，将微生物身份和表型性状联系起来。土壤微生物的特性将被用来建立生态策略，将它们与土壤碳库联系起来，并促进生态系统建模。具体而言，该项目将测试土壤异养生物可以分为初级分解者，同化复杂的植物碎片，次级分解者，同化微生物坏死物质，被动消费者，同化不稳定的溶解底物和捕食性微生物，消耗活微生物的假设。使用系统发育工具，研究人员将确定这些生态策略是否在进化上保守，促进分类学和功能之间的联系。经验数据将被用来完善和参数化的微生物显式分解模型。这项工作使用了最先进的经验工具，生物遗传学和生态理论，将微生物群落提炼成一种货币，模型可以直接用于增强我们对土壤碳循环的预测性理解。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Soil contains the second largest reservoir of carbon on earth. As climate change continues, altered temperature and precipitation can affect soil microorganisms and alter the cycling of carbon in soil, potentially mitigating or exacerbating climate change. The ability of scientists to predict this feedback remains poor, at least in part because the ecology and function of microorganisms in soil is not well understood. Further, soil carbon is a mixture of everything from simple sugars to complex plant and microbial debris. This research will determine which microorganisms consume key types of soil carbon. The experimental work will consider a range of soils from distinct regions, climates, and soil types to provide broadly applicable knowledge. The project will test the hypothesis that describing the populations of microorganisms that break down and consume different constituents of soil carbon will improve soil carbon models. Accurate predictions of ecosystem feedbacks to global change benefit society by allowing decision makers to prepare for the future. Additional broader impacts of this work include experiential learning opportunities for over one hundred high school students in a rural and economically depressed region of West Virginia. The project will contribute hands-on science learning activities to an early college program and STEM academy to improve scientific literacy with at-risk, economically disadvantaged, under-served youth in a county where fewer than 10% of adults have bachelor’s degrees.A single gram of soil contains thousands of microbial ‘species’, making soils among the most biodiverse habitats on earth. Perhaps due to this biodiversity, the struggle to connect composition with function in microbial communities persists. This research will connect microbial identity and phylogeny to phenotypic traits by quantifying taxon-specific rates of carbon assimilation and growth. The traits of soil microbes will be leveraged to build ecological strategies that connect them to soil carbon pools and facilitate ecosystem modeling. Specifically, the project will test the hypothesis that soil heterotrophs can be grouped as primary decomposers that assimilate complex plant debris, secondary decomposers that assimilate microbial necromass, passive consumers that assimilate labile dissolved substrates and predatory microbes that consume live microorganism. Using phylogenetic tools, the researchers will determine whether these ecological strategies are evolutionarily conserved, facilitating connections between taxonomy and function. The empirical data will be used to refine and parameterize a microbial-explicit decomposition model. This effort uses state-of-the-art empirical tools, phylogenetics, and ecological theory to distill microbial communities into a currency that models can directly use to enhance our predictive understanding of soil carbon cycling.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.