Biostimulation of microorganisms in peatlands through the weathering of atmospheric dusts at microbe-mineral interfaces

我提出的发现号研究的目标是了解微生物活动如何控制营养泥炭中的地球化学循环，以回应大气粉尘和火山灰的肥沃。泥炭地是重要的生态系统，占据了加拿大北部和全球的大片区域，它们在那里捕获重要的营养元素，并将二氧化碳隔离在植被中，土壤呼吸的损失抵消了这一点。土地开发、森林火灾增加和冰川融化导致的尘埃沉积增加对元素循环的影响基本上是未知的。尽管预计未来矿物和有机粉尘的数量会增加，但这种知识差距依然存在。很少有关于向加拿大泥炭地提供或从泥炭地移除营养和非营养元素的生物地球化学过程的研究，也没有研究将大气粉尘输入与微生物反应和碳收支联系起来。这是一个显著的赤字。我最近的研究集中在营养元素和被输送到湿地的令人担忧的元素之间的关系，以及能够化学转化这些元素的本地微生物的活动。这项研究提出了一个问题，即天然泥炭地依赖于大气输入的养分，如何从大气颗粒物中动员化学元素。这种动员可以在支持整个生态系统方面发挥关键作用，或者反过来释放地表水所关注的元素。我将通过三个不同的项目回答这个广泛的问题：1)确定当前和历史上大气颗粒物对泥炭地的输入，并将其与营养元素和生物生产力联系起来；2)评估泥炭地和与粉尘有关的微生物催化大气颗粒物风化释放化学元素的能力；3)将微生物活动和泥炭地土壤碳收支的变化与粉尘和灰尘的风化联系起来。实现这些目标的研究方法跨越了地球化学和微生物学中高度跨学科的一系列方法。三名博士生、两名硕士研究生和六名本科生将参与这项研究。HQP将从所有性别和种族群体中招募，并将接受培训，以相互协作和与其他科学家合作进行研究。项目2和项目3以从P1获得的基本知识为基础，将首次评估泥炭中粉尘在模拟野外条件下的元素迁移情况，包括风化速度；对泥炭地矿物沉积的调查很少，对泥炭生物地球化学循环的调查是新的。这项研究还将为碳循环提供新的见解，以制定更准确的泥炭地碳预算，并将开辟一个将微生物地球化学与泥炭地生产力联系起来的新的研究领域。

The goal of my proposed Discovery research is to understand how microbial activity controls geochemical cycling in ombrotrophic peat in response to fertilization by atmospheric dusts and ash. Peatlands are vital ecosystems that occupy vast areas in Canada's north and around the globe, where they trap important nutrient elements and sequester CO2 in vegetation that is offset by losses from soil respiration. The impacts of increased dust deposition due to land development, increased forest fires and loss of glacial ice on element cycling are essentially unknown. This knowledge gap persists despite projected future increases in mineral and organic dusts. There are few studies on the biogeochemical processes that provide or remove nutrient and non-nutrient elements to and from Canadian peatlands and none that relate atmospheric dust inputs to both microbial responses and carbon budgets. This is a remarkable deficit. My recent investigations have centered on the relationships between nutrient elements and elements of concern that are delivered to wetlands, and the activities of native microorganisms that can chemically transform these elements. That research has raised the question of how natural peatlands, with dependence on atmospheric inputs for nutrients, mobilize chemical elements from atmospheric particulates. Such mobilization could play a critical role in supporting entire ecosystems, or conversely release elements of concern to surface water. I will answer this broad question through three distinct projects: 1) Identify current and historical inputs of atmospheric particulates to peatlands and relate these to nutrient elements and biological productivity; 2) Assess the capacity of peatland and dust-associated microbes to catalyze the weathering of atmospheric particulates for release of chemical elements 3) Relate changes in microbial activity and peatland soil C budgets to weathering of dusts and ash. The research methods to achieve these objectives span a range of approaches in geochemistry and microbiology that is highly interdisciplinary. Three PhD students, two MSc students and six undergraduates will participate in the research. The HQP will be recruited from all gender and ethnic groups, and will be trained to approach their research collaboratively with each other and with other scientists. Projects 2 and 3, by building on fundamental knowledge gained from P1, will provide the first assessment of element mobilization from dusts in peat under simulated field conditions, including weathering rates; investigations of mineral deposition on peatland biogeochemical cycling are rare, and investigations of ash are novel. The research will also provide new insights on C cycling to develop more accurate C budgets for peatlands and will open a new area of investigation that relates microbial geochemistry to peatland productivity.