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Dissertation Research: Is organic matter chemistry or temperature a stronger driver of microbial community structure in permafrost soil?

论文研究：有机物化学或温度是永久冻土土壤微生物群落结构的更强驱动因素吗？

基本信息

批准号：
1210728
负责人：
Matthew Wallenstein
金额：
$ 1.5万
依托单位：
Colorado State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2012
资助国家：
美国
起止时间：
2012-05-01 至 2015-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1210728&HistoricalAwards=false
关键词：
Dissertation Research organic matter chemistry

项目摘要

On earth, carbon cycles through many reservoirs including the atmosphere, plants, soils, rivers, and the ocean. Permafrost (permanently frozen soil) contains almost as much carbon as is stored in plant biomass globally, and is therefore an important carbon reservoir. Climate warming in the Arctic has caused degradation and thaw of permafrost in some locations. The carbon in permafrost is stored in the form of organic materials that are less decomposed than in soils from warmer climates, because decomposition has been stalled under frozen conditions. If these soils thaw, this carbon may be decomposed by microorganisms and released to the atmosphere during their respiration. This would add much more carbon dioxide, as well as methane, to the atmosphere and lead to a positive feedback, where increased carbon concentrations in the air cause increased warming, which causes the release of more permafrost carbon into the atmosphere. The amount of carbon dioxide and methane that is released to the atmosphere upon permafrost thaw will be a function, in part, of which particular microbial species are present. Metabolic patterns vary among the microbes, and as a consequence so do the quantities and composition of the possible respiratory products, mainly carbon dioxide and methane. Thus, it is important to study the occurance of various microbes and their functioning so that we can predict how they may respond to permafrost thaw. This project will examine how the species of microbes in permafrost are assembled. This has not been studied in the past because these soils are often deep and of course hard, making them difficult to penetrate and sample. Also, recent advances in DNA sequencing methods now allow researchers to ask new questions that were not possible even a few years ago. The results from this project will advance understanding of how changes in the temperature of permafrost soils affects microbes and the carbon cycle. Undergraduate students will participate in the project and be mentored in research skills and laboratory practices. Finally, the results will be made available through publications and more directly to a public audience on the web and in through live presentations.

在地球上，碳在许多水库中循环，包括大气、植物、土壤、河流和海洋。永久冻土(永久冻土)含有的碳几乎与全球植物生物量中储存的碳一样多，因此是一个重要的碳库。北极气候变暖导致一些地方的永久冻土退化和融化。永久冻土中的碳以有机物质的形式储存，与气候较温暖的土壤相比，有机材料的分解较少，因为在冰冻条件下分解已经停止。如果这些土壤融化，这些碳可能会被微生物分解，并在呼吸过程中释放到大气中。这将向大气中增加更多的二氧化碳和甲烷，并产生积极的反馈，空气中碳浓度的增加会导致气候变暖，从而导致更多的永久冻土碳释放到大气中。永久冻土融化时释放到大气中的二氧化碳和甲烷的数量将在一定程度上与特定微生物物种的存在有关。微生物的代谢模式各不相同，因此可能的呼吸产物的数量和组成也不同，主要是二氧化碳和甲烷。因此，重要的是要研究各种微生物的出现和它们的功能，以便我们能够预测它们对永久冻土融化的反应。这个项目将研究永久冻土中的微生物物种是如何组装的。过去没有人研究过这一点，因为这些土壤往往很深，当然也很硬，很难渗透和取样。此外，DNA测序方法的最新进展现在允许研究人员提出新的问题，而这些问题在几年前都是不可能的。该项目的结果将增进对永冻土温度变化如何影响微生物和碳循环的理解。本科生将参与该项目，并接受研究技能和实验室实践方面的指导。最后，结果将通过出版物提供，并更直接地在网上和通过现场演示向公众受众提供。