DISSERTATION RESEARCH: Partitioning rhizosphere effects on microbial community structure and carbon cycling across a peatland water table gradient.

论文研究：根际分区对泥炭地地下水位梯度微生物群落结构和碳循环的影响。

• 批准号: 1501937
• 负责人: Adrien Finzi
• 金额: $ 2.11万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501937&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Partitioning; rhizosphere; effects

Peatlands, such as bogs, are unique ecosystems that occupy only a small fraction of the Earth's land surface but contain vast quantities of carbon. Peatlands store so much carbon because they are saturated with water, and this creates an anaerobic environment that slows decomposition of complex organic (carbon-containing) substances. Over the next 100 years, heightened drought frequency and severity is projected to reduce water table heights in high latitude peatlands, causing them to emit more carbon gases to the atmosphere. The goal of this project is to identify the effect of water table reduction and associated changes in plant community structure on the microorganisms living in a northern peatland. The release of carbon gasses is controlled by these microorganisms through their decomposition of organic material. The work will provide novel insight into the impact of physical and plant-mediated environmental changes on microbial community structure and activity, and will deepeour understanding of ecosystem responses to climate change. In addition to support the graduate student's doctoral dissertation research, this project will also provide opportunities for Boston University undergraduates to learn laboratory techniques and methods of data analysis, and the research scientists leading this project will develop educational modules related to peatland carbon storage that will be presented at area elementary schools and community festivals.Microbial (bacteria and funga) groups have distinct physiology and developmental histories that will impact their responses to water table decline and contribute to changes in ecosystem carbon and nitrogen cycling. Changes in vascular plant abundance and root biomass associated with water table decline may further impact the microbial environment through increased plant-carbon allocation to mycorrhizal fungal communities. In particular, this research seeks to determine if the physical effect of water table reduction on microbial community composition, enzyme production, and carbon mineralization is amplified by increased vascular plant abundance and carbon allocation to mycorrhizal fungal communities. The research will leverage an ongoing rhizosphere partitioning experiment across a natural water table gradient in Caribou Bog, Maine. Microbial community composition in three rhizosphere communities isolated within root and fungal ingrowth and exclusion cores installed across the water table gradient will be compared to separate the influence ofphysical changes in water table from the biological influence of plants and mycorrhizal fungi. The proposed analyses will complement ongoing microbial functional analyses and identify relationships between microbial activity and composition in response to declines in the water table and in the presence or absence of plant and mycorrrhizal inputs.

泥炭地，例如沼泽，是独特的生态系统，仅占地一小部分，但含有大量碳。 Peatlands将碳储存得如此之多，因为它们充满了水，这会产生一个厌氧环境，可以减慢复杂的有机（含碳）物质的分解。在接下来的100年中，预计干旱频率和严重程度的提高会降低高纬度泥炭地的水位高度，从而导致它们向大气中散发出更多的碳气体。该项目的目的是确定减少地下水位的影响以及植物群落结构的相关变化对生活在北部泥炭地北部的微生物的影响。 碳气体的释放是通过这些微生物通过其有机材料的分解来控制的。这项工作将提供对物理和植物介导的环境变化对微生物群落结构和活动的影响的新颖见解，并将深入了解生态系统对气候变化的反应。除了支持研究生的博士学位论文研究外，该项目还将为波士顿大学大学生提供学习实验室技术和数据分析方法的机会，领导该项目的研究科学家将开发与Peatland Carbon Storage相关的教育模块在地区小学和社区节上提出。Microbial（细菌和Funga）群体具有独特的生理和发育历史，这将影响其对地下水位下降的反应，并导致生态系统碳和氮气循环的变化。与地下水位下降相关的血管植物丰度和根生物量的变化可能会通过增加对菌根真菌群落的植物碳分配而进一步影响微生物环境。特别是，这项研究旨在确定减少地下水位对微生物群落组成，酶产生和碳矿化的物理影响是否会通过增加的血管植物丰度和对菌根真菌群落的碳分配而放大。这项研究将利用缅因州驯鹿沼泽天然地下水位梯度进行的持续的根际分配实验。将比较在根和真菌向内生长内分离的三个根际群落中的微生物群落组成，并将安装在地下水位梯度上的排除核心分离，以将地下水位变化的影响与植物和菌根真菌的生物学影响分开。所提出的分析将补充正在进行的微生物功能分析，并确定微生物活性与组成之间的关系，以响应地下水位的下降以及在存在或不存在植物和菌根输入的情况下。