Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys

合作研究：雪斑对南极干谷土壤微生物群落空间分布和生物地球化学循环的作用

• 批准号: 0838922
• 负责人: John Barrett
• 金额: $ 24.41万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838922&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Snow; Patches

AbstractThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Two models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities.

摘要这一奖项是根据2009年的《美国复苏与再投资法》（公法111-5）资助的。已提出了两个模型来描述对微生物生物地理学的控制。一个模型提出，微生物普遍存在在整个全球环境中分布，并且环境条件选择了适应局部物理状况的分类单元。另一种模型预测，分散是微生物分布的重要局限性，而微生物群落的空间异质性是分散和局部环境局限性的结果。根据这两种模型，微生物群落的空间异质性在极端生态系统中尤其明显，在这些生态系统中，对具有合适生理学的生物的环境选择最有很强的表现。我们建议南极陆地环境是检查微生物生物地理学的理想场所，原因有3个原因：1）南极的原始性质和偏远度最大程度可最大程度地减少通过人类载体分散的外来物种的流行； 2）南极环境的极端条件提供了强大的环境过滤器，该过滤器限制了非土著分类单元的建立； 3）陆地环境中极端异质性提供了土壤条件的自然梯度（温度，水和养分的可用性）。在拟议的研究中，我们将研究雪对土壤微生物群落的组成和空间分布的影响，并连接麦克穆尔多干谷中的生物地球化学循环。我们将在山谷和斑块量表（量化雪斑消融，微生物群落和尼文土壤中的生物地球化学循环）上以景观量表进行现场工作（重复遥感以表征雪分布）。我们假设积雪在构建土壤微生物群落的空间分布及其相关的生态系统功能方面起着重要作用，因为雪斑对土壤环境的物理和水文影响产生了物理和水文影响。这项研究将通过与国际南极研究所的公共外展活动的直接联系，包括将基于Web的基于Web的环境科学和微生物学的学习部门传播，这是针对中学和后教育者的资源，这将有助于公众对极地研究对生物学，生态学和水文学基本问题的重要性的认识。三名研究生，一名博士后学者和多名本科生将参加研究活动。