CAREER: Developing a Fire Ecology Framework for Soil Bacteria

职业：开发土壤细菌火灾生态框架

• 批准号: 2045864
• 负责人: Thea Whitman
• 金额: $ 99.31万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2045864&HistoricalAwards=false
• 关键词: CAREER; Developing; Fire; Ecology; Framework

Wildfires cause major ecological as well as economic disturbances. They are increasing in frequency and severity in many regions of the world and burn hundreds of millions of hectares of land every year. The burned landscape results in large losses of carbon and nitrogen from ecosystems. Microorganisms in the soil play a critical role in the recovery of wildfire-affected ecosystems through their roles in cycling nutrients and their interactions with plants. The ecological impacts of wildfires on plant life are somewhat understood. This is not the case for soil microbes. The goal of this NSF CAREER project is to develop a fire ecology framework for bacteria, to improve understanding of why certain bacteria are “pyrophilous” – i.e., why they thrive following exposure to fire. The approach will draw on field research on northern forest wildfires and controlled prairie burns, laboratory experiments, and genetic sequencing. At its core, improving our understanding of bacterial response to fires will help underpin our understanding of how fires and changing fire regimes will affect the climate, an issue of great societal importance. This project will realize a myriad of broader impacts through its education goals, which are tightly integrated with each research goal. Undergraduates will be trained in the lab throughout the grant, working with the University of Wisconsin-Madison Undergraduate Research Scholars program, which will help support full participation of women and members of underrepresented groups in STEM fields. A podcast about fire ecology, developed in collaboration with undergraduates in the Life Sciences Communication program, and a new public outreach booth, “What happens belowground during a fire?”, will both help increase public scientific literacy and engagement with science and fire ecology.The proposed research will build on the PI’s prior results to strengthen and integrate a trait-based understanding of bacterial responses to fire. The overarching hypothesis is that fire survival will be most relevant shortly after wildfires (~1 year), fast growth will be relevant over longer timescales (~5 years), and pyrogenic organic matter degradation will be relevant over longer periods of time (~10 years). The first theme will address the patterns and traits of pyrophilous soil bacteria. In seeking to determine which bacteria and genetic characteristics are associated with burned soils, the research team will add a ten-year timepoint to a current one- and five-year timepoints in a 40-site wildfire field experiment, building toward what will ultimately become a long-term field study of boreal forest wildfires. In addition, the research team will apply an untargeted metagenomics-based approach at multiple time points to characterizing post-fire functional potential. Part of the proposed approach to strengthening a fire ecology framework for bacteria lies in experimentally investigating bacterial fire response through its separate components, such as heat tolerance. The second theme focuses on the interactive effects of temperature and drought on bacterial survival and post-fire carbon (C) mineralization. The approach will use laboratory experiments with bacterial isolates, intact soil cores, and gas flux tracing to determine the temperature ranges that pyrophilous bacteria can survive and whether prior drought stress affects bacterial survival of high temperatures and influences post-fire C mineralization rates. The third theme will aim to develop an integrative understanding of fire ecology for soil bacteria. Here, the research team will draw on current and emerging datasets and cross-domain collaborations to determine the relative importance of different traits in determining post-fire success of pyrophilous bacteria over time and across burn severities. Studies will compare how the traits that make bacteria successful fire-responders correspond to (or contrast with) equivalent strategies in other organisms. Overall, the project will advance our understanding of fundamental questions about the effects of fire on bacteria – critical players in post-fire ecosystem recovery. Undergraduate training will be coupled with mentorship training for a PhD student and a research technician, helping them become better future educators, themselves. To help support a globally competitive STEM workforce, the PI will develop new metagenomics tutorials for soil microbiology courses, which will provide cutting-edge bioinformatics skills to students. These tutorials will be developed with a postdoctoral researcher, who will also participate in UW-Madison teaching workshops, further helping to improve both STEM education and educator development.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.

野火造成重大的生态和经济灾难。它们在世界许多地区的频率和严重程度都在增加，每年燃烧数亿公顷的土地。燃烧的景观导致生态系统的碳和氮损失很大。土壤中的微生物通过其在循环营养物质中的作用及其与植物的相互作用，在受野火影响的生态系统的恢复中起关键作用。野火对植物生命的生态影响是某种理解的。土壤微生物不是这种情况。这个NSF职业项目的目标是为细菌开发一个火生态框架，以提高人们对某些细菌为何“热电”的理解，即为什么它们在暴露于火之后会蓬勃发展。该方法将利用对北部森林野火和受控草原烧伤，实验室实验和遗传测序的现场研究。从本质上讲，提高我们对细菌对火灾反应的理解将有助于我们理解火灾和改变火灾制度将如何影响气候，这是一个非常重要的社会重要性问题。该项目将在整个教育目标中实现无数的广泛影响，这些影响与每个研究目标都紧密融合。本科生将在整个赠款的整个实验室中接受培训，并与威斯康星大学麦迪逊分校的本科生研究学者计划合作，该计划将有助于支持妇女的全面参与和代表性不足的人群在STEM领域。与生命科学传播计划中的基础合作开发的有关火灾生态学的播客，以及一个新的公共外展摊位，“在火灾中发生了什么？”，这两个都将有助于提高公共科学素养以及与科学和火灾生态学的参与。拟议的研究将基于PI的先前成果，以增强和整合基于特质的细菌反应的特质理解。总体假设是，在野火（约1年）之后不久，火灾生存率将是最相关的，快速增长将在更长的时间尺度（〜5年）中相关，而热源有机物降解将在更长的时间内（〜10年）相关。第一个主题将介绍昆虫细菌的模式和特征。在寻求确定哪些细菌和遗传特征与燃烧的土壤有关，研究小组将在40个地点野火野外实验中为当前的一年和五年时间点增加十年的时间点，从而朝着最终成为北方森林野火的长期现场研究。此外，研究团队将在多个时间点采用基于元基因组学的基于元基因组学的方法来表征火后功能潜力。加强细菌火灾生态框架的一部分方法在于实验研究细菌通过其单独的成分（例如热耐受）的火灾反应。第二个主题着重于温度和干旱对细菌存活和火灾后碳（C）矿化的互动效果。该方法将使用细菌分离株，完整的土壤核心和气通量追踪的实验室实验，以确定热电细菌可以生存的温度范围，以及先前的干旱胁迫是否会影响高温的细菌存活并影响火后C矿化率。第三个主题将旨在发展对土壤细菌火灾生态学的综合理解。在这里，研究团队将借鉴当前和新兴的数据集以及跨域协作，以确定不同特征在确定热电细菌后随着时间和燃烧严重程度的相对重要性。研究将比较使细菌成功的火反应者与其他组织中的等效策略相对应的特征。总体而言，该项目将促进我们对大火对细菌影响的基本问题的理解 - 后火生态系统恢复中的关键参与者。本科培训将与博士生和研究技术人员一起为心态培训，帮助他们成为更好的未来教育者。为了帮助支持全球竞争激烈的STEM劳动力，PI将为土壤微生物学课程开发新的宏基因组学教程，该课程将为学生提供尖端的生物信息学技能。这些教程将与博士后研究人员一起开发，他们还将参加UW-Madison教学讲习班，进一步帮助改善STEM教育和教育发展。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的审查标准来通过评估来获得支持的。