Collaborative Research: Biomass burning smoke as a driver of multi-scale microbial teleconnections

合作研究：生物质燃烧烟雾作为多尺度微生物遥相关的驱动因素

• 批准号: 2039545
• 负责人: Brent Christner
• 金额: $ 7.18万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039545&HistoricalAwards=false
• 关键词: Collaborative; Research; Biomass; burning; smoke

Microbes are found in all environments and play essential roles in nutrient cycling, gas exchange, and through associations with plants and animals. However, the ways that microbes are transported from one environment to another are not well understood. Each year, wildland fires emit millions of tons of smoke particles into the atmosphere and these particles likely carry microbes with them. Traditionally, wildfires have been studied in terms of direct impacts to terrestrial biota and the chemistry and physics of the atmosphere, but the role of smoke as an agent of biological dispersal has yet to be explored. Grasslands are one of the most widespread and frequently burned ecosystems, so this research will examine the impacts of smoke-driven microbial dispersal in tallgrass prairies of the central United States using unmanned aerial vehicles flying into smoke plumes, combustion experiments and soil incubations that mimic conditions in nature. This project uses an integrated approach to better understand the consequences of smoke to human, plant, and animal health across all environments where wildland fire occurs. The increasing size and severity of global wildfires, leading to increased interaction between biomass burning smoke and human populations, make this research relevant to a wide range of stakeholders including those interested in the potential transport of pathogenic microbes. In addition to mentoring three post-doctoral scholars, a graduate student, and undergraduate summer interns, the results will be disseminated to local communities through existing K-12 and informal learning programs at the Konza Prairie LTER and NEON sites. Microbial emissions in smoke from biomass burning are both quantitatively and qualitatively different from the bioaerosols observed from wind-driven emissions, implying that wildland fire may be a globally relevant and yet-unquantified mechanism for microbial teleconnections among ecosystems. To test how smoke drives microbial metacommunity ecology, this project will use an integrated approach that compares the composition and viability of smoke source and sink microbial assemblages in field- and laboratory-based experiments. Smoke and particulate deposition during repeated prescribed fires in grasslands will be sampled over two years to characterize the relationships among fire behavior, meteorological conditions, and survival of microbes transported in smoke. Sterilized and untreated soils from similar, unburned sites will be exposed to contrasting dosages of smoke with known microbial content to compare the relative influence of selection, dispersal, and drift on soil microbial community assembly. These data will be used to build new capacity for simulating smoke microbial dispersal across scales by parameterizing microbial emission fluxes and microbial dispersion in atmospheric, chemical transport, and coupled fire-atmosphere models. Results will lend insight into the relative importance of stochastic vs. deterministic processes in driving microbial community ecology in systems where fire disturbances are frequent, while modeling will enable predictions of the scale and impact of smoke-related microbial dispersal. This research will inform questions about microbial gene flow, microbial pathogen epidemiology, phytopathogens, and meteorological processes, and will expand fundamental understanding of fire’s ecological significance.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.

微生物存在于所有环境中，在营养循环、气体交换以及与植物和动物的联系中发挥着重要作用。然而，微生物从一种环境转移到另一种环境的方式尚不清楚。每年，荒地火灾都会向大气中排放数百万吨烟雾颗粒，这些颗粒可能携带微生物。传统上，人们研究野火对陆地生物群以及大气化学和物理的直接影响，但烟雾作为生物扩散剂的作用仍有待探索。草原是最广泛和最频繁燃烧的生态系统之一，因此这项研究将利用无人机飞入烟雾羽流、模拟自然条件的燃烧实验和土壤孵化，研究烟雾驱动的微生物扩散对美国中部高草草原的影响。该项目采用综合方法来更好地了解在发生野火的所有环境中烟雾对人类、植物和动物健康的影响。全球野火的规模和严重程度不断增加，导致生物质燃烧烟雾与人类之间的相互作用增加，使得这项研究与广泛的利益相关者相关，包括那些对病原微生物的潜在传播感兴趣的利益相关者。除了指导三名博士后学者、一名研究生和本科生暑期实习生外，研究结果还将通过 Konza Prairie LTER 和 NEON 基地现有的 K-12 和非正式学习项目传播给当地社区。生物质燃烧烟雾中的微生物排放在数量和质量上都与风驱动排放中观察到的生物气溶胶不同，这意味着荒地火灾可能是生态系统之间微生物遥相关的全球相关但尚未量化的机制。为了测试烟雾如何驱动微生物群落生态，该项目将使用一种综合方法，在现场和实验室实验中比较烟雾源和汇微生物组合的组成和活力。将在两年内对草原重复规定火灾期间的烟雾和颗粒物沉积进行采样，以表征火灾行为、气象条件和烟雾中传播的微生物存活之间的关系。来自类似未燃烧地点的灭菌和未经处理的土壤将暴露于具有已知微生物含量的对比剂量的烟雾中，以比较选择、扩散和漂移对土壤微生物群落组装的相对影响。这些数据将用于通过参数化大气、化学物质传输和火灾-大气耦合模型中的微生物排放通量和微生物扩散来建立模拟烟雾微生物跨尺度扩散的新能力。结果将有助于深入了解随机过程与确定性过程在火灾频繁发生的系统中驱动微生物群落生态的相对重要性，而建模将能够预测与烟雾相关的微生物扩散的规模和影响。这项研究将揭示有关微生物基因流、微生物病原体流行病学、植物病原体和气象过程的问题，并将扩大对火灾生态意义的基本理解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。