RAPID: Impacts of high magnitude wildfire on volcanic (lava tube) cave water chemistry, nutrient transport, activity and diversity of cave microbiome

快速：大规模野火对火山（熔岩管）洞穴水化学、营养物运输、洞穴微生物组活动和多样性的影响

• 批准号: 2203517
• 负责人: Saugata Datta
• 金额: $ 9.94万
• 依托单位: University of Texas at San Antonio
• 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: 2021-12-15 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2203517&HistoricalAwards=false
• 关键词: RAPID; Impacts; magnitude; wildfire; volcanic

Wildfires of high magnitude are known to cause destruction of surface vegetation, soil sterilization, and alteration of soil chemical and hydraulic properties; whereas their effects on subsurface environments are relatively unknown. Recent Caldwell and Antelope wildfires in northern California burnt over hundreds of acres of landscape which included 97% of the area in Lava Beds National Monument (Lava Beds) that protects volcanic (lava) caves. The volcanic caves provide a unique habitat for bacteria and archaea, and morphologically diverse secondary mineral features (speleothems) in the presence of water. This study investigates the impacts of intense wildfires on volcanic cave ecosystems by sampling cave water and microbial mats, and analyzing them for detailed inorganic and organic chemistry, microbial diversity and activity. This data from fire-affected caves will be compared with pre-fire data from earlier studies, and the control caves from the unburnt areas, to quantify the changes occurred within the caves due to wildfires. This RAPID project supports one minority graduate student at the University of Texas at San Antonio, a leading Hispanic Serving Institution (HSI) and several undergraduate students (Hispanic, minorities, women and first generation). In collaboration with the National Park Service, the findings of this study will help inform protection of the sensitive natural heritage at Lava Beds National Monument, and important scientific findings will be made available to the visitors of the park. Impacts of high magnitude wildfires on surface environments are well documented such as complete destruction of vegetation, soil sterilization, and alteration of physical, chemical and hydraulic soil properties. However, their effects on subsurface environments like vadose zones, shallow aquifers, and caves are relatively understudied. The Caldwell Fire in 2020 and Antelope Fire in 2021 in northern California have affected 97% of Lava Beds National Monument (California, USA) landscape that hosts numerous volcanic (lava) caves. Volcanic (lava) caves are nutrient-poor, aphotic environments, and yet they host a rich diversity of bacteria and archaea which often utilize reduced energy sources (e.g., reduced iron, sulfur, manganese, or nitrogen compounds) available within the host rock and mineral deposits within the caves. Availability of nutrients in caves greatly depends upon the interactions between host rock (basalt) and meteoric water that infiltrates through surface soils into caves through fractured cave walls. This RAPID study will obtain water and microbial samples from volcanic caves in wildfire affected and unaffected areas at Lava Beds, during a post-fire hydrologic response time, and correlate it with chemical and molecular signatures in the samples. Post-fire changes in cave water chemistry will be quantified by measuring concentrations of cations, anions, trace metals, and dissolved organic matter, and comparing with pre-fire data from earlier studies, and from control caves. Analysis of 16S rRNA gene sequencing and ATP will be used to track changes in microbial diversity and activity within the caves during the post-fire period. One graduate student and several undergraduate students from the University of Texas at San Antonio and University of New Mexico will perform samples collection and subsequent laboratory analyses. These results will provide a key information regarding impacts of surface wildfires on subsurface ecosystems.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.

已知野火会导致表面植被，土壤灭菌以及土壤化学和液压特性的改变。尽管它们对地下环境的影响相对尚不清楚。北加州的最近的考德威尔（Caldwell）和羚羊野火烧毁了数百英亩的景观，其中包括熔岩床国家纪念碑（熔岩床）的97％，保护火山洞（熔岩）洞穴。火山洞为细菌和古细菌提供了独特的栖息地，并在水存在的情况下提供了多样化的二级矿物特征（Speleothems）。这项研究通过对洞穴水和微生物垫进行采样，研究强烈野火对火山洞穴生态系统的影响，并分析它们以详细的无机和有机化学，微生物多样性和活性。这些来自受火灾影响的洞穴的数据将与早期研究的发生前数据以及未燃烧区域的对照洞穴进行比较，以量化由于野火引起的洞穴内发生的变化。这个快速的项目为德克萨斯大学圣安东尼奥分校的一名少数族裔研究生提供了支持，圣安东尼奥大学是一家领先的西班牙裔服务机构（HSI）和几位本科生（西班牙裔，少数民族，妇女和第一代）。与国家公园管理局合作，这项研究的结果将有助于为熔岩床国家纪念碑的敏感天然遗产提供保护，并将为公园的游客提供重要的科学发现。高尺寸野火对地表环境的影响有充分的文献记载，例如植被，土壤灭菌的完全破坏以及物理，化学和液压土壤特性的改变。但是，它们对远面环境（如vadose区，浅水层和洞穴）等地下环境的影响相对研究。 2020年的考德威尔大火和2021年北加州的羚羊大火影响了熔岩床国家纪念碑（美国加利福尼亚州）景观的97％，该景观占据了许多火山（熔岩）洞穴。火山（熔岩）洞穴是营养贫困的，格子环境，但它们拥有丰富的细菌和古细菌多样性，这些细菌和古细菌经常利用降低的能源（例如，铁，硫，硫磺，锰或氮化合物的减少，可用的宿主岩石和矿物质矿床中可用）。洞穴中养分的可用性在很大程度上取决于宿主岩石（玄武岩）和陨石水之间的相互作用，这些岩石（玄武岩）通过表面土壤通过裂缝的洞穴壁渗透到洞穴中。这项快速研究将从熔岩床的野火和未受影响区域的火山洞中获得水和微生物样品，在火灾后的水文反应时间内，并将其与样品中的化学和分子特征相关。通过测量阳离子，阴离子，痕量金属和溶解有机物的浓度，将对洞穴水化学的发生后变化进行量化，并与早期研究的射击前数据以及对照洞穴进行比较。对16S rRNA基因测序和ATP的分析将用于跟踪大火后洞穴内微生物多样性和活性的变化。得克萨斯大学圣安东尼奥大学和新墨西哥大学的一名研究生和几名本科生将进行样品收集和随后的实验室分析。这些结果将提供有关表面野火对地下生态系统影响的关键信息。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影响评估标准通过评估来支持的。