Collaborative Research: Evaluating the Unique Composition, Environmental Stability, and Export of Dissolved Pyrogenic Organic Matter in Wildfire-Impacted Watersheds

合作研究：评估受野火影响的流域中溶解的热解有机物的独特组成、环境稳定性和输出

• 批准号: 2326437
• 负责人: Amanda Hohner
• 金额: $ 22.54万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2326437&HistoricalAwards=false
• 关键词: Collaborative; Research; Evaluating; Unique; Composition

Forested watersheds have historically provided pristine sources of water to address approximately 50% of the Nation’s need for drinking water. However, the increased frequency and severity of wildfires in forested watersheds are adversely impacting downstream water quality due to the exports of sediments, nutrients, and dissolved organic matter. Heat from wildfires initiates and catalyzes a series of chemical reactions in soil organic matter that result in the formation of pyrogenic organic matter (PyOM). In a wildfire impacted watershed, PyOM has the potential to impact surface water quality, aquatic biogeochemical processes, and the operation of downstream water treatment plants. The overarching goal of this project is to evaluate the chemical composition, environmental fate and reactivity, and timing of PyOM release from a wildfire impacted watershed. To advance this goal, the Principal Investigators (PIs) propose to carry out an integrated laboratory and field research program to 1) characterize the chemical composition of PyOM using optical spectroscopy and ultra-high resolution mass spectrometry, 2) evaluate the environmental fate of PyOM during photodegradation and biodegradation, and 3) monitor the timing of PyOM export from a wildfire-impacted watershed with in-situ optical sensors. The successful completion of this project will benefit society through the generation of new fundamental knowledge and data to advance the assessment and evaluation of the environmental fate and transport of PyOM in forested watersheds and its potential impact on downstream water quality. Additional benefits to society will be achieved through outreach and education activities including the mentoring of one graduate student at Texas A&M University and one graduate student at Washington State University.Wildfires can drastically change the quantity and quality of dissolved organic matter (DOM) that is exported from burned watersheds to downstream surface water systems due to the formation of pyrogenic organic matter (PyOM). The presence of PyOM in wildfire-impacted watersheds has the potential to impact aquatic biogeochemical processes and the removal of organic matter during drinking water treatment. The goal of this project is to evaluate the chemical composition, environmental stability, and timing of dissolved PyOM export from wildfire-impacted watersheds. The specific objectives of the research are to: (1) Evaluate the differences in chemical compositions between background DOM and PyOM; (2) Assess the fate of PyOM during biodegradation, photodegradation, and photobiodegradation; and (3) Evaluate the timing of PyOM release from a wildfire-impacted watershed using in situ optical sensors. PyOM generated from water leaching experiments of laboratory-heated soils will be characterized by elemental composition, optical measurements, and ultra-high resolution mass spectrometry. A multi-year field campaign will evaluate the temporal dynamics of PyOM release from a wildfire-impacted watershed using in situ optical sensors. The successful completion of this research has the potential for transformative impact through the generation of new insight and data from both lab and field studies to advance the fundamental understanding of the fate and transport of PyOM in forested watersheds as climate change exacerbates the frequency and severity of wildfires. To implement the educational and training goals of this project, the PIs will leverage existing programs at their respective institutions to integrate the findings from this research into a K-12 teacher training program (Spark! PK-12 Outreach) at Texas A&M University and a field training program (Science at the Site) at Washington State University designed to attract and engage students from underrepresented groups.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.

森林流域历史上提供了原始水源，可满足国家约 50% 的饮用水需求。然而，森林流域野火的频率和严重性增加，由于沉积物、营养物和水的输出，对下游水质产生了不利影响。野火产生的热量会引发并催化土壤有机物中的一系列化学反应，从而导致受野火影响的热原有机物 (PyOM) 的形成。流域，PyOM 有可能影响地表水质、水生生物地球化学过程以及下游水处理厂的运行。该项目的总体目标是评估化学成分、环境归趋和反应性以及 PyOM 释放的时间。为了推进这一目标，主要研究人员 (PI) 建议开展一项综合实验室和现场研究计划，以 1) 使用光谱和超高分辨率质量表征 PyOM 的化学成分。光谱测定法，2）评估PyOM在光降解和生物降解过程中的环境命运，以及3）利用原位光学传感器监测PyOM从受野火影响的流域输出的时间。新的基础知识和数据将促进对森林流域中 PyOM 的环境命运和迁移及其对下游水质的潜在影响的评估和评估，这将通过包括外展和教育活动在内的活动实现。德克萨斯 A&M 大学的一名研究生和华盛顿州立大学的一名研究生的指导。野火可以极大地改变溶解有机物 (DOM) 的数量和质量，由于形成热原有机物 (PyOM)。受野火影响的流域中存在的 PyOM 有可能影响水生生物地球化学过程和饮用水处理过程中有机物的去除。评估受野火影响的流域中溶解的 PyOM 的化学成分、环境稳定性和时间。研究的具体目标是： (1) 评估背景 DOM 和 PyOM 之间化学成分的差异； (2) 评估最终结果。 (3) 使用原位光学传感器评估受野火影响的流域中 PyOM 的释放时间。实验室加热土壤的水浸出实验产生的 PyOM 将通过元素成分、光学测量和超高分辨率质谱进行表征。一项多年的现场活动将利用受野火影响的流域评估 PyOM 释放的时间动态。原位光学传感器的成功完成，通过从实验室和现场研究中产生新的见解和数据，有可能产生变革性的影响，以促进对森林流域中 PyOM 的命运和运输的基本了解。气候变化加剧了野火的频率和严重性 为了实现该项目的教育和培训目标，PI 将利用各自机构的现有计划将这项研究的结果纳入 K-12 教师培训计划 (Spark! PK)。 -12 Outreach）在德克萨斯农工大学和实地培训计划反映了华盛顿州立大学的（Science at the Site）旨在吸引和吸引来自代表性不足群体的学生。该奖项是 NSF 的法定使命，并通过评估被认为值得支持基金会的智力价值和更广泛的影响审查标准。