RAPID: Evaluation of post-wildfire effects on soil physical and chemical properties in response to the Caldor and Tamarack fires near Lake Tahoe

在火灾易发地区，野火引起的土壤特性变化影响入渗、径流和土壤可蚀性。最近内华达山脉东部的野火提供了一个独特的机会来量化自然野外环境中火灾对土壤特性的影响。这些野火代表了新一代高温林冠火灾，由于气候变化，这些火灾在该地区的发生频率可能会增加。火灾后入渗减少、径流增加与土壤孔隙系统结构和表面化学的变化有直接关系。火灾对土壤物理和化学性质的影响大多是在实验室中量化的，而不是在自然现场环境中量化的。该项目将量化两次大型野火（卡尔多和塔玛拉克）对土壤物理和化学特性的影响，以更好地了解火灾如何影响山坡水文过程（渗透、径流、侵蚀）、与火灾相关的次级风险（如洪水和泥石流）以及与火灾活动相关的森林管理实践。该项目将量化火灾后土壤物理和化学性质的变化，以更好地了解它们对自然环境中火灾后径流、入渗和侵蚀的影响。将从燃烧和未燃烧的地点收集样品，通过控制蒸发实验测量土壤的水力和导热功能，并使用质子核磁共振光谱法确定土壤有机质中影响土壤疏水性的官能团。此外，渗透和土壤疏水性将使用渗透计测试现场测量。研究结果将提交给火灾易发流域的当地利益相关者，以指导森林管理，提高水和生态系统资源的可持续性。结果将被转移到具有类似土壤条件的内华达山脉流域。该项目将为早期职业科学家提供研究机会，为博士生提供实地培训，并为本科生提供实践经验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Wildfire-induced changes to soil properties impact infiltration, runoff, and soil erodibility in fire-prone areas. Recent wildfires in the eastern Sierra Nevada mountains provide a unique opportunity to quantify fire effects on soil properties in natural field settings. These wildfires represent a new generation of large high-temperature canopy fires that are likely to increase in frequency in this region due to changing climate. Reduced infiltration and enhanced runoff after fire are directly related to changes in the structure and surface chemistry of the pore system within the soil. Fire effects on soil physical and chemical properties have been quantified mostly in the laboratory but not in natural field settings. This project will quantify the effect of two large wildfires (Caldor and Tamarack) on soil physical and chemical properties to better understand how fires affect hillslope hydrologic processes (infiltration, runoff, erosion), fire-related secondary risks such as flooding and debris flows, and forest management practices related to fire activity.This project will quantify post-fire changes to soil physical and chemical properties to better understand their impact on post-fire runoff, infiltration, and erosion in natural settings. Samples will be collected from burned and unburned locations both to measure soil hydraulic and thermal conductivity functions via controlled evaporation experiments and to identify functional groups in soil organic matter that influence soil hydrophobicity using proton nuclear magnetic resonance spectrometry. Additionally, infiltration and soil hydrophobicity will be measured in-situ using infiltrometer tests. Results will be presented to local stakeholders of fire-prone watersheds to guide forest management and improve the sustainability of water and ecosystem resources. Results will be transferable to watersheds in the Sierra Nevada with similar soil conditions. This project will provide research opportunities for an early career scientist, field training to a Ph.D. student, and hands-on experience for an undergraduate student.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.