ECO-CBET: Collaborative Research: Effect of surface-fuel attributes and forest-thinning patterns on wildfire, carbon storage, and advancing forest restoration

ECO-CBET：合作研究：地表燃料属性和森林间伐模式对野火、碳储存和推进森林恢复的影响

• 批准号: 2318717
• 负责人: Jeanette Cobian
• 金额: $ 117.95万
• 依托单位: University of California - Merced
• 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: 2023-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2318717&HistoricalAwards=false
• 关键词: ECO; CBET; Collaborative; Research; Effect

2318717 (Cobian). In recent years, high-severity wildfires have severely damaged forested mountain watersheds that store carbon, supply western-states’ water, and provide many co-benefits. While periodic low- to medium-severity wildfires are a natural part of western U.S. forests, too much of the area is burning at high severity owing to excessive fuel loads and a warming climate. Therefore, a critical goal of forest management is often the introduction of practices designed to reduce the risk of high severity fires. These practices, known collectively as forest restoration, involve thinning and removing or masticating the less-fire-resistant, smaller trees, while leaving larger, more widely spaced trees. A common restoration approach is applying mechanical thinning followed by mastication which changes the forest-canopy structure and surface-fuel loading and characteristics. While it is known that changing the arrangement and density of trees and other vegetation through mastication affects fire behavior, there is a lack a quantitative understanding of how attributes of masticated fuels affect subsequent fire severity. The goal of this project is to develop metrics of the impact of fuel treatments on fire behavior across a range of spatial and temporal scales. This project will contribute to improved understanding of how surface-fuel attributes, resulting from management decisions, influence fire behavior and severity and thus forest biomass carbon storage.Mechanical thinning followed by mastication changes the forest-canopy structure and surface-fuel loading and characteristics. While these changes can impact fire behavior significantly, their sensitivities to the type and degree of mastication are not well understood. The three main goals of the study are: (1) To establish the importance of heterogeneous and multiscale surface-fuel loadings and attributes, following mechanical fuel treatments, on the temperature, flame length, and spread of fire as these fuels burn; (2) To develop and assess predictive tools for wildfire severity and spread in the forest given these different fuel attributes, under contrasting micro-meteorological conditions; and (3) To demonstrate carbon-storage and related benefits from different fuel treatments designed to reduce the occurrence and impacts of high-severity wildfires. The study will use bench-scale combustion experiments, field measurements involving controlled burns in thinned and masticated stands in a mixed-conifer forest, and modeling of wildland fire and carbon storage. Results from experiments, modeling, and assessment of field-scale control burns will be used to identify key drivers of fire severity in ground fuels following thinning. Primary contributions of the study will be improved understanding of how surface-fuel attributes, resulting from management decisions, influence fire behavior and severity and thus forest biomass carbon storage. Results will improve modeling of flame length, fire spread and carbon balance and storage in the litter, mineral soil, and deeper regolith. This research will engage decision maker and stakeholder partnerships with organizations that are advancing landscape restoration, providing much-needed improvements in projection of how their investments may affect wildfire severity.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.

2318717 (Cobian)。近年来，高强度的野火严重破坏了森林山区流域，这些流域可以储存碳、为西部各州提供水源，并带来许多共同效益，而周期性的低至中度野火是自然的一部分。在美国西部的森林中，由于燃料负荷过多和气候变暖，太多地区正在严重燃烧，因此，森林管理的一个关键目标通常是引入设计的做法。这些做法统称为森林恢复，包括疏伐和清除或咀嚼耐火性较差的较小树木，同时保留较大且间距较宽的树木。常见的恢复方法是采用机械方法。间伐之后的咀嚼会改变森林冠层结构以及表面燃料负荷和特征。虽然众所周知，通过咀嚼改变树木和其他植被的排列和密度会影响火灾行为，但对属性如何影响缺乏定量的了解。塑炼燃料该项目的目标是制定燃料处理对一系列空间和时间尺度上的火灾行为的影响的指标，该项目将有助于更好地了解管理决策所产生的表面燃料属性。 ，影响火灾行为和严重程度，从而影响森林生物量碳储存。机械疏伐和咀嚼改变了森林冠层结构和表面燃料负荷和特征，虽然这些变化可以显着影响火灾行为，但它们对咀嚼类型和程度的敏感性。不是该研究的三个主要目标是：（1）确定机械燃料处理后的异质和多尺度表面燃料负载和属性对这些燃料燃烧时的温度、火焰长度和火势蔓延的重要性。 (2) 在对比微气象条件下，根据这些不同的燃料属性，开发和评估森林火灾严重程度和蔓延的预测工具；(3) 论证旨在减少森林火灾的不同燃料处理的碳储存和相关效益；的发生和影响该研究将使用实验室规模的燃烧实验、涉及混合针叶林间伐和咀嚼林的受控燃烧的现场测量，以及对荒地火灾和碳储存的模拟结果。现场规模的控制燃烧将用于确定间伐后地面燃料火灾严重程度的关键驱动因素，该研究的主要贡献将是提高对管理决策产生的地表燃料属性如何影响火灾行为和严重程度以及森林的理解。生物质碳结果将改善火焰长度、火蔓延和碳平衡以及垃圾、矿质土壤和更深的风化层中的储存的建模这项研究将让决策者和利益相关者与推动景观恢复的组织建立伙伴关系，提供急需的改进。预测他们的投资可能如何影响野火的严重程度。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。