Collaborative Research: RAPID: lake ecosystem responses to fire along gradients of burn characteristics and hydrologic connectivity

高质量的水是维持地球上所有生命所必需的。然而，不同类型的污染会降低水质，伤害依赖水生存的植物、动物和人类。具体来说，最近美国各地的野火可能会在几个方面降低水质。例如，野火产生的灰烬可能最终进入湖泊和河流，可能危害水生生物和饮用水供应。在这个项目中，一组研究人员将研究2021年格林伍德大火后明尼苏达州北方湖泊的水质。这场野火在2021年秋季烧毁了上级国家森林的大部分，包括28个湖泊附近的地区。研究人员预计，春季融雪或降雨后，灰烬和大片燃烧的植物将冲入这些湖泊，降低水质。他们将从2022年春季到夏末五次访问湖泊，以记录格林伍德大火后的任何水质变化。这项研究的结果将有助于明尼苏达州和其他地方的水资源管理人员预测未来野火后湖泊和水库的水质可能会如何变化。该项目还将帮助居住在湖泊附近的人们了解他们所关心的水上活动，如捕鱼和划船，可能会受到未来野火的影响。尽管美国各地的野火活动正在增加，人们对火灾对水资源的影响越来越关注，但很少有研究记录火灾对湖泊生态系统的影响。2021年上级国家森林的格林伍德大火面积为10844公顷，是10年来明尼苏达州最大的闪电引发的野火，截至2021年10月，覆盖了28个湖泊流域的全部或部分。该项目集合了一个综合性的水生生态系统，景观和火灾生态学家小组，研究明尼苏达州北方湖泊的物理，化学和生物响应格林伍德火灾。研究人员假设，（1）湖泊响应将与流域烧毁的百分比成比例变化，以及排水与孤立湖泊之间的变化，（2）火灾后的时间轨迹将根据主要水文事件而变化（例如，融雪、降水）。这两种假设都是使用贝叶斯方法进行测试的（即，信息理论建模和模型选择过程）。从春季融雪开始，以及整个2022年夏季，在（1）燃烧和（2）未燃烧的控制流域中分别对大约15个湖泊进行采样，这是从燃烧景观向湖泊输送营养物质和材料的关键时刻。该奖项反映了NSF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。

High-quality water is needed for sustaining all life on Earth. Different types of pollution, however, can reduce water quality and harm the plants, animals, and people that depend on water to live. Specifically, recent wildfires across the U.S. may reduce water quality in several ways. For example, ash from wildfires can end up in lakes and rivers, potentially harming aquatic organisms and drinking water supplies. In this project, a group of researchers will study water quality of northern Minnesota lakes after the 2021 Greenwood Fire. This wildfire burned a large part of Superior National Forest in fall 2021, including areas near 28 lakes. The researchers expect that after spring snowmelt or rain, ash and large pieces of burned plants will wash into these lakes and reduce water quality. They will visit lakes five times from spring to late summer of 2022 to document any water quality changes following the Greenwood Fire. Results of this study will help water managers in Minnesota and elsewhere predict how water quality in lakes and reservoirs may change after future wildfires. This project will also help people who live near lakes understand how the water activities they care about, such as fishing and boating, may be affected by future wildfires.Although wildfire activity is increasing across the U.S. and concern is mounting over fire effects on water resources, few studies have documented fire effects on lake ecosystems. At 10844 ha in size, the 2021 Greenwood Fire in Superior National Forest was the largest lightning-caused Minnesota wildfire in 10 years and covered all or parts of 28 lake watersheds through October 2021. This project assembled an integrative group of aquatic ecosystem, landscape, and fire ecologists to study the physical, chemical, and biological responses of northern Minnesota lakes to the Greenwood Fire. The researchers hypothesized that (1) lake responses will vary proportionally to the percent watershed burned and between drainage vs. isolated lakes and (2) post-fire temporal trajectories will vary according to major hydrologic events (e.g., snowmelt, precipitation). Both hypotheses are being tested using Bayesian approaches (i.e., information theoretic modeling and model choice procedures). Approximately 15 lakes are being sampled each in (1) burned and (2) unburned control watersheds beginning after spring snowmelt, a critical time for the delivery of nutrients and materials from the burned landscape to lakes, and throughout summer 2022.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.