Collaborative Research: Causes and consequences of fire-regime variability in Rocky Mountain forests

野火每年影响美国超过180，000平方公里，平均面积是黄石国家公园的20倍。在落基山脉，自20世纪80年代中期以来，大型野火烧毁的面积一直在增加，这一趋势与春季和夏季气温变暖密切相关，预计在未来几十年内将继续下去。社会对野火的计划和反应方式，例如通过联邦政策和土地管理，在很大程度上取决于我们对不同生态系统中火灾的原因、生态后果和历史先例的理解。这方面的重要问题包括：过去发生火灾的频率如何，这种情况如何随气候和人类活动而变化，火灾如何影响包括森林和水质在内的宝贵资源，生态系统需要多长时间才能恢复到火灾前的状况？研究森林和野火活动如何以及为什么在过去不同的气候和人类活动时期发生变化，为理解野火的影响提供了重要基础。这种长期视角还有助于为模拟未来环境变化（包括野火活动的变化）的影响提供信息和改进模型。更广泛影响的机制包括通过嵌入研究团队的新闻学研究生记录和交流研究结果，通过为高中教育工作者开发森林和火灾生态学课程来推进STEM教育，以及在实地，实验室和基于模型的研究中培训研究生和本科生。这项研究调查了气候变化，野火活动，和生态系统在过去2500年通过古生态重建和生态系统建模的独特组合。利用两个研究区域（即，9-12 1000 km 2以内的湖泊;和S.落基山脉），过去火灾活动的频率，严重性和同步性将被表征，并与古气候记录进行比较，以评估过去火灾活动的驱动因素。古火灾记录将辅以高分辨率的植被和地球化学变化记录在一个子集的焦点，以评估过去的火灾活动的生态系统影响。耦合的气候-火灾-生态系统动力学将在流域和次区域空间尺度上通过一组生态系统建模模拟进行研究，这些模拟将古信息与平衡情景进行比较。

Wildfires affect more than 180,000 km2 in the Unites States every year, on average, an area 20 times the size of Yellowstone National Park. In the Rocky Mountains, the amount of area burned in large wildfires has been increasing since the mid-1980s, a trend well linked to warming spring and summer temperatures, and expected to continue in upcoming decades. The way society plans for and reacts to wildfires, for example through federal policy and land management, is strongly shaped by our understanding of the causes, ecological consequences, and historical precedence of fire in different ecosystems. Important questions in this context include: how often have fires occurred in the past and how has this varied with climate and human activity, how have fires impacted valued resources including forests and water quality, and how long does it take for ecosystems to recover to pre-fire conditions? Studying how and why forests and wildfire activity have varied in the past, over periods of varying climate and human activity, provides a critical foundation for understanding the implications of wildfires. This long-term perspective also helps inform and improve models that simulate the impacts of future environmental change, including changes in wildfire activity. Mechanisms for broader impacts include documenting and communicating research results via a journalism graduate student embedded with the research team, advancing STEM education through the development of forest and fire ecology curricula for high school educators, and training graduate and undergraduate students in field-, lab-, and modeling-based research.This research investigates the relationships and feedbacks among changes in climate, wildfire activity, and ecosystems over the past 2500 years through a unique combination of paleoecological reconstructions and ecosystem modeling. Using an unusually dense network of lake-sediment records in two study regions (i.e., 9-12 lakes within 1000 km2 in the N. and S. Rockies), the frequency, severity, and synchrony of past fire activity will be characterized and compared to paleoclimate records to assess the drivers of past fire activity. Paleofire records will be supplemented with high-resolution records of vegetation and biogeochemical change at a subset of focal sites, to assess the ecosystem impacts of past fire activity. Coupled climate-fire-ecosystem dynamics will be examined at watershed and sub-regional spatial scales through a set of ecosystem modeling simulations that compare paleo-informed to equilibrium scenarios.