Collaborative Research: The Past, Present, and Future of Boreal Fire Feedbacks

北方森林环绕着地球仪，拥有地球上最大的碳储量。这些碳被锁在树木和土壤中，与大气隔离。但随着气候变暖，火灾变得越来越普遍-虽然野火在北方并不罕见，但越来越频繁的燃烧超过了森林进化所能承受的范围，导致森林损失和永久冻土融化。我们不知道接下来会发生什么。如果森林不能从高频率的火灾中恢复过来，草和灌木可能会接管，进一步增加易燃性。或者它们可以抑制未来的火灾活动。该项目对北方的火灾进行了独特的研究，通过湖泊沉积物核心调查火灾的深层历史，您可以看到数千年来的火灾历史，通过实地考察确定景观现在的弹性，并通过高性能计算机模型来估计火灾在未来的表现。该项目跨越许多时间尺度，将计算能力推向极限，并将告知对这个生物群落和地球未来的期望。该项目将培训研究生，本科生和博士后学者，组织为期两天的科学交流研讨会，并完善用于教授高中生碳-植被-火相互作用的火灾教学模型。该项目将采用综合和动态的方法，将联合收割机现有和新收集的沉积物数据结合起来，通过在短间隔火灾地区进行实地考察，探索北方短间隔火灾的古历史。虽然众所周知，现代火灾频率正在超过历史标准，但该项目将进一步确定当前的短间隔火灾是否正在创造新的结构。这些结构是未来火灾行为的基础，因此研究人员将联合收割机将这些测量结果与现代的基于物理学的火灾行为流体动力学模型相结合，该模型可以模拟近冠层和新型森林结构中的风。这是唯一可用的方法来探索真正新颖的物种组合和结构，似乎正在出现的火灾影响。这项工作将共同探索与北方森林火灾行为相关的火灾可能性反馈和结构阈值，并告知有关该地区将如何在野火和能量平衡方面应对气候变暖的预期。该项目将与非营利组织COMPASS合作，为更大学术界的研究生和科学家组织为期两天的科学交流研讨会。他们还将与Concord Consortium合作开发一个用于高中生教学的模块工具，与教师合作征求反馈。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Boreal forests circle the globe and contain some of the largest carbon stocks on the planet. Locked in the trees and soil, this carbon is sequestered from the atmosphere. But as the climate warms, fires are becoming more and more common – and while wildfire is not unusual in the boreal, the increasing frequency of burning is surpassing what the forests have evolved to tolerate, leading to forest loss and permafrost thaw. We do not know what comes next. It is possible that if the forest fails to recover from high frequency fires, grasses and shrubs may take over, further increasing flammability. Or they may dampen future fire activity. This project takes a unique look at fires in the boreal, by investigating the deep history of fire through lake sediment cores where you can see the history of fire over thousands of years, through fieldwork to determine how resilient the landscape is now, and through high-performance computer models to estimate how fires will behave in the future. The project spans many timescales and pushes computing powers to the limit and will inform expectations of the future for this biome and the planet. The project will train graduate students, undergraduate students, and postdoctoral scholars, organize a two-day science communication workshop, and refine a fire teaching model used to teach high schoolers about carbon-vegetation-fire interactions. Using an integrative and dynamic approach, this project will combine existing and newly collected sediment data to explore the paleohistory of short interval fires in the boreal with co-located fieldwork in short-interval fire areas. Although it is known that modern fire frequency is passing historical norms, this project will go further, to determine if current short interval fires are creating novel structures. Those structures are the basis for fire behavior in the future, so the researchers will then combine those measurements with modern, physics-based fluid dynamics modeling of fire behavior that can simulate wind in close canopies and in novel forest structures Further, this model will be extended to incorporate soil effects, critical in the boreal. This is the only available way to explore the fire implications of truly novel species assemblages and structures that seem to be emerging. Together, this work will explore fire likelihood feedbacks and structural thresholds associated with fire behavior in the boreal forest and inform expectations about how the region will respond, in terms of wildfire and energy balance, to climate warming. The project will work with the non-profit COMPASS to organize a two-day science communication workshop for graduate students and scientists in the larger academic community. They will also work with Concord Consortium to develop a module tool for teaching highschoolers, working with teachers to solicit feedback.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.