Forest fire regimes across boreal Eastern North America and Northern Europe (BENANE): towards understanding long-term dynamics, climate drivers, and future trends of forest fire activity

火灾驱动着北方森林的动态和生态系统功能，直接影响着全球碳平衡和大气微量气体的浓度。了解火灾活动的多尺度控制对于建立该生物群系过去和未来动态的良好机制模型，特别是其对未来气候变化的响应至关重要。我研究的主要长期目标是有助于理解作为生物地理和气候因素函数的环周火灾活动的长期动态。这方面的知识将有助于对未来的火灾活动进行合理的建模，特别是将大尺度大气环流模式缩小到对未来森林火灾活动的估计中，并评估北方生物群落在一系列气候条件下的恢复能力。拟议的项目侧重于北美东部和北欧的北方森林（BENANE），该研究的进展在很大程度上受到(a)充足参考数据集的可用性和(b)对复杂气候-火灾联系的了解有限。拟议的项目将(A)建立气候变率、次区域生物地理和区域火灾活动模式之间的机制关系，另一方面，特别关注BENANE地区火灾活动增加的年份和时期；(B)校准基于过程的建模框架，以预测和分析未来气候对BENANE地区火灾活动的影响，包括碳排放的动态。植被组成和动态变化、森林碳平衡、森林生物量和生产力。我的总体假设是，尽管BENANE内部存在生物地理差异，干扰事件的主要类型（地表与林分替代火灾）存在差异，并且考虑了大的地理尺度，但在次区域火灾活动中存在很强的遥连性模式，可以在多个时间尺度上进行回顾性观察。这种连通性源于BENANE上的大尺度大气环流异常，这与涉及北大西洋的系统能量状态的变化和相关的大气压力型有关。

Fire drives the dynamics and ecosystem functions of the boreal forest and directly affects global carbon balance and concentrations of the atmospheric trace gases. Understanding multi-scale controls of fire activity is paramount for sound mechanistic modeling of past and future dynamics of this biome, and particularly - its response to future climatic changes. The main long-term objective of my research is to contribute towards understanding of long-term dynamics of circumboreal fire activity as a function of biogeographical and climatic factors. This knowledge should allow for sound modelling of the future fire activity, and specifically - in downscaling the large-scale atmospheric circulation patterns into estimates of future forest fire activity and assessing the resilience of the boreal biome under a range of climate conditions. The proposed project focuses on the boreal forests of Eastern North America and Northern Europe (BENANE), where the progress in this research is largely limited by (a) the availability of adequate reference datasets, and (b) limited understanding of complex climate-fire linkages. The proposed project will (A) establish a mechanistic relationship between climate variability, sub-regional biogeography, on one hand, and regional patterns of fire activity, on the other, putting a particular focus on years and periods with increased fire activity across BENANE region, and (B) calibrate a process-based modeling framework to project and analyze the effects of future climate on fire activity in BENANE, including dynamics of carbon emissions, changes in composition and dynamics of vegetation, forest carbon balance, and forest biomass and productivity. My overall hypothesis is that despite biogeographical differences within BENANE, differences in the dominating type of disturbance events (surface vs. stand replacing fires) and large geographical scale under consideration, there is a strong teleconnectivity patterns in sub-regional fire activity, which could be observed restrospecitvely at multiple temporal scales. This connectivity stems from large scale atmospheric circulation anomalies over the BENANE, which are related to the changes in the energy states of the system involving Northern Atlantic Ocean and associated atmospheric pressure patterns.