Fire regimes in a warming world: the role of plant traits in the resilience to fire of Eurasian boreal forests

火灾可能会对社会和环境产生巨大的负面影响。然而，火是生态系统动力学中不可或缺的一部分，它控制着许多生物群落的一系列进化和生态过程。预计在未来气候变暖的情况下，北方森林将经历更频繁和/或更严重的火灾。这一点具有重要意义，因为北方森林占全球森林面积的三分之一，其中大部分位于俄罗斯(主要是西伯利亚)。欧亚森林火灾状况被归类为低至中等严重程度，但该区域内有很强的变异性，很可能与主要树种有关。然而，对植被组成和性质如何决定火势的全面了解仍然缺乏。一个根本的问题是，生态过程发生在几十年到几千年之间，因此不存在直接的观测。这一点，加上西伯利亚北部森林过去的火灾历史记录很少，导致我们对以下问题的理解产生了很大的不确定性：i)关键的西伯利亚北部类群对火灾频率和严重程度的耐受范围；ii)影响抗火能力和火灾后恢复潜力的最常见的植物功能特征；iii)将火情变化与植被特性联系起来的联系和反馈。在这个项目中，我将开发一种创新的跨学科方法，重点是了解火灾制度和植物特性之间的相互作用如何控制欧亚北部针叶林的分布。我将结合新的火、植被和气候化石记录，这些化石记录来自木炭形态、花粉、稳定同位素和迄今未发现的欧亚大陆北部西伯利亚部分的隐形变形虫，以及来自数据库的关键北方树种与火相关的功能特征的信息。将使用统计方法来结合数据集，以确定和理解火灾状况和火灾植被反馈变化的驱动因素。该项目的结果将提供：i)根据火灾频率和严重程度对欧亚大陆主要北方类群耐火范围的经验估计；ii)与抗火和火灾恢复有关的一组植物特性，以及这些特性是否在整个时间和空间上是普遍的；以及iii)确定火灾状况如何控制北方森林的状态变化。它还将为特定学科的专家以及火灾模型师、利益攸关方和环境管理人员提供建议，说明如何通过考虑与火灾有关的植物功能特征来培养抗火景观和管理潜在的火灾影响。

Fire can have dramatically negative impacts on societies and environment. However, fire is an integral part of ecosystem dynamics that controls a range of evolutionary and ecological processes in many biomes. Boreal forests are predicted to experience more frequent and/or severe fires under future climate warming. This has critical relevance as boreal forests account for one third of the global forested area, most of this located in Russia (mainly Siberia). The Eurasian forest fire regime is categorised as low to medium in severity, but there is a strong variability within this region, most probably linked to the dominant tree species. However, a comprehensive understanding of how exactly vegetation composition and properties determine fire regimes is still lacking. A fundamental problem is the ecological processes occur over decades to millennia and therefore no direct observations exist. This and the fact that past fire history in boreal forest of Siberia is poorly documented resulted in large uncertainties in our understanding of: i) tolerance range of key Siberian boreal taxa to fire frequency and severity; ii) the most common plant functional traits that influence resistance to fire and post fire recovery potential and iii) the linkages and feedbacks that tie changes in fire regime to vegetation properties. In this project I will develop an innovative inter-disciplinary approach focusing on understanding how interactions between fire regime and plant traits control the distribution of Eurasian boreal forests. I will combine new fossil records of fire, vegetation and climate derived from charcoal morphologies, pollen, stable isotopes and testate amoebae from hitherto uncovered Siberian parts of boreal Eurasia with information on fire-related functional traits of key boreal tree species derived from databases. Statistical approaches will be used to combine the datasets to determine and understand drivers of shifts in fire regime and fire-vegetation feedbacks. Results from this project will provide: i) empirical estimates of tolerance ranges of key Eurasian boreal taxa with respect to fire frequency and severity; ii) set of plant traits associated with resistance to fire and recovery from fire, and whether these are common across time and space; and iii) determine how fire regime controls state changes in boreal forests. It will also provide recommendations for subject-specific specialists, but also fire modellers, stakeholders and environmental managers, on how to foster fire-resilient landscapes and manage potential fire impacts by considering fire-relevant plant functional traits.