Boreal forest refugia for fire and climate change

生态学和自然保护的一个核心问题是生物多样性将如何对气候变化作出反应——本质上是确定可能或多或少易受伤害的物种和地方。最近关于气候变化速度的研究表明，宏观地形和海洋特征如何降低气候速度，从而导致物种可能持续存在的可定义的大避难所区域。尽管在宏观尺度上已经做了很多工作来了解避难所，但较小尺度的景观特征也可以将一个地点的温度与其周围气候脱钩，从而产生微避难所。与宏观避难所不同，微观避难所不容易从缩小的气候模型中预测，导致我们的理解和预测存在差距。关于微避难所的现有工作强调当地地形，令人惊讶的是，关于大型湖泊对邻近大陆微气候的影响的工作很少，因此潜在的微避难所区域。然而，已知一些大型湖泊在其海岸线上有分离的物种，其种群在其主要范围以南1000公里处，代表了以前较冷气候的遗迹。了解这些模式有助于了解当前的威胁和未来的应对措施。大型湖泊经常被低估的第二个方面是它们通过分散燃料和阻止火势蔓延来使火势多样化的能力。这不仅创造了火灾避难所，支持沿着海岸线和岛屿生长的古老物种，而且还潜在地支持更高景观规模的生物多样性。湖源性气候和火源性避难在区位上具有协同效应，进一步增强了避难效应。

A central question in ecology and conservation is how biodiversity will respond to climate change - essentially identifying species and places that are likely to be more or less vulnerable. Recent work on the velocity of climate change has illustrated how macro-terrain and maritime features can reduce climate velocity resulting in definable areas of macrorefugia where species are likely to persist. Although much has been done to understand refugia at macro-scales, smaller scale landscape features can also decouple a location's temperature from its surrounding climate resulting in microrefugia. And unlike macrorefugia, microrefugia can not be easily predicted from downscaled climate models resulting in gaps in our understanding and predictions. Existing work on microrefugia emphasizes local topography with surprisingly little work on the effects of large lakes on adjacent mainland microclimates and hence areas of potential microrefugia. Yet some large lakes are known to have disjunct species along their shoreline with populations >1,000 km south of their main range representing relicts of a previous cooler climate. Understanding these patterns informs current threats and future responses. A second aspect of large lakes that is often underappreciated is their ability to diversify fire regimes by fragmenting fuel and blocking fire spread. This not only creates fire refugia that supports old-growth species along their shorelines and on islands, but also potentially supporting higher landscape-scale biodiversity. When taken together, lake-derived climate and fire refugia can be synergistic in their location strengthening further the refugia effect. My long-term research goals are to understand the processes governing the distribution, dynamics, and interactions of species and ecosystems and to use this information to inform biodiversity conservation. I propose to address these questions and their applications to conservation in this grant under two complementary topics. The first is in understanding the factors associated with lakes that alter microclimates and promote disjunct patterns in biota thus informing local climate refugia. This includes measuring and predicting microclimatic and biotic responses along lake shorelines, relating these to existing patterns in relict species, and predicting future change. The second is in understanding how these lakes alter fire history within fire-prone boreal forests of western Canada, including locations of fire refugia and how this regulates the supply of old growth forests and biodiversity. This work will be done through a combination of field and remote sensing studies ultimately providing new insights, understandings, methods, and conservation applications to refugia (fire & climate) and biodiversity within Canada's boreal forest. The grant will also result in training of highly-quality personnel who will contribute towards addressing Canada's commitment to biodiversity protection.