Local Adaptation and Evolutionary and Adaptive Genetic Potential of Marginal Populations of Northern Forest Trees under Climate Change

气候变化已经成为北方北方和温带生态系统进化的主要驱动力，在这些生态系统中，树木通常是主要的关键物种，因为它使它们承受着巨大的进化和适应压力。气候变化对自然生态系统的影响从许多物种范围的极移中可见一斑。因此，物种范围边缘的种群有望为植物在气候变化下的适应、进化和范围转移提供边界。这些问题引发了一场关于辅助迁徙的辩论。边缘群体适应和扩展到新领域的潜力取决于他们的当地适应、遗传构成和遗传多样性，特别是对气候变化的反应和适应的基因。因此，了解物种对气候变化的基因反应、边缘种群局部适应的遗传基础以及它们在气候变化下的进化和适应遗传潜力，对于制定缓解措施至关重要。林木种群通常是局部适应的，但关于它们局部适应的遗传结构的知识仍然难以捉摸。 本研究的目的是了解东部白松边缘种群中心、前沿和后缘种群的遗传特征及其对气候变化的遗传响应；了解边缘种群和中心种群局部适应的遗传结构和机制；推断边缘种群在气候变化下的进化和适应遗传潜力。东方白松为本研究提供了一个理想的模型。它具有很高的生态和经济价值，广泛分布于各种气候和生态条件，是北美温带白松林生态系统中长寿的关键物种，其北部山脉边缘位于加拿大，并有望在气候变化下向北扩展其活动范围。它也是协助迁徙的目标物种。将研究其中部山脉和北部和南部山脉边缘的EWP种群。对气候变化条件作出反应的基因将被识别并在功能上进行注释。全基因组扫描将用于确定种群的遗传特征、局部适应的遗传架构以及EWP种群的进化和适应遗传潜力。 本研究将促进我们对林木对气候变化的遗传响应、局部适应、边缘种群的保护价值和适应遗传潜力、后缘种群的脆弱性以及气候变化下物种范围的进化等方面的认识。它对长期适应、可持续管理和保护森林资源具有重大意义，并将解决缓解措施问题，如协助移徙。

Climate change has become a prominent driving force of evolution in northern boreal and temperate ecosystems in which trees are normally the dominant keystone species as it is subjecting them to significant evolutionary and adaptive pressures. Impacts of climate change across natural ecosystems are evident from pole-ward shift of many species' range. Thus, populations at the species' range margins are expected to provide the frontiers for adaptation, evolution and range shifts of plants under climate change.These issues have ignited a debate on assisted migration. The potential of marginal populations to adapt and expand to new areas depends upon their local adaptation, genetic make-up and genetic diversity, especially in genes underlying responses and adaption to climate change. Hence, it is critical to understand the genic responses of a species to climate change, genetic basis of local adaptation of marginal populations, and their evolutionary and adaptive genetic potential under climate change in order to develop mitigation measures. Forest trees populations are usually locally adapted but knowledge of genetic architecture of their local adaptation remains elusive. The objectives of my research are to understand genetic characteristics of central and leading-edge and rear-edge marginal populations of eastern white pine (EWP) and its genetic responses to climate change; understand genetic architecture and mechanisms underlying local adaptation of marginal and central populations; and infer evolutionary and adaptive genetic potential of marginal populations under climate change. Eastern white pine provides an ideal model for the proposed research. It is of high ecological and economic importance, widely distributed across a variety of climate and ecological conditions, is a long-lived keystone species of the North American temperate white pine forest ecosystems, has its northern range margins in Canada, and is expected to extend its range northwards under climate change. It is also a target species for assisted migration. EWP populations from its central range and northern and southern range margins will be studied. Genes responsive to climate change conditions will be identified and functionally annotated. Genome-wide scans will be used to determine genetic characteristics of populations, genetic architecture of local adaptation, and evolutionary and adaptive genetic potential of EWP populations. My research will advance our knowledge of genetic responses of forest trees to climate change, local adaptation, conservation value and adaptive genetic potential of marginal populations, vulnerability of rear-edge populations, and evolution of species' range under climate change. It has major significance for long-term adaptation, sustainable management, and conservation of forest resources, and will address mitigation measure issues, such as assisted migration.