Predicting the capacity of conifer populations to adapt to new climates using ecologically relevant genetic markers

针叶林主导着加拿大的许多自然景观，在经济上具有巨大的重要性，为森林工业提供木材和纤维，在生态上为其他生物提供栖息地和一系列生态系统服务。气候变暖已经通过改变平均温度和极端温度、可用水分、竞争、昆虫和疾病，影响了加拿大和世界其他地区的森林健康。自然种群适应快速气候变化的程度将由无数因素决定。与局部气候适应有关的性状的遗传变异将发挥重要作用。我们已经确定了一些基因，这些基因共同参与了锡特卡云杉（Picea sitchensis）种群如何将其生长节奏与当地气候同步，以最大限度地提高生长速度，而不会受到寒冷的伤害。通过研究这些基因变异在锡特卡云杉、白云杉和恩格尔曼云杉以及自然发生的杂交种群中的地理分布，我们将能够预测种群通过自然选择适应新的季节性气候条件的速度，例如，全球变暖导致的生长季节延长。我们还将回顾性研究阿拉斯加Kodiak岛上一个孤立的锡特卡云杉种群的殖民化和遗传动力学，该种群最初是在大约四个世纪前通过长距离种子传播建立起来的，以更好地了解随着物种范围的扩大，殖民化、迁移和适应是如何相互作用的。最后，我们将沿着纬度和海拔梯度比较对温度的适应，以了解适应变化和光周期响应在不同地理尺度上的分布是否不同。这些研究的结果将用于预测天然针叶树种群适应新温度制度的速度；并将为我们社会当前的对话提供信息，即随着气候变化，我们是否应该帮助这些种群和物种迁移到新的地点。他们还将向树木育种者和森林管理者提供有关自然种群和云杉育种计划中遗传多样性水平的信息。

Coniferous forests dominate many of Canada's natural landscapes, and have tremendous importance both economically, providing wood and fiber to the forest industry, and ecologically, providing habitat for other organisms and a range of ecosystem services. Climate warming is already affecting the health of forests in Canada and in other parts of the world through changing average and extreme temperatures, available moisture, competition, insects and diseases. The extent to which natural populations can adapt to rapid climate change will be determined by a myriad of factors. Genetic variation for traits involved in local adaptation to climate will play an important role. We have identified genes that are collectively involved in how Sitka spruce (Picea sitchensis) populations synchronize their growth rhythms with their local climate to maximize growth without risking cold injury. By studying the geographic distribution of variation in these genes in Sitka spruce, white spruce (P. glauca) and Engelmann spruce (P. engelmannii), as well as naturally occurring hybrid populations, we will be able to predict how rapidly populations can adapt through natural selection to new seasonal climatic conditions, e.g, a longer growing season resulting from global warming. We will also retrospectively study the colonization and genetic dynamics of an isolated population of Sitka spruce on Kodiak Island, Alaska that was first established through long distance seed dispersal approximately four centuries ago to better understand how colonization, migration and adaptation interact as species ranges expand. Finally, we will compare adaptation to temperature along latitudinal and elevational gradients to see if adaptive variation and photoperiod responses are distributed differently at different geographic scales. The results of these studies will be used to predict how quickly natural conifer populations can adapt to new temperature regimes; and will inform the current dialogue in our society about whether we should be assisting the migration of these populations and species to new locations as climates change. They will also provide information to tree breeders and forest managers about levels of genetic diversity within natural populations and in spruce breeding programs.