If you build it, will they come? On the potential ecological and social benefits of assisted tree migration

我们的森林为加拿大人提供了不可替代的利益和服务，未来几十年对这些资源的需求将继续增加。与需求增加并行的是气候变化，不断上升的温度将使许多商业物种的最佳生长条件向北推进。横跨加拿大东部大部分地区的混交林将对这些变化作出反应，并要求我们制定适应措施，以确保其持续更新和生产力。我们的大学和政府科学家团队将利用大规模的、可操作规模的辅助迁移示范，开发新知识，以支持省级和国家有关森林适应的政策。2019年，在不同的造林处理下，在混合树种人工林中种植了8个物种和3个与现在和未来气候相似的种源（每个物种）。我们控制了冠层去除（部分与完全）、植被竞争控制（控制与不控制）和大型食草动物的食草性（封闭与不封闭）。在魁北克政府的大力支持下，我们将与4名学生（3名博士，1名硕士）组成一个团队，回答有关辅助树木迁移的四个基本和应用问题。什么样的物种相互作用可能受到不同树木物候的影响？昆虫和两栖动物对种植在它们活动范围之外的树木会有什么反应？种源不同，幼苗叶片和根系上的微生物群落有何变化？不同的森林使用者，如当地社区和专业林务人员如何看待辅助迁移方法？这些问题的答案将为加拿大政府机构制定新的森林管理战略提供信息。

Our forests provide irreplaceable benefits and services to Canadians, and demands for these will continue to increase in the next decades. Parallel to increasing needs is a changing climate where climbing temperatures will push the optimal growth conditions of many commercial species northward. The mixedwood forest that straddles much of eastern Canada will respond to these changes and require that we develop adaptation measures to ensure its continued renewal and productivity. Our team of university and government scientists will take advantage of a large, operational-scale demonstration of assisted migration, to develop new knowledge to support provincial and national policies around forest adaptation. In 2019, eight species and three provenances (of each species) analogue to present and future climates, were planted out in mixed species plantations under different silvicultural treatments. We manipulated canopy removal (partial vs complete), control of vegetation competition (control vs no control), and herbivory of large herbivores (exclosure vs no exclosure). With a team of 4 students (3 PhD, 1 MSc), as well as substantial support from the Quebec government, we will answer four fundamental and applied questions about assisted tree migration. What kind of species interactions might be affected by different tree phenology? How will insects and amphibians respond to tree provenances planted outside their range? How will the microbial communities on leaves and roots of seedlings vary according to provenance? How do different forest users such as local communities and professional foresters perceive the assisted migration approach. The answers to these questions will inform new forest management strategies of government agencies across Canada.