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好处和服务，对这些的需求在未来几十年将继续增加。与不断增长的需求并行的是不断变化的气候，气温的上升将推动许多商业物种的最佳生长条件向北移动。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、可操作的辅助移民示范，开发新知识，以支持省级和国家关于森林适应的政策。2019年，在不同营林处理下的混合树种种植园种植了8个树种和3个种源(每个树种)，以模拟现在和未来的气候。我们操作了树冠移除(部分与完全)，控制植被竞争(对照与非对照)，以及大型食草动物的草食(围栏与非围栏)。在一个由4名学生(3名博士，1名硕士)组成的团队以及魁北克政府的大力支持下，我们将回答有关树木辅助迁移的四个基本和应用问题。不同的树木物候可能会影响哪种物种的相互作用？昆虫和两栖动物对种植在它们活动范围之外的树木种源会有什么反应？幼苗叶和根上的微生物群落将如何根据种源的不同而变化？不同的森林使用者，如当地社区和专业林农，如何看待协助移徙办法。这些问题的答案将为加拿大各地政府机构制定新的森林管理战略提供参考。

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.