Assisted migration to address climate change in forestry: validating habitat and growth projections

在大规模的重新造林计划中，人类辅助的物种种群移动可能是一种有效且具有成本效益的气候变化适应策略。加拿大几个省级林业机构目前正在执行协助移徙的林业处方。然而，这种大规模的管理干预往往会带来意想不到的后果的风险，特别是在不完善的模型和部分信息的指导下。该项目将填补科学知识空白，开发强大的建模技术，在这一关键时刻直接为种子转移的政策制定提供信息。这项研究计划的中心思想是将北美树种引入欧洲，作为这些树种如何在新气候环境下生长和生存的试验台。特别是锡特卡云杉和道格拉斯冷杉已经在欧洲进行了几十年的广泛试验，并在许多地方进行了商业种植，这些地方证明了它们的生产力和弹性。我们利用这个机会用完全独立的数据来验证我们的北美栖息地模型，并通过暗示评估其现实性，以指导气候变化下的林业经营。具体来说，我们将测试一种新的物种分布模型，该模型是为了指导加拿大西部重新造林的树种选择而开发的。我们将把为锡特卡云杉和道格拉斯冷杉训练的模型应用到欧洲的种植环境中，并根据欧洲种源试验（已知种子来源的20至80年的实验种植园）的数据验证其预测。将对来自10个欧洲国家的树木年轮数据的生长记录和长达百年的森林清查记录进行进一步的验证。

Human-aided movement of species populations in large-scale reforestation programs could be an effective and cost-efficient climate change adaptation strategy. Assisted migration prescriptions in forestry are currently being implemented by several Canadian provincial forestry agencies. Such large-scale management interventions, however, tend to entail the risks of unintended consequences, especially when guided by imperfect models and partial information. This project will fill scientific knowledge gaps and develop robust modeling techniques that can directly inform policy developments for seed transfer at this critical juncture.The central idea of this research program is to use introductions of North American tree species to Europe as a test bed for how these species may grow and survive under novel climatic environments. Especially Sitka spruce and Douglas-fir have been widely tested in Europe for decades, and are commercially planted in many locations where they proved productive and resilient. We use this opportunity to validate our North American habitat models against completely independent data, and by implication evaluate their realism to guide forestry operations under climate change.Specifically, we will test a new class of species distribution model, which was developed to guide choice of planting stock for reforestation in western Canada. We will apply the model trained for Sitka spruce and Douglas-fir to European planting environments, and validate its predictions against data from European provenance trials (20- to 80-year old experimental plantations with known origin of seed sources). Additional validations will be carried out against growth records from tree ring data and up to hundred years of forest inventory records from ten European countries.