Canadian Facility for Ecoinformatics Research, Department of Biology, University of Ottawa, 30 Marie-Curie Private, Ottawa, ON, K1N 6N5, Canada.
Sci Rep. 2018 Oct 18;8(1):14464. doi: 10.1038/s41598-018-32665-y.
Climate change has shaped bee distributions over the past century. Here, we conducted the first species-specific assessment of future climate change impacts on North American bumblebee distributions, using the most recent global change scenarios developed in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). We assessed potential shifts in bumblebee species distributions with models generated using Maxent. We tested different assumptions about bumblebee species' dispersal capacities, drawing on observed patterns of range shifts to date, dispersal rates observed for bumblebee queens, and, lastly, assuming unlimited dispersal. Models show significant contractions of current ranges even under scenarios in which dispersal rates were high. Results suggest that dispersal rates may not suffice for bumblebees to track climate change as rapidly as required under any IPCC scenario for future climate change. Areas where species losses are projected overlap for many species and climate scenarios, and are concentrated in eastern parts of the continent. Models also show overlap for range expansions across many species, suggesting the presence of "hotspots" where management activities could benefit many species, across all climate scenarios. Broad-scale strategies are likely to be necessary to improve bumblebee conservation prospects under climate change.
气候变化在过去一个世纪塑造了蜜蜂的分布。在这里，我们首次针对北美熊蜂分布的未来气候变化影响进行了具体物种评估，使用了政府间气候变化专门委员会（IPCC）第五次评估报告中制定的最新全球变化情景。我们使用 Maxent 生成的模型评估了熊蜂物种分布的潜在变化。我们根据迄今为止观察到的范围变化模式、观察到的熊蜂女王的扩散率以及假设的无限扩散，测试了关于熊蜂物种扩散能力的不同假设。即使在扩散率较高的情况下，模型也显示出当前范围的显著收缩。结果表明，在未来气候变化的任何 IPCC 情景下，扩散率可能不足以使熊蜂像所需的那样迅速跟踪气候变化。预计物种损失的地区与许多物种和气候情景重叠，集中在大陆的东部。模型还显示了许多物种的范围扩大存在重叠，这表明在所有气候情景下，管理活动都可能使许多物种受益的“热点”存在。在气候变化下，要改善熊蜂保护前景，可能需要采取广泛的策略。
