Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland.
Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Austria.
Glob Chang Biol. 2018 Jul;24(7):3236-3253. doi: 10.1111/gcb.14087. Epub 2018 Mar 13.
Alpine and Arctic species are considered to be particularly vulnerable to climate change, which is expected to cause habitat loss, fragmentation and-ultimately-extinction of cold-adapted species. However, the impact of climate change on glacial relict populations is not well understood, and specific recommendations for adaptive conservation management are lacking. We focused on the mountain hare (Lepus timidus) as a model species and modelled species distribution in combination with patch and landscape-based connectivity metrics. They were derived from graph-theory models to quantify changes in species distribution and to estimate the current and future importance of habitat patches for overall population connectivity. Models were calibrated based on 1,046 locations of species presence distributed across three biogeographic regions in the Swiss Alps and extrapolated according to two IPCC scenarios of climate change (RCP 4.5 & 8.5), each represented by three downscaled global climate models. The models predicted an average habitat loss of 35% (22%-55%) by 2100, mainly due to an increase in temperature during the reproductive season. An increase in habitat fragmentation was reflected in a 43% decrease in patch size, a 17% increase in the number of habitat patches and a 34% increase in inter-patch distance. However, the predicted changes in habitat availability and connectivity varied considerably between biogeographic regions: Whereas the greatest habitat losses with an increase in inter-patch distance were predicted at the southern and northern edges of the species' Alpine distribution, the greatest increase in patch number and decrease in patch size is expected in the central Swiss Alps. Finally, both the number of isolated habitat patches and the number of patches crucial for maintaining the habitat network increased under the different variants of climate change. Focusing conservation action on the central Swiss Alps may help mitigate the predicted effects of climate change on population connectivity.
高山和北极物种被认为特别容易受到气候变化的影响，预计气候变化将导致适应寒冷的物种失去栖息地、破碎化，最终灭绝。然而，气候变化对冰川遗留种群的影响尚未得到很好的理解，也缺乏适应保护管理的具体建议。我们以山地野兔（Lepus timidus）为模式物种，结合斑块和景观连通性指标来模拟物种分布。这些指标是从图论模型中得出的，用于量化物种分布的变化，并估计栖息地斑块对整体种群连通性的当前和未来重要性。模型基于分布在瑞士阿尔卑斯山三个生物地理区域的 1046 个物种存在位置进行校准，并根据气候变化的两个 IPCC 情景（RCP 4.5 和 8.5）进行外推，每个情景都由三个降尺度的全球气候模型表示。模型预测到 2100 年，平均栖息地损失将达到 35%（22%-55%），主要是由于繁殖季节气温升高所致。栖息地破碎化的增加反映在斑块面积减少 43%、斑块数量增加 17%和斑块间距离增加 34%。然而，不同生物地理区域的栖息地可用性和连通性的预测变化差异很大：在物种阿尔卑斯分布的南部和北部边缘，预计栖息地损失最大，而斑块数量增加和斑块面积减小最大的地区则在瑞士阿尔卑斯山中部。最后，在不同的气候变化情景下，孤立栖息地斑块的数量和维持栖息地网络的关键斑块的数量都有所增加。将保护行动集中在瑞士阿尔卑斯山中部可能有助于减轻气候变化对种群连通性的预测影响。
