Brusch George A, Taylor Emily N, Whitfield Steven M
Oecologia. 2016 Feb;180(2):325-34. doi: 10.1007/s00442-015-3467-3.
Global temperature increases over the next century are predicted to contribute to the extinction of a number of taxa, including up to 40% of all lizard species. Lizards adapted to living in lowland tropical areas are especially vulnerable because of their dependence on specific microhabitats, low vagility, and a reduced capacity to physiologically adjust to environmental change. To assess the potential effects of climate change on lizards in the lowland tropics, we measured the critical thermal maximum (CTmax) of ten species from La Selva, Costa Rica. We also examined how well body size, microhabitat type, and species predicted the CTmax. We used current temperature data along with projected temperature increases for 2080 to predict which species may be at the greatest risk at La Selva. Of the ten species sampled, four are at serious risk of lowland extirpation and three others might also be at risk under the highest predicted temperature-increase models. Forest floor lizards at La Selva have already experienced significant population declines over the past 40 years, and we found that each of the forest floor species we studied is at serious risk of local extirpation. We also found that microhabitat type is the strongest predictor of CTmax, demonstrating the profound impact habitat specialization has on the thermal limits of tropical lizards.
预计下个世纪全球气温上升将导致许多分类群灭绝，包括多达40%的蜥蜴物种。由于依赖特定的微生境、低迁移能力以及生理上适应环境变化的能力降低，适应生活在低地热带地区的蜥蜴尤其脆弱。为了评估气候变化对低地热带地区蜥蜴的潜在影响，我们测量了来自哥斯达黎加拉塞尔瓦的10个物种的临界热最大值（CTmax）。我们还研究了体型、微生境类型和物种对CTmax的预测效果。我们利用当前的温度数据以及2080年预计的温度升高来预测拉塞尔瓦哪些物种可能面临最大风险。在抽样的10个物种中，有4个面临低地灭绝的严重风险，在预测温度升高幅度最大的模型下，另外3个物种也可能面临风险。拉塞尔瓦的森林地面蜥蜴在过去40年里种群数量已经显著下降，我们发现我们研究的每一种森林地面蜥蜴物种都面临局部灭绝的严重风险。我们还发现微生境类型是CTmax的最强预测因子，这表明生境专业化对热带蜥蜴的热极限有深远影响。
