Department of Ecology and Evolutionary Biology, La Kretz Center for Californian Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; Department of Biological Sciences and Museum of Natural History, Auburn University, Auburn, AL 36849, USA; Department of Biology, La Sierra University, Riverside, CA 92515, USA.
Department of Ecology and Evolutionary Biology, La Kretz Center for Californian Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; Department of Life, Earth, and Environmental Sciences, West Texas A&M University, Canyon, TX 79016, USA.
Mol Phylogenet Evol. 2022 Sep;174:107542. doi: 10.1016/j.ympev.2022.107542. Epub 2022 Jun 8.
The mountains of southern California represent unique, isolated ecosystems that support distinct high-elevation habitats found nowhere else in the area. Analyses of several moisture-dependent species across these sky-islands indicate they exist as locally endemic lineages that occur across these fragmented mountains ranges. The Rubber Boa is a semi-fossorial snake species that is widely distributed in the cooler and more moist ecoregions regions of western North America, including isolated populations across southern California mountain ranges. We developed a genomic and ecological dataset to examine genetic diversity within Rubber Boas and to determine if the endemic Southern Rubber Boa represents a distinct lineage. We quantified current and future habitat suitability under a range of climate change scenarios, and discuss the possible environmental threats facing these unique montane isolates. Our results support four major lineages within Rubber Boas, with genetic breaks that are consistent with biogeographic boundaries observed in other co-distributed, cool-temperature, moisture adapted species. Our data support previous studies that the Southern Rubber Boa is an independent evolutionary unit and now includes multiple locally endemic sky-island populations, restricted to isolated mountain tops and ranges across southern California. Analyses of future habitat suitability indicate that many of these sky-island populations will lose most of their suitable habitat over the next 70 years given predicted increases in drought, rising temperatures, and wildfires. Collectively these data emphasize the critical conservation needs of these montane ecosystems in southern California under current and projected climate change conditions.
南加州的山脉代表了独特的、孤立的生态系统，支持着该地区其他地方找不到的独特高海拔栖息地。对这些“天空岛屿”上的几种依赖湿度的物种进行分析表明，它们作为局部特有谱系存在，分布在这些破碎的山脉中。橡胶蟒是一种半穴居蛇类，广泛分布于北美西部较凉爽和潮湿的生态区，包括南加州山脉的孤立种群。我们开发了一个基因组和生态数据集，以研究橡胶蟒的遗传多样性，并确定地方性的南橡胶蟒是否代表一个独特的谱系。我们量化了在一系列气候变化情景下当前和未来的栖息地适宜性，并讨论了这些独特的山地隔离种群可能面临的环境威胁。我们的研究结果支持橡胶蟒的四个主要谱系，其遗传断裂与其他共同分布的、低温、适应湿度的物种观察到的生物地理边界一致。我们的数据支持了先前的研究，即南橡胶蟒是一个独立的进化单位，现在包括多个地方性的天空岛屿种群，这些种群局限于南加州的孤立山顶和山脉。对未来栖息地适宜性的分析表明，在未来 70 年内，由于干旱、气温上升和野火的预测增加，这些天空岛屿种群中的许多将失去大部分适宜栖息地。这些数据共同强调了南加州这些山地生态系统在当前和预测的气候变化条件下的关键保护需求。
