Klauke Nadine, Schaefer H Martin, Bauer Michael, Segelbacher Gernot
Animal Ecology and Evolution, Faculty of Biology, University of Freiburg, Freiburg, Germany.
Wildlife Ecology and Management, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany.
PLoS One. 2016 Dec 29;11(12):e0169165. doi: 10.1371/journal.pone.0169165. eCollection 2016.
Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined to specific habitat types within narrow altitudinal ranges. While deforestation put these ecosystems under threat, we still lack knowledge about how heterogeneous environments like the montane tropics promote population connectivity and persistence. We investigated the fine-scale genetic structure of the two largest subpopulations of the endangered El Oro parakeet (Pyrrhura orcesi) endemic to the Ecuadorian Andes. Specifically, we assessed the genetic divergence between three sites separated by small geographic distances but characterized by a heterogeneous habitat structure. Although geographical distances between sites are small (3-17 km), we found genetic differentiation between all sites. Even though dispersal capacity is generally high in parrots, our findings indicate that dispersal is limited even on this small geographic scale. Individual genotype assignment revealed similar genetic divergence across a valley (~ 3 km distance) compared to a continuous mountain range (~ 13 km distance). Our findings suggest that geographic barriers promote genetic divergence even on small spatial scales in this endangered endemic species. These results may have important implications for many other threatened and endemic species, particularly given the upslope shift of species predicted from climate change.
热带山地生态系统是生物多样性热点地区，拥有许多特有物种，这些物种局限于狭窄海拔范围内的特定栖息地类型。虽然森林砍伐使这些生态系统受到威胁，但我们仍然缺乏关于像山地热带这样的异质环境如何促进种群连通性和持久性的知识。我们研究了厄瓜多尔安第斯山脉特有的濒危奥罗鹦鹉（Pyrrhura orcesi）两个最大亚种群的精细尺度遗传结构。具体来说，我们评估了三个地理距离较小但栖息地结构异质的地点之间的遗传差异。尽管各地点之间的地理距离很小（3 - 17公里），但我们发现所有地点之间都存在遗传分化。尽管鹦鹉的扩散能力通常较高，但我们的研究结果表明，即使在这个小地理尺度上，扩散也是有限的。个体基因型分配显示，与连续山脉（约13公里距离）相比，山谷（约3公里距离）两侧的遗传差异相似。我们的研究结果表明，地理障碍即使在这个濒危特有物种的小空间尺度上也会促进遗传分化。这些结果可能对许多其他受威胁和特有物种具有重要意义，特别是考虑到气候变化预测的物种上坡迁移。
