Sky islands of southwest China. I: an overview of phylogeographic patterns

Sky islands are high-elevation areas in continental mountain ranges, which are geographically isolated. We adopted this concept for the mountains in southwest China, which are among the most important biodiversity hot spots on earth. We reviewed the phylogeographic studies of this area and highlighted the sky-island features. We concluded that the genetic structures of species in these islands were shaped by complex topography, climate and habitats. The global climate change, such as Pleistocene climate fluctuations and periodic uplift of the Qinghai-Tibetan Plateau, also have important effects on biodiversity and geographic patterns, when species have responded idiosyncratically by changing their distributions or through adaptation. Future research needs in sky islands include multilocus data and comparative phylogeographic studies, integrating with the methodological advances in the other fields. Using these approaches, we can examine to what degree the geographic, climate and/or biological factors, shape strong geographic patterns, promote diversification/speciation and preserve species/genetic diversity. We hope this paper will inspire future work to uncover the mechanism that has generated the endemic biodiversity and to further resolve the most essential problem: How to protect the biodiversity with limited funding during the coming drastic global climate change.