中国亚热带地区阔叶林植物的谱系地理历史

Phylogeographic history of broad-leaved forest plants in subtropical China

中国亚热带地区因丰富的植物物种多样性备受生物地理学研究关注,丰富的多样性与中新世以来的地质气候变化密切相关。谱系地理学已成为探讨植物分布模式和遗传格局受地质气候变化影响的主要手段。总结了该地区阔叶林植物对中新世以来地质气候变化的响应模式和种群分化的历史成因。在中新世和上新世时,由于全球变冷、青藏高原抬升和亚洲内陆干旱,阔叶林植物被迫向南退缩,形成不同的谱系。同时,亚洲季风的增强为遗传多样性的增加提供了良好的环境。在更新世冰期和间冰期时,大部分落叶阔叶林和常绿阔叶林植物在多个避难所间存在长期隔离,不同的避难所种群各自经历局部地区的收缩和扩张。长期的隔离使不同谱系间进一步分化,形成高水平的遗传多样性和遗传分化。少部分植物在冰期时向南退缩,并在间冰期时明显向北扩张。最后,就分化时间的准确估计和探究遗传格局背后的机制两方面展望了未来的研究趋势。

Subtropical China has drawn considerable attention for biogeography studies because of its high plant species diversity, which has been closely related to geo-climate changes since the Miocene. Phylogeography has become the main method for studying the influence of geo-climate changes on the distribution and genetic structure of plants. In this paper, we review the response patterns to geo-climatic changes since the Miocene and the historical causes of population-level genetic differentiation of broad-leaved forest plants in this region. During the Miocene and Pliocene, broad-leaved forest plants were forced to contract southward and form different lineages because of global cooling, the Qinghai-Tibet Plateau uplift, and Asian interior aridity. Meanwhile, the escalation of Asian monsoons provided suitable environment for diversification. During the glacial and interglacial ages in the Pleistocene, both deciduous and evergreen broad-leaved forests plants mainly underwent long-term isolation in multiple separated refugia. Different refugia populations respectively experienced localized contractions and expansions. Long-term isolation caused further divergence of different lineages, resulting in high genetic diversity and high differentiation. Few plants experienced southward contraction in glacial ages and obvious northward expansion in the interglacial ages. Finally, we speculate on the directions of future research based on accurate divergence time estimations and on mechanisms underlying the genetic structure.