四川盆地的陆地岛屿效应-基于三种鸟的比较系统地理学研究

The Sichuan Basin is one of the Four Big Basins in China and is a closed and typical inland basin surrounded by mountains, a physiogeographic structure that in essence can be described as a continental island. The proposed project uses comparative phylogeography to investigate the population genetic structure of bird species that are widely distributed in different habitats inside and outside of the Sichuan Basin. These include: the Common pheasant (Phasianus colchicus), The White-browed Laughingthrush (Garrulax sannio) and the Eurasian tree sparrow (Passer montanus).We will investigate if there is limited gene flow between populations outside of and inside of the Sichuan Basin and explore the effect of habitat availability on genetic structure and on population differentiation by combine Environmental Niche Modelling to clarify following hypotheses: 1) physiographic barriers is the main factor affecting population divergence 2) habitat and continuity of suitable habitat has an impact on the degree of differentiation/gene flow among populations. 3) Sichuan basin is an important refugia during the Late Quatenary climate fluctuations, the geographic features significantly shape the current genetic structures of avian. The overarching goal of the project, in the area is an interdisciplinary line of research invoking as well evolutionary biology, biogeography, molecular ecology and conservation biology as earth science and historical ecology. The project will provide important insights into the effects of geographic barriers on gene flow, differentiation and protection in biological diversity of natural populations.

四川盆地是中国四大盆地之一，四周高山环绕，是一个封闭盆地，是典型的陆地岛屿。本项目通过比较系统地理学研究不同生境及广泛分布于四川盆地内外的雉鸡 (Phasianus colchicus)、白颊噪鹛（Garrulax sannio）和树麻雀（Passer montanus）鸟类的种群遗传结构，分析四川盆地内外同种鸟类种群的基因流是否受阻，探究栖息环境对鸟类遗传结构和种群分化的影响，结合环境生态位模型阐明以下假说：1）地理屏障是影响种群分化的主要因素2）生境和栖息地的连贯性会影响种群的分化程度或基因流3）第四纪末气候波动期间，四川盆地是一个重要的避难地，地理特征形成了现今明显的鸟类遗传结构。其理论在进化生物学、生物地理学、分子生态学、保护生物学、地学和历史生态学等领域具有重要的科学价值；该项目在探究地理屏障对自然种群的基因流、遗传分化和生物多样性保护具有深远的影响。

本项目主要研究四川盆地对物种的隔离机制，为阐明四川盆地的陆地岛屿效应奠定了基础。通过对三种鸟的形态指标分析，发现其形态特征与环境因子的关系，树麻雀表现为身体大小随海拔升高而增大的趋势，白颊噪鹛和雉鸡则表现出相反的趋势。树麻雀系统地理研究的结果显示，基于线粒体基因串联序列2653bp的单倍型网络图表明，树麻雀的单倍型主要分为两个大支，一支为四川盆地内的树麻雀，其祖先单倍型为Hap31；另一支为四川盆地周边山区的树麻雀，其祖先单倍型为Hap51，表现为系统发生连续，具有部分空间隔离的模式。二代测序白颊噪鹛系统地理结构表现为：四川盆地内和盆地外形成明显的分支结构，盆地外云贵高原一带种群、盆地内种群分别形成两个大的分支，且盆地外种群比盆地内分化较早。研究结果从一定程度上反映了四川盆地的陆地岛屿效应。已发表相关论文8篇，其中SCI4篇，其余相关结果正在分析和撰写中；3项国家发明专利正在受理中。此外，完成了两名硕士研究生毕业论文。