高原隆升和第四纪气候波动对青藏高原种子植物多样性格局的影响研究

The Tibetan Plateau (TP) harbors exceptionally high biodiversity, and the Hengduan Mountains and East Himalaya in its southeastern part are regarded as global biodiversity hotspots. Many studies hypothesized that past plateau uplift and periodic climate fluctuations during the Quaternary probably promoted species diversification. However, there is little understanding of how the mechanisms associated with these geological and climatic processes produced the observed diversity patterns. To quantify the contribution of plateau uplift and climate fluctuations to the diversity patterns of TP’s seed plants, firstly we will collate data on seed-plant distribution based on county-level mapping from published monographs, herbarium collections, online databases, articles and plant specimen collections. Then, we will construct patterns of species richness and phylogenetic diversity. Secondly, based on eight quantified biogeographic hypotheses (predictors) associated with plateau uplift and climate fluctuations, we will calculate Pearson’s correlation between each predictor and diversity patterns. Then we will use partial regression analysis to quantify the independent and combined contributions of the plateau uplift and Quaternary climate fluctuations to species diversity and mixed conditional autoregression models to assess the relative contribution of each predictor to the extant diversity of the TP. This study will provide valuable insights on the evolution and conservation of biodiversity of the TP.

青藏高原地区拥有丰富的物种，其东南部的横断山脉和东喜马拉雅山脉是全球生物多样性的热点区域。很多研究推测青藏高原过去的快速隆升和第四纪周期性气候波动事件可能促进了物种的多样化，然而高原隆升和气候波动如何影响当前的物种多样性格局，目前还不清楚。为了定量分析高原隆升和第四纪气候波动对青藏高原种子植物多样性格局的贡献，首先，通过多种数据来源（专著、标本馆资料、在线数据库、文献）和野外植物标本采集，收集整理青藏高原种子植物的地理分布，在物种和谱系两种水平上构建青藏高原种子植物多样性格局；其次，基于8种生物地理假说（变量），运用多种统计方法（相关分析、偏回归分析、混合条件自回归模型），分析每种变量与多样性格局的相关关系，量化高原隆升和气候波动对多样性格局的影响程度，确定每种变量对多样性格局的相对贡献。本项目有助于理解青藏高原生物区系的形成和演化机制，为生物多样性保护提供科学依据。

青藏高原地区拥有丰富的物种，其东南部的横断山脉和东喜马拉雅山脉是全球生物多样性的热点区域。很多研究推测青藏高原过去的快速隆升和第四纪周期性气候波动事件可能促进了物种的多样化，然而高原隆升和气候波动如何影响当前的物种多样性格局，目前还不清楚。为了定量分析高原隆升和第四纪气候波动对青藏高原种子植物多样性格局的贡献，首先，通过多种数据来源和野外植物标本采集，收集整理了青藏高原种子植物名录及其地理分布；其次，在物种和谱系两种水平上构建青藏高原种子植物多样性格局，并识别出生物多样性热点地区；最后，基于8种生物地理假说(变量)，量化了高原隆升和气候波动对多样性格局的影响程度。研究发现：1)青藏高原共有种子植物12091种，隶属于200科，1574属；2)青藏高原植物多样性分布呈现从高原东南部到西北部逐渐递减的趋势，存在11处植物多样性热点地区；3)高原隆升对横断山脉和喜马拉雅山脉的植物多样性格局的影响程度更大，而第四纪气候波动对高原面的植物多样性格局的影响程度更大。这些结论对于揭示青藏高原物种多样性的形成机制及其生物多样性保护具有重要启示。