环境因子的变化与植物适应演化是长期以来受关注的问题。内蒙古高原及其沿着高原气候环境梯度分布的锦鸡儿属（Caragana (Fabr.)植物为研究环境因子对锦鸡儿种群分化的控制机制提供了独特的、具有代表性的自然单元。本项目采用多重因果关系模型（the causal multi-model）方法，进行运算，检验选择性假设，确定驱动锦鸡儿属植物遗传分化的主导因子。为此，我们提出4个假设：（1）遗传结构只与系统发育距离相关。(2）遗传结构只与种群间的地理距离相关。（3）种群遗传结构与气候梯度的分隔相关。（4）遗传结构受气候梯度和种间系统发育关系的共同驱动。通过对锦鸡儿种群遗传结构的研究、地理分布及其生物气候变量空间分布的研究、以及系统发育关系的研究，运用景观遗传学的理论和方法，分析评价这些假设，揭示在气候环境变化过程中，内蒙古高原锦鸡儿属植物遗传分化的环境与气候控制机制。

The genus Caragana (Fabr.) in the Inner Mongolia Plateau, provides a unique opportunity to investigate patterns of adaptive radiation along steep climatic gradients, and to identify the environmental factors most likely to be responsible for driving the radiation. The objective of the project is to determine the drivers of genetic differentiation of Caragana species across the Inner Mongolian Plateau. This study will use a factorial, multi-model approach to evaluate alternative hypotheses and identify the combination of environmental factors that appear to drive genetic divergence of Caragana in the Inner Mongolia Plateau. The project will evaluate five alternative hypotheses: genetic structure is panmictic, (1) genetic structure is related exclusively to phylogenetic distance, (2) genetic structure is related exclusively to geographic distance between populations, (3) genetic structure is related to climatic gradients separating the populations, (4) genetic structure is jointly driven by climatic gradients and phylogenetic relatedness among species. By employing state-of-the-art landscape genetic analyses to evaluate these four alternative hypotheses we will robustly identify the environmental factors that drive adaptive radiation and gene flow of Caragana populations across the Mongolian Plateau.