Unveiling current guanaco distribution in Chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests

Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distribution of the recently resolved phylogeography of guanaco (Lama guanicoe) lineages on the western slope of the southern Andes. Using a maximum entropy framework, field data, and information on climate, topography, human density, and vegetation cover, we identify differences between the two subspecies (L.g.cacsilensis, L.g.guanicoe) and their intermediate-hybrid lineage, that most likely determine the distribution of this species. While aridity seems to be a major factor influencing the distribution at the species-level (annual precipitation &lt;900 mm), we also document important differences in niche specificity for each subspecies, where distribut...大地理尺度下的生态位描述与分化，是近年来生态学与进化生物学领域的核心研究议题。对具备已知进化轨迹的姐妹类群的环境生态位结构进行解析，是理解物种生态位需求的有效研究手段。本研究针对安第斯山脉南段西坡、经新近解析系统地理学关系的原驼（guanaco, Lama guanicoe）支系，构建其环境生态位结构与分布格局模型。本研究采用最大熵（maximum entropy）建模框架，结合野外实测数据以及气候、地形、人类活动密度与植被覆盖等环境因子信息，明确了该物种的两个亚种（L.g. cacsilensis、L.g. guanicoe）及其中间杂交支系之间的生态位分化特征，这类分化极有可能主导该物种的整体分布格局。尽管干旱程度（年降水量<900mm）是影响该物种种级分布的关键因子，本研究同时揭示了各亚种间生态位特异性的显著差异，其分布特征……