Data from: Phylogenetic and morphological relationships between nonvolant small mammals reveal assembly processes at different spatial scales

The relative roles of historical processes, environmental filtering, and ecological interactions in the organization of species assemblages vary depending on the spatial scale. We evaluated the phylogenetic and morphological relationships between species and individuals (i.e., inter- and intraspecific variability) of Neotropical nonvolant small mammals coexisting in grassland-forest ecotones, in landscapes and in regions, that is, three different scales. We used a phylogenetic tree to infer evolutionary relationships, and morphological traits as indicators of performance and niche similarities between species and individuals. Subsequently, we applied phylogenetic and morphologic indexes of diversity and distance between species to evaluate small mammal assemblage structures on the three scales. The results indicated a repulsion pattern near forest edges, showing that phylogenetically similar species coexisted less often than expected by chance. The strategies for niche differentiation might explain the phylogenetic repulsion observed at the edge. Phylogenetic and morphological clustering in the grassland and at the forest interior indicated the coexistence of closely related and ecologically similar species and individuals. Coexistence patterns were similar whether species-trait values or individual values were used. At the landscape and regional scales, assemblages showed a predominant pattern of phylogenetic and morphological clustering. Environmental filters influenced the coexistence patterns at three scales, showing the importance of phylogenetically conserved ecological tolerances in enabling taxa co-occurrence. Evidence of phylogenetic repulsion in one region indicated that other processes beyond environmental filtering are important for community assembly at broad scales. Finally, ecological interactions and environmental filtering seemed important at the local scale, while environmental filtering and historical colonization seemed important for community assembly at broader scales.

物种群落构建过程中，历史过程、环境过滤与生态互作的相对重要性随空间尺度发生变化。本研究针对共存于林草生态交错带的新热带区非飞行小型哺乳动物，分别从局地、景观与区域三个不同空间尺度，解析物种与个体间的系统发育及形态学关联（即种间与种内变异）。本研究借助系统发育树推演演化关系，并以形态性状作为物种与个体间适合度与生态位相似性的指示指标。随后，本研究运用物种间系统发育与形态多样性指数及距离指数，对三个尺度下的小型哺乳动物群落结构进行评估。研究结果显示，森林边缘附近呈现系统发育排斥格局，即系统发育相似的物种共存概率低于随机预期水平。生态位分化策略或可解释边缘地带观测到的系统发育排斥现象。草原与森林内部的系统发育与形态聚集格局，则表明亲缘关系相近、生态特征相似的物种与个体实现共存。无论采用物种性状均值还是个体性状值，群落共存格局均保持一致。在景观与区域尺度下，小型哺乳动物群落整体呈现系统发育与形态聚集的主导格局。环境过滤作用对三个尺度下的共存格局均产生影响，这表明系统发育保守的生态位耐受能力在类群共存过程中发挥关键作用。某一区域内观测到的系统发育排斥现象表明，除环境过滤外，其他过程对大尺度下的群落构建同样具有重要意义。综上，生态互作与环境过滤在局地尺度下发挥关键作用，而环境过滤与历史定殖过程则对更大尺度的群落构建更为重要。