Data from: Phylogenetic community structure of North American desert bats: influence of environment at multiple spatial and taxonomic scales

1. Numerous processes influence community structure. The relative importance of these processes are thought to vary with spatial, temporal, and taxonomic scale: density dependent interactions are thought to be most influential at small scales, at intermediate scales environmental conditions may be the most influential factor, and biogeographic processes are thought to be of greater importance at larger scales. Additionally, the stress-dominance hypothesis suggests that communities experiencing harsher environmental conditions will be predominantly structured by habitat filtering whereas communities experiencing more favorable conditions will be structured predominantly by density dependent interactions such as competition. 2. The aim of this study was to investigate the influence of environmental factors on phylogenetic community structure (PCS) of North American desert bats at multiple spatial and taxonomic scales. We also examined if the stress-dominance hypothesis is upheld in desert bats across an environmental gradient. 3. PCS metrics were calculated using species pools that differed in spatial (from all deserts to individual deserts) and taxonomic (all bat taxa, a single family, and a single genus) scale. We calculated mean temperature, precipitation, and seasonality for each site to determine if environmental gradients were related to degree of community structure. 4. At the largest spatial and taxonomic scales, communities were significantly phylogenetically clustered while degree of clustering decreased at the smallest spatial and taxonomic scales. Climatic data, particularly mean temperature and temperature seasonality, were important predictors of PCS at larger scales and under harsher conditions, but at smaller scales and in less stressful conditions there was a weaker relationship between PCS and climate. 5. This suggests that North American deserts, while harsh, are not uniform in the challenges they present to the faunas residing in them. Overall, the relationship between PCS and climatic data at large spatial and taxonomic scales, and in harsher conditions, suggests the influence of habitat filtering has been important in North American desert bat community assembly and that other processes have been important at smaller scales.1. 诸多生态过程共同影响群落结构。学界普遍认为，这些过程的相对重要性会随空间、时间及分类学尺度发生变化：密度依赖相互作用在小尺度下的影响最为显著；中尺度下环境条件或为主导调控因素；而大尺度下生物地理过程的重要性则更高。此外，胁迫优势假说（stress-dominance hypothesis）提出，环境条件更为严苛的群落，其结构主要由生境过滤作用塑造；而环境条件更优越的群落，则主要由竞争等密度依赖相互作用主导群落构建。 2. 本研究旨在探究多空间与分类学尺度下，环境因子对北美荒漠蝙蝠系统发育群落结构（phylogenetic community structure, PCS）的影响；同时验证胁迫优势假说在环境梯度下的荒漠蝙蝠群落中是否成立。 3. 本研究以不同空间尺度（涵盖所有荒漠至单个荒漠）与分类学尺度（涵盖所有蝙蝠类群、单一蝙蝠科、单一蝙蝠属）的物种库为基础，计算系统发育群落结构指标。同时，我们针对每个采样点计算了平均温度、降水量及温度季节性，以探究环境梯度与群落结构程度之间的关联。 4. 在最大的空间与分类学尺度下，群落呈现显著的系统发育聚集特征，而随着空间与分类学尺度缩小，聚集程度逐渐降低。气候数据（尤其是平均温度与温度季节性）在大尺度及严苛环境下，是系统发育群落结构的重要预测因子；但在小尺度与低胁迫环境中，系统发育群落结构与气候的关联则相对较弱。 5. 这表明，北美荒漠虽环境严苛，但其对栖息其中的动物区系所构成的挑战并非完全一致。综合来看，在大空间与分类学尺度以及严苛环境下，系统发育群落结构与气候数据的关联，说明生境过滤作用在北美荒漠蝙蝠的群落构建过程中发挥了重要作用；而在小尺度下，则有其他过程主导群落构建。