Data from: Spatial-temporal dynamics of Neotropical velvet ant (Hymenoptera: Mutillidae) communities along a forest-savanna gradient

Understanding how and why biological communities are organized over space and time is a major challenge and can aid biodiversity conservation in times of global changes. Herein, spatial-temporal variation in the structure of velvet ant communities was examined along a forest-savanna gradient in the Brazilian Cerrado to assess the roles of environmental filters and interspecific interactions upon community assembly. Velvet ants were sampled using 25 arrays of Y-shaped pitfall traps with drift fences for one year along an environmental gradient from cerrado sensu stricto (open canopy, warmer, drier) to cerradão (closed canopy, cooler, moister). Dataloggers installed on each trap recorded microclimate parameters throughout the study period. The effects of spatial distances, microclimate parameters and shared ancestry on species abundances and turnover were assessed with canonical correspondence analysis, generalized dissimilarity modelling and variance components analysis. Velvet ant diversity and abundance were higher in the cerrado sensu stricto and early in the wet season. There was pronounced compositional turnover along the environmental gradient, and temporal variation in richness and abundance was stronger than spatial variation. The dry season blooming of woody plant species fosters host abundance and, subsequently, velvet ant captures. Species were taxonomically clustered along the gradient with Sphaeropthalmina (especially Traumatomutilla spp.) and Pseudomethocina more associated, respectively, with cerrado sensu stricto and cerradão. This suggests a predominant role of environmental filters on community assemble, with physiological tolerances and host preferences being shared among members of the same lineages. Induced environmental changes in Cerrado can impact communities of wasps and their hosts with unpredictable consequences upon ecosystem functioning and services.

阐明生物群落如何随空间与时间维度构建及其背后机制，是生态学领域的核心难题之一，同时在全球变化背景下可为生物多样性保护提供关键支撑。本研究以巴西塞拉多（Brazilian Cerrado）的林-稀树草原梯度为研究对象，调查绒蚁蜂（velvet ant）群落结构的时空变化，以解析环境过滤与种间相互作用在群落构建过程中的作用。研究团队沿从严格型塞拉多（cerrado sensu stricto，冠层开阔、温暖干燥）到密灌塞拉多（cerradão，冠层闭合、凉爽湿润）的环境梯度，采用25组带漂移围栏的Y型陷阱罐进行了为期一年的绒蚁蜂采样。每个陷阱均安装了微型数据记录仪，在整个研究周期内记录微气候参数。本研究采用典范对应分析（canonical correspondence analysis）、广义差异模型（generalized dissimilarity modelling）与方差分量分析（variance components analysis），解析空间距离、微气候参数及系统发育共祖性对物种种群丰度与物种更替的影响。严格型塞拉多生境与湿季初期的绒蚁蜂多样性及种群丰度更高。沿环境梯度存在显著的群落组成更替，且物种丰富度与种群丰度的时间变异强度高于空间变异。木本植物在旱季开花，可提升寄主种群丰度，进而增加绒蚁蜂的捕获量。沿环境梯度，物种呈现分类学聚类特征：球眼绒蚁蜂亚族（Sphaeropthalmina，尤其是创伤蚁蜂属Traumatomutilla spp.）与伪毛蚁蜂亚族（Pseudomethocina）分别更偏向分布于严格型塞拉多与密灌塞拉多生境。这表明环境过滤在群落构建中占据主导作用，同一演化支系的类群往往共享相似的生理耐受性与寄主偏好。塞拉多地区的人为诱导环境变化，可能会对蚁蜂类群及其寄主群落造成冲击，进而对生态系统功能与服务产生难以预测的影响。