Alvarenga Júlio Miguel, Vieira Cecília Rodrigues, Godinho Leandro Braga, Campelo Pedro Henrique, Pitts James Purser, Colli Guarino Rinaldi
Programa de Pós-Graduação em Ecologia e Conservação, Departamento de Biologia, Universidade do Estado de Mato Grosso, Nova Xavantina, Mato Grosso, Brazil.
Department of Biology, Utah State University, Logan, Utah, United States of America.
PLoS One. 2017 Oct 27;12(10):e0187142. doi: 10.1371/journal.pone.0187142. eCollection 2017.
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.
理解生物群落如何以及为何在空间和时间上组织起来是一项重大挑战，并且在全球变化时期有助于生物多样性保护。在此，沿着巴西塞拉多的森林 - 稀树草原梯度，研究了天鹅绒蚁群落结构的时空变化，以评估环境过滤和种间相互作用在群落组装中的作用。使用25组带有漂移围栏的Y形陷阱阵列对天鹅绒蚁进行采样，沿着从严格意义上的塞拉多（开阔树冠、温暖、干燥）到塞拉多森林（封闭树冠、凉爽、潮湿）的环境梯度进行了一年的采样。安装在每个陷阱上的数据记录器在整个研究期间记录了小气候参数。通过典范对应分析、广义差异建模和方差成分分析评估了空间距离、小气候参数和共同祖先对物种丰度和周转率的影响。天鹅绒蚁的多样性和丰度在严格意义上的塞拉多和雨季早期较高。沿着环境梯度存在明显的组成变化，丰富度和丰度的时间变化比空间变化更强。木本植物物种的旱季开花促进了宿主的丰度，进而增加了天鹅绒蚁的捕获量。物种在梯度上按分类学聚类，Sphaeropthalmina（特别是Traumatomutilla spp.）和Pseudomethocina分别与严格意义上的塞拉多和塞拉多森林更相关。这表明环境过滤在群落组装中起主要作用，同一谱系的成员具有共同的生理耐受性和宿主偏好。塞拉多环境的变化可能会影响黄蜂及其宿主群落，对生态系统功能和服务产生不可预测的后果。
