Accessing the subterranean ant fauna (Hymenoptera: Formicidae) in native and modified subtropical landscapes in the Neotropics

Abstract: Several studies have characterized and delimited subterranean ant assemblages. Soil extraction, one of the methods employed to access this fauna, employs the removal of monoliths. One of the most widely used methods for the extraction of soil sampling is called TSBF (developed by the Tropical Soil Biology and Fertility Programme). This method provides relevant data about the species associated with the soil. In the present study we characterized assemblages of subterranean ants using the TSBF method in different subtropical areas of the Neotropics. We considered two sampling designs in different localities. The first design resulted in 315 TSBF samples obtained from layers at distinct depths. The second design resulted in 270 TSBF samples and 270 epigaeic pitfall trap samples. This material was used to delimit the species that occur exclusively in the subterranean stratum (TSBF) and that are not found on the soil surface. A total of 281 species were recorded. Of these, 57 can be considered subterranean, based on their occurrence in subterranean strata. We also verified that the highest occurrence of ants was in the first 10 cm of soil depth. Due to the importance of using methods that efficiently extract the subterranean ant fauna in studies, we suggest the TSBF method should be used to sample ants or to associate this method with epigaeic pitfall traps to delimit strictly subterranean assemblages in specific community stratification studies.

摘要：已有多项研究对地下蚂蚁群落进行了特征描述与类群界定。获取该地下蚁类的常用方法之一为土壤取样法，其中一类操作是采集完整土柱。当前应用最为广泛的土壤取样方法之一为TSBF法，该方法由热带土壤生物学与肥力计划（Tropical Soil Biology and Fertility Programme）开发，可获取与土壤中共存蚂蚁物种相关的有效研究数据。本研究以新热带区不同亚热带区域为研究区域，采用TSBF法对地下蚂蚁群落开展特征分析。本研究设置了两种采样方案：第一种方案在不同采样点采集了315份不同土层深度的TSBF样本；第二种方案则采集了270份TSBF样本与270份地表巴氏诱捕器样本。依托上述采样材料，本研究划定了仅分布于地下土层（TSBF样本）且未在土壤表层被采集到的蚂蚁物种。本研究共记录到281个蚂蚁物种，其中基于其在地下土层的出现记录，可确定57个物种为地下蚁类。同时本研究证实，蚂蚁的最高发生丰度集中在0至10厘米的浅层土壤中。鉴于高效获取地下蚁类类群的方法在相关研究中的重要性，本研究建议，在开展特定群落分层研究时，可采用TSBF法开展蚂蚁采样，或将该方法与地表巴氏诱捕器结合使用，以精准界定严格意义上的地下蚂蚁群落。