Data from: Landscape genetics of a top neotropical predator

Habitat loss and fragmentation as a consequence of human activities is a worldwide phenomenon and one of the major threats to global biodiversity. Habitat loss and fragmentation is particularly a concern in the biodiverse tropics, where deforestation is occurring at unprecedented rates. Although insects are one of the most diverse and functionally important groups in tropical ecosystems, the quantitative effect of landscape features on their gene flow remains unknown. Here, we used a robust landscape genetics approach to quantify the effect of ten landscape features (deforestation, mature forests, other forest types, the River Chagres, streams, stream banks, roads, sea, lakes and swamps) and interactions between them, on the gene flow of a neotropical forest keystone species, the army ant Eciton burchellii. The influence of landscape on E. burchellii's gene flow reflected the different dispersal capability of its sexes; aerial for males and pedestrian for females, and the different depths of population history inferred from microsatellites and mitochondrial DNA. In contrast to the gene flow-facilitating effect of mature forests, deforested areas were found to be strong barriers for E. burchellii's gene flow. Other forest types were found to be gene flow facilitators but only when interacting with mature secondary forests, therefore indicating the importance of mature forests for the survival of E. burchelii and its associate species. The River Chagres was identified as a major historical gene flow barrier for E. burchellii, suggesting that an important loss of connectivity may occur because of large artificial waterways such as the Panama Canal.

人类活动引发的生境丧失与片段化是全球性现象，亦是全球生物多样性面临的核心威胁之一。在生物多样性富集的热带地区，生境丧失与片段化问题尤为严峻，当地森林正以史无前例的速率遭到砍伐。尽管昆虫是热带生态系统中物种多样性最高、功能重要性最突出的类群之一，但景观特征对其基因流（gene flow）的量化影响迄今仍未明确。本研究采用稳健的景观遗传学（landscape genetics）方法，定量分析了10种景观要素——森林砍伐、成熟林、其他林型、查格雷斯河（River Chagres）、溪流、溪岸、道路、海洋、湖泊与沼泽——及其相互作用，对新热带界森林关键物种布氏行军蚁（Eciton burchellii）的基因流所产生的影响。景观对布氏行军蚁基因流的影响，体现了其不同性别的扩散能力差异：雄性依靠空中扩散，雌性则以步行扩散为主，同时也呼应了基于微卫星（microsatellites）与线粒体DNA（mitochondrial DNA）推断出的种群历史深度差异。与成熟林促进基因流的作用相悖，砍伐迹地被证实是布氏行军蚁基因流的强阻隔因子。其余林型仅在与成熟次生林产生交互作用时，才会发挥基因流促进效应，这表明成熟林对布氏行军蚁及其伴生物种的存续至关重要。查格雷斯河被确定为布氏行军蚁历史基因流的主要阻隔因子，这暗示诸如巴拿马运河（Panama Canal）这类大型人工水道，可能会造成连通性的显著丧失。