Impact of Argentine ant on the native ant community in fynbos: spatial distribution and bait station dynamics

This study examines the impact of the invasive Argentine ant on the spatial distribution of the native ant community in fynbos plots in Jonkershoek Nature Reserve, Western Cape Province, South Africa. Both the fine scale distribution and temporal bait colonisation patterns were examined. Two invaded and two uninvaded 50x50 m plots of 50 tuna-baited traps were used to sample the ant fauna (baits left out for between 5 min to 1 h). Results show that where the Argentine ant is present, species richness of native ants is significantly reduced. It also found that with the presence of this invader there are areas which are depleted of ants and two hypotheses are suggested to explain this. It also considers temporal dynamics at bait stations. Native ants shared a bait station with the Argentine ant on only two occasions, and in these cases there were very few Argentine ant individuals present. This study shows that the Argentine ant has a significant effect not only on native ant richness, but also on the distribution and abundance of individual ants at a fine scale.

本研究旨在探讨入侵性阿根廷蚂蚁对南非西开普省Jonkershoek自然保护区内金合欢群落原生蚂蚁群落空间分布的影响。研究涵盖了蚂蚁群落的细粒度分布和时空诱饵殖民模式。研究采用了两个被入侵和两个未被入侵的50x50米样地，每个样地设有50个装有金枪鱼诱饵的陷阱（诱饵放置时间为5分钟至1小时不等）以采集蚂蚁群落（诱饵放置时间在5分钟至1小时之间）。研究结果显示，在阿根廷蚂蚁存在的情况下，原生蚂蚁物种多样性显著降低。此外，研究发现，随着入侵者的存在，存在蚂蚁资源枯竭的区域，并提出了两个假设来解释这一现象。研究还考虑了诱饵站点的时空动态。原生蚂蚁仅在两次与阿根廷蚂蚁共享诱饵站点，且在这些情况下，阿根廷蚂蚁个体数量非常有限。本研究表明，阿根廷蚂蚁不仅对原生蚂蚁物种多样性有显著影响，而且对细粒度尺度上单个蚂蚁的分布和丰度也有显著影响。