| Ants are diverse, abundant and dominant soil invertebrates known to provide significant ecosystem services and shape ecological communities. Global patterns of ant diversity, distribution and community structure, however, are poorly understood. I surveyed the ant fauna of Tiputini Biodiversity Station (TBS), in the western Amazonian lowland rainforest of Ecuador to describe patterns of ant biodiversity, abundance and distribution and analyze the determinants of species richness in one of the most diverse regions on earth. First, I explored the poorly- known subterranean ant fauna using subterranean probes, and discovered that the species assemblage of ants collected 12.5 cm below the surface was significantly different from those found at 25, 37.5 and 50 cm as well as those collected using other methods. Second, I compared ant species richness in primary and secondary forest at TBS to examine how ants respond to deforestation as secondary forest regenerates. Species overlap between sites was low (42.6%) and ant species composition was significantly different. Third, I comprehensively surveyed ant species richness from the canopy to below the soil surface. A total of 489 ant species was identified within only 16 hectares, suggesting that the ant fauna at TBS is the most diverse yet recorded. I project actual richness to be 647-736 species. Ant species composition across strata was significantly different, indicating strong vertical stratification. Finally, I investigated the relationship between ant species richness and that of termites, another abundant soil invertebrate. The diversity of these two clades was positively correlated. The richness of ant genera known to include termite predators did not influence termite richness. However, a positive correlation was found between termite species richness and the species richness of twig- and log- nesting ants. When ant richness was compared to the richness of termites employing different predator defenses, a positive correlation was found for soldierless termite genera, but not for termites with chemical or mandibular defense. Collectively, the components of my thesis provide significant contributions to the study of the diversity, distribution and ecology of Neotromcal ants. |
