Recovery dynamics of ants in the Ecuadorian Chocó

A question of global importance is if, and how fast, ecosystems can naturally recover to regain their previous biodiversity and ecosystem functions. Given the decrease of old-growth forest cover in tropical landscapes, previously disturbed forests and their ability to recover are gaining importance. This is especially relevant for biodiversity hotspots, which are areas with many endemic species under severe threat through human activities. However, current knowledge on the recovery potential and underlying processes is limited, especially for animals. Ants constitute one of the most abundant insects in tropical ecosystems and are of paramount importance for ecosystem functioning, making them ideal indicators for disturbance and recovery processes. In my thesis, I therefore investigated the recovery of ant communities in the Ecuadorian Chocó, which is part of the Tumbes-Chocó-Magdalena biodiversity hotspot. By using a chronosequence approach spanning 0 – 34 years of recovery, I explored the recovery of ant communities after forest clearance for agriculture, and if legacy effects from past land-use (cacao plantations and pastures) affect the recovery. In my first study, I found that ant communities recover quickly in approximately less than four decades, with former cacao plantations having a slight advantage over former pastures. My second study is devoted to stratification patterns during recovery, as stratification strongly affects insect communities and abundance. For instance, ant communities in the leaf litter constitute different sets of species than those on tree trunks. However, the role of such stratification patterns during recovery is barely known. I sampled ants in three strata (ground, leaf litter, lower tree trunk) and assembled a comprehensive dataset with a total of 183 assemblages (three strata in 61 plots, comprising 283 species). I assessed the ants’ species composition, 13 morphological traits (measured from over 600 specimens), and functional and phylogenetic diversity to compare their recovery trajectories. My results supported the hypothesis that the ants’ reassembly is influenced by recovery age and, most importantly, differs among strata. By providing a curated ant collection of the Chocó region, my research represents a valuable resource for future work of this underexplored region. The collecting effort resulted in the description of two new trap-jaw ant species, Odontomachus davidsoni (third study) and Strumigenys ayersthey (fourth study). These species are morphologically outstanding, and possibly endemic to the Chocó. The discovery of new, conspicuous species highlights the biological relevance of the Chocó as threatened biodiversity hotspot. Most importantly, my study demonstrated that the small-scale agricultural areas in the region have a high recovery potential, suggesting that conservation measures in the area have good chances to succeed in preserving biodiversity