Ant community recovery in regenerating Caatinga dry forest following slash-and-burn agriculture

Abstract

The conversion of old-growth forests to agricultural fields, followed by abandonment, has resulted in worldwide expansion of secondary forests. Secondary succession can bring back many organisms, restoring ecosystem functions and services, but studies often focus on the recovery of plant rather than animal communities. Here, we investigate whether ground and arboreal ant species and functional groups recover during secondary succession in the Caatinga dry forest. We adopted a space-for-time chronosequence approach with 10 regenerating forest stands following slash-and-burn agriculture (8–54 years old) and five old-growth forest stands (no record of agriculture for over 100 years). We recorded 71 ant species (59 ground species, 27 arboreal, and 15 in both strata) belonging to 26 genera and six subfamilies. We found no significant differences in both taxonomic and functional diversities between regenerating and old-growth forest stands, considering the whole community and ground and arboreal ants separately. However, increases in plant biomass were positively related to taxonomic and functional diversities of ground ants, while arboreal ants remained unaltered across the entire biomass gradient. Species and functional group compositions did not differ between forest type. Nevertheless, increased similarity in plant biomass between regenerating and old-growth forests was positively related to species similarity for the whole ant community and ground ants, while arboreal ant species composition remained unresponsive. These findings suggest that either ant communities are not significantly altered by slash-and-burn agricultural practices or they recover quickly during secondary succession. Given that previous studies have documented the loss of ant species and functional groups due to increasing disturbance, it is reasonable to expect that these communities recover quickly as secondary succession progresses.