Recovery of dung beetle biodiversity and traits in a regenerating rainforest: a case study from Costa Rica's Osa Peninsula

Dung beetles are frequently used to assess tropical biodiversity patterns and recovery in human-modified forests. We conducted a comprehensive dung beetle survey (coprophagous and necrophagous communities) within five habitat types, across a land-use gradient, in the ecologically biodiverse Osa Peninsula, located in Costa Rica's south Pacific. In addition to assessing species richness, abundance, and biomass, we also assessed community level traits and species-specific responses using a generalised joint attribute modelling approach. We found that under favourable conditions (40-50 years of regeneration, close proximity to contiguous old-growth forest and control of poaching), secondary rainforest recovered similar levels of species richness, and key traits of old-growth forest dung beetle communities. However, at the community-level, dung beetle abundance, richness, biomass, and diversity varied between habitat types of different anthropogenic disturbance and land-use. Generally, the carrion beetle community did not recover as well as the dung beetle community and the abundance of dung beetles was a third lower in naturally regenerating secondary forest compared with old growth. Regenerating secondary growth and plantation forests showed community compositions similar to old growth forests, while open and fragmented habitats had degraded and impoverished levels of dung beetle biodiversity. Overall, the levels of dung-beetle biodiversity detected are encouraging for naturally regenerating secondary forest, suggesting a high potential value of these areas to buffer the pressure of deforestation and habitat alteration on remaining old-growth tropical forests.

Automated summary

Under favorable conditions, secondary rainforest showed similar levels of recovery in dung beetle community traits compared to old-growth forest. However, dung beetle abundance, richness, biomass, and diversity varied between habitat types with different levels of anthropogenic disturbance and land use.