What Can Restoration Do for Bee Communities? An Example in the Atlantic Rainforest in Paraná State, Southern Brazil

Biodiversity conservation is a challenge for today. Studies regarding different ecosystems have become extremely important for understanding communities and promoting strategies for conservation, especially those involving forest restoration as strategy to reverse biodiversity loss. We compared bee diversity indices between three remnants of Atlantic rainforest in southern Brazil and four adjacent areas that were reforested after shale mining, and which are now under different restoration levels. Seven sites were monitored for over 5 years (2011-2016), by sampling bees directly on flowers or in flight using an entomological net, with 400 collected individuals/site/year. Bee species composition differed between post-mining ages and between sites. In all, we sampled 14.185 specimens and 236 bee species. The introduced Africanized Apis mellifera Linnaeus was the most frequent and abundant species, followed by Trigona spinipes and Psaenythia bergii Holmberg. Among habitats, the reforested area in initial phase showed lower richness and diversity in relation all others sample sites. Conversely, all indices were higher in forest remnants, middle phase II, and advanced phase reforested areas, reinforcing the importance of reforestation for conservation, notably endangered species, such as Oxytrigona sp., Schwarziana quadripunctata (Lepeletier), and the solitary species of the genus Hylaeus, all found in the restored areas. These results represent an important contribution for understanding the recovery of the bee fauna in restored mining habitats. The dataset reveals an interesting response in areas that were mined for shale extraction and are now undergoing different levels of restoration, suggesting that older reforested habitats have a higher probability of having a fully recovered bee community.