Different-aged Pinus afforestation does not support typical Atlantic Forest fruit-feeding butterfly assemblages

Abstract

The Atlantic Forest of the southern Brazilian highlands is a biocultural mosaic of Araucaria Forest and grasslands. Despite adverse impacts on biodiversity, extensive areas are being afforested with non-native pine (Pinus spp.), triggering forest succession on areas that were previously native grasslands. The long-term effects of afforestation with these non-native trees for biodiversity conservation are still unknown. Here, we assess this issue by comparing the fruit-feeding butterfly assemblages in young (20 year) and old (70 year) pine plots with nearby native Araucaria Forest. Abundance and richness of butterflies were positively correlated with temperature and mean humidity only in the native forest. Abiotic conditions differed between vegetation types: there was more sunlight, and was warmer and drier in the pine afforestation plots than in the Araucaria Forest. Butterfly species composition was similar between young and old pine plots, but distinct from the native Araucaria Forest. Butterfly species abundances in native forests were more evenly distributed than in afforestation sites. In these pine sites, assemblages were dominated by small, grass-feeding satyrines, whereas old pine sites had more liana-feeding biblidines, and the Araucaria Forest had more large-sized bamboo-feeding species. Our results indicate that even after 70 years of succession a non-native pine afforestation cannot support a butterfly assemblage as that found in the neighboring preserved forest. Moreover, threatened grassland specialist species have been locally extinct after only 20 years of pine afforestation. The evidence gathered here points against the use of silviculture with non-native trees in these biocultural mosaic landscapes.