Bird perches and artificial bat roosts increase seed rain and seedling establishment in tropical bracken-dominated deforested areas

Abstract

Tropical forests are being reduced by human activities. The use of fire for agricultural expansion generates areas dominated by the bracken fern Pteridium, where forest regeneration is slow. This may be caused by seed limitation, especially of animal-dispersed seeds, due to the absence of seed dispersers from the forest in deforested areas, calling for restoration strategies to assist forest regeneration. We installed bird perches and artificial bat roosts to evaluate their effect on the density, species richness, and composition of animal-dispersed seeds and seedlings of tree and non-tree species in bracken-dominated areas in the tropical montane forest of Bolivia. We found that perches and bat roosts increased the density and species richness of animal-dispersed seeds and established seedlings. The seeds and seedlings dispersed by birds were clumped under the perches, while the seeds and seedlings dispersed by bats were distributed around the roosts. Perches had a higher density and species richness of seeds and seedlings compared to bat roosts, suggesting that the use of perches could be a better option as a restoration tool in bracken-dominated areas. The increase in seed rain and seedling establishment of animal-dispersed species in perches and bat roosts supports seed limitation, hindering forest succession in bracken-dominated areas. The use of bird perches accompanying other restoration techniques is a promising restoration strategy to accelerate forest regeneration in tropical areas dominated by Pteridium, which are widely distributed.