Vertical diversity patterns and biotic interactions of trap-nesting bees along a fragmentation gradient of small secondary rainforest remnants

Abstract

Secondary rainforest remnants might contribute to biodiversity conservation and preservation of healthy interspecific interactions with ongoing fragmentation. We studied the vertical distribution of trap-nesting bees along a fragmentation gradient of secondary forest remnants in Costa Rica. Fragment size did not affect bee abundance, diversity, and parasitism and mortality rates. However, height and edge effects influenced bee communities. Bees were more abundant in the canopy and the understory compared to an intermediate height, and bee diversity was higher in the canopy. Tree location (forest edge, intermediate distance, forest center) did not affect abundance but did affect bee diversity since most species preferred the forest interior. The cuckoo bees Aglaomelissa duckei and Coelioxys sp. 1 only partly followed their hosts’ patterns, two Centris species. We conclude that an increasing amount of edge habitat will have negative consequences for bee communities and will reduce the conservation value of secondary forest fragments.