Foraging traits modulate stingless bee community disassembly under forest loss

Abstract

Anthropogenic land use change is an important driver of impacts to biological communities and the ecosystem services they provide. Pollination is one ecosystem service that may be threatened by community disassembly. Relatively little is known about changes in bee community composition in the tropics, where pollination limitation is most severe and land use change is rapid. Understanding how anthropogenic changes alter community composition and functioning has been hampered by high variability in responses of individual species. Trait-based approaches, however, are emerging as a potential method for understanding responses of ecologically similar species to global change. We studied how communities of tropical, eusocial stingless bees (Apidae: Meliponini) disassemble when forest is lost. These bees are vital tropical pollinators that exhibit high trait diversity, but are under considerable threat from human activities. We compared functional traits of stingless bee species found in pastures surrounded by differing amounts of forest in an extensively deforested landscape in southern Costa Rica. Our results suggest that foraging traits modulate competitive interactions that underlie community disassembly patterns. In contrast to both theoretical predictions and temperate bee communities, we found that stingless bee species with the widest diet breadths were less likely to persist in sites with less forest. These wide-diet-breadth species also tend to be solitary foragers, and are competitively subordinate to group-foraging stingless bee species. Thus, displacement by dominant, group-foraging species may make subordinate species more dependent on the larger or more diversified resource pool that natural habitats offer. We also found that traits that may reduce reliance on trees-nesting in the ground or inside nests of other species-correlated with persistence in highly deforested landscapes. The functional trait perspective we employed enabled capturing community processes in analyses and suggests that land use change may disassemble bee communities via different mechanisms in temperate and tropical areas. Our results further suggest that community processes, such as competition, can be important regulators of community disassembly under land use change. A better understanding of community disassembly processes is critical for conserving and restoring pollinator communities and the ecosystem services and functions they provide.

Anthropogenic disturbance of tropical forests threatens pollination services to açaí palm in the Amazon river delta

“…Separation of taxa into functional groups would help clarify which species are affected by disturbance and traits that determine environmental sensitivity (e.g. body size, nesting requirements, diet breadth; Lichtenberg, Mendenhall, & Brosi, 2017).…”

Phylogenetic homogenization of bee communities across ecoregions

“…We chose wild bees as our study taxon because bees provide an essential ecosystem function as the main pollinators of flowering plants (Ollerton, Winfree, & Tarrant, ), and because they are diverse, with over 500 species in our region. Bee communities show strongly different composition across habitat types (Brosi, Daily, Shih, Oviedo, & Durán, ; Lichtenberg, Mendenhall, & Brosi, ; Winfree, Griswold, & Kremen, ); however, the bee literature has been slower than other fields in moving beyond alpha richness as the primary measure of communities (Winfree et al, ). Therefore, it is not well understood if agricultural habitats support bee beta diversity at levels found among natural habitats (Laliberté & Tylianakis, ), and the role of urban land use in homogenizing bee communities across larger spatial scales is virtually unknown (Baldock et al, ).…”

Bee pollinator functional responses and functional effects in restored tropical forests

“…, Lichtenberg et al. , Öckinger et al. ), given the correlation between bee body size and flight range and dispersal capability (Greenleaf et al.…”

“…, Lichtenberg et al. , Coutinho et al. ), which is attributed to their need for large preexisting cavities and available floral resources during their longer yearly activity periods.…”

“…, Lichtenberg et al. , Coutinho et al. ) and restored habitats (Kremen and M'Gonigle , Öckinger et al.…”