Open habitats in a tropical biodiversity hotspot support pollinator diversity in both protected and unprotected areas

Protected areas (PAs) are vital in the global effort to preserve
biodiversity, particularly for disturbance-intolerant pollinator species
in the tropics. As there is little information on the potential of PAs for
pollinator conservation in sensitive tropical ecosystems, we assessed here
insect pollinator diversity in protected vs. unprotected areas in two
vegetation zones in Nigeria, within the West African Guinea Biodiversity
Hotspot. We selected two land-use types based on predominant canopy cover
type (open and tree-shaded habitats) and these were sampled in both
protected and unprotected areas of tropical rain forest and savanna
vegetation zones. Pollinator composition varied significantly between
protected vs. unprotected areas in each vegetation zone, signifying both
areas support unique assemblages of insect pollinators. However,
pollinator diversity varied according to land-use type (open vs. shaded
habitats) rather than protected area per se, such that pollinators were
more abundant and species-rich in open habitat than shaded habitat. These
findings emphasize that beyond the protection of ecosystems, fine scale
habitat management promoting the availability of adequate floral resources
in natural areas is critical for ensuring conservation of these
pollinators in tropical ecosystems.