Forest cover and non-forest landscape heterogeneity modulate pollination of tropical understory plants

Context In human-altered landscapes, native vegetation cover is essential for pollination maintenance. Heterogeneous land-uses may provide complementary resources for some pollinator species, contributing to the connectivity of landscapes and the maintenance of pollination. Objectives To investigate the effect of forest cover and non-forest landscape heterogeneity on pollination of native understory forest plant assemblages. Methods We quantified pollen deposited on understory native flowers in gradients of forest cover and heterogeneity of land-uses (Shannon-Wiener diversity index) in a central forest patch in 14 landscapes. Results Forest cover and the non-forest heterogeneity of land-uses interacted, favoring pollination in landscapes with high amount of forest and low heterogeneity, and in landscapes with low amount of forest and high heterogeneity. Forest promotes high-quality habitats and higher connectivity for pollinators, increasing pollination. Forest cover and non-forest landscape heterogeneity seemed to increase pollinator efficiency, since pollination increased regardless of pollinator diversity. In landscapes with a low amount of forest, high land-use heterogeneity may partially compensate for forest loss due to land-uses that offered complementary resources for the maintenance of pollinators and pollination. Conclusions We have seen that pollination is favored by forest cover and the interaction between native forest and other land-uses that can add complementary resources and landscape connectivity to pollinators. For management policies, priority should be on the maintenance and increase of native forest cover in the landscapes, followed by promoting heterogeneity of other favorable land-uses to pollinators.