BEYOND GOOD AND EVIL: CONTEXT-DEPENDENT EFFECTS OF AGRICULTURE ON POLLINATORS’ COMMUNITIES AND ITS INTERACTIONS

Abstract

The role of agriculture as a menace or a contribution to the maintenance of the biodiversity and ecosystems function (such as pollination) in heterogeneous landscapes is critical to the balance in the tradeoff relationships between food production and biodiversity. Recent studies suggested that the role of agriculture to the maintenance of biodiversity can be context dependent. Therefore, this study aimed to evaluate the interplay between the proportion of agriculture and landscape heterogeneity on the maintenance of pollinators richness and abundance, and plant-pollinators interactions in agro-natural landscapes. Plant-pollinator surveys were conducted in seminatural areas near agricultural areas in 22 landscapes in the agricultural pole of Chapada Diamantina, Bahia, Brazil. By a combination of PCA and clustering analysis the landscapes were divided into two groups characterized by the inverse correlation of proportion of agriculture and heterogeneity. The first group had low proportion of agriculture and high landscape diversity and the second group had high proportion of agriculture and low landscape diversity. Using linear models, we investigated the differences in plant-pollinator networks structure between these two landscape groups and its relationship with the proportion of agriculture. Our results showed that there is a positive relationship between the plant-pollinator networks number of links, the pollinator species richness and native pollinators abundance with the proportion of agriculture in the landscapes. However, the most heterogeneous landscapes, with smaller proportions of agriculture have networks with more links, higher pollinator species richness and native pollinators abundance than more homogenous landscapes with greater proportions of agriculture. In this sense, even if agricultural areas can favor some pollinators, there are evident losses of pollinator diversity and plant-pollinator interactions associated with the landscape homogenization.