The Structure Matters: Bees Visitors of Coffee Flowers and Agroecological Main Structure (Mas)

Abstract

Cross pollination in coffee increases their quality and the efficiency of pollination has a positive trend with richness of pollinators. The Main Agroecological Structure (MAS) is a new concept to identify and characterize the agroecosystems. The method uses local variables related with agricultural management, landscape and cultural variables. As a first approach to study the relationship between MAS and pollination, we characterized nine systems (five coffee farms, four forests) located in Cundinamarca, using ten local variables, the distance to the forest as a landscape variable and bees (visitors of coffee flowers). The field work was done during the flowerings of 2011 y 2012. After the capture, bees were identified and the pollen loads were analyzed. We found 130 bees of the subfamilies: Halictinae (three species), Megachilidae (one species) and Apinae (nine species). Trigona was the richest genera. The most common visitors of coffee flowers were Apis mellifera and Paratrigona eutaeniata. The bees richness was positive related with plants richness (P = 0.031, R2 = 0.96) and the forest proximity (P = 0.0075, R2 = 0.52), Also, we found a negatively trend with the increase in coffee density (P = 0.045, R2 = 0.67). In the analysis of the pollen loads we identified trees, herbs and epiphytes species, this suggested that bees foraging in all vegetation strata. In this analysis we also found species related with the coffee system and others more related with forest and hedges. We concluded that a change in MAS affecting bee's composition and richness, and preserving richness of bees, implies protection of plant diversity inside the coffee farm and also the maintenance of nearby ecosystems.