Richness, Abundance and Community Composition of Male Euglossine Bees in Coffee Agroecosystems

Abstract

The complex ways in which bees--the most important group of pollinators worldwide--are impacted by habitat loss and fragmentation are still poorly understood. I studied the response of euglossine bees (Hymenoptera:Apidae:Euglossini), to varying coffee management styles (sun coffee in a simple monoculture versus traditional shade coffee) and among three distances from the forest; 1m, 200m, 400m. I sampled May-August in the Soconusco region of Chiapas, Mexico, an area containing many organic and conventional coffee farms as well as forest fragments of varying sizes. Euglossine bees are a group of ecologically and economically important tropical pollinators responsible for long distance pollination of many rare plants. While many studies have addressed the influence that habitat loss and forest fragmentation have on these bees, few studies have considered the impact of the agricultural matrix. Estimated species richness was different between shade monoculture and shade polyculture farms. The species richness and abundance of euglossine bees did not differ between the two coffee systems and the forest. Species composition differed between the two management systems, but was statistically indistinguishable between the forest and the shade polyculture. There was no difference in species composition, richness or abundance with regard to distance from forest, regardless of matrix quality. An unexpected trend of increasing abundance and richness with increasing distance

from the forest was evident in both coffee systems and may be explained by competitive exclusion at forest edge. Given the ecological importance of euglossine bees, it is necessary to better understand how both forest fragmentation and matrix quality influences these bees. This study shows that agricultural the agricultural matrix may be important for retaining habitat for euglossine bees, and could allow for greater movement potential between resource rich areas. The management of these matrix habitats is key, and diverse, organic shade coffee appears to have higher habitat value for euglossines than conventional shade monocultures.