Bee diversity and pollination services within coffee agro-forestry systems: Land management mediates community structure

A number of studies have suggested that native bee diversity and abundance are influenced by local landscape composition. However, few studies have examined the specific parameters that mediate tropical bee diversity and abundance within a local landscape. Tropical agro-forestry systems are ideal systems for the study of local bee diversity because they are uniform across large expanses of land, yet still exhibit varying styles of land management. In this study, I conducted extensive pan-trapping experiments across eight different coffee agro-forestry systems in Chiapas, Mexico. Results across sites indicate that bee abundance and diversity varied widely across the sampling season, with the greatest bee diversity and abundance occurring at the peak flowering time of the under-story plants. Bee abundance was significantly higher in the agro-forestry sites with greater over-story tree density and greater over-story tree basal area. Bee diversity positively correlated with the diversity of under-story plants as well as the density and basal area of over-story trees and negatively correlated with the density of coffee plants. These results indicate that management of both canopy-level and ground-level vegetation in tropical coffee agro-forestry systems directly influences the availability of bee pollinators. Pollination studies conducted on native plants within the coffee agro-forestry systems also suggest that local agro-forestry management influences pollinator services available for native plants living within the agro-forestry system.