Diversity of Life-History Traits, Functional Groups and Indicator Species of Bee Communities from Farmlands of Central Uganda

Bees are keystone organisms that sustain human life on earth through their pollination services. However, very little is known about functional groups and indicator species of bee communities from agricultural landscapes in Sub-Saharan Africa and Uganda. Responses to anthropogenic disturbances and the quality of pollination services delivered by different bee species are often associated with bee life-history traits. Diverse bee functional groups have different pollination service impacts on wild and cultivated plants. Efficient bee species are often good indicator species belonging to the same functional group. To provide baseline data on functional traits of bee communities in agricultural landscapes, a study was conducted in 2006 at 26 sites with varying local and landscape characteristics in central Uganda. Bees were sampled using colored pantraps, hand nets and line transect counts. The farmland bee community was characterized by a diversity of functional traits and guilds. Most of the bee species and individuals collected by the three sampling methods applied were solitary (37-70%), ground-nesting (41-65%), polylectic (74-91%), long-tongued (73-87%) and of small ( 5.5mm) to medium (5.5-10.5mm) body sizes (18-37%). Using Indicator value method (IndVal), more than 17 species were recorded as indicator species or “species characteristics of the farmland habitats”. Indicator species are generally ubiquitous species potentially delivering pollination services of high quality to cultivated and wild plants in farmland environments. They were recommended by to monitoring programs aiming at detecting the status and trends in Apoidea communities in central Uganda. To prevent future decline in the functional diversity, it is important to develop strategies to conserve landscape and habitats as reservoirs of different functional groups of bees. This will greatly contribute to the spatio-temporal stability of yield of pollinator-dependent crops that are pollinated by different pollinator groups. Monitoring programs aiming at detecting changes in bee faunas in farmlands of central Uganda may focus on the 17 indicator species identified by this study