Pollen diversity and protein content indifferentially degraded semi-arid landscapes inKenya

Abstract

In Africa there is a scarcity of information on how plant species that can provide forage for honey bees vary across dif-ferentially structured landscapes, and what are the implications of such variabilities on colony integrity. This researchpresents new insights into the diversity and richness of pollen collected byApis mellifera scutellata, a subspecies of theWestern honey bee native to sub-Saharan Africa, at six study sites of different degradation levels within a semi-aridlandscape in Kenya. Ten colonies were established at each site and land cover characteristics were extracted usingnovel remote sensing methods. The sites differed by the proportions of natural vegetation, cropland, grassland andhedges within each site. Bee bread was collected five times, with three colonies in each of the six sites repeatedlysampled during the period from May 2017 to November 2018. Pollen identification and protein analysis within the studysites were thereafter conducted to establish the linkage between landscape degradation levels and abundance and diver-sity of pollen. Out of 124 plant species identified,Terminaliaspp., Cleomespp. andAcaciaspp. were identified as themost abundant species. Moreover, species richness and diversity were highest in the two sites located in moderatelydegraded landscapes. Pollen protein content showed statistically significant differences across season rather than geo-graphical location. This study demonstrated that landscape degradation negatively affected the diversity and richness ofpollen collected by honey bees. Consequently, this helps our understanding of native honey bees’forage resource usageand plant species preferences in landscapes with varying degrees of degradation.