Intensification of Ethiopian coffee agroforestry drives impoverishment of the Arabica coffee flower visiting bee and fly communities
Intensively managed shade coffee plantations are expanding in SW Ethiopia, at the cost of the more natural coffee agroforestry systems. Here, we investigated consequences for the potential pollinator community of Arabica coffee (Coffea arabica L.) in its natural range. We surveyed coffee flower visitors at six different sites in the Jimma region in SW Ethiopia, and compared species richness and abundance between semi-natural coffee forests and shaded coffee plantations. Overall, we found six bee (Hymenoptera: Anthophila) and twenty fly species (Diptera: Brachycera) visiting C. arabica flowers. Species richness and overall abundance of flower visitors was significantly higher in the semi-natural forests compared to the plantations. A significantly higher abundance of non-Apis bees and hoverflies (Syrphidae) visiting C. arabica flowers was observed in the semi-natural forest plots, but numbers for other Diptera and honeybees (Apis mellifera L.) did not differ significantly between the agroforestry systems. Our results show an impoverishment of the coffee flower visiting insect community in response to agricultural intensification. This suggests a functional shift of the coffee pollinator community and, hence, may influence the stability of the provided pollination ecosystem services and coffee yield in the long term. We did, however, not quantify pollination services in this study.
KeywordsCoffea arabica Anthophila Brachycera Flower visitors Moist Afromontane forest
This research was financially supported by the Flemish Interuniversity Council (VLIR-UOS) and by the Flemish Fund for Scientific Research (FWO) (Project G.0565.17). We gratefully thank Daniel Damtew, Research Assistant at Jimma University, for his high-level field expertise and translation skills during data collection. We are also very thankful to Gerba Daba, Bemhiretu Boka, and Dr. Debissa Lemessa for their logistical help, to Yalew and Kasu for their hospitality and extra field support, and to Horizon Plantations P.L.C. for permission to access the coffee plantations. We gratefully acknowledge Alain Pauly (Royal Belgian Institute of Natural Sciences) for the species-level identifications of the Anthophila (Hymenoptera: Anthophila). This study benefited from the comments and suggestions of three anonymous reviewers. There are no disputes over the ownership of the data presented in the paper. All authors approved the final manuscript and agreed to be accountable for all aspects of the work.
OH, RA, KJ, GB and LG conceived and designed the study; LG and SW collected field data and exported insects to Belgium with permission of the Ethiopian Biodiversity Institute (Reference number: EBI71/5065/2016); LG, OH, RA, and ID performed the statistical analysis; LG prepared the initial draft of the manuscript. LG and ID prepared the insect specimens for identification. KJ identified all Brachycera (Diptera: Brachycera) to family level, and identified the Syrphidae, Calliphoridae, Rhiniidae, and Sarcophagidae to species level; MC identified the Muscidae to species level. All authors contributed to interpretation of research data, to preparing, discussing and editing of the manuscript.
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Conflict of interest
The authors declare that they have no conflict of interest.
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