Agriculture dominates 40% of terrestrial environments, producing food and products that sustain human life but replacing highly-biodiverse habitats. As demand for food increases from changing diets and increased population, it falls on scientists and farmers to find ways to balance biodiversity conservation with agricultural intensification. Win-wins like saving natural habitat that exports pest control agents or implementing no-till systems that increase soil biodiversity and water retention are still being uncovered. Yet, research has primarily focused on crops outside of their native range which limits understanding of interaction-based ecosystem services like pollination.
Cacao, a cash crop grown primarily by small-holder farmers to diversify their livelihoods, has been gaining research momentum. While studies from Ghana and Indonesia have shown proximity to natural landscapes, like primary rainforest, does not increase pollination services to cacao, little research has been done within the Upper Amazon Basin, the native range of Theobroma cacao.
We examined how different landscape contexts affected pollination dynamics on cacao farms in Ecuador. Our major questions were: (1)How does landscape context affect the pollinator communities of T. cacao? (2)Does the abundance of ceratopogonids, the documented pollinator, or other floral visitors predict pollination success rates for open flowers? (3)Does landscape context affect the pollination rates of T. cacao? If there is an effect, can it be explained by differences in pollinator communities? We marked both open and hand pollinated flowers to measure pollination rates/service and collected ~2000 floral visitors to study the pollinator communities, comparing fields surrounded by four different landscape contexts (agricultural, forest fragment-adjacent, forest reserve-adjacent, and forest reserve-embedded).
Results/Conclusions
The results of the pollinator community analysis are still preliminary. However, these analyses show that the abundance of ceratopogonids decreases with increasing natural habitat and that there is no correlation between Ceratopogonidae abundance and pollination success of open flowers. Natural areas did not increase pollination rates nor decrease pollen limitation but proximity to natural areas did increase fruit set from hand pollination. Our results suggest natural areas might be providing resources other than pollinators to cacao farms. More study is needed to know what types of resources are being exporting to fields and how to increase pollination through management strategies.