Sacred church forests as sources of wild pollinators for the surrounding smallholder agricultural farms: a unique combination of religion and crop pollination in the Lake Tana basin, Ethiopia

Sacred church forest habitats act as a source of wild pollinators that significantly contribute to crop pollination and yield. In addition to their cultural significance, Ethiopian church forests scattered across intensified agricultural landscapes harbor wild insect pollinators that provide pollination services for nearby smallholder crop fields. In this era of habitat loss and fragmentation, the unique contribution of wild pollinators nesting in culturally protected church forests for crop pollination to surrounding smallholder crop fields is relevant. This study assessed the local-scale pollination service flows from church forest habitats within the pollinator foraging range (1500 m). The study area comprises crop fields adjacent to 15 sample church forest patches surrounded by a matrix of six economically important pollinator-dependent crop fields in north-western Ethiopia (during the crop growing seasons 2019 and 2020). We studied flower visitations of four wild pollinator functional groups (honey bees, wild bees, bumblebees, and hoverflies) in 72 sites along a distance gradient from the church forests. We constructed generalized additive mixed models (GAMMs) to fit the crop flower visitation rate with six fixed effect explanatory variables nested with transects that are known in advance to influence pollinator visitation in crop fields. Our study empirically measures the church forest floral resource phenology and nesting sites, patch size, and patch proximity and their effects on crop flower visitation along distance gradients from church forest habitats. An in-depth understanding of the nexuses among church forest biodiversity, cultural value, and local crop pollination service enable the promotion of ongoing stewardship through consideration of sacred natural forests in local and regional policies. This could help support the limited knowledge of farmers about pollination services and enhance more sustainable conservation practices.