Is there a relationship between distance to natural habitat and pollination services in tropical smallholder farms? A systematic review and meta-analysis

Ennia Bosshard , Mark E Harrison, Frank J. F. van Veen, Nagaraja Badenahally Chikkarangappa, John E Banks, Parthiba Basu, Bo Dalsgaard, Aditi Dutta, Eunice Enríquez, Natalia Escobedo-Kenefic, Barbara Gemmill-Herren, Jaboury Ghazoul, Katrine Hansen, Annika L Hass, Olivier Honnay, John Muo Kasina, Alexandra-Maria Klein, Iris Kormann Motzke, Smitha Krishnan, Patricia Landaverde, Anderson Oliveira Latini, Kevin Li, Rodrigo Lucas-Garcia, Theodore Munyuli, Deepthi Narasimhaiah, Diana Obregon, J. Javier G. Quezada-Euán, Victor Rosas-Guerrero, Julian Schrader, Fernando Severiano-Galeana, Tegegne Molla Sitotaw, Tuanjit Sritongchuay, Pornpimon Tangtorwangsakul, Manuel Toledo-Hernandez, Poornima Viswanathan, Cassandra Vogel, Kanuengnit Wayo, Catrin Westphal, Matt Lloyd Jones , Christopher N. Kaiser-Bunbury

Proximity to natural habitat is known to enhance pollination services in agricultural landscapes, particularly in large-scale industrialised farms. However, it remains unclear whether these patterns hold in tropical smallholder farms – ecologically complex landscapes that sustain millions of the world’s most food-insecure communities and depend heavily on biodiversity-derived ecosystem services. Here, we present a systematic review and meta-analysis of 32 studies assessing the relationship between distance from natural habitat and pollinator abundance, species richness, and crop fruit set in tropical smallholder farms. We found no consistent effect of distance on pollinator abundance and crop fruit set. While pollinator species richness declined with increasing distance to natural habitat, especially when excluding managed honeybees, this relationship was highly variable across studies, constraining the generalisability of observed trends. Our results thus indicate that diverse smallholder landscapes may buffer against negative effects of distance to natural habitat on pollination services. Yet, variability in study methodologies and spatial scales – ranging from a few hundred meters to several kilometres – limits the ability to determine clear patterns. More standardised, open-access research is needed to clarify the nuanced pollination dynamics in tropical smallholder farms and inform conservation strategies that support both biodiversity and rural livelihoods.