The pollinator conservation approach "Farming with Alternative Pollinators": Success and drivers.

Global food security is heavily reliant on crop pollination. However, evidence on pollinator decline has been reported in all continents. Globally affordable conservation strategies need to be developed, as high-cost measures like European agri-environment schemes are not scalable in all countries. Here, we test, if a low-cost conservation approach named "Farming with Alternative Pollinators" (FAP) can benefit wild pollinator abundance and richness in agro-ecosystems and in crops, through establishment of marketable habitat enhancement plants (MHEP). The study was carried out in four Moroccan agro-climatic regions, during two years, using 6 main crops (pumpkin, zucchini, faba bean, tomato, eggplant and apple) and 201 sites. Additionally, we investigated how crop type, crop-MHEP composition (i.e. phylogenetic distances among crop and MHEP) and local climate can drive the success of the approach in comparison to monocultural fields. Based on 7097 recorded specimens, our results show that the wild pollinators of the entire FAP fields (i.e. 75% main crop and 25% MHEP) were significantly more abundant and species-rich than those of control fields (i.e. 100% main crop). Considering the main crop wild pollinators, FAP did not display any significant effect either on wild pollinator abundance or on pollinator richness. The mean phylogenetic distance between the main crop and MHEP, and climatic variables were not correlated with increase in wild pollinator abundance and richness in FAP fields. The crop type was found to influence the effect of the FAP approach. Our study provides strong evidence that FAP constitutes a relevant method for wild pollinator conservation in agro-ecosystems. Further research on additional environmental factors is necessary to outline the circumstances under which the FAP approach can positively affect wild pollinator communities. • Marketable habitat plants support pollinator abundance and richness in agro-ecosystems. • Marketable habitat plants does not promote crop pollinator abundance and richness. • Phylogeny of habitat plants and crop does not affect pollinator abundance and richness. • The climate does not shape the effect of habitat plants on pollinator communities. • The crop type modulates the impact of marketable habitat plants on pollinators. [ABSTRACT FROM AUTHOR]