Bees are important pollinators of native and cultivated plants, and consequently there is considerable research on bees in agricultural settings. However, there is limited knowledge of how legal cannabis (Cannabis sativa) cultivation may impact these communities, and the potential for licensed farms to support native bee diversity. This project provides baseline data on Bombus communities across six farms located in Humboldt County, California. Furthermore, this project seeks to assess the effectiveness of native hedgerows on bee diversity at these sites. From May to August of 2022 and 2023, native bees were surveyed monthly with a combination of pan and blue vane traps; in 2023 these efforts were expanded to natural habitats surrounding these farms to allow comparison of these wildlife communities to areas that are representative of the habitat before conversion to cannabis production. Additionally, data on floral resources were collected to assess their influence on bee communities. In this presentation, we share preliminary findings on patterns of community richness and abundance for Bombus species, and how they vary between landcover types (coastal grassland and mixed hardwood-conifer forests). In general, grassland sites had more even and abundant bee communities, but forest sites supported rarer species.

Mac Wilson is a master’s student in Matt Johnson’s Habitat Ecology Lab at Cal Poly Humboldt. His master’s research is focused on documenting bird, bee, and bat communities present on cannabis farms in Humboldt County. This includes exploring potential factors associated with patterns of diversity and how these wildlife communities respond to habitat enhancements such as native hedgerows and songbird nest boxes. This project is in collaboration with Cannabis for Conservation, a Humboldt-based non-profit, that is seeking to develop a scientifically informed eco-label certification, Wildlife Conscious Cannabis, based on the findings of this research.