Diversified agriculture to support bee biodiversity

The history of the bee lineage goes far back into the past, about 140 million years to the Middle Cretaceous. It is no coincidence that flowering plants also began to appear at this time. Throughout the evolutionary development of the Earth, many changes in both biotic (e.g. vegetation) and abiotic (e.g. climate) factors have occurred, bringing with them an influence on the evolution of bee taxonomy between continents and also a high level of continental endemism.

Since understanding the taxonomic differences or similarities of individual bee species is of ecological and socio-economic importance, scientists have chosen to study bees in both great detail and great breadth. An international team of experts studied a total of 177 commercial apple orchards in 33 countries and four biogeographical biomes, inevstigationg a total of 644 bee species.

The male of Andrena pandellei is one of the species that has a positive effect on the heterogenization of pollinator communities.
Source: Flicker.com, Author: David Genoud.

When comparing individual bee species between biogeographic zones, authors found their significant taxonomic dissimilarity. To investigate the influence of habitat characteristics on bee diversity in more detail, several factors were taken into account: landscape management type (organic vs. non-organic agriculture), land use, and land cover. The results of their models were quite intriguing. Despite the taxonomic divergence between biogeographic zones, the authors revealed a trend of homogenization in both phylogenetic (the diversity of evolutionary lineages) and functional (the variability of traits of organisms) diversity, which is worrying as the biodiversity of wild bee species could be threatened. The trend towards homogenisation of communities is most likely associated with the perennial monoculture systems in agriculture, which are intensively managed for crop production.

The dominant species in the apple orchards was the honey bee, while other species were present only in lower numbers. The presence of herbaceous, uncultivated open areas and organic farming practices appeared to have a positive effect, supporting a richer wild bee diversity.

The results of the study underline the importance of specific habitat characteristics, management practices, and land cover as key factors contributing to the diversity of bee communities needed to maintain ecosystem function and agricultural production. The study also highlights the need for further research to provide information for effective management, conservation strategies, and targeted approaches to protect pollinator populations and thus promote sustainable agricultural practices.

Kateřina Fraindová

Leclercq, N., et al. (2023): Global taxonomic, functional, and phylogenetic diversity of bees in apple orchards. Science of the Total Environment 901, 165933. https://doi.org/10.1016/j.scitotenv.2023.165933