【生態】ありふれた野生のミツバチが最大の経済的利益をもたらす

Almost 80% of crop pollination by wild bees is provided by only 2% of the most common species, finds a study published in Nature Communications. This indicates that the benefits of conserving only economically important organisms are not the same as the benefits of conserving a broad diversity of species.

Higher levels of biodiversity are known to provide greater benefits to the functioning and stability of ecosystems, with some of these functions also being economically beneficial for humans. However, the extent to which these economically important ecosystem services rely on the diversity of species that can provide them is unclear.

David Kleijn and colleagues combined data from more than 90 studies on wild bees in five continents, including Europe and North America, analysing which of the 785 species studied provide the best economic returns from crop pollination. They find that wild bee communities contribute an average of over $3,000 per hectare to the production of crops, providing the same economic contributions as managed honey bee colonies. However, they also note that the majority of crop pollination services provided by wild bees are done so by only a small subset of the most common species.

These results suggest that conservation efforts targeted directly at a few species providing the majority of ecosystem services, such as crop pollination, would represent a good strategy if the goal is to improve economic returns. However, such a strategy is unlikely to be compatible with conserving threatened species and biological diversity if the goal is to improve the functioning and stability of ecosystems.