A first study of its kind conducted by a team of international scientists has found that fields and farms with more variety of insect pollinator species -- such as bees, hoverflies, butterflies, and beetles -- provide more stable pollination services to nearby crops year on year.
The study, which was led by researchers from the University of Reading, reveals that areas with diverse communities of pollinators, and areas with stable populations of dominant insect species, suffered fewer year-to-year fluctuations in pollinator numbers and species richness. The idea was to investigate how to reduce fluctuations in crop pollination over time.
According to an official release, pollination by insects supports the reproduction of at least 78% of wild plants, while contributing to the pollination of 75% of major crops globally. However, wild insect pollinators are declining in areas of north-west Europe and North America where these crops are widely grown, making understanding how their populations change over time, and the impacts of this, increasingly important.
A February 2020 Reuters report noted that climate change and rising temperatures have led to a drastic decline in the population of bumblebees, for instance, across Europe and North America. The rates of this decline were “consistent with a mass extinction” and threatened food cultivation, the report explained.
For this new study, the researchers collected wild pollinator data from hundreds of field sites in 12 different countries across six continents over multiple years.
Deepa Senapathi, an ecologist at the University of Reading who led the study, says most of the previous research into pollinator stability has focused on space, not time. "However, year-to-year variations in pollination services cause boom and bust cycles in crop harvests, which can have a damaging impact on agriculture and livelihoods globally," she says. "This study has revealed that the secret to consistent crop harvests could be to encourage pollinator diversity on or near farmland. If we want pollinators to help us, first we need to help them."
Researchers studied populations of pollinating insects, such as bees, hoverflies, butterflies, and beetles, in the vicinity of 21 different crop species to explore influences on their stability over time. The findings of the study were published in the journal Proceedings of the Royal Society B on 17 March. In intensive farming systems, where there might be a reduced diversity of pollinators, the research showed that protecting the dominant species there was also effective in providing long-term stability in pollination.
Senapathi adds that stable and consistent pollination services are important for not only underpinning businesses and livelihoods, but also providing a reliable supply of food for retailers and consumers.