Bumblebees are among the UK’s estimated 1,500 species of wild pollinators and play a vital role in the environment. They transfer pollen from plant to plant – and thus ensure that plants reproduce. It is estimated that 75% of the crops we eat depend on pollination. Over the past 80 years or so, there has been a dramatic decline in the distributions of some bumblebee species. Two of the 26 species of bumblebee once common in the UK are now extinct.
Dr Lynn Dicks is an expert in the ecology of flower-visiting insects, and has used her knowledge of the requirements of pollinators to contribute to policy development by Natural England in its Countryside Stewardship scheme to try and reverse the decline in wild pollinators such as bumblebees.
In 2013, Dr Dicks took advantage of an opportunity opened up for scientists to contribute to the development of an ‘agri-environment package’ for wild pollinators as part of the new Countryside Stewardship scheme. Dicks used this ‘policy window’ to bring together a wide range of available information and ask key questions about wild pollinators and their relationship with the farmed environment. In providing tentative answers to these questions, her research provides ballpark figures on aspects of land management that determine population levels of wild pollinators, including bumblebees, and bolsters arguments for policies that encourage farmers to sow a mix of wild flowers.
By calculating the pollen demands of individual bees, and the resulting demand for flowers, Dicks has come up with some approximate figures in terms of the percentage of land and hedgerow needed to resource a healthy population of selected wild pollinators. Using a 100-hectare block of land as the basis for calculations, she estimates that the provision of a 2% flower-rich habitat and 1km flowering hedgerow will supply the six pollinator species with enough pollen to feed their larvae. “We suggest that farmers sow headlands, field corners and other areas with mixes that will flower in the summer months, but they also need to manage hedgerows, woodland edges, margins and verges to enhance early and late flowering species and provide nesting and hibernating opportunities,” says Dicks.
According to James Phillips, Senior Advisor, the Agri-environment Team at Natural England:
“We looked at [Lynn’s] research and we applied that research to the Wild Pollinator Strategy and the key thing was that it was evidence-based, and it was all about putting in the right options in the right place and at the right scale to deliver the lifecycle needs of wild pollinators and that was key to the package that we have developed.”