Flower-rich habitats do benefit bumbebees
Tuesday 21 March 2017
Major new research led by the Centre for Ecology & Hydrology (CEH) has shown that flower-rich habitats are key to enhancing the survival of bumblebee families between years.
According to CEH, the study was the largest ever of its kind on wild bumblebee populations. Researchers said their results will help farmers and political leaders manage the countryside more effectively to provide for wild bees, which are vital pollinators, but have suffered worrying population declines across the northern hemisphere.
The study used DNA technology and remote sensing to identify, map and track mother, daughter and sister bumblebees over two years to reveal that access to a range of pollen and nectar-rich flowers is vital to the survival of their populations.
Lead author Dr Claire Carvell, a Senior Ecologist at the Centre for Ecology & Hydrology, explained, “By decoding the clues hidden within the DNA of bumblebee queens and workers, and combining these with detailed landscape surveys, our research demonstrates that the survival of bumblebee families between years is positively linked with habitat quality at a landscape scale.”
CEH researchers studied three species of bee (Bombus terrestris, the buff-tailed bumblebee; Bombus lapidarius, the red-tailed bumblebee and Bombus pascuorum, the common carder bee), tracking more than 1,600 families across a farmed landscape. They discovered that colonies produced more daughter queens that survived to the following year when they were located within 250-1,000 metres of habitats with high-quality food resources. These resources include spring and summer-flowering plants that provide pollen and nectar throughout the bees’ lifecycle.
In the UK most bumblebee colonies live for less than a year; nests are formed in the spring by a single queen and produce up to a few hundred daughter workers. At the end of the summer new queens are produced which, after mating and hibernation, go on to start new colonies the following spring.
However, understanding survival between these critical lifecycle stages has proved challenging because in the wild, colonies are almost impossible to find. The CEH team managed to match daughter queens to their mothers and sisters using advanced molecular genetics, and estimating the locations of colonies in the Buckinghamshire countryside from the locations of their workers.
Environmentally-minded farm management can support bees
The researchers said their results provide strong support for environmentally-friendly management of farmland to provide more flowers in hedgerows, meadows and along the edges of arable fields. They will also help farmers and land managers decide where best to plant flowers in the landscape.
CEH’s Dr Carvell said, ”The findings suggest that increasing flowers provided by spring-flowering trees, hedgerow plants and crops across the landscape – in combination with summer flower resources along field edges – can increase the probability of family survival by up to four times.”
The findings come as the National Trust, one of the UK’s largest landowners, has promised massive increases to the land it manages as habitat for wild species, which will rely on work with its tenant farmers. Farmers' involvement in conservation projects in the UK is essential, as more than 70% of the country is farmland.
Senior author Dr Matthew Heard, a Principal Ecologist at the Centre for Ecology & Hydrology, added, “While there is an urgent need for more robust data on the patterns and causes of pollinator population decline, our study strongly suggests that conservation interventions can have a lasting, positive impact on wild pollinators in agricultural landscapes.”
Commenting on the findings, the government’s Minister for Rural Affairs and Biosecurity Lord Gardiner said, “Bees are not only an iconic part of the countryside – they are vital to our environment and play a crucial role in food production. Thousands of volunteers and farmers across the country alongside businesses, councils and government departments are committed to protecting our pollinator population and this new research provides crucial new intelligence on how they can help.”
CEH researchers worked with colleagues from University of East Anglia, ZSL (Zoological Society of London) and University College London on the project. The study was published last week in the journal Nature and received funding from the UK’s environmental and agricultural research councils, Defra, the Scottish government, with more private support from the Wellcome Trust and pesticide company Syngenta.