View all news

Nature and nurture (Nonesuch spring 2015)

15 May 2015

Insects play a vital role in the pollination of many plants, but pollinators – and their natural habitats – are on the decline. The Urban Pollinators project, led by the University of Bristol, is the first comprehensive study to investigate the status of these diligent winged workers in urban areas and consider ways of improving their lot.

For a nation of gardeners, what better way to spend a Sunday afternoon than browsing at the garden centre? But next time you're stocking up on bedding plants, spare a thought for the hoverfly settling on that primrose. Ninety-seven per cent of the UK's wildflower meadows – a rich source of food for many such insect pollinators – have disappeared since the 1930s, giving way to urban development, and agricultural and grazing land.

It's a paradox, then, that for food production we depend on the ecological services of the very creatures whose habitats we compromise: we need pollinators to transfer pollen between crop plants, leading to fertilisation and seed production. So what if we encouraged insects in our cities? Would that help restore pollinator populations in other areas and build more robust local food systems?

Where have all the pollinators gone?

The Urban Pollinators project is part of the wider UK Insect Pollinators Initiative that aims to research the causes and consequences of threats to insect pollinators, and inform future mitigation strategies. It is funded by the Biotechnology and Biological Sciences Research Council, the Department for Environment, Food and Rural Affairs (Defra), the Natural Environment Research Council (NERC), the Scottish Government and the Wellcome Trust.

The project, led by Cabot Institute member Jane Memmott, Professor of Ecology in the School of Biological Sciences, is a partnership between the Universities of Bristol, Reading, Leeds and Edinburgh, with collaboration from taxonomists at the National Museum Wales. It is the first large-scale study to compare the suitability of different landscapes for pollinating insects across the UK – urban areas, farmland and nature reserves – and to build up a picture of pollinator biodiversity across a range of urban habitats.

Dr Katherine Baldock (BSc 2000), who has been the post-doctoral researcher for the project since it began in 2011, explains: 'There's been very little research around urban pollinators. Most previous studies have involved one type of urban habitat – mainly gardens. One of the unique things about this research is that we've systematically collected data in a range of habitats – allotments, gardens, cemeteries, road verges, car parks – to try to identify pollinator "oases" in urban areas.'

Working with local authorities and wildlife trusts as well as academic colleagues, Baldock developed the project protocols, and co-ordinated and trained the fieldworkers, who spent three and a half years building up a picture of the community of pollinators in different habitats, and the types of plants they feed on. The team then went on to plant 15 new flower meadows in each of four cities – Bristol, Reading, Leeds and Edinburgh – to assess whether the introduction of new food sources could boost urban pollinator diversity and abundance.

Sanctuary in the city

The initial project findings were published in February in Proceedings of the Royal Society B and found that pollinating insects thrive as well in towns and cities as they do on farmland and in nature reserves. The study also found that bee diversity is higher in urban areas than farmland. 'Pollinators are driven by the availability of food and suitable nesting sites,' says Baldock. 'Urban areas contain a huge variety of plant species, particularly non-native garden plants, which may explain the corresponding richness in pollinator diversity.'

The findings have important implications for pollinator conservation as our towns and cities continue to grow. With the total value of crops pollinated by insects estimated at more than £510 million per year in the UK, there is scope for policymakers to increase the number of urban insect havens and improve the quality of existing green spaces in order to conserve and encourage pollinators.

All together now

The findings are timely in more ways than one. First, they will support the development of Defra's National Pollinator Strategy, which was launched in November 2014 and promotes measures that support pollinator conservation. This will give Baldock, who has now embarked on a three-year Knowledge Exchange Fellowship funded by NERC and supported by the Cabot Institute, an opportunity to engage with policymakers.

Second, they will help inform the development of a pollinator strategy for Greater Bristol. Building on partnerships established during the Urban Pollinators project, Baldock has been working with Bristol City Council, the Avon Wildlife Trust, Bristol Friends of the Earth, Buglife, South Gloucestershire Council, and the University of the West of England to draft the strategy, which went out to public consultation earlier this year.

The strategy is a key component of the Get Bristol Buzzing initiative, which will link local activities related to pollinator conservation. 'It's a great opportunity to share the science with a wider audience, and work in a structured way with individuals and organisations to create suitable habitats for insect pollinators across the Greater Bristol urban area – in gardens, public spaces and on business sites, too,' says Baldock.

Get your green fingers out

That Bristol 2015 European Green Capital year should fall during Baldock's fellowship is a happy coincidence. Defra has contributed funding to support the Greater Bristol Pollinator Strategy and Get Bristol Buzzing as part of Bristol 2015 European Green Capital. This work will act as a case study to be rolled out to other towns and cities across the UK. Defra is also funding the creation of three flower meadows, one in South Gloucestershire and two alongside the M32 motorway, providing new food sources for insects and contributing to public awareness of pollinator conservation.

But such large-scale projects are only part of the story, says Baldock: 'For any wildlife habitat conservation project to be successful, you need people on the ground taking action.' And with between 25 and 35 per cent of our cities comprising gardens – a great potential food source for pollinators – that means bringing members of the public on board. Judging by the experience of the Urban Pollinators team, that shouldn’t be too difficult. 'We had no shortage of householders willing to offer their gardens as sampling sites,' says Baldock. 'Our fieldworkers shared many a cup of tea with gardeners keen to find out more.'

Who would have known, for example, that there are more than 250 solitary bee species in the UK? And while we're all familiar with the honeybee, we may not be aware of the many other species – including hoverflies and butterflies – essential for pollinating crop plants, including some of the fruits and vegetables commonly grown in gardens and allotments.

Such was the level of interest that the team set up a blog to keep stakeholders up to date with the project's progress and provide more information about the intriguing world of insect pollinators. Baldock intends to continue to harness the enthusiasm of communities around the city and get folk planting with pollinators in mind. A thoughtfully sown window box may be all it takes to help pollinators thrive and ensure that there will be 'honey still for tea'. Not to mention strawberries at Wimbledon. 

Bristol in bloom

A Stoke Bishop hall of residence is the site of one of the 15 flower meadows planted in Bristol as part of the Urban Pollinators project. 'Although the University has a large estate, identifying the location for a pollination study wasn't as simple as sticking a pin in a map,' says Alan Stealey, Head of External Estates. 'It was important to the researchers that we chose a site that could be classified as urban, as opposed to more open space such as parkland, and we also wanted to maximise the visual impact of the meadow and raise awareness of the project among students. We settled on what is almost a natural amphitheatre in the grounds above University Hall.’

The Estates team planted the perennial meadow with a wildflower seed mix containing 12 native plant species specially selected for pollinators. Volunteers continue to collect seeds with the intention of establishing similar displays elsewhere in the University grounds in future years.

Visitors can witness the benefits of plant diversity at the University’s Botanic Garden, which in recent years has established an enviable plant display that attracts a wide variety of pollinators. The Botanic Garden also hosts an annual Bee and Pollination Festival in September.

Towards a sustainable food future

Food security is a major research strand at Bristol. Cabot Institute members are involved in a wide range of projects that are helping to build resilient food systems.

Dr Eric Morgan (Veterinary Sciences) is looking at sheep breeds that are naturally resistant to infection in order to reduce routine drug treatment of livestock, while Professor Mike Eisler and Dr Michael Lee have been instrumental in establishing the Global Farm Platform, an international programme examining strategies for rearing ruminant livestock sustainably.

Professor Keith Edwards and colleagues (Biological Sciences) have sequenced a large portion of the bread wheat genome, and are sharing data with other plant geneticists so that producers can improve the resilience of wheat species.

Dr Naomi Miller and Dr Mark Jackson (Geographical Sciences) are working with a rural community in El Salvador and an urban community in Bristol to examine different approaches towards combatting food poverty and guarding against environmental changes that threaten food production.

Dr Patricia Lucas (Policy Studies) is investigating the links between global food insecurity and local food poverty.

Listen to audio version (mp3)

Back to Nonesuch index

Further information

To find out more, please visit bristol.ac.uk/urban-pollinators.

Didn't receive your copy of Nonesuch? Please update your details online or email us at alumni@bristol.ac.uk. In the meantime, please download the spring 2015 issue (PDF, 3MB) so you don't miss out on the latest news from Bristol.