Tag Archives: Food security

Urban bee diversity – a new study

Bee on apple blossom 2 - 1st May 2015

Over the past couple of years I’ve mentioned urban pollinators, and specifically the work of my PhD student Muzafar Hussain Sirohi, several times; for example here and here.  Muzafar is currently finishing off the writing of his thesis, and during that time he’s also managed to publish the first paper from the study.

We are really pleased with this paper because not only is it the product of a lot of hard work to systematically sample and identify the bees, but the results are really exciting: Muzafar has shown that the centre of Northampton is home to a more diverse set of bee species than expected. In fact at least 50 species of bees are thought to live within a 500m radius of All Saints Church, which is significantly more than are found in the nature reserves at the edge of the town.

Muzafar’s work involved surveying the small gardens, road verges, traffic islands, and other patches of plants in the urban centre of Northampton.  These areas provide important nectar and pollen sources for the bees, whilst old stone walls and bare soil offer opportunities for nesting sites. This community of bees includes one nationally rare Red Data Book species called Coelioxys quadridentata that is known from rather few sites.

Our estimate of about 50 species of bees is certainly too low because we focussed on the more neglected groups of bees and didn’t include the social bumblebees. The true figure is likely to be over 60 species, a remarkable number given the small area surveyed.

As I’ve discussed many times on this blog, pollinators such as bees are hugely important both ecologically (most plants require them for reproduction) and economically (much of our food production relies directly or indirectly on pollination by animals). However a significant proportion of bee species in the UK are declining in abundance, and some have gone extinct. Understanding how these bees are distributed across the landscape, including urban areas, is crucial to the conservation of such pollinators in a rapidly changing world. The project therefore has implications not only for conservation of biodiversity, but also food security, given the number of urban gardeners who grow their own food, and the ability of many bees to travel significant distance from urban to rural areas.

The research is published in the international, peer-reviewed Journal of Insect Conservation. The full reference (with a link to the abstract) is:

Sirohi, M.H., Jackson, J., Edwards, M. & Ollerton, J. (2015) Diversity and abundance of solitary and primitively eusocial bees in an urban centre: a case study from Northampton (England). Journal of Insect Conservation DOI 10.1007/s10841-015-9769-2

If anyone would like to receive a PDF of the paper, please leave a comment below or drop me an email: jeff.ollerton[at]northampton.ac.uk

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Filed under Bees, Biodiversity, Ecosystem services, Gardens, Pollination, University of Northampton, Urban biodiversity

Urban pollinators for urban agriculture (and horticulture!)

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Over the past few weeks I’ve been thinking a lot about urban pollinators, that is to say bees, hoverflies, butterflies, and other animals, living and foraging in towns and cities.  As I recounted in my recent post about the National Pollinator Strategy seminar at Westminster, Jane Memmott presented some of the first data from the Urban Pollinators Initiative which is looking very interesting.  At the same time, Muzafar Hussain has submitted the first manuscript from his PhD study of urban solitary bees in Northampton, and will hopefully be defending his thesis early next year.  More recently I was asked to examine the PhD thesis of  Rob Fowler at the University of Birmingham, whose focus has been on pollinators across an urban-rural gradient.  Rob did very well and I look forward to seeing his work published.

Interesting though all this work is, it’s largely being done outside the context of crop pollination per se, focusing mainly on the identity and abundance of these urban pollinators.  It’s timely, therefore that a study has just been published by Thebo et al. in the journal Environmental Research Letters entitled  “Global assessment of urban and peri-urban agriculture: irrigated and rainfed croplands” which gives the first comprehensive figures on the extent of agriculture in and around the world’s large towns and cities.  The paper is open-access so you can read its findings for yourself, but the main message is that urban agriculture is more extensive and important than previously assumed, and there are significant implications for food security and water resources.

The research has (justifiably) received quite a lot of publicity in the media, for example on the BBC News website, and is a great contribution to a still limited field of study.  One aspect jumped out at me though; when discussing the limitations of their methods the authors state that: “the scale and methods used……are not structured to capture very small, spatially dispersed areas of urban croplands”.  In other words, urban gardens and allotments are not included in this assessment.  In the UK at least this is a significant limitation as we know that urban fruit and vegetable growing is widespread, though as far as I’m aware there’s no published figures on the volume and value of this local horticulture of food crops.

Which brings us back to urban pollinators: a significant fraction of these crops (large-scale and local garden) requires pollination by insects.  As I reported back in July, in our own urban garden this includes at least 15 crops (strawberries, apples, greengages, cherries, blackcurrants, squashes, courgettes, blackberries, fennel, runner beans, french beans, passion fruit, tomatoes, raspberries, and radish pods).  An integrated study of urban agriculture/horticulture in the context of pollinator diversity and abundance would be a great piece of research and is long overdue.

 

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Filed under Bees, Biodiversity, Butterflies, Ecosystem services, Gardens, Honey bees, Hoverflies, Personal biodiversity, Pollination, Urban biodiversity