There’s a thought-provoking essay in Conservation Biology by Hall et al., The city as a refuge for insect pollinators. The authors say that while there’s a lot of conservation outreach in cities there’s less actual conservation. The cities are where people are educated or energised to support conservation efforts, but the conservation happens elsewhere. If you take the view that you’re not going to find nature among the concrete that makes sense, but research shows that’s not the case.
Annals of Botany readers will be familiar with Hanley et al.’s work on pollinators in urban gardens, but Hall et al. point to a much wider range of urban bees. Obviously, urban bee keepers are one source of bees, but there’s a lot more to bees than the honey bee, and there’s a surprisingly large number of bees species, many solitary bees, in the city. It’s not just bees that can benefit from conservation, though.
Honeybees pollinate about a third of the crops in the UK. It’s a massive amount but to put it another way, two-thirds of crops are pollinated by something else. I’d love to pretend this is my wise insight, but it’s something I found on Jeff Ollerton’s site. I was surprised by this, but it is backed by a study showing honeybees are part of a wide range of pollinating insects.
A move from a honeybee-centred conservation to a pollinator-centred conservation would have the benefit of tackling the problems that have been damaging pollinators, including honeybees, for a century. I don’t doubt pesticides are a problem, but removing 98% of wildflower meadows must have had a massive effect on pollinator habitats in the UK.
As an example of what can be found in the city, there’s a study by Sirohi et al who studied bees in Northamption. They found for solitary and primitively eusocial bees the city was a better site for diversity than nature reserves. Baldock et al. also found that the city also beat farmland for diversity.
In their essay Hall et al. emphasise that because of the limited requirements of pollinators, major results for conservation programmes are achievable, concluding:
Attending to the needs of insect pollinators in conjunction with a suite of other conservation measures (e.g., green-infrastructure and environmental quality-of-life provision and climate-change mitigation) can inform current and future generations how to urbanize sustainably. To do so, requires an ecological understanding of the city and a requisite conservation that fits the city: conservation for the city.
The city as a refuge for insect pollinators is Open Access at Conservation Biology.
Hall, D., Camilo, G., Tonietto, R., Ollerton, J., Ahrné, K., Arduser, M., Ascher, J., Baldock, K., Fowler, R., Frankie, G., Goulson, D., Gunnarsson, B., Hanley, M., Jackson, J., Langellotto, G., Lowenstein, D., Minor, E., Philpott, S., Potts, S., Sirohi, M., Spevak, E., Stone, G., & Threlfall, C. (2017). The city as a refuge for insect pollinators Conservation Biology, 31 (1), 24-29 DOI: http://dx.doi.org/10.1111/cobi.12840
Hanley, M., Awbi, A., & Franco, M. (2014). Going native? Flower use by bumblebees in English urban gardens Annals of Botany, 113 (5), 799-806 DOI: 10.1093/aob/mcu006
Breeze, T., Bailey, A., Balcombe, K., & Potts, S. (2011). Pollination services in the UK: How important are honeybees? Agriculture, Ecosystems & Environment, 142 (3-4), 137-143 DOI: 10.1016/j.agee.2011.03.020
Sirohi, M., 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, 19 (3), 487-500 DOI: 10.1007/s10841-015-9769-2
Baldock, K., Goddard, M., Hicks, D., Kunin, W., Mitschunas, N., Osgathorpe, L., Potts, S., Robertson, K., Scott, A., Stone, G., Vaughan, I., & Memmott, J. (2015). Where is the UK's pollinator biodiversity? The importance of urban areas for flower-visiting insects Proceedings of the Royal Society B: Biological Sciences, 282 (1803), 20142849-20142849 DOI: 10.1098/rspb.2014.2849