How to attract more butterflies and bees to your city
30 September 2019
Interview with proGIreg’s pollinators expert, Professor Simona Bonelli, University of Turin
Please introduce yourself
Good morning I'm Simona Bonelli I'm from Turin University in Italy. I'm a biologist and I work on biodiversity conservation, in particular on butterfly conservation.
What is your role within proGIreg?
I'm involved in making the urban tissue more pollinator-friendly. Butterflies, bees and bumblebees are all pollinators and our urban tissue often is not permeable to these insects that are restricted to the surrounding of the city. They are isolated and this isolation decreases their opportunity for long-term survival. So we decided within the project to work on greening [the city] and changing a little bit the idea of ‘the urban green’ according to pollinators’ needs.
Please tell us how cities can become more pollinator-friendly
They should select a large green area and also a very small green area, [to become the] urban green area. It (the small area) could be a public or private area like a school garden or public garden, and in this area, they change at least one part of the plants according to pollinators’ needs. That means they select plants that are used by pollinators as a source of nectar or for butterflies to lay their eggs on. We know that butterflies need particular plants, both for nectar and also for reproducing to feed the caterpillar, the larvae. So, cities have to select these plants and greening in a different way; not from a human point of view, but by selecting from biodiversity point of view.
Then the second step is to introduce these plants [to the small area] and see if pollinators appreciate the initiative. So that means they need to watch the butterflies, bees and bumblebees that are using this new green area with the plants.
So how can a city monitor its butterflies and bees?
This is not so impossible because butterflies are very well-known, very colourful, and are not so difficult to recognize. A scientist can train people - citizens including children, adults and retired people - to monitor the butterflies or bumblebees and to recognize different species in order to see how much this new green area is appreciated by these pollinators.
This way we have also scientific data that we can compare to other situations, for example to outside of the urban context, or to different municipalities. That's really important, to be sure that this effort was not only to have a general idea [of encouraging more] pollinators to our municipality, but also to be sure that they are increasing.
Is it difficult for a city to do this?
In practical terms, no. But is difficult to start because from the historical point of view, the choice of [urban] green was always made thinking from the human point of view; so urban green usually is nice to see, easy to keep, and it has a recreational purpose. But in the European context, we make a wide use of exotic plants. These exotic plants often have no functional role; they are just green and ornamental. They could be a refuge for some animals, but they are not used by pollinators to reproduce or keep nectar, and there is no connection to our native species. So it is this change of criteria, that make it a little bit difficult to start. Once we start, it is absolutely not so difficult.
Increasing pollinator biodiversity is one of nature-based solutions being implemented within the framework of the proGIreg project, which creates productive green infrastructure to help improve living conditions, public health and reduce vulnerability to climate change in post-industrial urban districts.
Image: Marc Rentschler /Unsplash