Small patches of wildflowers sown in cities can be a good substitute for a natural meadow, according to a study which showed butterflies, bees and hoverflies like them just as much.
Councils are increasingly making space for wildflower meadows in cities in a bid to tackle insect decline, but their role in helping pollinating insects was unclear. Researchers working in the Polish city of Warsaw wanted to find out if these efforts were producing good results.
They found there was no difference in the diversity of species that visited sown wildflower meadows in cities compared with natural ones, according to the study published in the journal Ecological Entomology, and led by researchers from Warsaw University. The researchers said: “In inner-city areas, flower meadows can compensate insects for the lack of large natural meadows that are usually found in the countryside.”
This study confirmed that small areas of urban wildflowers have a high concentration of pollinating insects, and are as valuable to many pollinators as larger areas of natural meadow that you would typically find rurally. “In this way, we can alleviate the hostile environment of urban space for wildlife,” the researchers wrote.
Some insects did prefer the countryside: the number of butterflies was twice as high in natural meadows as it was in sown floral meadows, although the diversity of species was the same. No differences were found for wild bees and hoverflies.
The research team chose 10 locations across the centre of Warsaw and one 20km south of it. Observers sat out from June to August on sunny days without strong winds. Insects were either observed on site, or captured and taken to a laboratory to be identified. In total, they recorded more than 10,200 insects, made up of 162 species.
About 50% of all European butterflies partly live in natural grasslands, and although there were fewer in cities, researchers found rare and protected species in the centre of Warsaw, including large coppers (Lycaena dispar) and scarce swallowtails (Iphiclides podalirius).
“We are of the opinion that replacing some mowed green areas with flower meadows may enhance biodiversity, especially by providing a mosaic of meadow types,” researchers wrote. “By sowing flower meadows, we quickly create colourful habitats that are eagerly visited by city inhabitants.”
Wildflower meadows are cornerstones of biodiversity, and yet an estimated 97% in the UK have been destroyed since the second world war.
