Since humans have industrialised farming to feed a growing world population, pollinators, which are essential for the reproduction of plants – are seeing their food source decrease. In the UK, intensive agriculture has reduced the biodiversity of large areas of the countryside, with vast areas of cereals and grass grass pastures that are now replacing habitats with flowers.

For pollinators like hoverflies, bees, and butterflies, the loss of flowers results in a loss of pollen and nectar, which is their food source. The decrease in the amount and variety of their food sources is a significant reason for the decrease in their populations.

We discovered that urban areas aren’t at all bleak. They have the same resources as the countryside gardens and provide an abundance of nectar-rich oases that support those pollinating bugs.

Urban potential

Within the UK, 83% of the population lives in urban areas. These landscapes are intricate mosaics of landscapes, ranging from open spaces such as gardens and parks to car parks and pavements.

In our research, we determined the amount of nectar-producing flowers made through sampling in a variety of urban settings such as botanical and private gardens, roads, allotments, and other gardens. We also incorporated other studies published about nectar production to evaluate our results against the nectar production and variety of rural environments.

Buddleia is a great source of nectar to butterflies. Linda Bestwick/Shutterstock

It can be difficult to measure nectar; however, it’s interesting to observe how different flowers have developed ways to supply insects with a reward. With a small glass capillary tube that is roughly replicating the bee’s tongue it was possible to extract nectar, and weighed its volume of nectar, which is often less than one hundredth of the size of a raindrop.

We then had to determine the sugar content that we could achieve with the Refractometer. This advanced device, which brewers commonly employ, determines the amount of light that bends while it is passing through the solution and determines how much sugar has been dissolved. Nectar could be as high as 60 percent sugar by weight, equivalent to putting 100 spoonfuls into your tea. After repeating this procedure over three thousand flowers, We were able to make nectar calculations that were large enough to examine entire specimens of the habitats we sampled.

Our research suggests the urban areas are areas for nectar variety. This implies that there are more types of flowering plants producing nectar in cities and towns than in the farmland or nature reserve sites we observed. Like humans, eating a balanced diet is essential for maintaining the health of pollinators and assisting them to combat diseases.

In addition, flowers can come in different colors, scents, shapes, and dimensions, and pollinators differ in their preference. For instance, butterflies prefer to feed on thin tubular flowers that have scents of sweetness, such as Buddleia, while hoverflies prefer easy access to nectar, such as the ones found in carrot flowers. Understanding that urban landscapes offer an array of blooms is vital since it indicates that they are able to be a source of a broad range of pollinator types.

Gardens are important.

The spaces within cities and towns differ in the amount of energy-rich sugar they release. In a particular area, residential gardens produce an equal amount to allotments, however, they are four times the amount as public parks. The reason is that gardens are nectar-rich and widespread, with a huge area covering about 30 percent of the urban area – they provided around 85% of nectar produced in the four cities that we studied (Bristol, Edinburgh, Leeds, and Reading).

This implies that between eight and nine of every 10 kilograms that we consume in urban areas originates from a garden. It’s no exaggeration to declare that parks are essential to the pollinator food source in cities and towns. The choices that every gardener makes regarding their garden are crucial to the protection of butterflies, bees, and other pollinators.