Written by: Phoebe Carter and Sabrina Yelin
Biodiversity loss is occurring at an unprecedented rate across the globe with significant implications for both planet and people. Biodiversity is the variety of all life on Earth – animals, plants, fungi and microorganisms like bacteria, and this rich web of life provides us humans with everything we need for survival, from fresh water and clean air to food and medicines. The twin climate and biodiversity crises are justly gaining more attention in the mainstream media, and while we all need to hear about what’s going on, its easy to feel overwhelmed by the severity of the situation and left wondering what we can do on an individual level to make a positive difference.
The value of gardens in an urban landscape
A recent review of the evidence on the biodiversity value of urban gardens by Nature Positive’s Richard Delahay and colleagues describes how maximising these benefits is becoming increasingly important as urban areas expand and nature continues to be depleted in the wider environment. Taking action on an individual level in your garden or outdoor area (patio/balcony/window boxes) can, therefore, make a real difference to local biodiversity and collectively, the small actions of many people can amount to a significant positive impact.
By 2030, it’s estimated that 60% of the human population will live in urban areas, which will be accompanied by further loss and fragmentation of habitats, disruption to ecosystem services and the displacement and disturbance of wildlife. Gardens and public open spaces will therefore become even more important to nature, with the potential to connect habitats directly or act as ‘stepping stones’, helping plants and animals disperse throughout the urban environment.
The study by Delahay and colleagues reviewed the evidence from over 400 published articles and found that cultivating a diversity of plants, increasing vegetation cover and creating a variety of habitats were key to maximising the biodiversity value of gardens. Although not surprising findings, they serve as powerful reminders of the potential value of gardens at a time when more and more are being converted to decking, patios and car parking spaces.
Residential gardens may be particularly important in helping support populations of urban pollinators such as bees and flies. Many of these species have evolved intricate adaptations that enable efficient nectar collection from native plant species but may find it more difficult to exploit some non-native species. However, non-native plant species are not without their benefits, as they can serve as important sources of food, pollen and nectar for other species, particularly at times when native species are seasonally unavailable or scarce. As climate change impacts our native plants and invertebrates, more drought-tolerant non-native species may become important resources for our pollinators and other species.
Evidence from the literature suggests that gardens with a more ‘natural’ appearance tend to have a greater diversity of habitats and in turn, more invertebrates and their predators. Mowing the lawn less frequently or leaving patches of lawn to rewild are simple ways to create a mosaic of habitats in most gardens. Other simple steps to increase the value of your garden or open space for wildlife include providing a source of water for wildlife, putting up bird feeders and nest boxes, installing bat boxes and carefully selecting plants that provide a source of nectar and pollen from early spring to late autumn.
Although individual gardens are often small and can be fragmented across the urban landscape, together they account for a significant proportion of urban green infrastructure. As a result, they can connect urban green spaces to one another, joining up tree canopy cover and making a greater contribution to urban biodiversity than the sum of their parts. When residential gardens are sufficiently connected to one another and to other green spaces, they can collectively function as continuous habitat, bringing great biodiversity benefits. The review concludes that coordinated local garden biodiversity initiatives can play an important role in greening the grey of our urban environments.
How can your business boost biodiversity?
From the smallest of office buildings to the biggest business park, there are simple things that can be done to encourage biodiversity and create spaces that enable staff and visitors to enjoy nature and benefit from the wellbeing it delivers.
- Look at creating soft landscaping across as much of the operational site as possible. This might consist of flower beds packed with native pollinator-friendly plants, native trees and hedgerow planting to create natural corridors for wildlife to move through or a pond or bog garden. In small offices, install window boxes and outdoor pots instead.
- Reduce your grounds maintenance to save money and welcome more wildlife – reduce the frequency of lawn mowing, cut hedgerows only outside of the breeding bird season and reduce the use of herbicides and pesticides.
- Turn areas of unused lawn into wild flower lawn, mowing just a few pathways through it to give people the opportunity to enjoy getting up close to nature.
- Turn unused roof spaces into green roofs, possibly with solar panels (biosolar).
- Put up bird boxes targeting birds of conservation concern, such as swifts, house martins and house sparrows.
- Use permeable paving in parking areas and walkways to help soak up surface water and reduce the likelihood of flooding.
- Create an orchard of native fruit varieties or install some raised beds for growing food.
- Engage staff directly in these activities or better still, start a wildlife gardening club!
Banner image by Levi Arnold on Unsplash