Urban Planning - Case Study - Sheffield, UK - Research into
Biodiversity in Domestic Gardens
Sheffield's domestic gardens enhance the quality of life and are a biodiversity asset to the city
Domestic gardens cover about 23% of the built up area of Sheffield. As with other British cities Sheffield contains a "patchwork" of gardens, in addition to its parks and other well-recognised greenspaces, which have developed as the City has grown out into the countryside. They vary greatly in size and character, dependant on when they were first laid out and the subsequent maintenance regime. In area of land that they cover, domestic gardens are the major green spaces of the residential zones. Sheffield is particularly fortunate in the quantity and quality of its domestic gardens. The value of gardens for biodiversity has long been debated and a recent research project into this question is now beginning to report its findings - Sheffield City is the case study for this project.
The Biodiversity in Urban Gardens in Sheffield (BUGS) project is a collaboration between Prof. Kevin J Gaston, Ken Thompson and Phil Warren at the University of Sheffield, with Richard Smith. The following notes are taken from the team's recent publications in the press - their academic papers are available online.
This webpage gives you links to the researchers and access to their most recent findings. Papers can be downloaded.
The research is based on the premise that the form and management of domestic gardens profoundly affects not only the quality of life of the human population in cities, but also the closely related issue of biodiversity in urban areas. It is a 3 year research project that has been underway since 1999 at the Univerity of Sheffield. It is led by Prof. Kevin Gaston.
The aim of the project is to identify :
From the early findings it appears that the answers will aid in the decision making about the regeneration and planning of the urban environment throughout British cities. The project has had funding from the NERC Urban Regeneration and the Environment (URGENT) thematic programme.
In mapping the garden greenspaces BUGS has three main objectives:
1. To work out the size of the resource
The extent of urban gardens within a sample city (Sheffield) and the important biodiversity features they contain. Internationally there is a lack of data on such issues - one of the few other studies was undertaken in the late 1990s in Jutland, Denmark by the Building Research Council of Denmark.
The BUGS project team has calculated that domestic gardens cover about 23% of urban Sheffield (the built up area). It is noteable that even in Sheffield, which has an exceptionally high level of open space provision, this area is more than all the other forms of green space combined. (Note: this statement applies to the built up area and excludes the rural and Peak District parts of Sheffield Metropolitan District). This area of the domestic gardens is highly subdivided, as in Sheffield there are a very large number of small gardens and it is these that contribute most to the overall extent of gardens within the City. The large domestic gardens contribute much less in total area, being comparatively scarce.
Across urban Sheffield, the BUGS project has estimated that in gardens alone there may be:
although such features may not all be as suitable for biodiversity, as ecologists might desire (for example, the nest-boxes do not always suit the needs of their intended occupants). However, the research team note that some of these features are occurring at densities greater than in the wider countryside. These findings suggest that together all the garden spaces could be exerting a significant effect on biodiversity within the City.
2. To determine which garden features attract greater levels of biodiversity
A network of 61 gardens across Sheffield were chosen as case study sites. They were chosen to reflect: size, age, management, degree of urbanisation, as well as proximity to city edge. Plants, insects and birdlife were recorded using sampling techniques in each of the gardens in the study. In sampling these gardens' biodiversity, BUGS emphasised wildlife that is less obvious to the typical owner, such as lichens, liverworts and mosses, molluscs, beetles, hoverflies and craneflies. As the team leader has written ".... sorting this material has been a mammoth task. It would have been impossible without the tremendous support of an army of taxonomic specialists." There are an unusual number of taxonomists in Sheffield who for many decades have taken an active part in the City's well established natural history tradition; all are keen to see what role gardens have for their own group of interest.
The results are just emerging, but the team is already highlighting nationally rare and threatened species growing in the garden environment and recognising the role of gardens in extending the ranges of some species. The researchers state they have already shown that the occurrence of species such as lichens that cannot move about, depends on the features of individual gardens, but that the occurrence of species that can move, such as flying insects, is more independent of these features.
3. To work out how best to improve biodiversity in gardens
The team wanted to find out whether the advice which has been given through gardening programmes on TV and in other media in Britain on how to turn your garden into a nature reserve can do anything to enhance biodiversity. For this reason as part of their research the ideas behind this advice are being experimentally tested as part of the BUGS study. This allows any increase in wildlife that occurs to be monitored, and an assessment made of whether the ideas work on the scale of a typical Sheffield domestic garden.
In this study five additional features are being examined:
This is a three year experiment . Early results to date suggest that some additions are almost totally ineffective (small nettle patches), but that others are very good.
There is optimism that with 175,000 domestic gardens in Sheffield there are in effect that number of potential opportunities to effectively enhance urban biodiversity. A huge number of garden owners want to be involved in the project and once the research is completed efforts will be made to give advice as to the best approach to take with gardens.
Given the contribution by the domestic garden to the overall extent of green space in the City and the potential for more and better biodiversity, the role of gardens within the City is at last being recognised. Enhancing the biodiversity value of just some of these gardens could improve this urban area's chance to be a viable habitat for a range of species and so enhance the general sustainability of the urban area as a whole.
For information about this project and the latest findings visit
Professor Kevin J Gaston is the lead investigator on the BUGS project. He is based in the Department of Animal & Plant Sciences, University of Sheffield, Sheffield S10 2TN.
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