Elsevier

Landscape and Urban Planning

Volume 83, Issue 4, 7 December 2007, Pages 308-317
Landscape and Urban Planning

Urban form, biodiversity potential and ecosystem services

https://doi.org/10.1016/j.landurbplan.2007.05.003Get rights and content

Abstract

Using data from selected areas in five UK cities, we studied the relationships between urban form and the following measures of ecosystem performance: availability and patch characteristics of tree cover, gardens and green space; storm-water run-off; maximum temperature; carbon sequestration. Although most measures of ecosystem performance declined with increasing urban density, there was considerable variability in the relationships. This suggests that at any given density, there is substantial scope for maximising ecological performance. The social status of residents was related to measures of tree cover. Housing type was significantly associated with some types of ecosystem service provision, indicating that the type of development may be important independent of its density. These findings have implications for understanding the distribution of ecosystem services and biodiversity across urban landscapes, and the management of development aimed at meeting UK government housing density targets.

Introduction

More than half the world's population now lives in cities, compared with about 14% a century ago (United Nations, 2001). This increasing urbanisation radically modifies the ecology of landscapes. The effects include alteration of habitat, such as loss and fragmentation of natural vegetation, and the creation of novel habitat types (Davis, 1978, Niemelä, 1999a, Niemelä, 1999b, Wood and Pullin, 2000); the alteration of resource flows, including reduction in net primary production, increase in regional temperature, and degradation of air and water quality (Henry and Dicks, 1987, Rebele, 1994, Donovan et al., 2005, Bonan, 2000); the alteration of disturbance regimes, with many habitats experiencing more frequent disruption (Rebele, 1994); the alteration of species composition, species diversity, and proportions of aliens (Davis, 1978, Ruszczyk and de Araujo, 1992, Rebele, 1994, Roy et al., 1999, Hardy and Dennis, 1999, McKinney, 2002).

One approach to reduce the impact of increasing urbanisation is to minimise the spatial extent of urban areas by developing more compact city forms. There has been much recent debate over the “compact city” paradigm, with its aims of centralising services and reducing urban land take (Jenks et al., 1996, Williams et al., 2000, Jenks and Dempsey, 2005). Such developments reduce urban sprawl, and significant long-term social and ecological benefits have been claimed (Burton, 2000, Jenks and Burgess, 2000). However, whilst the focus has been on the benefits of reducing urban area, we know much less about how urban densification changes the ecosystem characteristics of the urban areas themselves. For example, is it possible to build dense, compact cities that maintain areas of natural habitat and provide useful levels of ecosystem services, such as carbon sequestration and storm-water interception? The net ecological effect of moving towards high-density urban forms clearly depends on the balance of the benefits of reduced land take against the changes in ecosystem function of the higher density urban areas.

In the UK, current policy is to build new developments at high net density, partly as a response to increasing urban populations and social and demographic pressures resulting in a reduction in average household size (ODPM, 2002). One possible ramification of increased urban density might be deterioration in ecosystem service provision in urban areas and declines in both urban biodiversity and the quality of life of the urban human population. As ecosystem services such as carbon sequestration, storm-water interception, climate regulation and biodiversity potential are influenced by the availability and type of vegetated ground cover, increased densification, if it brings with it a reduction in the proportion of such cover and changes in its spatial configuration, may have undesirable effects on these services (Arnold and Gibbons, 1996, McPherson, 1998, Simpson, 1998, Xiao et al., 1998, Weng, 2001, Whitford et al., 2001). This would be a particular concern for at least three reasons. First, many of the ecosystem services provided by urban green spaces carry with them significant economic implications, both locally and regionally (McPherson, 1992, Chee, 2004, Farber et al., 2006). These include implications for house prices, the costs of lighting, cooling and heating of buildings, and the ease of attracting businesses and employees (e.g. Luttik, 2000, Tyrväinen and Miettinen, 2000, Morancho, 2003, CABE Space, 2004). Second, in the face of intensive agriculture in the wider landscape, in some regions urban green spaces now act as important havens for native plant and animal populations (Mörtberg and Wallentinus, 2000, Gregory and Baillie, 1998, Mason, 2000, Gaston et al., 2005). Third, there is growing evidence that local green spaces contribute to both the physical and mental well-being of people living in urban areas (Hartig et al., 1991, Chiesura, 2004, Takano et al., 2002, de Vries et al., 2003), and that the pattern of provision of such spaces is an important issue for social equity (Whitford et al., 2001, Pauleit et al., 2005).

In this paper we investigate how urban form affects the ecological performance of the urban environment through an evaluation of the relationships between urban form and measures of environmental quality and biodiversity potential, over 15 sites distributed across five UK cities. This work forms part of a much broader consortium project to assess multiple dimensions of the sustainability of a variety of urban forms using these study areas (Jones, 2002; http://www.city-form.com).

Section snippets

Data

In each of five UK cities, Edinburgh, Glasgow, Leicester, Oxford and Sheffield, three study sites were selected, each containing ca. 2000 households (Fig. 1). Sites were selected on the basis that each city should contain a city centre site (Inner), an outer suburban site (Outer) and a site situated between the centre and suburbs (Middle). This is similar to the urban gradient approach widely used in urban ecology (see, for example, McDonnell and Pickett, 1990, Hahs and McDonnell, 2006). It was

Comparison of ecosystem performance among 15 study sites

The Inner, Middle and Outer site categorisations were intended to reflect variations in urban form within cities rather than between them, and to provide an overall continuum in urban form across all the cities, and thus formal comparisons between these groups were not conducted (almost all variables did indeed exhibit continuous variation across the 15 study sites; see below). Thus, whilst cover of green space and gardens generally increased from Inner to Outer sites, the proportion of this

Discussion

In this study across five cities in the UK, we have shown that high-density urban developments were generally associated with poor environmental performance, as measured by green space patch size and the levels of provision of key environmental services. More densely urbanised areas had less coverage by green space and gardens, smaller habitat patch sizes, greater predicted run-off, higher predicted maximum temperatures and lower predicted carbon sequestration (and hence tree cover) (Table 1,

Acknowledgements

This work was supported by EPSRC grant GR/S20529/1 to the CityForm consortium. Ordnance Survey kindly provided MasterMap data under license to CityForm. We are grateful to I. Fishburn and C. Gascoigne for assistance, and to two anonymous referees for helpful suggestions to improve the paper.

References (58)

  • V. Whitford et al.

    City form and natural process—indicators for the ecological performance on urban areas and their application to Merseyside, UK

    Landscape Urban Plann.

    (2001)
  • C.L. Arnold et al.

    Impervious surface coverage. The emergence of a key environmental indicator

    J. Am. Plann. Assoc.

    (1996)
  • P. Boyle et al.

    The 2001 UK census: remarkable resource or bygone legacy of the ‘pencil and paper era’?

    Area

    (2004)
  • E. Burton

    The compact city: just or just compact? A preliminary analysis

    Urban Stud.

    (2000)
  • CABE Space, 2004. The Value of Public Space: How High Quality Parks and Public Spaces Create Economic, Social and...
  • B.N.K. Davis

    Urbanisation and the diversity of insects

  • S. de Vries et al.

    Natural environments—healthy environments? An exploratory analysis of the relationship between greenspace and health

    Environ. Plann. A

    (2003)
  • R.G. Donovan et al.

    Development and application of an Urban Tree Air Quality Score for photochemical pollution episodes using the Birmingham, United Kingdom, area as a case study

    Environ. Sci. Technol.

    (2005)
  • W.R. Effland et al.

    The genesis, classification, and mapping of soils in urban areas

    Urban Ecosyst.

    (1997)
  • S. Farber et al.

    Linking ecology and economics for ecosystem management

    BioScience

    (2006)
  • K.J. Gaston et al.

    Urban domestic gardens (IV): the extent of the resource and its associated features

    Biodivers. Conserv.

    (2005)
  • R.D. Gregory et al.

    Large-scale habitat use of some declining British birds

    J. Appl. Ecol.

    (1998)
  • P.B. Hardy et al.

    The impact of urban development on butterflies within a city region

    Biodiv. Conserv.

    (1999)
  • T. Hartig et al.

    Restorative effects of natural environment experiences

    Environ. Behav.

    (1991)
  • C.A. Jones

    Research reports—EPSRC Sustainable Urban Form Consortium

    Plann. Practice Res.

    (2002)
  • A.P. Kinzig et al.

    The effects of human socioeconomic status and cultural characteristics on urban patterns of biodiversity

    Ecol. Soc.

    (2005)
  • Cited by (515)

    View all citing articles on Scopus
    View full text