ABSTRACT
In his excellent description of places to see wildlife in London, David Goode (1986) describes railway lines were often the best place to see foxes in London. He also extolled the ecological interest of walks along abandoned railways, such as that from Mill Hill to Edgware. Without specifically using the word ‘corridor’ he was advocating the virtues of linear habitats in cities (Figure 22.1). In a similar book on Belfast, published almost 20 years later, Robert Scott (2004) describes the Lagan Valley as a two-way corridor, enticing wild creatures upstream from the marine environment of Belfast Lough and downstream from the surrounding countryside into the heart of the city; a pattern mirrored in other large cities with riparian corridors (e.g. Newcastle and the Tyne valley). Connective features such as green networks and corridors have been influential in guiding planning policies in many areas of the world (Turner 2006; von Haaren and Reich 2006), but are also subject to considerable debate and confusion (Hess and Fischer 2001). They have long been seen as providing connectivity, linking greenspaces, and minimizing the potential effects of fragmentation on wildlife (Jongman et al. 2004), while providing important recreational, leisure and nature experience possibilities for people (Gobster and Westphal 2004). The idea of urban wildlife corridors is now firmly established in natural history and has become part of urban environmental planning. Urban greenways have developed from the cleaning up of rivers such as the American River in Sacramento California, damaged by gold mining and the Willamette River in Portland, Oregon damaged by paper mill effluent (Bauer 1980). River valley greenways in these cities were initiated in the 1960s, initially to provide riverside parkland for people to enjoy close to the city centre. Over time the emphasis of the plans for these greenways has changed to give greater importance to their role as wildlife habitat and potential wildlife corridors. By 1995, more than 500 communities, in North America alone, had greenway projects under way (Searns 1995). Modern greenways set out to be multi-purpose, going beyond recreation and beautification to address such areas as habitat needs of wildlife, promoting urban flood damage reduction, enhancing water quality, and providing a resource for outdoor education (Figure 22.2). Some greenway projects specifically recognize the needs of wildlife and aim to provide corridors for wildlife migration. Following a report recommending that Tuscon, Arizona, set up and maintain a system of interconnected open spaces with adequate water and vegetation to sustain wildlife, the city adopted an ‘environmental resource zone’
ordinance help protect areas essential to wildlife, including migration corridors (Schwab 1994). Many cities incorporate a concept of green network or set of open spaces in their local plans. One of them is Telford New Town, some 50 km to the west of Birmingham in the West Midlands region of England. A planned new town comprising a number of existing villages which, from the early 1960s onwards, have been extended and linked by major new housing, industrial and commercial areas. Greenspace development in the town involved combining natural regeneration of old industrial areas with high-quality mass planting involving around six million trees and ten million shrubs (Douglas and Box 2000). Thirty-eight per cent of Telford’s area is now open space, including much of the Ironbridge Gorge, a World Heritage site as the home of some of the earliest stages of the Industrial Revolution, but now also an important wildlife corridor (see also Chapter 41 this volume). Some 80 km north of Telford, the old industrial areas around Liverpool and Manchester in the UK, for decades a landscape dominated by signs of former mining and heavy industry, are now gaining new woodlands and areas of natural vegetation as land is restored and tree-planting is carried out (Figure 22.3). Some of the greenspaces so created are being incorporated into new systems of linear parks, especially along river valleys. Such linear systems have begun to provide green corridors from the heart of the cities to the open countryside beyond the suburbs (Barker 1997). Two of the agencies involved, the Mersey Forest and the Red Forest, work with partners to develop the Green Infrastructure for this part of north-west England. The vision for Green
Infrastructure (GI) is to bring together a coherent network of components, such as open spaces, green corridors and woodlands, for the benefit of people and wildlife. This will be achieved through adopting a more systematic approach to planning and managing these components across local authority boundaries and all spatial planning levels. In this way GI will become as important a consideration in the growth and development of communities as transport, grey infrastructure, built infrastructure and social infrastructure. GI differs from conventional approaches to open space planning by considering the multiple functions and benefits of green infrastructure alongside land development, growth management and built infrastructure planning issues. As such it is integral to the management of growth and development and essential for building well-designed and sustainable communities. Many other industrial and urban regions are thinking similarly. A report on the English Midlands plateau notes:
The potential for creating wildlife corridors and multi-functional green networks in the Midlands Plateau, via non-statutory site linkage, is great. By improving the wildlife value of buildings, gardens, local authority-owned open spaces, canals, disused railway lines, and road verges, a connectivity can be achieved.
