Various types of woodlands may first be differentiated based on their location relative to urban areas. By this spatial approach, urban woodlands can be differentiated from peri – and non-urban woodlands (Table 1).
• Urban woodlands may be completely surrounded by developed areas and therefore be forest islands within the city. Most of the time, however, they lie on the city’s fringe and have direct contact with developed urban areas on one side and with the open landscape on the other side.
• Peri-urban woodlands lie in the vicinity of the city and are deeply imbedded in the peri-urban cultural landscape. Most such peri-urban cultural landscapes were previously shaped by agriculture or village life. Today, however, they are mostly subject to increasing suburbanization.
• Non-urban woodlands, in contrast, lie far outside the urban impact area and are mostly interwoven with elements of the traditional cultural landscape.
This spatial organization generally corresponds to the different functions of the woodlands. With increasing proximity to the city, the accessibility of the woodlands for recreation-seeking urban residents grows and thereby so does the woodlands’ social function (e. g. Roovers et al. 2002). To the same extent, the ecological function of the woodlands in terms of traditional wood production and hunting yield decreases. It would be rash, however, to start from the assumption of a general replacement of economic functions with social ones in urban woodlands. It is far more true that social and ecological functions (“ecosystem services”) can also be given value (Shaw and Bible 1996; Costanza et al. 1997; Tyrvainen and Vaananen 1998; Tyrvainen 2001).
Table 1. Spatial differentiation of urban, peri-urban, and non-urban woodlands according to their location relative to urban areas. In general, with changes in the location of the woods, their social and production functions change as does the level of influence of urban impacts
|
Forest type |
Sub-type /Description |
Spatial characteristics |
|
Urban woodlands |
Woodlands within urban areas |
Isolated in built-up areas |
|
Woodlands on the urban fringe |
Between built-up areas and the open landscape |
|
|
Peri-urban woodlands |
Woodlands in the vicinity of urban areas |
Part of the open (cultural) landscape close to urban areas |
|
Non-urban woodlands |
Woodlands far from urban areas |
Part of the open (near-natural) landscape far from urban areas |
|
Function Urban social produc – impacts tion |
 |
An ecological perspective: urban impacts change traditional woodlands
Numerous studies have shown that urban conditions have significant impacts on climate, soils, and biodiversity patterns. Such changes are effected with decreasing intensity along urban-rural gradients (Kunick 1982;
McDonnell and Picket 1990; McKinney 2002; Baxter et al. 2002; Niemela et al. 2002; Venn et al. 2003). Urban conditions have effects as well on the types of woodlands, which are ordered in Table 1 along a urban-rural gradient. In the following, a few of such changes will be described. The next section will describe how, on urban-industrial sites, new types of woodlands may emerge that differ profoundly from the original ones.
