Independent of their location relative to urban agglomerations, peri-urban as well as non-urban woodlands can vary tremendously in their origins and development history. In addition to the spatial dimension illustrated in Table 1, the urban woodland matrix is also determined by its origins. In this second dimension, four woodland types can be differentiated (Table 2). They differ fundamentally in regard to habitat continuity and to the agency of natural versus cultural mechanisms. It should be said, however, that the illustration in Table 2 presents idealized types. In practice, there are numerous points of overlap, just as there are narrow spatial overlaps and interweavings between the various types of woodlands.
For our understanding and also for developing urban woodlands, the con... >
The spatial interweaving of urban woodlands and developed areas favors the exchange of species in both directions. Numerous cultivated plants disperse themselves as escapees from gardens and parks into neighboring woodlands or are carried into such areas as garden waste (Hodkinson and Thompson 1997). Urban woodlands are generally rich in non-native species especially along their edge areas (Asmus 1981; Moran 1984; Walther 1999). In the other direction, attractive forest plants are usually transplanted into urban gardens (Kosmale 1981) where they survive, but generally are not able to spread, in contrast to the escapees... >
Peri-urban woodlands are especially affected by wet or dry deposition as well as that resulting from recreational activities. The spread of nitrophi – lous species is interpreted to be a result of nitrogen deposition (Kowarik and Sukopp 1984). Muller et al. (1978) correlated the presence of high-N indicator species (Ellenberg’s indicator species) with the use frequency of forest paths by recreationalists. The distribution of macrofungi in pine forests can also be related to an urban pollution gradient (Tarvainen et al. 2003). Deposition from urban-industrial sources can also clearly balance out the limiting effects of the original conditions of the site... >
Urban uses often lead to the fragmentation of woodlands and to stark divisions within stands through intended and unintended paths and horsebackriding trails as well as roads. In this way, small woodland patches with high edge-to-interior ratios are created. Forest fragmentation generally enhances pioneer species or non-native species that respond well to an increased availability of light (Brothers and Spingarn 1992; Godefroid and Koedam 2003a). Fragmentation by roads supports species that are dispersed by vehicles (Parendes et al. 2000; Ebrecht and Schmidt 2003). However, typical forest plant species, including rare species, may also occur along forest edges (Godefroid and Koedam 2003b). Bird species are often negatively affected by decreasing patch size (e. g. Mortberg 2001)... >
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-urb... >
Based solely on their location in the center of urban agglomerations, new urban-industrial woodlands could provide substantial social functions for the nearby residents and fulfill significant ecological functions. There are, however, obstacles in the way. The acceptance of the new woodlands by the local public, is, to put it carefully, uncertain. While “the forest” in certain areas is often held in a deep, symbolically rooted high regard (e. g. Harrison 1992), this is not the case with urban-industrial woodlands. With these, people are directly experiencing how an economic structure, which once functioned and from which they secured their existence, is being overwhelmed by elements of nature in a surprisingly short time. The decline of the former economic structure is therefore blatant... >
Institute of Ecology, Technical University Berlin
New woodlands as a response to social and economic changes
Since the Neolithic Revolution, a decline in pristine forests has occurred in Europe. Around 750 AD Germany was still approximately 90% covered by forest. The growth in agriculture and the wave of cities being founded led to the intense clearing of forests at a rate never before experienced. Only a few centuries later, in the late 13th century, the greatest extent of deforestation in Germany was reached, with forest cover of only 17%. From then on, the forest cover increased to the current level of 30%, with periods of forest growth alternating with periods of decline... >
The outstanding social and ecological roles of urban forests in the growth of cities has become widely known. In many parts of the world, despite or even because of continuing suburbanization, initiatives are being put forth to preserve urban forests, to develop them further and to make them accessible to the public.
This volume focuses on a particular component of the urban forest matrix – urban wild woodlands. We understand these to be stands of woody plants, within the impact area of cities, whose form is characterized by trees and in which a large leeway for natural processes makes possible a convergence toward wilderness. The wilderness character of these urban woodlands can vary greatly. We differentiate between two kinds of wilderness... >