In the light of the above considerations, biodiversity and “naturalness” aspects may seem less central to urban forestry, where social and environmental services are favoured. Studies have shown, however, that urban green space can support significant biodiversity, for example, in terms of habitat and species diversity (e. g. Sukopp and Werner 1987). In recognition of biodiversity and high natural values, sometimes in combination with cultural-historical importance, many major European cities, such as
Moscow, Stockholm, Vienna and Warsaw, host national parks and nature reserves within their boundaries.
The primary role of urban forests, however, is a social one, i. e. to provide attractive environments for urban dwellers to live, work, and spend their leisure time. Among all forests, those situated closest to cities are by far the most visited, as evidence from Sweden shows (Rydberg 2001). Visitor numbers for urban woodlands may be in the thousands per hectare on an annual basis (see Konijnendijk 1999 for examples). Urban forests provide people with the opportunity to get away from hectic urban life and to experience nature. Urban forests are also areas of fun and play. Braun (1998) relates changing lifestyles to changing outdoor recreational patterns, e. g. demonstrating that more adventurous types of forest recreation, such as mountain biking, have become more popular. The need for children to have areas to play and experience nature has led to the establishment of special “play forests”, for example, in Sweden (Rydberg 2001). “Wild” thus does not necessarily have to relate to natural per se, but rather to a forest that users’ perceive as being wild and thus suitable for their preferred use in terms of variation, topography, lack of human artefacts and visual interference, and so forth.
However, the “wild” element of urban forests in terms of their natural values and natural processes – with or without human interference – can certainly also be of social importance. Trees, for example, indicate the changing of seasons. The Dutch “Nature Calendar” initiative (www. natuurkalender. nl; in Dutch only) has linked up to this daily relationship between people and nature in their immediate living environment. Residents are asked to enter their first sightings of selected bird species, flowering of plants, and so forth on a special website. The researchers behind the site use the information for phenological studies, e. g. of the impacts of climate change on Dutch nature. But enhancing people’s everyday involvement with nature is a clear secondary objective. Having “wild woodlands” where there is room for natural processes is also important in cities from a nature education perspective (e. g. Rydberg 2001). Many of Europe’s urban woodlands host “forest schools” where school classes can spend a day or more learning about nature (e. g. Konijnendijk 1999).