Spontaneous vegetation and its creative management

A common feature of urban and post-industrial environments is the rich but often rather chaotic looking vegetation that arises after the demolition of existing structures. Public perception is likely to see this only as ‘weedy’, whereas, with time, unique and complex habitats can develop. Landscape and ecology practitioners in Germany have led the way

Spontaneous vegetation and its creative management

3.5

Self-sowing of Verbascum nigrum can be relied upon to create spectacular effects. This planting at the Klenzepark, Ingoistadt, is on an occasionally dry but fertile soil, and includes crimson Knautia macedonica, an extremely useful plant for this style of planting because of its long flowering season and vivid colour (July)

in trying to encourage a more positive perception of this ‘spontaneous’ vegetation (Figure 3.5).

Soils underlying such areas are highly atypical, owing to the presence of large quantities of material derived from buildings or industrial processes. The plant communities that develop inevitably reflect this (Heintz et al. 1999). Ktihn points out that conventional plant community concepts do not necessarily work in the city, with its distinct climate and soils, and that the ruderal plants that thrive are seen as untidy, whereas in fact they may have a history that should be valued, many being former medicinal herbs or garden plants. They could have their place in a new post-industrial urban aesthetic’ (Ktihn 2000).

Given the level of biodiversity and often the visual beauty of the succession communities of post-industrial wasteland, to say nothing of the apparent ease with which they colonise what would be extremely difficult places to ‘restore’ in any conventional sense, it would make sense if society made a more positive evaluation of them. As Luken points out, ‘the unwillingness—or inability—of ecologists to successfully incorporate the human species in ecological theory has by default devalued ecological processes associated with human activity’ (Luken 1997). Conflicts over how ecologists should react to these plantings have been exemplified by the disagreements over buddleia, according to Ktihn; a splendid butterfly plant or an invasive alien? (Ktihn 1999).

There are two approaches to the use of ‘post-industrial vegetation’. One is to manage what comes up by itself, so that the chaos of dereliction may be turned to ecological, functional and aesthetic advantage as part of a new landscape, the other is to learn from these natural test-beds in the creation of attractive but robust new plant mixtures for urban areas. Environmental concerns and the closing down of a lot of old industries have led to the development of a number of projects in northern Germany that imaginatively make the most of successional wasteland plant communities. Succession is regarded as a key concept in these environments, with a number of possibilities for management: allowing succession to run its course from ruderal to woody communities, halting the succession at a particular stage, perhaps by mowing to eliminate woody plant seedlings, thus maintaining a herbaceous vegetation and, finally, undertaking steps to put the succession process back to an earlier stage, for example by rotovating to maintain annuals and other pioneer vegetation (Eckhardt et al. 1999).

Two projects provide successful examples of these processes, as well showing how it is possible to give meaning to what might have been regarded as complete wastelands. The Harbour-Island in Saarbrticken, in Saarland, was developed in the 1980s from an old dockside and industrial area, aiming to convey a ‘dream of nature’ in a park with a defined geometrical/architectural character. The ruins of old industrial installations were preserved, with spontaneous vegetation (a mixture of native ruderals and garden escapes, such as buddleia and mahonia) allowed a place alongside the development of new areas of planted native meadow species and contrasted with more ordered conventional planting. Staff were given special training in the techniques of steering the succession vegetation appropriately (Latz 1987:42; Rupp 1991:102-110).

The old marshalling yards near Tempelfhof station in Berlin were abandoned in 1952, turning into a habitat rich in fauna and flora, including some endangered species. The area was given to the city and in 1995 plans, financially supported by the Foundation for the Protection of Nature, were made for its development as a public park, Natur-Park Stidgelande. The public can explore it by following paths running on old railway lines or on raised walkways, appreciating contemporary artworks along the way. The park motto is ‘Dynamism and Constancy’, which expresses the desire to manage the various succession communities according to aesthetic and ecological criteria. Management plays an important role in ensuring that a variety of succession stages are present, for example by ensuring that woodland glades do not close up or grasslands disappear. One paper written about the park notes that ‘what landscape architect could design such a place, riven with memories of the railways, filled with woodland, groves and flower-filled glades’ (Knoll et al. 1997).2

Kuhn’s research at the Technical University of Berlin is one of the few projects currently looking at the creation of viable plant communities based on spontaneous vegetation. With a focus on drought and heat-tolerant species, he has established test plots to evaluate the progress of two different groups of plants for different soil nitrogen levels. The aesthetic criteria used for selection are structure, texture and flowering intensity and duration. Grasses and forbs from North America, continental Europe and Mediterranean Europe are included (Ktihn 2000:11).