Sabine Tischew, Antje Lorenz
Vegetation Science and Landscape Ecology, University of Applied Sciences Anhalt
In the eastern German federal states of Saxony, Saxony-Anhalt and Brandenburg, open-cast mining has destroyed vast landscapes of near-natural floodplain ecosystems and forests as well as elements of cultural landscapes or has affected them by lowering of the ground water table. On the one hand, forests have been considerably extended in total area compared to the situation before the open-cast lignite mining by the afforestation of spoil dumps. In Saxony and Saxony-Anhalt, for example, the destroyed forests have been replaced by 163 %. However, afforestation with monocultures of non-native species and low structural diversity has led to a mostly reduced ecological value of these forests (Berkner 1998). On the other hand, some spoil dumps have, more-or-less by chance, been settled by spontaneous succession since the 1930s. The result of this natural colonization is astonishing: on these sites, often called “lunar landscapes,” grasslands, heaths and fens as well as varied woodlands have developed. Stages of development, species composition and stand structure of these woodlands are very different.
Due to their accessibility for urban residents and their location in postindustrial landscapes, these woodlands can be classified as “peri-urban woodlands.” Species composition and stand structure mainly result from natural processes, but the site factors have been changed by the impact of open-cast mining. Therefore, these woodlands represent typical examples of “nature of the fourth kind” (see Kowarik 2005).
Thirty-two active surface mines were shut down after the German reunification in 1990. An area of nearly 1,000 km2 was included in a reclamation process (LMBV 2002). Since the beginning of this process, scientists
Kowarik I, Korner S (eds) Wild Urban Woodlands.
© Springer-Verlag Berlin Heidelberg 2005, pp 163-180
and conservationists have demanded a stronger integration of natural processes in the development of woodlands. Gradually, this demand has been accepted by the reclamation company. About 3,400 ha of reclamation area are currently developing spontaneously into woodlands. With the designation of further successional areas, an additional 3,500 ha will develop into woodlands over different periods of time.
This paper summarizes the results of our studies on spontaneous woodland development on more than a hundred sites of eastern German lignite surface mines. The aim was to determine opportunities for the integration of spontaneous colonization processes into former mining areas. The present summary of results will focus on the following:
• the analysis of migration processes and the impact of isolating effects
• the analysis of site conditions and chronological differentiation of pioneer woodlands
• the integration of woodland development into general successional processes of post-mining landscapes
• opportunities and perspectives for peri-urban woodland development in post-mining landscapes