Spontaneous development of urban woody vegetation on differing soils

The general aim of the study was to follow the development of spontaneous woody vegetation on man-made urban habitats in Berlin, Germany. In spring 1968, the vegetation was removed completely in five groups of plots, which had been filled with five different transferred soil material in 1928. The spontaneous vegetation was monitored annually from 1968 to 2006. Especially, the development of shrubs and trees was followed. In addition the growth of the most important herbaceous species, Solidago canadensis, was investigated.

The soils varied from moderately rich sandy soils to rich sandy or loamy soils. On the two sandy soils S. canadensis developed poorly. Tree species dominated (>50% of total cover) on these plots after 14–18 years. On the soils rich in nutrients, S. canadensis developed strongly. Tree species did not dominate there before 21–25 years. The diversity of woody species increased over time and reached 33 species altogether. Indigenous Acer, Quercus and Betula species prevailed. Alien species, typical for urban ruderal sites, were rare.

The results support the idea of establishing urban woodlands by spontaneous succession as a cheap way to develop near-natural plant communities rich in species.