Woody species succession and spontaneous forest development in post-mining sites after coal mining in the Czech Republic

Abstract

There is little information about long-term spontaneous forest development after industrial disturbances. A field study was done along the chronosequence of unreclaimed post-mining sites (12, 25, 32, 60 and 90 years old), developing by spontaneous succession in the northwestern Czech Republic. Initial stages of forest development (12- to 60-yr-old) were dominated mainly by silver birch (Betula pendula) goat willow (Salix caprea) and aspen (Populus tremula), Norway spruce (Picea abies) also established naturally in the intermediate stages of succession. A 90-yr-old site was close to the expected climax forest with 21 woody species dominated by European oak (Quercus robus L.), supplemented by beech (Fagus sylvatica). The youngest and oldest sites were more diverse and richer sites in woody species than others, as expressed by the Shannon-Weiner and Simpson indices. Conversely, spatial heterogeneity (aggregation) increased with increasing age; however, it became lower at the age of 90 years. Woody species in the understory were more diverse than in the tree layer. Overall, our study found that spontaneous processes can lead to the development of the late-successional forest in fewer than 100 years in Central Europe.