Main conclusions emerging from comparisons of a large number of successional series in human-made habitats in the Czech Republic

Despite the enormous number of studies of succession, there is a lack of quantitative comparisons of a large number of successional series. Such comparisons may provide substantial theoretical as well as practical findings. We have developed a Database of Successional Series (DaSS) which currently comprises more than 3000 phytosociological relevés of 40 successional series from the Czech Republic. In this paper, we present the following main generalizations: (a) The different series form a successional continuum along the composed environmental gradient of substrate pH and moisture. This gradient was more important in determining vegetation composition than successional age itself. (b) Succession generally proceeds towards a ‘climax’ (potential natural vegetation) and all species recorded in the corresponding relevés from the potential natural vegetation were also recorded in the successional series. (c) Using extrapolation, primary successions reached the potential natural vegetation faster than secondary successions: on average 180 and 260 years, respectively. (d) The number of target and woody species generally increased during succession while the number of neophytes decreased; Red List species represented one-quarter of all species present in DaSS. (e) Based on participation in DaSS, we developed two indices of colonization ability of Czech flora species and expressed successional age at which the species occur (i.e. their successional status). Besides theoretical outputs, the results contribute to practical applications where spontaneous succession appears to be a highly efficient tool for the restoration of most disturbed sites.