Advance Fagus sylvatica and Acer pseudoplatanus seedlings dominate tree regeneration in a mixed broadleaved former coppice-with-standards forest

摘要

This study assessed the species composition and the development of regeneration plots in gaps created by a windstorm in a mixed-species broadleaved stand. The stand was a former coppice-with-standards characterized by a high broadleaved tree species diversity. Thirteen years after gap creation, all gaps were fully stocked and the regeneration was almost exclusively dominated by Fagus sylvatica and Acer pseudoplatanus seedlings, two species characterized by a high shade tolerance in their early stages. All other species (Quercus sp., Fraxinus excelsior , Carpinus betulus , Acer campestre , Acer platanoides , Sorbus torminalis , Tilia sp.) were either absent from the regeneration or completely over-topped by the two dominant species. These features were ascribed to a regime of periodic natural or anthropic disturbance of intermediate intensity, where small gaps are regularly created in the canopy. This regime results in a succession of short, open and closed canopy episodes that eventually promote shade-tolerant species. During this regime, the shade-tolerant species are able to build a strong advance regeneration that is ready to outgrow the other species when gaps are created. If the management objective is to maintain species diversity during the regeneration process, the development of this advance regeneration will have to be strictly controlled.