| Abstract: | Shrub seedling emergences were studied in a beech-birch forest in the Basque Country (Spain). During four years (1998–2001) all emerging shrubs were tagged and regularly monitored in 198 1 m2 plots. Seedling emergence was intense during the entire study period and primarily occurred in early spring. Emerging seedlings mainly belonged to Hedera helix , Rubus gr. glandulosus and several heath species (including genera Erica , Calluna and Daboecia ). In contrast, some dominant species components of the shrub layer ( Vaccinium myrtillus and Lonicera periclymenum ) showed no emergences. While small seeded species (heath species and Rubus ) showed clear microsite preferences, avoiding litter for emergence, that was not the case of large seeded Hedera helix. Strict microsite requirements appear clearly associated with having seed bank, suggesting that this trait may allow these species to select favourable microenvironment prior to germination. Average life varied largely among the different taxa. It was very low for Rubus (7.4 months) and heath (4.9), and high for Hedera seedlings (23.1). Final survival was extremely low in the case of small-seeded species. Survival of Hedera seedlings was high, although their growth was very low, suggesting the existence of a conspicuous seedling bank. Our results clearly show that several shrubs species have dramatic seedling dynamics in full closed forest stands. Small seeded species preferentially emerge on bare surfaces in early spring from the soil seed banks. On the other hand, Hedera seedlings are able to emerge on litter and maintain a conspicuous seedling bank based on an efficient dispersal capability. |
