Dynamics of seedling banks in beech forest: results of a 10-year study on germination, growth and survival

The dynamics of a seedling bank was studied in four plots located in the Kr ynica Experimental Forest, southern Poland. Each sample plot was divided in to eight sectors, in which germinants and seedlings were mapped, measured, and labelled; their survival was checked twice a year between 1989 and 1996 . Maps of relative light intensities on the forest floor in sample plots we re produced on the basis of measurements conducted in June and August 1991. During the entire period of study, European beech (Fagus sylvatica L.) mad e up over 96% of germinants and seedlings. Numbers of beech germinants vari ed strongly (from 0 to 1178) among plots and years. Each year of abundant g ermination was followed by one or two years of scarce germination, and ther e was an increasing trend in the number of germinants in three plots betwee n 1989 and 1996. Seedling emergence was almost independent of relative ligh t intensity and first-season survival was positively, but weakly correlated with it. Long-term survival of seedlings was low and strongly related to r elative illumination. Results of analyses of spatial patterns in seedlings suggested that some microsites were more conducive than others to germinati on and early survival of seedlings. Survival among taller germinants was gr eater than among shorter ones. A true seedling bank was observed only in tw o plots, where relative light intensities were 9 and 15% of full sunlight. In a plot with relative light intensity of 4%, the seedling bank was unstab le and in the least illuminated plot (<3% of full sunlight) no seedling ban k was formed. Results indicate that, even in a strongly shade-tolerant spec ies like beech, formation of a seedling bank requires the occurrence of can opy openings in the close proximity. (C) 2001 Elsevier Science B.V. All rig hts reserved.