Natural regeneration of beech and competition from weed in the summit part of the Jizerske hory Mts. (Czech Republic)

摘要

The most problematic factors of the natural as well as artificial regeneration of beech in mountain regions are deer browsing and competition of forest weed species. To compare the survival and growth of beech seedlings in relationship to forest weedsin the summit part of the Jizerske hory Mts., 17 to 23 little plots respectively, sized 2x2 m, in the variants "C. villosa sparse", "C. villosa medium dense", "C. villosa dense", "Vaccinium myrtillus", "Avenella flexuosa" and "litter" were established.In autumn 2004, seedlings were counted by age groups; deer browsing and possible other damage was registered. In 2005, the investigation was supplemented by measurements of the height and last height increment. For this study, competition by forest weedwas considered a key factor determining the occurrence and growth of the natural regeneration of beech. Selected results were statistically tested by a two-factor ANOVA or non-parametrical Kruskal-Wallis test (a = 0.05). As far as the survival is concerned, no statistically significant differences could be found between the different vegetation types. This may be due to the high variability of natural regeneration on the research plots and the limited sample size. The slight hint at an adverse effect ofdense C. villosa on the survival of beech (p ~ 0.07) might be confirmed by studies with larger sample size and using canopy closure as an additional predictor for survival. Despite the more exact statistical results, there seemed to be no logical explanation for the difference in the growth of the seedlings in different variants. Therefore the assumption of a higher height increment of seedlings on the plots with a high density of forest weed in response to the competition from weed, was not validated.Deer browsing had no significant relation to the forest weed species. Additional investigations which might cover the high variability of the natural regeneration more precisely, might produce more exact results.