The rejuvenation of the white fir in the area of the Kalkalpen National Park

Silver fir (Abies alba Mill.) is an important tree species in Austria and is considered to increase the stability of forest ecosystems. Yet it has a lower proportion in the Austrian forests compared to what would be expected naturally, which makes it particularly important to understand the factors limiting the regeneration of silver fir. The objective of this thesis was to provide information on the limiting factors for the regeneration of silver fir in unmanaged forests, and to contrast these factors to a commercial forest. Study areas were the Kalkalpen National Park and the neighbouring Steyrtal enterprise of the Austrian Federal Forests. Circular Study plots were created in areas requiring regeneration, and regeneration success was recorded on 223 sample plots in the national park and 43 sample plots in the commercial forest enterprise. I investigated whether the effect of game on Fir regeneration can be influenced by hunting. Furthermore, the influence of seed trees, exposure and canopy cover was examined. Response variables were the presence of Silver Fir Regeneration and the Height of Regenerating Silver Fir. The proximity of a Fir seed tree was found to be the major factor influencing the presence of Silver Fir in the regeneration (p. 001). When a seed tree was within a 25 m radius of the plot the probability for silver fir regeneration increased from 12.8 % to 55.6 %. Browsing had an influence on the tree height of silver fir in the regeneration but did not influence its presence significantly. Furthermore, canopy cover had a significant influence on the height of silver fir trees in the regeneration. When comparing Kalkalpen National Park and the Steyrtal forest enterprise, a trend (p =.059) emerged show that the probability of finding a seed tree area is higher in the national park. Canopy cover differed significantly, canopy cover in the national park on average 19.20 % higher than that of the Steyrtal forest enterprise (p. 001), special attention should be paid to its ecology and needs.