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.欧洲白冷杉（Silver fir, Abies alba Mill.）是奥地利境内的重要乡土林木树种，被认为可有效提升森林生态系统的稳定性。然而相较于其自然分布的理论占比，奥地利现有森林中欧洲白冷杉的占比偏低，因此明确限制其天然更新的关键因素具有重要研究价值。本研究旨在阐明天然林内欧洲白冷杉更新的限制因子，并将这些因子与商业经营林场的情况进行对比分析。研究区域涵盖卡尔阿尔彭国家公园（Kalkalpen National Park）以及奥地利联邦林务局下属的施泰尔塔尔企业林场。在需开展更新修复的区域设置圆形样地，共记录国家公园内223个样地、商业林场内43个样地的更新状况。本研究首先探讨了狩猎活动是否会对野生动物取食影响冷杉更新的效应产生调节作用；同时分析了母树分布、生境朝向以及林冠覆盖度对冷杉更新的影响。本研究的响应变量为欧洲白冷杉更新株的存在与否，以及更新植株的高度。研究结果显示，欧洲白冷杉母树的邻近程度是影响更新株存在与否的核心影响因子（p=0.001）。当样地25米半径范围内存在母树时，欧洲白冷杉更新的发生概率从12.8%提升至55.6%。野生动物啃食对更新植株的树高存在显著影响，但对其存在与否无显著作用。此外，林冠覆盖度对欧洲白冷杉更新植株的高度存在显著影响。对比卡尔阿尔彭国家公园与施泰尔塔尔林场，研究发现一项趋势性结果（p=0.059）：国家公园内存在母树集群的概率更高。林冠覆盖度也存在显著组间差异，国家公园内的平均林冠覆盖度较施泰尔塔尔林场高出19.20%（p=0.001），对此类树种的生态特性与生长需求应予以重点关注。