ZLV Online

Abstract

This paper analyses the structure of natural regeneration in spruce subalpine primary forest forest in the Zadná Poľana National Nature Reserve (NNR), Slovakia. The analysis was focused on tree species composition, height structure and increment, intensity of damage by deer browsing, and the proportion of natural regeneration growing on coarse woody debris. Two altitudinal zones (AZ), 1412–1452 m a.s.l. and 1314–1355 m a.s.l., were chosen to show the influence of different stand structure on the natural regeneration properties. In the upper AZ, the natural regeneration consisted of nearby balanced mixture of Norway spruce (Picea abies L.) and rowan (Sorbus aucuparia L.). To the contrary, rowan obviously dominated in the lower AZ. Rowan was damaged substantially by ungulate browsing – at least 60% of rowan saplings were browsed in upper AZ, and almost 100% in lower AZ. However, the damage of spruce did not exceed 10% in both AZ. The mean height and the height differentiation of spruce saplings were higher in the upper AZ. The height of rowan was unceasingly reduced by browsing, therefore rowan was not able to compete with the spruce saplings in both AZ. Coarse woody debris (CWD) was confirmed as the favourable substrate for spruce natural regeneration. More than 50% of spruce saplings grew on CWD. Spruce saplings growing on the CWD in the upper AZ were also significantly higher than those from lower AZ and also higher than spruce saplings growing on the soils in the both AZ.