Natural regeneration of Silver fir (Abies alba Mill.) in the National nature reserve Salajka

This study addressed the development of natural regeneration of tree species over the period 2009-2016 in a temperate fir-beech old-growth forest left to a spontaneous development since 1930s. The research site was located in the strictly protected National Nature Reserve Salajka, lying in the Western Carpathians mountain range. Ungulate game browsing, establishment and mortality of natural regeneration as the main drivers of species coexistence were studied, using two alternative sampling methods, permanent network of 98 inventory plots regularly positioned across the whole forest reserve and transect with 54 transect plots. Beech was found to secure gradually absolute dominance over other tree species in natural regeneration. The growth of fir, maple and spruce was hindered by browsing since the individuals rarely exceeded the height of 0.5 m. Further, the resource concentration effect was found in fir as browsing was more intense under high conspecific densities. Establishment and mortality of fir and beech differed, suggesting the species-specific life-history strategies. The results demonstrated the importance of regular and inextensive establishment of fir and huge but relatively less frequent establishment of beech. Mortality overweighed establishment in both species, though fir ratio tended to be almost balanced. The height of natural regeneration was revealed to be the only good predictor of mortality. Browsing, establishment and mortality of natural regeneration comprise an important part of forest regeneration processes and their role should be acknowledged by both forest and nature conservation management