The effect of canopy gaps on growth and development of silver fir (Abies alba Mill.) regeneration in mixed stands in the Jata reserve

The study was carried out in mixed stands in Jata reserve. All gaps over than 20 m(2) were localized. The aim of the study was to describe the structure and vitality of silver fir regeneration in gaps and under stand canopy. Following hypothesis was tested: better condition for fir growth is in small gaps, in bigger gaps fir is decreased by the development of deciduous tree species. It was found that gap size did not influence on the quantity of fir regeneration. The hypothesis was rejected. In mixed stands of the Jata reserve fir was not the dominant tree species not only in gaps but also under the stand canopy. The vitality of fir trees has been improved in last years, what suggests the increment in tree crowns lenght.