Dynamika naturalnych faz rozwojowych drzewostanów w Białowieskim Parku Narodowym

The aim of the research was to determine the current changes occurring in the natural forest using the classification based on the natural phases of stand development. The oldest part of the Białowieski National Park, formerly known as the Strict Reserve, was the object of the study. Material was collected from temporary sample plots (460 ones both in 1995 and 2005) and 160 permanent sample plots (in the years 2000, 2002 and 2004). Leibundgut’s classification was used to determine the natural development phases. All of them occurred in the Białowieski National Park in variable proportions, and this structure changed during the study period. They differed in terms of standing volume, tree density, total tree height of regeneration, current volume increment, losses and changes in standing volume. The regeneration of stands preceded in four different ways – in open areas, under the overstory of reduced closure, in small gaps or continuously when replacing separate dead trees.