Fig. 1. Age structure and tree species composition in the strictly protected part of the Białowieża National Park (BNP), managed parts of the Białowieża Primeval Forest (BPF), and in all Polish forests in the mid-1990s. Before large-scale timber extraction started in 1915, tree species composition and age structure did not differ between the two parts of the BPF. Source: Jędrzejewski and Jędrzejewska (1995) (mod.), DGLP (1997).