Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Introduction. One of the most common diseases of forest trees in Poland is the red ring rot in pines caused by a fungus Porodaedalea pini (Brott.) Murrill, resulting in significant damage to stands, as it inhabits the most valuable parts of the trunk in stands of age classes IV and older. Its range covers heartwood from the butt to the middle part of the tree. As a result of infection, destructive rot (variegated or white pocket rot) develops in tree trunks. The aim of the study was to determine the relationship between the degree of infection of pines (Pinus sylvestris L.) and the presence of hole-nesters.

Material and methods. The research was conducted in selected stands in the Miradz Forest District, in 10 selected measurement plots. After analyzing the results, the degree of infection of stands by P. pini was determined.

Results and conclusions. Single trees with visible disease symptoms were found, the number of which was on average 4/ha. A total of 18 cavity trees were observed, and their colonization in individual stands ranged from 0% to 100%. The occurrence of primary and secondary hollow-nesters was recorded. Due to the pilot nature of the study, the results should be treated as preliminary and exploratory, providing a basis for future, more extensive research.