Zasoby oraz zróżnicowanie martwego drewna w uroczysku Wapienny Las w Nadleśnictwie Polanów

Managed forests, which account for the vast majority of woodland areas in Poland, play a major role in preserving biodiversity. The objective of this work was to determine the diversity of woody microsites in a managed forest covering 27 ha of land in Polanów Forest District (north−western Poland). The study was conducted in 2014 on 20 sampling plots with an area of 0.04 ha each. An inventory of deadwood was conducted involving standing dead trees, snags, stumps, and lying deadwood with a diameter of at least 7 cm (in the case of standing deadwood, the diameter was measured at breast height). Deadwood was classified according to a five−level decay scale. The studied forest was found to contain an average of 26.9 m³/ha of deadwood from several tree species. Lying deadwood accounted for 17.3 m³/ha, standing dead trees for 0.9 m³/ha, snags for 4.9 m³/ha, and stumps for 3.8 m³/ha. Deadwood in all decay stages was identified. The most abundant category of deadwood was moderately decomposed wood in decay stage III (31.3%), followed by decay stage II (24.4%), and decay stage IV (19.7%). Deadwood (both standing and lying) was also very diverse in terms of piece diameters. The diameter at breast height of standing dead trees was up to 26 cm, and that of snags up to 50 cm. The thickest pieces of lying deadwood were 48 cm in diameter. However, pieces of less than 35 cm in diameter accounted for 96% of the total volume of lying deadwood. The volume of deadwood in the studied forest stand was very large, much higher than the average for Polish forests in general (5.8 m³/ha). Deadwood was highly varied and contributed to a substantial diversity of organisms that depend on it, as shown by previous research. Wapienny Las is an example of a managed forest that plays an important role in preserving woodland biodiversity.