Beech (Fagus sylvatica L.) forests of a selection structure in the Bieszczady Mountains (southeastern Poland)
The characteristics of two beech (Fagus sylvatica L.) stands are presented in this paper. One, the Tarnicki stand, situated in the Bieszczadzki National Park, represents the growing up stage and selection phase of a forest of primeval character. The other one, the Otryt stand, is situated in managed forests of the Lutowiska Forest District. In each stand two sample plots were established. The distribution of the number of trees in each sample plot agreed with de Liocourt sequence and Meyer curve. Both stands were characterized by the structure of many generations. The Otryt stand, with respective volumes of 238 and 324 m<sup>3</sup>/hain two sample plots, was characterized by a lack of large diameter trees and a high percent of trees of the smallest diameters, while the Tarnicki stand, with volumes of 442 and 517 m<sup>3</sup>/ha, was characterized by the presence of large diameter trees (d<sub>1.3</sub> ≥ 72 cm). The phase of the selection forest in the Tarnicki stand is of temporary character because, due to natural processes, a two-storied structure may develop there, and with time, a one-storied structure in the optimal stage. In the Otryt stand, representing a managed forest, the maintenance of the selection structure may be expected due to selection cuttings. It has to be acknowledged that managed stands of characteristics similar to those presented in this paper makes it possible to carry out selection cutting, especially in the protection zone surrounding the Bieszczadzki National Park.