Impact of thinning on the dynamics of mixed forest stands: an example from the Bialowieza forest, north-eastern Poland

Warsaw

2006

S. 117-127

4 Abb., 8 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200139207

In the paper, the problems concerning silvicultural treatment of mixed Stands as well as methods of their conversion into the desired direction (increase of target tree species) are analysed on the example of 80-year old forest stand, located in the Bialowieza Forest. The origin of the stand sampled is related to the activity of forest Company "Timber Corporation" in 20-ties of XX Century. To explore the current stand structure and to predict the future stand development, two sample plots, 50x50 m each, were established. One plot (A) was established in that part of the stand which was not regularly thinned since > 20 years. The other plot (B) was established in the part of the stand thinned in 1994. In the plots, d.b.h., top height and spatial coordinates of trees were measured and their species identification performed. Also, the Classification of trees into 4 quality classes was done and elite trees and trees for removal were selected. The data were analysed by means of BWINPro Software. The results obtained were used to demonstrate the current stand structure and to predict its development within the next 10 years. Two scenarios were adapted: 1) no thinning, 2) thinning aimed at removal of birches and freeing oaks. It was demonstrated that proper silvicultural treatment (timing and intensity of cuttings, species structure of harvested timber) can help to convert gradually tree species composition of mixed Stands into desirable direction, taking into consideration both natural developmental processes, and the need to optimize the financial effects.