Decline of Norway spruce stands in the Beskid Slaski Mts.

The dynamics of decline of Norway spruce forests in the Beskid Śląski Mts. (S Poland) in a 2007−2016 period was analysed based on data from the State Forests Information System. For that purpose we used modified growth model and wind damage risk model. The harvested timber volume (salvage cuts) exceeded the allowable harvest modeled with the stand growth model by 270% in years 2007−2010 (earlier period) and by 89% in the 2011−2016 (later period) period. The highest volume exceed (503 and 307% for earlier and later period respectively) was recorded for the Wisła Forest District. For the deadwood, the harvested volume exceeded the modeled one by 45% (162 in earlier, and 59% in later period). In the Węgierska Górka Forest District the harvested volume amounted to 287% of the modeled one (438 in earlier, and 70% in later period). The largest amount of wind−broken and wind−fallen trees was found in Wisła. Their volume amounted to 48% of the modeled volume (59 in earlier, and 40% in later period). The highest exceed occurred in Węgierska Górka (89 and 70% in the later period respectively). The species composition in the analysed region changed significantly as the share of spruce decreased and share of beech and fir increased (tab. 1). Changes in the aeral fraction of stands in age classes in the Bielsko and Ustroń forest districts were insignificant (tab. 2). For Węgierska Górka, share of stands in age class