The Effect of Forest Management Practices on the Deadwood Resources and Structure in Protected and Managed Montane Forests During Tree-stand Reconstruction after a Dieback of Norway Spruce

Forest management practices can not only influence the amount of deadwood but also the proportions of particular elements. In addition, deadwood resources can depend on the forest community and the dominant tree species. The goal of the present paper was to compare the number of logs, stumps and snags and their volume between the protected and managed forests and among the forest communities in the Karkonosze Mts. after a huge dieback of Picea abies. A massive decline of Norway spruce has been observed since the 1980s. The protected forests belong to the Karkonosze National Park and the managed forests are situated in its buffer zone. A total of 1366 elements of coarse woody debris (CWD) were included in the study. They were distributed on 180 study plots (10 m x 10 m) that were randomly selected. Among the deadwood elements, spruce Picea abies dominated (80.3%) tree species followed by beech Fagus sylvatica (14.3%). More logs were found in the protected forest (57.3%) than in the managed forests (42.7%). More of the snags and stumps were found in the managed forests, 56.9% and 52.8%, respectively, then in the protected forests, 43.1% and 47.2%, respectively. The mean volume of CWD was ca. 114 m(3) ha(-1) in the protected forests, whereas it was ca. 70 m(3) ha(-1) in the managed forests. The differences in the number of particular elements of CWD between the forests of different statuses were biased by differences among the types of forest community. The mean number of stumps per study plot was the highest in the planted spruce forest and in the natural spruce-fir forest. The mean volume of logs and snags was the highest in specific forest communities (beech forest and subalpine spruce forest, respectively) in the protected part, whereas the mean volume of stumps was higher in the managed beech forests. Regardless of how the deadwood was deposited, this was a positive phenomenon that contributed to maintaining biodiversity.