No abstract

The aim of the study was to analyse butt rot incidences in silver fir stands of selected nature reserves and national parks. The study included 11 stands in Carpathian forests and for comparison 4 stands outside the Carpathians. To identify butt rot in fir trees, we used the non-invasive method of acoustic tomography. We tested 30 randomly selected fir trees in each of the 15 stands using Picus Sonic tomography to determine butt rot occurrence and to assess the proportion (%) of healthy wood in cross-sections of the tree trunk. The results indicate significant differences in the frequency of butt rot in silver fir at the individual level as well as the population level. This variability in frequency was not dependent on geographical location of the investigated stands.

Abstract.One of the tree species appearing after a decline of Norway spruce Picea abies (L.) H. Karst. in the Silesian Beskid Mountains is Silver Birch Betula pendula Roth. Therefore our study was aimed at evaluating this birch regeneration and the dynamics of changes resulting from experimental cutting. Measurements and inventories of trees were conducted on research plots located in a ten-year old birch regeneration site with either no cutting, partial cutting (50%) or clear cutting (100%) of birch. We observed an introduction of biocenotic species (rowan, willow, aspen) as well as the target species (spruce, fir, beech) under the birch canopy. Fir and beech were also planted, because of their slow natural regeneration. The clear cut treatment caused a great number of sprouts growing from birch stumps, reaching a height of about 2 m over 3 years, resulting in competition with the regeneration of other species. Partial cutting did not cause such a drastic amount of sprouting. Furthermore, we found that only the spruce height increment is significantly less under a birch canopy compared to open space. The obtained results indicate a necessity to adjust the density and species composition of regenerating tree species under a birch canopy, avoiding complete removal of the first generation birch cover and the need to moderately thin out birch.

Due to its hidden character, butt rot occurrence is not commonly included in the assessment of plus trees’ health status. Thus, the trees’ varied susceptibility to wood decay is not a target of breeding efforts. The aim of the study was to determine the extent of butt rot in fir and spruce plus trees from Carpathian seed stands. We employed the novel and non-invasive diagnostic method of sonic tomography to determine presence and severity of decay at the base of 110 plus trees of silver fir and 42 of Norway spruce. Butt rot in various stages of development occurred in 63% of investigated fir trees and in 45% of spruce trees. The proportion of damaged wood on the tomogram ranged from 0–38% in fir and 0–47% in spruce with similar average proportions of solid wood in all forest districts. The vast majority of trees was in the range of 80–90% solid wood. Plus trees of fir and spruce were affected by butt rot to a similar extent and the degree of damage increased with age in both species. However, a large variation in susceptibility to butt rot was found between individual trees leading to the conclusion that the identification of old trees, which wood is not decayed, may be the basis for further research on the resistance to butt rot.

The aim of this work was to determine the biometric features of Scots pine Pinus sylvestris L. regeneration in terms of their susceptibility to weather-inflicted damage. We compared the damage between three sites located in the Polish part of the Carpathians: Scots pine planted in (I) fertile sites of mountain broadleaved and mixed broadleaved forest, (II) poor sites of mountain coniferous forest and (III) sites of Scots pine natural refuges during the post-glacial period. In each of the three sites of pine regeneration, 11 research plots were established with 50 pine trees on each plot. For each tree, the following biometric measurements were taken: diameter at breast height, height, 3-year height increment, crown length and crown width measured along the contour line. The Scots pine regeneration was found to vary in terms of their biometric features depending on the site fertility. In fertile sites, the biometric parameters of the trees increased at a faster rate compared to low-fertility sites causing an increase in their susceptibility to damage by adverse weather conditions such as snow and rime. Therefore, the silvicultural risk in fertile sites is high and thus the introduction of pine for regeneration should be avoided in fertile broadleaved and mixed broadleaved forests even if pine provenances from a mountain origin are to be planted. Furthermore, tending cuts in regeneration should be made frequently, but with moderate intensity so as to avoid excessive reductions in tree density. Intensive cuts, especially in fertile sites, promote the expansion of pine crowns, which further increases the risk of damage.