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The volume of incidental wood products due to the catastrophic windfalls that occurred on the 17th of September 2017 was estimated, at national level at 460 thousand m3, of which over 200 thousand m3 were registered in the area administered by the Bihor County Forest Administration. The main objective of this paper is the study of the changes that appear in the micro-relief and of the influence of some environmental characteristics, in the beech stands (Fagus sylvatica L.) from the Forest District Sudrigiu, Management Unit U.P. VII Văratec, Bihor County Forest Administration, Romania, as an effect of windfalls. The field observations had the purpose of: determining the displaced volume (DV); breast height diameter (D1.3); height of tree (HT); average root diameter (ARD); age (A); depth of micro-depression (DM) and depth of rock / parent material (DRP). Bifactorial linear regression of the DV according to the two characteristics of the tree (D1.3) and the soil (DRP) allows an assessment of the volume of displaced soil with an accuracy of 95%. The volume of soil dislocated in the beech stands (Fagus sylvatica L.) from the Forest District Sudrigiu, Management Unit U.P. VII Văratec, Bihor County Forest Administration, Romania, evaluated with the help of the two-factor linear regression based on the basic diameter of tree D1.3 and the depth of the rock / parent material DRP and respectively the number of felled trees is between 2589.89 m3 for u.a. 100 A, partially affected and 13694.46 m3 for u.a. 104 A, affected by mass felling. To acknowledge the total volume of dislocated land and of the specific volume (m3/ ha), for the different compartments, is important for the analysis and differentiation of the variants of works necessary for the forest reconstruction of the lands affected by windfalls.

The research was performed on Norway spruce growing at the IUFRO 1964/68 experimental trial in Krynica (the Carpathians, S Poland). The growth and stability of Norway spruce were assessed taking into account the division into geographical regions proposed by Krutzsch. The height and breast height diameter were measured, on the basis of which the volume and the slenderness ratio were calculated. The stability class of each tree was also determined based on the slenderness. Significant differences were found between the Krutzsch regions for each of the analyzed traits. Spruces from region 75 (Belarus), as well as spruces from regions in the north−eastern range of the species occurrence in Poland, had above−average values of each trait. Spruces from regions in the southern part of Poland also had a good growth, but they were characterized by a large share of trees with unfavorable stability (slenderness ratio>80). The worst growth was noted for spruces from all regions located on the Scandinavian Peninsula. In the cluster analysis, four groups of Krutzsch regions were distinguished. They differed in terms of mean values of the analysed features. The best growth, tree volume and stability were characteristic for spruces from regions located in Germany, the Czech Republic, Slovakia, Poland, Belarus, Lithuania, Latvia and Russia (group C). Contrary to group D, which includes regions from the central part of the Scandinavian Peninsula, France, Tyrol and Dalmatia, the rest of spruce trees had the worst growth, low stem volume and large share of trees (>50%) classified as very unstabile., Sylwan 165 (1): 9-20

The objective of this study was to identify eucalyptus clones for the production of sawed timber based on dendrometric variables and longitudinal residual deformation (LRD), analyzing the correlation between these characteristics. 20 Eucalyptus grandis x Eucalyptus urophylla clones with 13 years of age were analyzed. The crown size, diameter at breast height (DBH) and bark thickness were measured. There was a significant difference between the clones for DBH, LRD and bark thickness. There was no significant correlation between DBH and DRL. The correlation was significant between DBH and crown size, its being possible to affirm that crown size affects the diametrical growth of trees. DBH and bark thickness were also significantly correlated, in so far as trees with a wider diameter possess thicker bark. It was possible to select clones with better potential for sawed timber production, that is to say, elevated DBH with a reduced LRD.