Journal of Forest Science, 2008 (vol. 54), issue 1
Effect of provenance on the volume increment of grand fir (Abies grandis Lindl.) under mountain conditions of Poland
M. Kulej, J. Socha
J. For. Sci., 2008, 54(1):1-8 | DOI: 10.17221/794-JFS 
The purpose of this study was to assess the volume increment diversification of selected provenances of grand fir growing under mountain conditions of Poland. The mean increment was determined on the basis of volume reached by the respective provenances when trees were 30 years old while the current increment was calculated from a difference between the volume when trees were 30 years old and the volume when they were 26 years old. It was found that the productive (increment) potential of tested grand fir partial populations is determined by the genotype (provenance). Among the tested provenances grand fir from Salmon River on Vancouver Island in Canada...
Quality of wood in the stands of poplar clones
R. Petráš, J. Mecko, V. Nociar
J. For. Sci., 2008, 54(1):9-16 | DOI: 10.17221/791-JFS
The results obtained in research on the quality of raw timber by means of the structure of assortments for the stands of poplar clones Robusta and I-214 are presented in the paper. Models for an estimation of the structure of basic assortments of poplar stands were constructed separately for each clone in dependence on mean diameter, quality of stems, and damage to stems in the stand. The clone Robusta has higher proportions of higher-quality assortments than the clone I-214. The accuracy of models was determined on empirical material. It was confirmed by statistical tests that the models did not have a systematic error. The relative root mean-square...
Effects of nitrogen on the selection of food by Phyllobius arborator (Herbst)
E. Kula, A. Pešlová, D. Buchtová
J. For. Sci., 2008, 54(1):17-23 | DOI: 10.17221/792-JFS
The selection of a nutritive plant and the consumption of food (Betula pendula Roth) affected by differentiated inputs of nitrogen after the repeated application of ammonium nitrate into soil was monitored at Phyllobius arborator (Herbst) under field (polythene greenhouse) and laboratory (Climacell) conditions. In birch leaves, the content of nitrogen increased. The diameter and height increment was stimulated by the application of 0.5-1 g, higher doses induced stress and the fall of increment. According to the frequency of feeding marks on leaves and food consumption by weevils of the genus Phyllobius in a polythene greenhouse,...
Influence of human factor on the time of work stages of harvesters and crane-equipped forwarders
J. Dvořák, Z. Malkovský, J. Macků
J. For. Sci., 2008, 54(1):24-30 | DOI: 10.17221/790-JFS
Harvester technologies represent the second most common logging system in the Czech Republic. The high productivity of this technology is very necessary to cover its acquisition and operational costs. A human factor - a machine operator is the most important factor that surely influences the machine productivity. That is why the aim of this study is as follows: to analyze the mutual dependence of machine operator's education and working experience and harvester and forwarder productivity. The analysis proves that the operator's education and even more his working experience are very important. The time of harvesting work stages was measured when the...
A contribution to the resistance of combined plywood materials to abrasion
P. Král, J. Hrázský
J. For. Sci., 2008, 54(1):31-39 | DOI: 10.17221/793-JFS
The aim of the paper was to propose the methodology of testing the abrasion resistance of combined water-proof plywood materials with the phenol-formaldehyde foil surface finish and to assess the surface resistance of a new combined plywood material of a given construction to abrasion. For sheathing, phenol-formaldehyde foils with the low content of resins were used, which are combined with unwoven and woven glass fibres highly resistant to mechanical wear. The paper for phenol-formaldehyde foils manufactured of sulphate pulp (basis weight 60 g/m2) was impregnated by a low-molecular resin with the resin deposit 150% DM (dry matter) per paper...