Template-Type: ReDIF-Article 1.0 Author-Name: M. Kulej Author-Workplace-Name: Department of Forest Tree Breeding, Faculty of Forestry, Agricultural University of Cracow, Poland Author-Name: J. Socha Author-Workplace-Name: Department of Forest Mensuration, Faculty of Forestry, Agricultural University of Cracow, Poland Title: Effect of provenance on the volume increment of grand fir (Abies grandis Lindl.) under mountain conditions of Poland Abstract: 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 is characterized by the greatest productive capacity. Keywords: genotype, planting experiment, productivity Journal: Journal of Forest Science Pages: 1-8 Volume: 54 Issue: 1 Year: 2008 DOI: 10.17221/794-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/794-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200801-0001.txt Handle: RePEc:caa:jnljfs:v:54:y:2008:i:1:id:794-JFS Template-Type: ReDIF-Article 1.0 Author-Name: R. Petráš Author-Workplace-Name: National Forest Centre - Forest Research Institute in Zvolen, Zvolen, Slovakia Author-Name: J. Mecko Author-Workplace-Name: National Forest Centre - Forest Research Institute in Zvolen, Zvolen, Slovakia Author-Name: V. Nociar Author-Workplace-Name: National Forest Centre - Forest Research Institute in Zvolen, Zvolen, Slovakia Title: Quality of wood in the stands of poplar clones Abstract: 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 error for main assortments of the clone I-214 is 15-27% and Robusta 13-24%. Keywords: poplar clones, wood quality, assortment structure Journal: Journal of Forest Science Pages: 9-16 Volume: 54 Issue: 1 Year: 2008 DOI: 10.17221/791-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/791-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200801-0002.txt Handle: RePEc:caa:jnljfs:v:54:y:2008:i:1:id:791-JFS Template-Type: ReDIF-Article 1.0 Author-Name: E. Kula Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry in Brno, Brno, Czech Republic Author-Name: A. Pešlová Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry in Brno, Brno, Czech Republic Author-Name: D. Buchtová Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry in Brno, Brno, Czech Republic Title: Effects of nitrogen on the selection of food by Phyllobius arborator (Herbst) Abstract: 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, birch with the higher content of nitrogen was preferred. In laboratory rearing, females showed higher food requirements. In short-term rearing, differentiation did not occur in the amount of consumed food in males and females depending on the nitrogen content. Keywords: nitrogen, Betula pendula (Roth), Phyllobius arborator (Herbst) Journal: Journal of Forest Science Pages: 17-23 Volume: 54 Issue: 1 Year: 2008 DOI: 10.17221/792-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/792-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200801-0003.txt Handle: RePEc:caa:jnljfs:v:54:y:2008:i:1:id:792-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Dvořák Author-Workplace-Name: Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Z. Malkovský Author-Workplace-Name: Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: J. Macků Author-Workplace-Name: Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Influence of human factor on the time of work stages of harvesters and crane-equipped forwarders Abstract: 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 harvester was operated by an operator with two-year working experience and by an operator with no experience. The average time difference between the harvester operators was 64.9 seconds in one work stage. The statistical significance of different operation times was confirmed during technically demanding segments in the working stage (the boom out the felling head and tree processing). Operators with the same working experience in forestry mechanization - about 13 years but with different education carried out the haulage work stage. In this case, the statistical significance between calculated differences was not proved. This fact proves that the operator's working experience is more important than his education. Keywords: harvester, forwarder, work stages, job standardization Journal: Journal of Forest Science Pages: 24-30 Volume: 54 Issue: 1 Year: 2008 DOI: 10.17221/790-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/790-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200801-0004.txt Handle: RePEc:caa:jnljfs:v:54:y:2008:i:1:id:790-JFS Template-Type: ReDIF-Article 1.0 Author-Name: P. Král Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry in Brno, Brno, Czech Republic Author-Name: J. Hrázský Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry in Brno, Brno, Czech Republic Title: A contribution to the resistance of combined plywood materials to abrasion Abstract: 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 DM. To evaluate the newly designed material our testing methodology was prepared in such a way that it will conform to related European standards. It is completed by the method of sampling and preparation of samples for tests including their acclimation. According to our proposal, measurements were carried out of selected constructions of water-resistant plied veneer materials with jackets of various basis weight combined with glass fibres. Data on the abrasion resistance were acquired which can be considered to be reliable. The values of abrasion resistance were assessed with respect to standards valid in the EU which determine fields of their use. Keywords: abrasion resistance, foliated plywood, phenol foil, glass fibre, high-pressure laminate, abrasion, phenol-formaldehyde resin, Taber abraser Journal: Journal of Forest Science Pages: 31-39 Volume: 54 Issue: 1 Year: 2008 DOI: 10.17221/793-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/793-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200801-0005.txt Handle: RePEc:caa:jnljfs:v:54:y:2008:i:1:id:793-JFS