Template-Type: ReDIF-Article 1.0 Author-Name: M. Slodičák Author-Workplace-Name: Forestry and Game Management Research Institute, Jíloviště-Strnady, Research Station Opočno, Czech Republic Author-Name: J. Novák Author-Workplace-Name: Forestry and Game Management Research Institute, Jíloviště-Strnady, Research Station Opočno, Czech Republic Title: Thinning experiments in Norway spruce stands after 40 years of investigation - 1st series Abstract: Forestry and Game Management Research Institute at Jíloviště-Strnady has created a new experimental base for thinning research since 1956. A total of 46 experimental series were founded in Norway spruce (Picea abies [L.] Karst.); 24 series are still maintained. This paper focuses on the series established in young Norway spruce stands in 1958 (Rumburk, Mostek, Vim­perk I, Vimperk II and Nisa). The goal of thinning experiment was to compare two basic methods of thinning: positive selection from above (2a) and negative selection from below (3b or 5b). Each experimental series has a control plot (1c) where no thinning was conducted. The effect of thinning by positive selection from above carried out in the 40-year period of investigations was a 10-45% decrease in the abundance of trees in lower diameter classes compared with control plots. Negative selection from below resulted in a more pronounced decrease in thin trees abundance (50-69% compared with control plots). The abundance of thick trees (diameter of 30 cm and more) increased by 5-50% on all comparative plots with thinning. Static stability characterised by the h/d ratio of mean stem and h/d ratio of dominant trees (200 thickest trees per hectare) was influenced by thinning mostly positively (final value of h/d ratio found by the last revision was considerably lower). Keywords: positive selection from above, negative selection from below, thinning, Norway spruce Journal: Journal of Forest Science Pages: 45-73 Volume: 49 Issue: 2 Year: 2003 DOI: 10.17221/4681-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4681-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200302-0001.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:2:id:4681-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Viewegh Author-Workplace-Name: Czech University of Agriculture, Faculty of Forestry, Prague, Czech Republic Author-Name: A. Kusbach Author-Workplace-Name: Czech University of Agriculture, Faculty of Forestry, Prague, Czech Republic Author-Name: M. Mikeska Author-Workplace-Name: Czech University of Agriculture, Faculty of Forestry, Prague, Czech Republic Title: Czech forest ecosystem classification Abstract: Forest classification, made up by Plíva and Průša (Plíva 1971), has been used in the Czech Republic forestry since 1970. This classification is based on ecological factors of the environment. Edaphic conditions are at the first position, then climatic conditions follow (by their vertical [altitudinal] distribution mainly). These two factors form the basic construction called ecological grid (Table 1). Keywords: forest classification, Czech Republic, ecological factors Journal: Journal of Forest Science Pages: 74-82 Volume: 49 Issue: 2 Year: 2003 DOI: 10.17221/4682-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4682-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200302-0002.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:2:id:4682-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Hrázský Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Author-Name: P. Král Author-Workplace-Name: Mendel University of Agriculture and Forestry, Faculty of Forestry and Wood Technology, Brno, Czech Republic Title: The influence of particle composition in a three-layer particleboard on its physical and mechanical properties Abstract: The paper deals with results of research aimed at the problem of the maximum possible amount of added sawdust to standard particles into surface and central layers of three-layer particleboards in order that the physical and mechanical properties of particleboards will comply with the CSN 49 2614 Standard. Waste from wood processing is widely used for the production of particleboards. For that purpose, three-layer particleboards with computed density of 740 kg/m3 at seven versions A-G with 0-30% sawdust addition to standard particles were manufactured in a laboratory. Five particleboards 500 × 500 × 16 mm were made for each version. These air-conditioned particleboards were cut into specimens in which physical and mechanical properties such as moisture, density, swelling, perpendicular tensile strength and bending strength were determined. It is obvious from the results of physical and mechanical properties that during the production of particleboards sawdust at a quantity of max. 25% can be added to standard particles when all values of physical and mechanical properties are in accordance with the CSN 49 2614 Standard. Keywords: particleboard, physical and mechanical properties, density, moisture, bending strength, tensile strength, swelling, statistical analysis, sawdust Journal: Journal of Forest Science Pages: 83-93 Volume: 49 Issue: 2 Year: 2003 DOI: 10.17221/4683-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4683-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200302-0003.txt Handle: RePEc:caa:jnljfs:v:49:y:2003:i:2:id:4683-JFS