Template-Type: ReDIF-Article 1.0 Author-Name: J. Zawadzki Author-Name: Ch.J. Cieszewski Author-Name: M. Zasada Title: Semivariogram analysis of Landsat 5 TM textural data for loblolly pine forests Abstract: The objective of this study was to evaluate the applicability of Landsat 5 TM images for analysing the textural information on pine forest stands in western Georgia, United States. Analysing spatial correlations between pixels measured by semivariances and cross-semivariances (cross-correlation between two radiometric bands) calculated from transects of Landsat TM images, we explored differences between semivariances associated with images of stands of various ages, origins (natural vs. planted) and species (loblolly pine - Pinus taeda L. - versus longleaf pine - Pinus palustris Mill.). We analysed both ground measurements and the satellite images using the visible, the near infrared, and the middle-infrared bands. We also analysed semivariances and cross-semivariances calculated from the Normalized Difference Vegetation Index and the Ratio Vegetation Index. The results showed that in spite of the relatively low Landsat TM spatial resolution (30m) the semivariograms and cross-semivariograms provided potentially useful information about the above-mentioned classes. The semivariances and cross-semivariances calculated from Landsat TM images of loblolly pine stands depend both on the age and the stand origin. In particular, large differences exist in semivariance and cross-semivariance sills. Significant differences also exist between semivariances calculated from stands of loblolly and longleaf pine. Keywords: semivariance, textural classification, remote sensing, loblolly pine, Landsat TM Journal: Journal of Forest Science Pages: 47-59 Volume: 51 Issue: 2 Year: 2005 DOI: 10.17221/4543-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4543-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200502-0001.txt Handle: RePEc:caa:jnljfs:v:51:y:2005:i:2:id:4543-JFS Template-Type: ReDIF-Article 1.0 Author-Name: V. V. Podrázský Author-Workplace-Name: Faculty of Forestry and Environment, Czech University of Agriculture in Prague, Prague, Czech Republic Author-Name: J. Remeš Author-Workplace-Name: Faculty of Forestry and Environment, Czech University of Agriculture in Prague, Prague, Czech Republic Title: Effect of forest tree species on the humus form state at lower altitudes Abstract: The paper documents the effects of forest stands of different species composition on the humus form state and soil profile chemistry. It compares the situation in mixed broadleaved (ash, oak, hornbeam), basswood and spruce stands. Spruce demonstrates the site degradation effects: raw humus accumulation, soil acidification, negative effects on nutrient dynamics. Both broadleaved stands were similar as for site effects, lower litter accumulation, more rapid organic matter mineralization and more rapid nutrient cycling and intense uptake were documented in the basswood stand. Keywords: humus forms, species composition, site degradation, species effect on soil Journal: Journal of Forest Science Pages: 60-66 Volume: 51 Issue: 2 Year: 2005 DOI: 10.17221/4544-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4544-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200502-0002.txt Handle: RePEc:caa:jnljfs:v:51:y:2005:i:2:id:4544-JFS Template-Type: ReDIF-Article 1.0 Author-Name: F. Tokár Author-Workplace-Name: Institute of Forest Ecology Slovak Academy of Sciences, Branch for Woody Plant Biology, Nitra, Slovak Republic Author-Name: E. Krekulová Author-Workplace-Name: Institute of Forest Ecology Slovak Academy of Sciences, Branch for Woody Plant Biology, Nitra, Slovak Republic Title: Structure, quality, production, LAI and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) stand Abstract: The paper evaluates the growth, structure, production, quality, leaf area index and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) monoculture situated in the forest type group Fageto-Quercetum in the locality Horné Lefantovce (Nitrianska Streda Forest District, Topoľčianky Forest Enterprise). Codominant trees, trees with stem of high quality, with medium-sized crown, medium dense and straight crown are the most abundant in the stand. The tree number in the stand is 1,024 trees/ha, basal area 51.75 m2/ha, growing stock 571.56 m3/ha, aboveground biomass stock 348.76 t/ha and leaf area index 21.85 ha/ha. Dendrochronological analyses examined the response in individual sample trees and minimum annual ring width was found in 1920, 1922, 1925, 1929, 1933, 1938, 1944, 1946, 1947, 1949, 1952, 1954, 1963, 1968, 1976, 1982, 1990, 1993, 1998, 2001. Marked maximum values of annual ring width in the years 1919, 1923, 1926, 1930, 1936, 1937, 1941, 1948, 1951, 1955, 1959, 1966, 1972, 1975, 1980, 1985, 1997 were found as a positive productive feature. Beginning in the year 1993, dry Austrian pine trees occurred in the stand as a result of the fungal infection by Sphaeropsis sapinea (Fr.) Dyko et Sutton. Keywords: Keywords: Pinus nigra ARNOLD, structure, production, LAI, dendrochronology, Sphaeropsis sapinea fungus Journal: Journal of Forest Science Pages: 67-76 Volume: 51 Issue: 2 Year: 2005 DOI: 10.17221/4545-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4545-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200502-0003.txt Handle: RePEc:caa:jnljfs:v:51:y:2005:i:2:id:4545-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Hrázský Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic Author-Name: P. Král Author-Workplace-Name: Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic Title: Assessing the bending strength and modulus of elasticity in bending of exterior foiled plywoods in relation to their construction Abstract: The paper summarizes results of an institutional research aimed at assessing the bending strength and modulus of elasticity in bending of exterior foiled combined and all-beech plywoods in relation to their construction. A relationship was studied of the plywood construction and selected physical and mechanical properties. In studied sheets, moisture, density, bending strength and modulus of elasticity were analysed along and across the grain of the upper veneer. All measurements were carried out in water-resistant plywoods with surface treatment with a phenolformaldehyde foil 8, 10, 12 and 15 mm thick in combined plywoods and 10, 12, 15 and 18 mm thick in all-beech plywoods. The construction of plywoods significantly influences their quality that is determined particularly by the bending strength and modulus of elasticity. Using regression analysis relationships were demonstrated particularly that with the increasing moisture content of plywoods the bending strength decreased and with the increasing density the bending strength and modulus of elasticity increased. The same trend was also proved in connection with the increasing number of veneers of plywood sheets. Using correlation analysis, combinations of interrelationships of the given properties were statistically tested. Keywords: plywood, density, surface density, moisture, thickness, bending strength, modulus of elasticity in bending, veneer, statistical analysis Journal: Journal of Forest Science Pages: 76-94 Volume: 51 Issue: 2 Year: 2005 DOI: 10.17221/4546-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/4546-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-200502-0004.txt Handle: RePEc:caa:jnljfs:v:51:y:2005:i:2:id:4546-JFS