Journal of Forest Science, 2006 (vol. 52), issue 6
Changes in humus forms in gaps of the canopy of semi-natural beech stand
V. V. Podrázský, J. Remeš
J. For. Sci., 2006, 52(6):243-248 | DOI: 10.17221/4507-JFS 
The article presents original results of research on the humus form dynamics in a semi-natural European beech stand in the National Natural Reserve Voděradské bučiny, in the area of Training Forest Enterprise at Kostelec nad Černými lesy (Czech University of Agriculture inPrague). The accumulation and soil chemical characteristics of particular humus forms were studied: dry matter amount, pH, soil adsorption and exchangeable acidity characteristics as well as plant available and total nutrient contents. The humus form samples were taken in four replications from the particular humus form layers (L, F, H, Ah), and the analyses were performed individually....
The occurrence of Megastigmus pictus (Förster) (Hymenoptera: Torymidae) and Resseliella skuhravyorum Skrzypcz. (Diptera: Cecidomyiidae) in the Chełmowa Góra forest reserve of theŚwiętokrzyskiNational Park (Poland)
J. Bąk
J. For. Sci., 2006, 52(6):249-254 | DOI: 10.17221/4508-JFS
A study conducted in 1999-2000 in 6 compartments of the Chełmowa Góra forest reserve, situated in the ŚwiętokrzyskieMountains, was aimed at harmful insects infesting cones and seeds of Larix decidua Mill. subsp. polonica (Racib.) Domin. Insect rearing and seed and cone cutting yielded 1,045 specimens of insects belonging to 8 species. Resseliella skuhravyorum Skrzypcz. (Diptera: Cecidomyiidae) and Megastigmus pictus (Förster) (Hymeno-ptera: Torymidae) were the most abundantly represented species. They were present in cone samples of all investigated trees. The index of infestation of cones by insects (WZS) was higher...
Occurrence, bionomics and harmfulness of Chrysomela populi L. (Coleoptera, Chrysomelidae)
J. Urban
J. For. Sci., 2006, 52(6):255-284 | DOI: 10.17221/4509-JFS
In 2003 to 2005, Chrysomela populi L. gradated on yearly cut Populus nigra var. italica in street alleys in Brno and elsewhere. Imagoes occurred on trees from the end of April or from the beginning of May. In rearing, the chrysomelid consumed unwillingly leaves of 2-year shoots and laid on average 142 eggs. On leaves of shoots, imagoes damaged 100 to 200 cm2 during 5 to 7 weeks, produced 480 to 900 frass pellets and laid on average 506 eggs. Oviposition was continual with breaks amounting to on average 2.6 days. Embryonal development took 6 to 8 (in the laboratory 5) days. Larvae of the 1st generation...
Effects of different pressing conditions on properties of spruce plywoods
P. Král, J. Hrázský
J. For. Sci., 2006, 52(6):285-292 | DOI: 10.17221/4510-JFS
The paper presents results of an institutional research aimed at assessing the effect of different technological conditions in pressing on physical and mechanical properties of plywood sheets. Spruce plywood sheets of the veneer nominal thickness of 3.0 and 3.5 mm were analyzed. The plywood sheets were produced as five-ply and BAKELITE PF B118 phenol-formaldehyde adhesives were used for there manufacture. In relation to a different pressing temperature 115, 120 and 125°C and a different specific pressure, density, bending strength, MOE in bending and glue-bond strength by a shear test were assessed. The determined values of properties were statistically...