|
|
Posouzení využitelnosti vybraných listnatých dřev pro výrobu kompozitu na bázi dřeva
Kašpařík, Matěj
The bachelor thesis deals with the issue of the possibility of replacing spruce wood in the production of OSB with hornbeam and birch wood. The purpose of the thesis is to compare selected physical and mechanical properties of OSB made of these woods with standardized properties of OSB. In the first part, the origin, characteristics and current use of OSB are presented. The second part deals with the material and methodology of all the tests performed. The following properties of the boards were investigated: moisture content, flexural strength and elastic limit, density profile, swelling, delamination and shear strength of the glued joint. In the third part of the paper, the results of the tests and their comparison with the standard requirements for OSB are presented, followed by a summary and discussion.
|
|
|
Initial vegetative regeneration of broad-leaved woody plants on the experimental site of reserved coppice-with-standards woodland in the NR Na Voskopě, Czech Karst
Dekan, Petr ; Černý, Tomáš (advisor) ; Čada, Vojtěch (referee)
This thesis deals with the intensity of tree regeneration in the initial phase of development of future coppice stand. The research was conducted in PR Na Voskopě in the Czech Karst on an experimental strip measuring 25x125 m. This strip was felled in the early spring of 2015 (JELENECKÁ, 2015), there were 14 standards left for the future development of coppice-with-standards forest. The most abundant tree species are hornbeam (Carpinus betulus) and oak (Quercus sp.), there is also the maple (Acer campestre) and service tree (Sorbus torminalis), other trees have only a minimal representation. The average measured age of the felled oak equals 87 years and that of hornbeam equals 74 years, after model calculation for the hornbeam the average age was assessed as 68 years. On the felled strip there were 538 stumps recorded at the end of the growing season (3. - 4. 10. 2015), eight parameters of stump and root re-sprouting (height of the highest sprouts, total number of sprouts, the average height of sprouts, the largest horizontal width of the whole sprouting bunch, browsing rate of sprouts, presence of root sprouts and the sprout cluster presence). The analysis used data taken from Field-Map inventory (JELENECKÁ, 2015). Evaluation of the data showed that DBH has a significant effect on the regeneration of sprouts mainly for the hornbeam, but no effect for the oak. Topographic gradient along the strip also has some effect on the regeneration of sprouts, oak more intensively regenerates at the bottom of the slope and hornbeam in the upper part of the slope. Amid the slope there was some reduction in regeneration, most probably due to the game influence (mouflons). Browsing sprouts is on this experimental strip enormous. Despite adverse weather conditions (drought and heat) in 2015 regenerates in this relatively extreme habitat 91 % stumps.
|
guest ::
