Journal of Forest Science, 2011 (vol. 57), issue 1

Changes in phenolic acids and stilbenes induced in embryogenic cell cultures of Norway spruce by two fractions of Sirococcus strobilinus mycelian

J. Malá, M. Hrubcová, P. Máchová, H. Cvrčková, O. Martincová, M. Cvikrová

J. For. Sci., 2011, 57(1):1-7 | DOI: 10.17221/55/2010-JFS  

We examined defence responses in embryogenic cell suspension cultures of Norway spruce (Picea abies [L.] Karst) elicited by intracellular protein and cell wall fractions (PF and WF, respectively) prepared from mycelia of the fungus Sirococcus strobilinus Preuss focusing on changes in (soluble and cell wall-bound) phenolic and stilbene concentrations. Treatment with both preparations induced an increase in the total contents of phenolic acids in Norway spruce cells and variations in the levels of stilbene glycosides. More rapid and intense induction of defence response was observed in cells after WF application. The contents of soluble...

Aboveground biomass of substitute tree species stand with respect to thinning - European larch (Larix decidua Mill.)

J. Novák, M. Slodičák, D. Dušek

J. For. Sci., 2011, 57(1):8-15 | DOI: 10.17221/24/2010-JFS  

This study is focused on substitute European larch stands in the Krušné hory Mts. (northern part of the Czech Republic). Research was conducted within larch thinning experiment Kalek (780 m a.s.l. in the category Piceeto-Fagetum oligo-mesotrophicum - Calamagrostis villosa). Results showed that the aboveground biomass of the investigated substitute unthinned larch stand represented approximately 102 thousand kg of dry matter per ha at the age of 20 years. Stemwood (ca 59%) is the most important part of the aboveground biomass. Needles, live and dead branches accounted approximately for 6%, 17% and 11%, respectively, and stem bark only...

Cluster reforestation near the timber line

J. Souček, O. Špulák

J. For. Sci., 2011, 57(1):16-23 | DOI: 10.17221/114/2009-JFS  

Plantation of spruce in clusters (small collectives with 20-30 individuals with dense spacing) was realized on a small clear-cut and under the forest stand near the timber line in the Krkonoše Mts. in 1993. Gaps among the collectives were planted with dwarf pine and rowan. The height of trees aged 16 years occurring in centres of the small collectives is greater than trees growing on their edges. Lower height growth of underplantings is affected more by the stand shelter than by the position of individuals within collectives. Health status of plantations is comparable on both plots. Tree samples (spruce, dwarf pine) from the underplanting had lower...

Cambioxylophagous fauna developing on logging residues of blue spruce (Picea pungens Engelmann)

E. Kula, R. Kajfosz, J. Polívka

J. For. Sci., 2011, 57(1):24-33 | DOI: 10.17221/3/2010-JFS  

Cutting down 20- to 30-years-old trees of blue spruce (Picea pungens Engelm.) (October, May) and cross-cutting them to sections of different volume (0.5-75 dm3) under conditions of half-shade × open area resulted in a potential food offer for cambiophages. Ips amitinus (Eichh.) and Pityogenes chalcographus (L.) reached the higher frequency of occurrence on sections placed in the open area than in half-shade and on stems felled in the autumn season than in the spring season. Dryocoetes autographus (Ratz.) was markedly profiled on sections in half-shade with the gradual desiccation of phloem. P. chalcographus preferring...

Energy consumption of chipper coupled to a universal wheel skidder in the process of chipping wood

J. Kováč, J. Krilek, M. Mikleš

J. For. Sci., 2011, 57(1):34-40 | DOI: 10.17221/27/2010-JFS  

The chipper for chips is an energy consuming machine. Many factors influence the result of chipping which influence the whole process. The paper deals with the process of wood chipping by a chipper in order to determine its energy consumption. The main purpose was the determination of input power and comparison of revolution frequency on the outlet shaft of a skidder regarding the dimension of the torque depending on variable parameters which characterize the process of wood chipping during the measurement and the analysis of energy consumption of a chipping machine was carried out.