Journal of Forest Science, 2007 (vol. 53), issue 10

Feeding ecology of pine shoot beetles (Tomicus spp.) in tree crowns of Scots pine (Pinus sylvestris L.) stands under one-year outbreak

A. Borkowski

J. For. Sci., 2007, 53(10):445-451 | DOI: 10.17221/2084-JFS  

Studies were carried out in southern Poland during 2002-2006 in Scots pine stands under the effect of an outbreak of pine shoot beetles. The qualitative aspects of beetle feeding in tree crowns, studied on the basis of fallen shoots collected on experimental plots, are presented in this paper. The beetle numbers affected the age distribution of damaged shoots and the proportion of multiple attacks. The proportions of one-year-old shoots and the numbers of shoots with more than two attacks increased in the marginal part of the stand in the year of intensive feeding of beetles and in the subsequent year. A similar proportion of shoots with two attacks...

Root system development and health condition of sycamore maple (Acer pseudoplatanus L.) in the air-polluted region of Krušné hory Mts.

O. Mauer, M. Pop, E. Palátová

J. For. Sci., 2007, 53(10):452-461 | DOI: 10.17221/2086-JFS  

The paper presents results from a study of sycamore maple development, health condition and growth in forest altitudinal vegetation zones (FAVZ) 6 and 7 occurring in pollution damage zones A and B in the air-polluted region of Krušné hory Mts. as compared with the trees of identical height in FAVZ 4 and 5 occurring in pollution damage zone D in the Bohemian-Moravian Upland. Sycamore maple develops a fully diversified root system. On spread mounds it creates only a superficial root system and its growth is retarded. The growth of sycamore maple is limited by the layer of humus horizons. If the layer thickness is over 20 cm, the sycamore roots would...

Methods of complex evaluation of the necrotic disease of beech

A. Cicák, I. Mihál, Ch. Tsakov, P. Petkov

J. For. Sci., 2007, 53(10):462-466 | DOI: 10.17221/2089-JFS  

The authors elaborated a new complex methodical approach to the evaluation of necrotic disease of beeches. They used two evaluation scales: a scale for the evaluation of stems and a scale for the evaluation of beech crowns. A four-degree scale for the evaluation of necrotisation of crowns completed the existing five-degree scale for the evaluation of necrotisation of stems. Combination of both these scales into one methodical approach produced the third, complex scale for the evaluation of necrotisation of whole trees. The proposed combined scale is recommended for the monitoring of beech necroses.

Regeneration under a shelterwood system of spruce-dominated forest stands at middle altitudes

J. Souček

J. For. Sci., 2007, 53(10):467-475 | DOI: 10.17221/2085-JFS  

An experiment with regeneration under the shelterwood of spruce-dominated mature stand was established at middle altitudes of the Žďárské vrchy Hills in 1971. The paper brings a comparison of the development of basic forest stand characteristics for the plot under shelterwood and for the control plot. Analyses of annual rings demonstrated a higher diameter increment of sample trees on the plot under shelterwood, a more pronounced increase in the increment being however observed only 12 years after release. A subsequent forest from the combined regeneration occurs on 88% of the plot under shelterwood and on 67% of the control plot. The required proportion...

Productivity and costs of the mechanised cut-to-length wood harvesting system in clear-felling operations

R. Jiroušek, R. Klvač, A. Skoupý

J. For. Sci., 2007, 53(10):476-482 | DOI: 10.17221/2088-JFS  

A study of labour productivity was conducted in fully mechanised harvesting technologies. The study revealed that the productivity of harvesters was particularly affected by the average tree volume of the felled trees, and the productivity of forwarders was affected mainly by two factors - haulage distance and machine payload. Dependences of other factors such as natural and site conditions, technical parameters and skills of operators could not be demonstrated. Regression equations of dependences were created for all these three significant criteria and costs per cubic meter of processed timber were calculated for them according to the cost function....

A contribution to the properties of combined plywood materials

J. Hrázský, P. Král

J. For. Sci., 2007, 53(10):483-490 | DOI: 10.17221/2087-JFS  

The paper summarizes the results of institutional research aimed at new types of combined plywood materials. Under pilot plant conditions, three variants of combined plywood materials were pressed, namely with the layer of fibreglass, with a core cork layer and with a cork wear layer on one side of the plywood surface and a cork core. Tests of selected physical and mechanical properties were carried out on these materials including the basic statistical evaluation. Comparisons with plywood materials Multiplex 15 and 20 mm in thickness were also made.