Airborne Laser Scanning is a remote sensing method that is being used in different spatial sciences. It is becoming more and more interesting also in Forestry. In forestry ALS can be used for valuation of directly measurable stand parameters (e.g. tree height) and for indirectly executed stand characteristics (e.g. growing stock). Increasing trend can be noticed in applications of ALS data in time series studies. This article describes basics of ALS data processing. Different spatial scales of ALS data processing are presented (e.g. landscape, forest stand, and single tree). All the presented examples refer to the area of dinaric silver fir % European beech forests Omphalodo-Fagetum s.lat., FMU Leskova dolina.
COBISS.SI-ID: 3888550
The article presents and critically evaluates trends of roundwood production, consumption, and external trade flows with emphasis on industrial roundwood. Two records were achieved in the forest-wood production chain in the year 2011: the largest harvest and the largest export of the unprocessed roundwood.The trends of roundwood production and roundwood consumption diverge and this results in increasing export. Slovenia drifts in the direction where it can become a raw material pool for wood processing plants abroad.
COBISS.SI-ID: 3383974
In addition to forest area, growing stock is one of the most often measured data about forests. The first data on growing stock in forests were based on the basis of ocular estimates. Nowadays statistical sampling is used. In the foreign countries, evaluation of growing stock based on airborne laser scanning and lidar data is already well established. In this paper, the possibility of such estimates of growing stock in case of uneven aged Dinaric silver fir-European beech forests is presented. Similarly as in comparable studies on the evaluation of the growing stock based on laser scanning data, we confirmed this possibility also in this study. Considering the average tree height and canopy transparency on the plot level in the model, we explained 82% of the variability of growing stock, root mean square error RMSE is 55.2 m3/ha or 8.6%.
COBISS.SI-ID: 3888294
With the changes brought to forest management technologies, the productivity and economy of forest production have changed a great deal. Together with them, the negative impacts of these technologies on forests have changed as well. Due to the current economic situation, competitiveness on the technology and labour markets can be secured only by neglecting some of environmental aspects. The article presents an operative tool for practical decision-making in the selection of most suitable technology for round wood production, which considers the general terrain conditions to the greatest possible extent as well as expected working conditions (humidity, infrastructure) on worksites.
In the present study, the conditions of chip propagation or fracture in orthogonal oblique cutting of beech wood (Fagus silvatica) in the 90° direction for a type-I chip has been investigated. The force required for orthogonal wood cutting is pronouncedly variable, which is the consequence of exchangeable different ways of material breakdown. The chip formation process is discontinuous because of interrupted splitting of the material in front of the cutting tool. A 10-mm-thick specimen was cut at a rake angle of 31° and 42° with chip thicknesses ranging from 0.1 to 0.3 mm. The chip segment length increased with the chip thickness. A chip of varying length and thickness was modelled using the finite element method. For each case, the bending or compressive stress in the chip and the stress intensity factor at the crack tip was calculated. The segment length of the chip can be calculated by taking into account the condition that a crack propagates when the stress intensity factor K I at the crack tip equals the critical stress intensity factor K IC, and the bending or compressive stress sigma x in the chip is smaller than the strength sigm u . Good agreement between the calculated and the measured values was observed. The chip segment length can change considerably already with small changes in the bending strength and critical stress intensity factor. This large sensitivity is also confirmed by the fluctuation of the measured chip segment lengths by as much as 400%.
COBISS.SI-ID: 1989001