1721 research outputs found
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Bucking of conifers using the woody H60 processor on the Syncrofalke 3 T cable yarder in Alpine foothills
No full textThe paper investigates mechanized bucking of conifers with a processor mounted on a cable crane system in the mountain conditions of the Alpine foothills. It analyses the measurement accuracy of various log types and explains its effect on the market price of these products. In the studied area, trees were felled by chain saw and the full-tree method was used to skid the felled trees to the cable yarder site using the Syncrofalke cable crane with a mounted Woody H 60 processor head. Further wood processing operations were carried out at the yarder site. Length measurement accuracy was illustrated through the frequency distribution and the modus of various lengths. The share of logs within a 5 cm interval - modus - (the best five) was 54.3%. The difference between the nominal log length and the minimum required length resulted in a loss of 4.38% of the total log value. Further more, it was established that the first quarter of the stem actually contained 64% of the total stem value. This means that the first cross-cut was responsible for nearly 50% of the total loss and the second crosscut pushed the figure to 80%. The present research only considered the losses incurred either by positive or negative cross-cut allowance or by insufficiently accurate length measurement of a certain log type
Silver fir Abies alba Mill. wood as raw material and tree tissue
No full textWe present the structure, properties and use of European silver fir (Abies alba Mill.) wood, which is known for its uncoloured heartwood, medium density,relatively good mechanical properties and the fact that it can be used for a great variety of products. The value and usefulness of fir wood are reduced due to low resistance against decay and deterioration, and frequent occurrence of wet heart, and ring shakes. The properties of fir wood are comparable to those of Norway spruce (Picea abies Karst.). Fir is favoured where resin is not desired, where durability against acids and bases is important, and for water constructions. We present some examples of wooden constructions in archaeological or historical objects in Slovenia. The dendrochronologically dated wood was up to 500 years old. In the past centuries, fir was used more frequently than Norway spruce. On the cellular level, the wood of fir consists of tracheids and parenchyma cells. In Slovenia, several studies of wood formation have been conducted e in recent years, which are important for a better understanding of the physiology of trees and quality of wood as material. Secondary phloem, which is particularly important for the survival of trees, has been studied as well. We review some main results of such studies
Stand diversity in the Dinaric fir-beech forests
No full textData from forest research and permanent sampling plots were used to quantify stand structure and forest diversity in uneven-aged Dinaric silver fir and beech forest at the level of forest management unit. The study examined the indicators that are expected to be used in the monitoring of biodiversity and the favourable conservation status of forest habitat types in Natura 2000 sites. By comparing the present and past stand structures, it was possible to establish the developmental dynamics of the stands and the changes of structure indices of the forest stands on the 2-hectare research plots in the last 50 years. We adopted the indicators for the assessment of biotic and stand structure diversity based on tree species composition, stand densities, mean DBH and coefficient of variation, species and DBH-based Shannonćs index, spatial mingling and size differentiation of trees on the permanent sampling plots. The indicators confirmed stand structural diversity in four forest management classes of uneven-aged Dinaric fir-beech forests in the Leskova dolina (valley) of the Sneznik-Javorniki high Karst region. Continuous forest inventory and the presented indicators of stand structure and diversity may potentially represent the framework for the monitoring of the favourable conservation status of forest habitat types
Social context as a pillar of sustainable forest management - a Slovenian case
No full textSocial context as more or less neglected field of sustainable development is crucial for the implementation of forest management measures. We can consider it as a basis to cope with (changing) structure characteristics. Realisation of public services, which we face when coping with economic crisis, might take this into consideration. The Forest Service network serves as a scanner of needs in their social context. It is also a respondent to local specifics in the form of forest management measures. Evidence of research on the social research in Slovenian forestry is weak, although not non-existent. We tested asystem approach, a structuring method of general public. Segmentation, a method presented, is generally known in marketing and has not been used in Slovenian forestry up to now. The two-step clustering analysis of quantitative data gathered with an inquiry of study circles (form of community learning) was used and is described herewith. The results show three general value based segments of study circle participants. The role of Slovenian foresty is changing and is not independent of its dynamic and colourful social contexts, Recognition of the society structure and dynamics may contribute to the rationalisation of organisational models during the crisis period. Hoewer, grounded actualisation of recent organisational models is possible only by considering priorities of the society's segments. We conclude with suggestion for more R&D engagement in the social pillar of multifunctional forest management, in particular as the Slovenian social context is defined by dominance of private property and forest owners' ageing, which are far from being analysed and responded to
Using the process-based stand model ANAFORE including bayesian optimisation to predict wood quality and quantity and their uncertainty in Slovenian Beech
Get PDFThe purpose of this study was to expand an existing semi-mechanistic forest model, ANAFORE (ANAlysing Forest Ecosystems), to allow for the prediction of log quality and the accompanying uncertainty as influenced by climate and management. The forest stand is described as consisting of trees of different cohorts, either of the same or of different species (deciduous or coniferous). In addition to photosynthesis, transpiration, total growth and yield, the model simulates the daily evolution in vessel biomass and radius, parenchyma and branch development. From these data early and latewood biomass, wood tissue composition, knot formation and density are calculated. The new version presented here, includes the description of log quality, including red heart formation of beeches.
A Bayesian optimisation routine for the species parameters was added to the stand model. From a given range of input parameters (prior), the model calculates an optimised range for the parameters (posterior) based on given output data, as well as an uncertainty on the predicted values.
A case study was performed for Slovenian beech forests to illustrate the main model functioning and more in particular the simulation of the wood quality. The results indicate that the ANAFORE model is a useful tool for analyzing wood quality development and forest ecosystem functioning in response to management, climate and stand characteristics. However, the Bayesian optimization showed that the remaining uncertainty on the input parameters for the chosen stand was very large, due to the large number of input parameters in comparison to the limited stand data
