1721 research outputs found
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GIS-based model of wood precurement from stump to small sawmills in the Alpine region - a case study
No full textWith wood logistics and forest operation modelling, we have connected a technologic chain of cutting, skidding and road wood transport operations. The goal of the paper is to present the possibilities of simulating forest operation activities including cost flow prediction. The case study regarding wood flow and forest operation cost modelling was conducted in four municipalities located in western Slovenia (bordering to Italy). Input data of forest inventory and basic forest data were used in order to predict the wood flow in the test area. We modelled the available cutting volumes with the capacities of local sinks - notably sawmills. Unbalanced hinterland areas of specific sinks that do not cover the local sink capacities were changed (reduced or enlarged) on account of the adjacent hinterland areas with surplus or shortage of wood volume. The hauling distances and wood volumes for covering the sawmillsć capacities of the adopted (balanced) hinterland areas were studied
How the estimates of home range size and composition are affected by diurnal, nocturnal and 24-hour sampling methods: example of the red deer (Cervus elaphus) in Slovenia
No full textMost of the previous research on the mammals' home range (HR) is based on diurnal sampling, while the results are often implicitly considered as representative for an entire 24-h period. However, there is a growing body of research on populations, whose habitat selection changes circadianly, which leads to the hypothesis that HR patterns may vary at different periods of the day. This study used 24-h data from 15 red deer equipped with GPS collars to explore differences in the size and composition of their HRs, estimated on diurnal, nocturnal and 24-h samplings. The differences in composition were shown on the forest/non-forest variable. We established that nocturnal, and inparticular the 24-h HRs, largely overlapped with the diurnal HRs (64% and 76%, respectively) and that parts of the HRs that are used exclusively nocturnally are contiguous or adjacent to diurnal HRs. The differences in HR sizes were significant only between diurnal and 24-h HRs. However, the HR composition varied substantially: the average proportion of non-forest areas was 15% in diurnal, 26% in 24-h and 31% in nocturnal HRs. This study demonstrated that with diurnal sampling it is impossible to assess accurately the size and composition of 24-h HRs of red deer in Slovenia. There are several indices that the same is true of several other populations/species. It is therefore important to be aware that HR patterns estimated on the basis of diurnal sampling may be incomplete or even wrong if generalised across the 24-h period
Topochemical investigations of cell walls in developing xylem of beech (Fagus sylvatica L.)
No full textFormation and lignification of xylem cells in mature beech (Fagus sylvatica L.) trees growing in a forest site in Slovenia (46° N, 14°40â? E, 400 m a.s.l.) were studied on the cellular and subcellular level. Samples containing the cambial zone and developing xylem were taken from six beech trees every week throughout the 2006 vegetation period. Cell wall thickening and lignification in individual cell wall layers and cell types were determined by light microscopy, cellular UV-microspectrophotometry and transmission electron microscopy, respectively. Cell division started between the 18th and the 24th of April 2006. Lignification began in the newly formed xylem tissue on the 2nd of May. After 1 month, the developing earlywood portion contained fully differentiated vessels with completed wall deposition and lignification, and differentiated fibres and axial parenchyma became visible after 2 months. At the end of cambial cell division on the 9th August,the differentiation of the most recently formed fibres in the terminal zone of the growth ring continued for approximately 4 weeks. This indicates that the process of lignification in earlywood is slower than in latewood. The high temporal resolution of the investigated processes and the combination of the above-mentioned microscopic techniques provides a detailed insight in to the process of cell wall thickening and lignification of woody tissue in beech
Wood formation in Silver fir (Abies alba Mill.) and Common beech (Fagus sylvatica L.) - differentiation of terminal cells in the xylem growth ring
No full textRecent studies on wood formation in Slovenia and the present study on differentiation of last formed cells in the xylem growth rings of silver fir (Abies alba) and common beech (Fagus sylvatica) were overviewed. Intact tissue samples containing xylem, cambium and phloem from mature living trees during the 2003 (fir) and 2006 (beech) vegetation periods were collected. Light microscopy and UV-microspectrophotometry were used for analyses. In silver fir, cell divisions in the cambium stopped between 20 August and 3 September 2003. At that time, the cambium consisted of 7-10 layers of cells and the last formed xylem growth ring contained 15 layers of undifferentiated tracheids. The differentiation of terminal tracheids was completed after 5-7 weeks. In beech, the cambial divisions stopped between 25 July and 8 August 2006, when the cambium contained 5-6 layers of cells and the last formed xylem growth ring had 30 layers of undifferentiated fibres. The differentiation of terminal fibres was completed after 4-5 weeks. The differences in composition of lignin and the degree of lignification between species were presented. The presented studies are important for the understanding of tree physiology and productivity, and wood properties
Dendrochronological research at the pile-dwelling settlements Stare gmajne and Blatna Brezovica
No full textWe present the results of dendrochronological and radiometric
researches on the pile-dwelling settlements Stare gmajne and Blatna Brezovica, both located at the Ljubljansko barje.
The pile-dwelling settlements date to c. 3100 BC. The research
has also showed that they were contemporary or that Blatna Brezovica existed somewhat later
Preliminary archaeological and dendrochronological researches at the pile-dwelling settlement Veliki Otavnik Ib near Bistra
No full textIn 2006, we discovered remains of a pile-dwelling settlement
Veliki Otavnik Ib during underwater survey of the riverbed of the Bistra stream at the Ljubljansko barje, not far from the foot of the mountainous Karstic fringe. Dendrochronological analysis of wooden foundation piles showed that the settlement dates to the horizon of pile-dwellings from 4th millennium BC and that is contemporary with the settlement Stare gmajne
Slovenian roundwood conversion factors for external trade statistic data
No full textNational roundwood trade data are important for international reporting and are an integral and important part of roundwood flow analysis. The main objective of the study was to calculate objective national conversion factors for transformation of mass into cubic metres solid volume under bark (net m3) and to propose uniform factors for main tree species. Official trade statistics data for the 2003-2006 period were used as raw data. Uniform proposed conversion factors for spruce and fir combined, beech and oak are 0.77 t/m3, 0.98 t/m3, and 1.12 t/m3, respectively. International conversion factors proposed by FAO are too low for Slovenia and consequently give higher official trade statistics data. The used method for calculation of national roundwood conversion factors for trade statistics is universal and repeatable. We propose periodical review of conversion factors
An analysis of horizontal structure in beech stands using data from permanent sample plots
No full textOn the sample of five forest management units, we analysed horizontal structure of beech stands by prevalent stand types. We used several diversity indices to describe horizontal stand structure (spatial distribution of trees and differentiation of their DBH). We checked if spatial distribution is influenced by site parameters and cutting intensity. Data was used from measurements on permanent sample plots of the Slovenia Forest Service. The results show mainly average DBH differentiation and random tree positions withsome tendency to clustered and regular arrangement. Trees in younger stages are prone to clustered distribution and their DBH differentiation is smaller. Small DBH differentiation in younger stages is caused by higher intensity of cutting and clustered arrangement is more common on steeper slopes. Several diversity indices can be calculated based on data from PSP, which are suitable mostly for sampling method of reference tree and its four nearest neighbours. A pattern of horizontal stand structure gives a more precise insight in stand structure and is also important when assessing stand stability, biodiversity, stand density and management impact
