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Precipitation regime in selected gaps and mature stands of Dinaric silver fir-beech forest
Get PDFThe precipitation amount, form and timing are of particular importance to forest ecosystems. They have a significant impact on water supply, nutrient cycling and dynamics of carbon in the ecosystem. In our study, the precipitation regime of the selected forest stands and gaps in the Snežna jamamanaged forest and in the Rajhenavski Rog virgin forest remnant has been determined. During the 2003 and 2004 growing seasons, throughfall and stemflowwere recorded in the gaps and forest stands. In the years 2001 till 2007, monthly precipitation in the open was measured. Precipitation measurements are rarely performed in forested landscapes, although they constitute an important input variable for process modelling in forest ecosystems. Substitution with measurements from the closest meteorological station is, due to their distance, questionable. Therefore we compared the measured precipitation in the open to daily and monthly precipitation at the Climatological Station Kočevje and EMEP Iskrba Station at Kočevska Reka
Dendrokronološka metoda za datiranje lesa v Sloveniji
No full textThe article describes the latest achievements of dendrochronology at the Department of wood Science and Technology, Biotechnical faculty, University of Ljubljana, in cooperation with several institutions that are engaged in the study of wood as part of the cultural heritage. Dendrochronological dating usually tells us in which year the last ring on a wooden object was formed, but other known data have to be considered to interpret the results. In recent years we have worked on extending and improving the tree-ring chronologies that are necessary for dating. This resulted in the conclusion that for different parts of Slovenia and different periods we require chronologies of different tree species. The dendrochronological method enables us to date fir, larch, spruce, oak, and beech wood from the past millennium. Wood used in buildings (roofs, multi-floor structures, etc.) is usually preserved up to 500 years, older wood normally only under water or in wet soil (e.g. the foundation piles of buildings). Today, we are able to date wood from the Roman era. The dendrochronological analysis of wood from the pile dwellings at the Ljubljansko barje (Ljubljana Marsh) made it possible to create several chronologies from the period between 3800 and 2400 BC, which were later dated with an accuracy of ± 10 years with radiometric analysis
Dendrochronological dating of two violins from private collections in Slovenia
Get PDFDendrochronological analyses were made in two violins from private collectionsin Slovenia with an aim to date the wood of their resonance boards,to assess the time of their fabrication, to define the provenance of the wood, and to establish whether the labels of the instruments were original. The origin, the history and the exact age of the instruments had previously not been known. Tree-ring measurements were done on the surface of the bellies. In violin 1, it was made of one radial board, in violin 2 of two radial boards of Norway spruce (Picea abies). In violin 1, we measured 248 tree-rings and the year of the youngest ring was 1808. The dating was confirmed with more than 20 tree-ring chronologies from Austria, Germany, and Italy. The maximal value of the cross-dating parameter t-value after Hollstein(TH) was 12.4. In violin 2, we measured 141 and 137 tree-rings on each side of the belly, and the year of the youngest ring was 1640. The dating was also obtained by cross-dating with over 20 chronologies and confirmed with statistically significant TH up to 9.2. The year of the last ring in both cases corresponded with the terminus post quem, which indicated that the belly (instrument) was fabricated after the year of formation of the youngest ring. There is no evidence about the duration of seasoning and storage of the lumber, or how many tree-rings were removed when the instrumentwas manufactured. Our dendro-provenance study showed that the violin 1 most likely originated from Austria or southern Germany. The wood for the belly of the violin 2 possibly originated from Austria and the sequence significantly matched a chronology built from the instruments made by Jacob Stainer. In both instruments, the dendrochronological dating did not confirm the inscriptions on the labels on the inside of the instrument. The presented investigation was performed in 2008 and 2009 and is to our knowledge the first dendrochronological dating of music instruments in Slovenia
Bioindication of fluoride pollution by the use of roe deer (Capreolus capreolus L.) mandibles: situation and perspectives
No full textDue to the increasing concentrations of fluorides in the environment, several bioindication methods for assessing the impact of fluoride pollution on living organisms have been developed in the last few decades. Studies of the exposure and impact of fluorides on mammals (primarily ungulates) are performed either as different methods of accumulative bioindication (i.e. determination of fluoride levels in bones, e.g. mandibles) and/or as methods of response bioindication (e.g. macroscopic assessment of the presence and severity of dental fluorosis as a specific morphologic change, which is the consequence of fluorides affecting the formation and development of the enamelin the time of tooth formation). Suitability of ungulates (particularly roe deer) mandibles as a perfect biomonitoring tool for assessingthe fluoride pollution has often been confirmed by the determination of strong positive correlations between fluoride concentrations in the environment and: (i) fluoride levels in mandibles of red/roe deer; (ii) severity of dental fluorosis in both deer species. A high potential of roe deer mandibles for bioindication purposes is stimulated by the fact that lower jaws of ungulates are often (in Slovenia they even must be) systematically collected with the purpose of cognitive management and control. Therefore, huge numbers of mandibles are available in Europe, equipped with all the needed individual (e.g. age, sex, health status) and geographical data (culling location). This enables large-scale (even national-wide, as seen in the case of Slovenia), but nevertheless spatially accurate environmental biomonitoring of fluoride pollution, in a reliable and cost effective way. Such biomonitoring programme started in Slovenia in 2008
Service life prediction of wood treated with wax emulsions and copper amine based solutions exposed in third use class
Get PDFIn our research, service life of wood exposed outdoor in the third use class, determined with double layer test, was investigated. In the first part of the investigation, Norway spruce wood specimens were impregnated with montan and polyethylene water based wax emulsion in combination with boron compounds. In the second part of the research, Norway spruce wood samples were impregnated with a copper-ethanolamine (Silvanolin) water based solution and aqueous solutions of individual components. For comparison, untreated Norway spruce, larch, beech and oak wood specimens were exposed as well. During exposition time, climate data under specimens and at weather station were recorded. The results showed that impregnation with wax emulsions and copper based solutions prolongs service life of wood, but protection with copper-ethanolamine solutions is considerably better. Resistance of wood, preserved with wax emulsions and copper-ethanolamine solutions, was influencedby concentration of emulsions/solutions and wood quality. The parallel measurements of wood moisture content and wood temperature clearly showed that there were more suitable conditions in wood for development and growth of fungi than indicated by air temperature and relative air humidity measurements
Predstavitve raziskovalnih projektov programa "Konkurenčnost Slovenije 2006-2013" in aplikativnih raziskovalnih projektov, ki potekajo na Gozdarskem inštitutu Slovenije in jih sofinancirata Ministrstvo za kmetijstvo, gozdarstvo in prehrano in Javna agencija za raziskovalno dejavnost RS : javna predstavitev delnih in končnih rezultatov projketov z vsebinskimi usmeritvami za nadaljnje raziskovalne vsebine s področja
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