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Promotion of residual forestry biomass in the Mediterranean basin : situation report on forest biomass use in Mediterranean region
Get PDFThe advantages of flow cytometry in comparison to fluorometric measurement in algal toxicity test
No full textFluorometric measurements in algal toxicity tests are very commonly used as surrogate parameters for algal biomass. Although, fluorometry is a powerful technique, we have demonstrated that it is not suitable for determination of toxic effects of chemicals, which alter the fluorescence spectra. We recommend the flow cytometry as the best technique for detecting algal and/or cyanobacterial cell count and fluorescence per cell. Flow cytometry has many advantages: little volume of algal/cyanobacterial sample required, suitable also for little algal/cyanobacterial cells, distinction between live and dead cells. Furthermore, flow cytometry reveals the early changes in fluorescence spectra as a consequence of the specific chemicals presence or stress, even though the cell count is not yet affected (an early marker for ecotoxicology testing)
Na Gozdarskem inštitutu Slovenije se ogrevamo z lesom : prijazno okolju - neodvisno - lokalno : Ljubljana
No full textWood from prehistoric pile dwellings at Ljubljansko barje, Slovenia, and its research potential
No full textWe present results of investigations of archaeological wood from prehistoric pile dwellings at the Ljubljansko barje
near Ljubljana, Slovenia. They were systematically conducted since 1995. Dendrochronology and radiocarbon dating enabled us to accurately determine the periods when the dwellings were settled. The oldest Resnikov prekop was already inhabited around 4600 BC. In addition we dated eight settlements from the 4th millennium, and five from the 3rd millennium BC. On the youngest one occupation ceased around 2400 BC, at the time when the Eneolithic period in Slovenia ended. Most archaeological wood originated from the piles on which the dwellings were built. The most commonly used wood species were oak, ash and alder. Among the most valuable prehistoric wooden objects found in the recent years are: approximately 5600 years old bow made of yew wood, the wooden wheel with axis aged approximately 5150 years and two logboats approximately 5150 and 5120 years old. All items show that the pile dwellers knew how to properly select, process and use the wood
EMoNFUr - Zasnova mreže za spremljanje stanja nižinskega gozda in pogozditev v urbanem prostoru v Lombardiji in urbanega gozda v Sloveniji : poročilo o izvajanju projektne naloge : po pogodbi štev. 2330-12-85-004
Get PDFVariation of maximum tree height and annual shoot growth of Smith fir at various elevations in the Sygera mountains, Southeastern Tibetan Plateau
No full textLittle is known about tree height and height growth (as annual shoot elongation of the apical part of vertical stems) of coniferous trees growing at various altitudes on the Tibetan Plateau, which provides a high-elevation natural platform for assessing tree growth performance in relation to future climate change. We here investigated the variation of maximum tree height and annual height increment of Smith fir (Abies georgei var. smithii) in seven forest plots (30m x 40m) along two altitudinal transects between 3,800 m and 4,200/4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. Four plots were located on north-facing slopes and three plots on southeast-facing slopes. At each site, annual shoot growth was obtained by measuring the distance between successive terminal bud scars alongthe main stem of 25 trees that were between 2 and 4 m high. Maximum/mean tree height and mean annual height increment of Smith fir decreased with increasing altitude up to the tree line, indicative of a stress gradient (the dominant temperature gradient) along the altitudinal transect. Above-average mean minimum summer (particularly July) temperatures affected height in crementpositively, whereas precipitation had no significant effect on shoot growth. The time series of annual height increments of Smith fir can be used for the reconstruction of past climate on the southeastern Tibetan Plateau. In addition, it can be expected that the rising summer temperatures observed in the recent past and anticipated for the future will enhance Smith fir's growth throughout its altitudinal distribution range
Cellular and topochemical characteristics of secondary changes in bark tissues of beech (Fagus sylvatica)
No full textAnatomical and histometrical investigations were carried out
on bark tissues (non-collapsed and collapsed phloem, and periderm) of beech (Fagus sylvatica L.) trees growing at a
forest site near Ljubljana, Slovenia (400 m a.s.l.). Secondary changes in bark, especially sclereid formation and lignification, were followed at cellular and sub-cellular levels by light microscopy (LM), UV microspectrophotometry (UMSP), and transmission electron microscopy (TEM). The average width of the whole bark was 5960 mm; non-collapsed phloem on average occupied 4%, collapsed phloem 89%, and periderm 7% of the bark. Secondary changes in mature phloem were characterized by a collapse of sieve tubes, inflation of axial parenchyma, and development of sclereids. The percentage of sclereid areas and the stage of their development elevated with increasing distance from the cambium. The most pronounced increment in the sclereid proportion was observed in the second- and third-fifth of the bark. Sclereid cell walls were thick and poly-lamellated and had similar spectral characteristics but distinctly higher UV absorbance values than xylem fibers. By means of a combination of LM, TEM and UMSP techniques, the structure and secondary changes in the bark could be precisely identified
