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Development of biomass trade and logistics centres for sustainable mobilisation of local wood biomass resources: promotion/dissemination projects - save, altener, steer and integrated initiatives, part B - detailed description of the action
Get PDFEnhanced ozone strongly reduces carbon sink strength of adult beech (Fagus sylvatica) – Resume from the free-air fumigation study at Kranzberg Forest
No full textGround-level ozone (O3) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O3-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O3 exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O3 levels. Elevated O3 significantly weakened the C sink strength of the tree–soil system as evidenced by lowered photosynthesis and 44% reduction in whole-stem growth, but increased soil respiration. Associated effects in leaves and roots at the gene, cell and organ level varied from year to year, with drought being a crucial determinant of O3 responsiveness. Regarding adult individuals of a late-successional tree species, empirical proof is provided first time in relation to recent modelling predictions that enhanced ground-level O3 can substantially mitigate the C sequestration of forests in view of climate change
Improvement of truffle cultivation via novel quality control, soil analysis and inoculation methods : advanced inoculation methods, novel site selection tools and the establishmentof mycelial gene banks for economically important truffle specieswill improve truffle cultivation : Eureka: E! 3835-cultuber : final report
Get PDFOblique cutting as a method for determination of the fractural properties of oriented wood tissue
No full textThe method for determination of critical stress intensity factor based on chip segment length of chip type-I originating from orthogonal
oblique cutting of beech wood (Fagus silvatica) in the 90°-0° direction is shown. Experimental cuts on 10 mm thick specimen with
rake angles 31° and 42° were made, and the chip thickness varied between 0,1 mm and 0,3 mm. Using the finite element method, we
modelled a representative chip segment of varying length and thicknesses. We varied the load at the chip segment and calculated, for
each case, stress intensity at the crack tip and compressive stress in hypothetical chip.
On presumption that the crack propagates during tissue separation only when the stress intensity at the crack tip equals the critical
stress intensity and the compressive stress rises in chip formation process up to the limit strength, we can calculate the critical stress
intensity factor by knowing the chip segment length and compressive strength in longitudinal direction.
Specifically, the crack propagates until the compressive stress reaches the strength, which occurs at the place of chip break. Critical
stress intensity factor calculated from representative 0.3 mm thick chip segment length agrees well with values obtained with classical
fracture tests. The results obtained from thinner chip segments deviates to a lesser extent, which is most probably a consequence of highly
unsymmetrical specimen. The method has been undoubtedly shown as effective and reliable, which is the most important. The method
is very simple and fast, enabling us to determine the fracture properties practically with a single oblique cut. It has to be emphasized,
that the specimen preparation is also undemanding, for the only thing we have to pay attention to is the tissue orientation
Poročilo o spremljanju stanja gozdov za l. 2009 : vsebinsko poročilo o spremljanju stanja gozdov v l. 2009 v skladu s Pravilnikom o varstvu gozdov (2009)
No full textRisk assessment of lead contamination for small mammal food chains (case studyfor shooting ranges)
Get PDFPb levels were measured in tissues of small mammals (Microtus agrestis, Apodemus flavicollis, Sorex araneus and Crocidura leucodon), inhabiting shooting ranges of the Slovenian Army (Apače, Bač, Bloška polica, Crngrob, Mačkovec, Poček); in addition, Pb content was analysed in their diet as well. The present research was performed with the aim to confirm the use of small mammals as bioindicators of Pb contamination of shooting ranges and to performthe risk assessment of military shooting ranges for small mammals. Increased Pb levels were determined in livers of small mammals, inhabiting theshooting ranges. Food is probably the most significant route of Pb exposurefor small mammals since the elevated concentrations of Pb were measured in grasses, clovers, herbs and earthworms, sampled at the shooting ranges. On the basis of presented results we suggest that shooting ranges could pose an elevated risk for receptor organisms (Microtus agrestis), although Pb concentrations relatively quickly decreased with distance from backstop berms, which are particularly loaded with Pb