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Iskalni niz: "ključne besede" (leaf) .

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1.
In-plane seismic behaviour of ashlar three-leaf stone masonry walls : verifying performance limits
Meta Kržan, Vlatko Bosiljkov, 2021, izvirni znanstveni članek

Povzetek: In light of the forthcoming second generation Eurocodes (EC), the results of conducted systematic in-plane cyclic and compressive tests on three-leaf stone masonry walls are discussed following new requirements and provisions. The new proposal for EC8-3 for existing buildings is based on partial factors safety approach, though it considers different uncertainties in defining input parameters for effective seismic performance-based assessment. Prior to its application, massive calibration effort will be needed since there is no standardized method for shear testing of masonry walls. In this paper, the performance limit states damage, resistance, and displacement capacities from conducted test results were evaluated and assessed through comparison with analytical solutions and imposed limit values, as stated in existing codes. The test results provide a much higher deformation capacity than the limits provided in both existing and new proposal of EC8-3 as well as those in the ASCE code provisions. The reason for this lies in the soft, "ductile" mortar for which the presumed resistance according to code provisions should be significantly higher when considering good quality ashlar three-leaf stone masonry.
Ključne besede: historical masonry, multi-leaf stone masonry, mechanical properties, compression tests, in-plane shear tests, failure mechanisms, drift limits, boundary conditions
Objavljeno v DiRROS: 19.05.2023; Ogledov: 290; Prenosov: 150
.pdf Celotno besedilo (4,47 MB)
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2.
Use of an arboretum and DNA barcoding for the detection and identification of leaf-mining insects on alien woody plants
Natalia I. Kirichenko, Stanislav Gomboc, Barbara Piškur, Maarten De Groot, 2023, izvirni znanstveni članek

Povzetek: Arboreta serve as effective tools for identifying alien insect pests and novel trophic associations. In this study, we used an arboretum in Slovenia to survey woody plants and identify both alien and native leaf miners. The leaves and twigs of 50 woody plant species and their cultivars were examined for characteristic damage. We used an integrative approach that combined identification based on leaf mines and DNA barcoding of the larvae and pupae found in the mines. In total, 62 leaf-mining species were identified, including eight alien species, of which the heliozelid Coptodisca lucifluella (Clemens, 1860) and the agromyzid Cerodontha unisetiorbita Zlobin, 1992 were documented for Slovenia for the first time. Additionally, three presumably native Gracillariidae moths Phyllocnistis labyrinthella (Bjerkander, 1790), P. ramulicola Langmaid & Corley, 2007 and P. saligna (Zeller, 1839) represented the first record for Slovenia. Furthermore, we documented 23 novel-to-science trophic associations, 20 of which involved native insects and alien woody plants, primarily from Asia. This study highlights the importance of arboreta and botanical gardens for the interception of invasive alien insects and the early detection of trophic shifts of native insects to alien plants, which can aid in predicting their potential spread.
Ključne besede: botanical garden, sentinels, leaf miners, alien species, non-native trees, novel trophic associations, DNA barcoding, Slovenia
Objavljeno v DiRROS: 24.03.2023; Ogledov: 467; Prenosov: 215
.pdf Celotno besedilo (6,32 MB)
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3.
Combined effects of early season leaf removal and climatic conditions on aroma precursors in Sauvignon blanc grapes
Paolo Sivilotti, Branka Škvarč, Lorena Butinar, Melita Sternad Lemut, Klemen Lisjak, Andreja Vanzo, 2017, izvirni znanstveni članek

Povzetek: Early leaf removal around the cluster zone is a common technique applied in cool climate viticulture, to regulate yield components and improve fruit quality. Despite the increasing amount of information on early leaf removal and its impact on total soluble solids, anthocyanins and polyphenols, less is known regarding aroma compounds. In order to verify the hypothesis that defoliation, applied before or after flowering, could impact the biosynthesis of thiol precursors, we performed a two year (2013 and 2014) experiment on Sauvignon blanc. We provided evidence that differential accumulation of thiols precursors in berries is affected by the timing of defoliation and this impact was related to modifications in biosynthetic pathway. Furthermore, the possible interaction between leaf removal treatment and seasonal weather conditions, and its effect on the biosynthesis of volatile precursors are discussed. Our results suggested that in Sauvignon blanc the relative proportion of 4-S-glutathionyl-4-methylpentan-2-one (G-4MSP) and 3-S-glutathionylhexan-1-ol (G-3SH) precursors can be affected by defoliation, and this could be related to the induction of two specific genes encoding glutathione-S-transferases (VvGST3 and VvGST5), while no significant effects on basic fruit chemical parameters, polyphenols and methoxypyrazines were ascertained under our experimental conditions.
Ključne besede: early leaf removal, cluster exposure, thiol precursors, methoxypyrazines, Vitis vinifera
Objavljeno v DiRROS: 06.09.2022; Ogledov: 421; Prenosov: 186
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4.
Morphologic variability of the Acer campestre L. populations in Bosnia and Herzegovina
Stjepan Kvesić, Mirzeta Memišević Hodžić, Matjaž Čater, Dalibor Ballian, 2021, izvirni znanstveni članek

Povzetek: Morphologic variability from 25 populations of Acer campestre L. in Bosnia and Herzegovina was analyzed. Morphometric structure of variability and between-population variability was performed based on 10 fruit-parameter characteristics and 19 leaf-parameter characteristics using multivariate statistical analysis. Results confirmed the separation of three submediterranean populations as a group in relation to other tested populations, from which the Banja Luka population is different. Measured leaf parameters were confirmed as a predominant carrier of the morphologic separation between populations. In other Acer species populations within A. monspessulanum and A. intermedium species are separated mainly by fruit and much less by leaf parameters. The southernmost submediterranean populations from Trebinje, Ljubuški, and Mostar regions have smaller leaf areas, which consequently places them within the same morphologic group; their variability is in tight connection with eco-geo-graphical factors, where the ecological distance is a much better predictor of morphological variability compared to geographical distance. The air temperature had the biggest influence on morphological variability regarding the highest in-between correlation. Achieved results may serve for the continuation of the research in other areas of Acer campestre to determine the interactive effect of ecological, geographical, climatic, and migrational factors on their morphologic population plasticity.
Ključne besede: differentiation, field maple, fruit, leaf, morphologic variability
Objavljeno v DiRROS: 03.01.2022; Ogledov: 659; Prenosov: 505
.pdf Celotno besedilo (960,45 KB)
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5.
Phenological variability and resistance to late spring frost of common beech in the international provenance test in Bosnia and Herzegovina
Mirzeta Memišević Hodžić, Almedin Hebibović, Dalibor Ballian, 2021, izvirni znanstveni članek

Povzetek: The research aimed to determine the start, end and duration of leafing phases, the degree of plant damage caused by late spring frost, and the retention of leaves in autumn. The research was conducted in the international common beech provenance test in Bosnia and Herzegovina. The test contains eight provenances from Bosnia and Herzegovina, four from Germany, three from Serbia, two each from Croatia, Romania and Switzerland, and one from Hungary. Leafing phenology, canopy damage caused by late spring frost, and leaf retention were assessed in 2019. Most provenances started opening buds on 17 April 2019. Complete canopy damage affected the highest percentage of plants in provenance BW Bad Wildbad, Germany (68 %), and the lowest in provenance Konjuh Kladanj, Bosnia and Herzegovina (3.2 %). Provenance Herzogenbuchsee from Switzerland had the highest percentage of winter leaf retention (37.5 % of plants). The results can be used in choosing provenances that are resistant to low temperatures in zones of late spring and early autumn frost.
Ključne besede: common beech, international provenance test, leafing phenophases, frost damage, winter leaf retention
Objavljeno v DiRROS: 01.12.2021; Ogledov: 3385; Prenosov: 1888
.pdf Celotno besedilo (1,61 MB)
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6.
Climatic regulation of leaf and cambial phenology in Quercus pubescens : their interlinkage and impact on xylem and phloem conduits
Jožica Gričar, Jernej Jevšenak, Polona Hafner, Peter Prislan, Mitja Ferlan, Martina Lavrič, Dominik Vodnik, Klemen Eler, 2022, izvirni znanstveni članek

Povzetek: Increased frequency and severity of stressful events affects the growth patterns and functioning of trees which adjust their phenology to given conditions. Here, we analysed environmental effects (temperature, precipitation, VPD and SWC) on the timing of leaf phenology, seasonal stem radial growth patterns, and xylem and phloem anatomy of Quercus pubescens in the sub-Mediterranean in the period 2014%2019, when various adverse weather events occurred, i.e. spring drought in 2015, summer fire in 2016 and summer drought in 2017. Results showed that the timings of leaf and cambium phenology do not occur simultaneously in Q. pubescens, reflecting different environmental and internal constraints. Although year-to-year variability in the timings of leaf and cambial phenology exists, their chronological sequence is fairly fixed. Different effects of weather conditions on different stages of leaf development in spring were observed. Common climatic drivers (i.e., negative effect of hot and dry summers and a positive effect of increasing moisture availability in winter and summer) were found to affect the widths of xylem and phloem increments with more pronounced effect on late formed parts. A legacy effect of the timing of leaf and cambial phenology of the previous growing season on the timing of phenology of the following spring was confirmed. Rarely available phloem data permitted a comprehensive insight into the interlinkage of the timing of cambium and leaf phenology and adjustment strategies of vascular tissues in Mediterranean pubescent oak to various environmental constraints, including frequent extreme events (drought, fire). Our results suggest that predicted changes in autumn/winter and spring climatic conditions for this area could affect the timings of leaf and stem cambial phenology of Q. pubescens in the coming years, which would affect stem xylem and phloem structure and hydraulic properties, and ultimately its performance.
Ključne besede: pubescent oak, leaf development, radial growth, initial earlywood vessel, sieve tube, anatomy, cambial cell production, extreme weather events
Objavljeno v DiRROS: 06.09.2021; Ogledov: 927; Prenosov: 265
.pdf Celotno besedilo (7,00 MB)
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7.
Inter-individual variability in spring phenology of temperate deciduous trees depends on species, tree size and previous year autumn phenology
Lorène Julia Marchand, Inge Dox, Jožica Gričar, Peter Prislan, Sebastien Leys, Jan Van den Bulcke, Patrick Fonti, Holger Lange, Erik Matthysen, Josep Peñuelas, Paolo Zuccarini, Matteo Campioli, 2020, izvirni znanstveni članek

Povzetek: We explored the inter-individual variability in bud-burst and its potential drivers, in homogeneous mature stands of temperate deciduous trees. Phenological observations of leaves and wood formation were performed weekly from summer 2017 to summer 2018 for pedunculate oak, European beech and silver birch in Belgium. The variability of bud-burst was correlated to previous' year autumn phenology (i.e. the onset of leaf senescence and the cessation of wood formation) and tree size but with important differences among species. In fact, variability of bud-burst was primarily related to onset of leaf senescence, cessation of wood formation and tree height for oak, beech and birch, respectively. The inter-individual variability of onset of leaf senescence was not related to the tree characteristics considered and was much larger than the inter-individual variability in bud-burst. Multispecies multivariate models could explain up to 66% of the bud-burst variability. These findings represent an important advance in our fundamental understanding and modelling of phenology and tree functioning of deciduous tree species.
Ključne besede: leaf unfolding, wood formation, coloration, Pedunculate oak, European beech, Silver birch
Objavljeno v DiRROS: 10.06.2020; Ogledov: 1819; Prenosov: 1056
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8.
9.
Pseudodidymella fagi in Slovenia : first report and expansion of host range
Nikica Ogris, Ana Brglez, Barbara Piškur, 2019, izvirni znanstveni članek

Povzetek: The fungus Pseudodidymella fagi is spreading in Europe and causing leaf blotch of European beech, Fagus sylvatica. Between 2008 and 2017, outbreaks of P. fagi were observed on European beech in Switzerland, Germany (also on F. orientalis), Austria, and Slovakia. In Slovenia, leaf blotch symptoms were first observed on F. sylvatica in 2018. P. fagi was identified as the causal agent of the observed symptoms in Slovenia by morphological examinations together with sequencing of the internal transcribed spacer (ITS) region of the rDNA. This study links the fungus to the expansion of the known distribution of the disease to Slovenia, and based on in vitro pathogenicity trials, also to a new potential host, Quercus petraea. The pathogenicity tests confirmed F. sylvatica and F. orientalis as hosts for P. fagi, but not Castanea sativa, where pathogenicity to F. orientalis was proved for first time in vitro. Although Koch%s postulates could not be proven for C. sativa, it seems to be partially susceptible in vitro because some of the inoculation points developed lesions. Additionally, damage to Carpinus betulus related to P. fagi near heavily infected beech trees was observed in vivo but was not tested in laboratory trials. Based on the results and our observations in the field, it is likely that P. fagi has a wider host range than previously thought and that we might be witnessing host switching.
Ključne besede: Pycnopleiospora fagi, leaf blotch, pathogenicity test, inoculation test, Fagus orientalis, Fagus sylvatica, Quercus petraea, mycopappus-like propagule, Carpinus betulus, host switching
Objavljeno v DiRROS: 23.08.2019; Ogledov: 2424; Prenosov: 1524
.pdf Celotno besedilo (4,90 MB)
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10.
Morfološka analiza puhastega hrasta (Quercus pubescens Willd.) v Sloveniji
Mateja Jerše, Franc Batič, 2007, izvirni znanstveni članek

Povzetek: Z raziskavo smo poskusili ovrednotiti morfološke raznolikosti puhastega hrasta(Quercus pubescens Willd.) v Sloveniji. Raznolikost je posledica pestrosti rastišč in možnosti križanja z drugimi vrstami hrastov. Rezultati analize so bili dobljeni na osnovi meritev in opazovanja listov, plodov in kratkih poganjkov puhastegarasta, vzorčenih v osmih populacijah po Sloveniji. Na posamezni lokaciji je bilo izbranih do pet dreves in na posameznem drevesu nabranih do sto listov s kratkih poganjkov v osvetljenem delu krošnje. Na osebkih s plodovi so bili nabrani tudi plodovi. V laboratoriju je bilo na listih izmerjenih, ocenjenih in izračunanih 13 parametrov, na plodovih in kratkih poganjkih pa po en parameter. Uporabljene so bile deskriptivne, univariatne in multivariatne statistične metode za izvrednotenje rezultatov. Analize morfoloških parametrov so pokazale značilne razlike tako med posameznimi osebki v populacijah kot med populacijami. Ugotovljeno je bilo tudi, da vrsto Q. virgiliana (Ten.) Ten. lahko obravnavamo znotraj vrste Q. pubescens.
Ključne besede: puhasti hrast, Quercus pubescens Willd., Quercus virgiliana (Ten.), morfologija, listi, plodovi, Slovenija, oak, morphology, leaf, fruit, Slovenia
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4857; Prenosov: 2008
.pdf Celotno besedilo (857,31 KB)

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