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Iskalni niz: "ključne besede" (European beech) .

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1.
Temporal and spatial variability of phloem structure in Picea abies and Fagus sylvatica and its link to climate
Jožica Gričar, Jernej Jevšenak, Kyriaki Giagli, Klemen Eler, Dimitrios Tsalagkas, Vladimir Gryc, Hanuš Vavrčík, Katarina Čufar, Peter Prislan, 2024, izvirni znanstveni članek

Povzetek: Using a unique 8-year data set (2010–2017) of phloem data, we studied the effect of temperature and precipitation on the phloem anatomy (conduit area, widths of ring, early and late phloem) and xylem-ring width in two coexisting temperate tree species, Picea abies and Fagus sylvatica, from three contrasting European temperate forest sites. Histometric analyses were performed on microcores taken from tree stems in autumn. We found high interannual variability and sensitivity of phloem anatomy and xylem-ring widths to precipitation and temperature; however, the responses were species- and site-specific. The contrasting response of xylem and phloem-ring widths of the same tree species to weather conditions was found at the two Slovenian sites generally well supplied with precipitation, while at the driest Czech site, the influence of weather factors on xylem and phloem ring widths was synchronised. Since widths of mean annual xylem and phloem increments were narrowest at the Czech site, this site is suggested to be most restrictive for the radial growth of both species. By influencing the seasonal patterns of xylem and phloem development, water availability appears to be the most important determinant of tissue- and species-specific responses to local weather conditions.
Ključne besede: wood anatomy, early phloem, European beech, late phloem, Norway spruce, sieve element area, xylem-ring width
Objavljeno v DiRROS: 19.01.2024; Ogledov: 185; Prenosov: 84
.pdf Celotno besedilo (5,31 MB)
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2.
Radial increment of beech (Fagus sylvatica L.) Is under a strong impact of climate in the continental biogeographical region of Croatia
Tom Levanič, Damir Ugarković, Ivan Seletković, Mladen Ognjenović, Mia Marušić, Robert Bogdanić, Nenad Potočić, 2023, izvirni znanstveni članek

Povzetek: European beech (Fagus sylvatica L.) is an important component of forests in the alpine and continental biogeographical regions of Croatia. This study aimed to (1) analyze the long-term response of beech to climate, (2) identify potentially critical climatic conditions that could negatively affect the radial increment (RI) and vitality of beech, and (3) evaluate differences in the response of beech between the two biogeographical regions in Croatia. We used the 16 × 16 km Croatian ICP Forests Level 1 network. On a total of 25 plots, we cored between 5 and 24 trees for dendrochronological analysis. Tree-ring widths (TRW) were measured and standardized using cubic spline. TRW chronologies for the two regions were calculated and correlated to the temperature and precipitation data and Standardized Precipitation and Evapotranspiration Index (SPEI) using bootstrapped correlations. Continental region precipitation from April to August and alpine region precipitation from June to August were significantly important for RI. Temperature was less important for RI than precipitation in both regions, but the importance of the negative impact of above-average temperatures in the continental region and the positive impact of above-average precipitation in the alpine region has increased over the last two decades. A comparison with the 3-month SPEI confirmed the significant influence of high temperatures and the lack of precipitation in August on the RI of beech trees in both regions.
Ključne besede: climate change, tree growth, forest productivity, drought, European beech
Objavljeno v DiRROS: 28.06.2023; Ogledov: 401; Prenosov: 201
.pdf Celotno besedilo (4,96 MB)
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3.
Mode I fracture of beech-adhesive bondline at three different temperatures
Jaka Gašper Pečnik, Andreja Pondelak, Michael David Burnard, Václav Sebera, 2022, izvirni znanstveni članek

Povzetek: Single edge-notched three-point bending tests (SEN-TPB) for mode I were utilized to experimentallyevaluate fracture properties of adhesive bondlines in European beech (Fagus SylvaticaL.). Thebondline was examined at two anatomical planes with TR and RT orientation and at control andtwo elevated temperatures (70°C and 140°C). Among epoxy (EPI), melamine-urea formaldehyde (MUF), and polyurethane (PUR) adhesives, the highest average critical energyGcwith 0.80 N/mmand fracture energyGfwith 1079.4 N/mm were obtained for EPI in the TR plane and understandard climate conditions (20°C/65% relative humidity), followed by MUF (Gc= 0.50 N/mm andGf= 620 N/mm) and PUR (Gc= 0.25 N/mm andGf= 290.9 N/mm), respectively. PUR was leasteffected by elevated temperature, and no significant differences forGcandGfbetween TR and RTbondline orientations were found for MUF and PUR treated at 20°C/65% relative humidity whilecomparisons between other factors varied significantly. Treatment of specimens at elevatedtemperatures resulted in reduced fracture performance regardless of wood grain orientation orthe adhesive system.
Ključne besede: crack, fracture, grain orientation, temperature, European Beech, odprti dostop
Objavljeno v DiRROS: 03.05.2023; Ogledov: 412; Prenosov: 331
.pdf Celotno besedilo (3,32 MB)
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4.
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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