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Wyszukujesz frazę "latewood" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
Zmienność wybranych cech makrostruktury i gęstości drewna dębu czerwonego (Quercus rubra L.) z Polski południowo-wschodniej
Variability of selected macrostructural features and the wood density of northern red oak (Quercus rubra L.) from south-eastern Poland
Autorzy:
Wąsik, R.
Michalec, K.
Powiązania:
https://bibliotekanauki.pl/articles/979284.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
red oak
sapwood
annual rings
latewood
density
Opis:
The aim of the paper was to determine the variability of selected macrostructural features and wood density for northern red oak growing in south−eastern Poland. On 4 study plots, we sampled each tree, taking an increment core from the northern side of the trunk, from the height of 1.3 m. The number of tree rings, width and the share of sapwood was measured. The cores were scanned and then tree ring and latewood widths were measured. The latewood proportion in each ring was calculated. Next, starting from the bark, the cores were divided into sections containing 10 annual rings. The relative wood density was determined for each section, then the density was calculated for entire stem cross−section. The mean sapwood width was 1.5 cm. It included 7 annual rings on average, and its share in the trunk cross−sectional area reached 17%. Younger red oaks (II and III age classes) had a significantly higher share of sapwood compared to older trees (IV and V age classes). The investigated red oaks formed narrow−ring wood with an average width of 2.16 mm. The trees growing on deciduous forest habitat had a more equal tree ring width compared to trees from coniferous forest habitats, where this feature showed also higher variability. The latewood proportion in the studied red oaks was 60% on average. The mean relative wood density was 0.578 g/cm3 and it was slightly higher than the value given for red oaks growing in North America. The calculated absolute density (with an assumed volumetric shrinkage from 12.9 to 13.7%) varied from 0.664 to 0.670 g/cm3. It classifies the investigated wood as moderately heavy. Similar density values are given for native oaks, which allows to assume that the technical quality of the wood of red oaks growing in Poland is similar to native oak species. The wood of trees from deciduous forest habitat showed a significantly higher density and a more equal distribution compared to the trees from coniferous forest sites. The raw material of red oaks obtained from deciduous forest habitats should characterize by a better technical quality of wood in comparison with that obtained from coniferous forest sites.
Źródło:
Sylwan; 2020, 164, 10; 850-859
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between the share of latewood and the density of sawn timber from the Silesian Forestry Region
Autorzy:
Mańkowski, Piotr
Krzosek, Sławomir
Burawska-Kupniewska, Izabela
Grześkiewicz, Marek
Mirski, Radosław
Powiązania:
https://bibliotekanauki.pl/articles/2200224.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
pine wood
Silesia
latewood proportion (LWP)
density
Opis:
Correlation between the share of latewood and the density of sawn timber from the Silesian Forestry Region. The paper describes the results of density measurements and the share of latewood in pine wood samples (Pinus sylvestris L.) from the Silesian Forestry Region in Poland. The samples were obtained from sawn timber from different kinds of log: butt, middle and top. The place from which the timber was obtained (three different log kinds) was taken into account when assessing the correlation between wood density and the share of latewood.
Zależność pomiędzy udziałem drewna późnego a gęstością drewna tartacznego pochodzącego ze Śląskiej KP-L. W pracy przedstawiono wyniki pomiarów gęstości drewna i udziału drewna późnego dla próbek drewna sosnowego pobranych z tarcicy pozyskanej z kłód odziomkowych, środkowych i wierzchołkowych pochodzących ze Śląskiej Krainy Przyrodniczo-Leśnej. Wraz z rosnącą gęstością drewna rośnie udział drewna późnego. Dla drewna strefy odziomkowej zależność jest słaba, dla stref środkowej i wierzchołkowej R2 jest zdecydowanie wyższa. Charakter zmian dla części odziomkowej (O), środkowej (S) i wierzchołkowej (W) jest zbliżony.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 109; 70--75
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wskaźnika zadrzewienia drzewostanu na wybrane cechy makrostruktury i gęstość drewna świerkowego (Picea abies (L.) Karst.)
Effect of stand density index on selected features of macrostructure and density of Norway spruce (Picea abies (L.) Karst.) wood
Autorzy:
Michalec, K.
Powiązania:
https://bibliotekanauki.pl/articles/978906.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
tree−ring width
latewood proportion
wood density
Norway spruce
Opis:
The aim of the study was to determine the influence of stand density index on the tree−ring width, latewood proportion and wood density for Norway spruce. Study sites were located as follows: 12 within the north−eastern species range in Poland, 7 in the south−western range, in the Sudety Mts., and 9 in the Carpathians (southern range). Clustering stands according to their stand density index, 10 data groups were established: stand density index values from 0.3 to 1.2. The study plots were 100×100 m squares. On each plot 15 trees were chosen and increment cores were sampled using the Pressler borer. The smoothed cores served for measuring the width of annual rings, latewood zones and the share of latewood as well as for determination of relative wood density. The performed analyses indicate that mean tree−ring width was the highest in trees from stands with density index from 0.3 to 0.8 (with the exception of 0.7), whereas the it was gradually decreasing in stands with index higher than 0.9. The statistically significant differences between the analyzed stands were observed (p<0.0001). The analysis of the influence of stand density index and the width of annual rings revealed significant, negative weak correlation (r=–0.242, p<0.001). In turn, the latewood proportion was the highest in trees from stands characterised by the highest stand density index and the lowest in trees from stands with the lowest one. The differences between analyzed groups of stands were statistically significant (p<0.0001), as well as the correlation which was significant, positive and weak (r=0.269, p<0.001). Wood density was the highest in trees from stands with the highest stand density index (1.1 – 363 kg/m3 i 1.2 – 365 kg/m3) as well as in those from stands characterised by 0.7 density index (369 kg/m3). Significant differences were observed (p<0.0001) only between stand density index 0.3−0.7 and 0.7−0.8. Significant correlation was not observed.
Źródło:
Sylwan; 2020, 164, 09; 719-725
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pattern of carbohydrate changes in maturing xylem and phloem during growth to dormancy transition phase in Picea abies (L.) Karst.
Autorzy:
Traversari, S.
Emiliani, G.
Traversi, M.L.
Anichini, M.
Giovannelli, A.
Powiązania:
https://bibliotekanauki.pl/articles/2078285.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Cell wall biosynthesis
latewood
starch
sugars
wood formation
wood quality
Opis:
Wood production is a metabolic process requiring high amount of soluble carbohydrates as source of carbon skeletons, energy, or signalling molecules. Nevertheless, the role of soluble sugars and starch has been rarely investigated in the growth to dormancy transition phase. The aim of this work was to investigate the carbohydrate concentrations and the transcription level of some candidate genes involved in cellulose and starch metabolisms in competitive carbon sinks such as phloem, maturing xylem, and xylem during the active growth to dormancy transition phase in Picea abies (L.) Karst. Stems were sampled every two weeks between July and October from potted eight-year-old Norway spruce plants. Results highlight that the cel- lulose biosynthesis regulated the pattern of carbohydrate changes in the phloem and maturing xylem during the transition to dormancy. In particular, the cessation of CesA (α-cellulose synthase) mRNA accumulation in maturing xylem determined a shift in the carbohydrate partitioning from the utilization sinks to the storage compartment. The content of carbohydrates was modulated in the maturing xylem by cellulose metabolism during the xylogenesis and by starch metabolism during the cambium dormancy. On the contrary, the carbon competition between utilization and storage sinks seemed to be less connected within the phloem. Since the amount of soluble carbohydrates within the maturing xylem and phloem has never been limited during the growth to dormancy transition phase, the cessation of the CesA transcription was probably determined by environmental conditions rather than by carbon limitation or sink competition.
Źródło:
Dendrobiology; 2018, 80; 12-23
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spruce tree-ring proxy signals during cold and warm periods
Autorzy:
Esper, Jan
Carnelli, Adriana L.
Kamenik, Christian
Filot, Marc
Leuenberger, Markus
Treydte, Kerstin
Powiązania:
https://bibliotekanauki.pl/articles/956991.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
stable isotopes
maximum latewood density
reconstruction model
picea abies
engadin
alps
Opis:
The strength and temporal rigidity of climate signals are important characteristics of proxy data used to reconstruct climate variability over pre-instrumental periods. Here, we assess the performance of different tree-ring proxies, including ring width, maximum latewood density, δ13C, and δ18O, during exceptional cold (1800–1850) and warm periods (1946–2000). The analysis was conducted at a spruce (Picea abies) timberline site in the Swiss Alps in proximity to long homogenized instrumental records to support calibration tests against early temperature and precipitation data. In this cold environment, tree-ring width, maximum latewood density, and δ18O are mainly controlled by temperature variations. δ13C is influenced by various factors including temperature, precipitation, sunshine, and relative humidity. When comparing the response patterns during cold and warm periods, ring width and maximum latewood density revealed temporally stable temperature signals. In contrast, the association between the stable isotopes and climate changed considerably between the early 19th and late 20th centuries. The temperature signal in δ18O was stronger during the recent warm period, whereas the opposite is true for δ13C. In δ13C, the temperature signal weakened from the early 19th to the late 20th centuries, but an (inverse) precipitation signal evolved indicating that soil moisture conditions additionally limited recent carbon isotope ratios. An attempt to combine the tree-ring proxies in a multiple regression model did not substantially improve the strength of the dominating temperature signal retained in the latewood density data as this proxy already explained a significant fraction of summer temperature variability. Our findings underscore the importance of split calibration/verification approaches including cold and warm periods, and challenge transfer models based on only late 20th century observational data.
Źródło:
Dendrobiology; 2017, 77; 3-18
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability of selected macrostructure features, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.)
Autorzy:
Wąsik, Radosław
Michalec, Krzysztof
Barszcz, Anna
Mudryk, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/342694.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
pine
annual ring width
share of latewood
physical properties
mechanical properties
Opis:
The aim of the study was to determine the variability of annual ring width, share of latewood, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.). The wood samples for examination were obtained from three trunks of 260-year-old Scots pines felled in the Sosny Taborskie Nature Reserve. In total, 106 samples were obtained, with cross-sectional dimensions of 20 × 20 mm and a length of 30 mm along the grain. The mean values for all tested wood samples were as follows: annual ring width 1.28 mm, share of latewood 28.9%, wood density 0.487 g·cm-3, and compression strength 47.3 MPa. The least variability within trees was found for wood density and compressive strength along the grain. Very high positive correlation was found between wood density and compressive strength, and high positive correlations were found between share of latewood and wood density and between share of latewood and compressive strength. To the authors’ knowledge, the results presented here are the first empirical data published concerning the features of wood macrostructure, density and compression strength along the grain of the Tabórz Scots pine, the trunks of which are considered a valuable timber in Europe.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 62, 205; 171-182
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of stand origin on the wood structure of Norway spruce
Autorzy:
Michalec, Krzysztof
Wąsik, Radosław
Barszcz, Anna
Sowa, Janusz M.
Powiązania:
https://bibliotekanauki.pl/articles/2010886.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
annual ring width
latewood share
north-eastern Norway spruce range
south-western range
Opis:
A study was carried out to compare the annual ring width, latewood share and density of spruce wood from the north eastern a nd south w estern ranges of Norway spruce. Twelve trial plots were located in the north eastern range, while within the south w estern range eight trial plots were established in the Sudeten Mountains and twelve trial plots in the Carpathian Mountains. On ev ery trial plot fifteen spruce trees were chosen, from which increment cores were sampled using a Pressler borer. Next, the increment cores had their surfaces smoothed and measurements were made of the width of annual rings, latewood zones and the share of latewood. Then the cores were divided into 2 cm sections, for which the relative wood density was determined. The analyses indicate that annual rings were wider in trees growing within the north eastern range than in those from the south western range an d the Kruskal Wallis test showed the differences to be statistically significant. T he latewood share followed an opposite pattern: t he wood from the Mazury region had a higher proportion of latewood than the wood from the mountainous areas and the statist ical test again indicated that the differences were significant. The analys i s of wood density showed slight differences between the density of wood from the north eastern and south western ranges, but in this case the Kruskal Wallis test showed the differe nces to be statistically insignificant.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 63, 206; 137-146
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie alternatywnych metod przetwarzania danych w analizie dendroklimatologicznej modrzewia Larix decidua Mill. z Polski południowej
Alternative methods of data processing in dendroclimatological analysis of larch Larix decidua Mill. from southern Poland
Autorzy:
Danek, M.
Danek, T.
Powiązania:
https://bibliotekanauki.pl/articles/973808.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
analiza dendroklimatyczna
dendroklimatologia
Larix decidua
modrzew europejski
przetwarzanie danych
szeregi czasowe
leśnictwo
drzewa leśne
słoje przyrostu rocznego
tree ring analysis
latewood
earlywood
dendroclimatology
larix decidua mill.
data processing
Opis:
The aim of this study was to assess the impact of climatic factors (temperature and precipitation) on tree ring width of larches from stands localised in southern part of Poland. Total ring as well as early− and latewood widths were taken in consideration. At the beginning authors used only standard processing and methods. Classic approach were insufficient to make some data useful for the correlation analysis, so authors decided to use more robust, custom methods.
Źródło:
Sylwan; 2011, 155, 03; 147-158
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmienność wybranych cech makrostruktury i gęstości drewna świerkowego pochodzącego z drzewostanów gospodarczych i terenów pogórniczych
Variability of selected features of macrostructure and density of spruce wood from commercial stands and post-mining areas
Autorzy:
Michalec, K.
Wąsik, R.
Pająk, M.
Sikora, F.
Powiązania:
https://bibliotekanauki.pl/articles/974056.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
tereny zdegradowane
drzewostany gospodarcze
makrostruktura
sloje przyrostu rocznego
leśnictwo
tereny pogórnicze
drzewostany świerkowe
drewno świerkowe
szerokość
drewno późne
gęstość drewna
tree−rings width
latewood share
post−mining areas
reclamation
Opis:
The aim of this work was to analyze the tree−ring width, the share of the latewood as well as the density of wood of trees growing in commercial and degraded stands. The research was carried out in the Brynek Forest District (southern Poland) in 3 commercial stands and in 4 degraded stands. For every study plot fifteen spruces were chosen and increment cores were sampled using the Pressler borer. Next, the surface of the cores was smoothed and the width of the annual rings was measured. Latewood zones were determined and the share of latewood was calculated. It was found that the average and minimum tree−ring width was the same in both commercial and degraded stands, while the maximum values were slightly and insignificantly different. In turn, the average share of latewood was higher in trees from commercial stands, but higher minimum and maximum values were recorded in stands on degraded sites. In this case, the differences turned to be statistically significant. The average density of wood was slightly lower in trees from degraded stands compared to wood from commercial stands (413 vs 418 kg/m3). Theminimum and maximum values were also higher in trees from commercial stands. However, this feature did not show a significant difference between analysed groups of stands. We found that despite such significant differences in the terrain formed during the production of zinc and lead ores, the wood of trees growing in these areas hardly shows any differences (except for the share of latewood) in comparison to wood from commercial stands.
Źródło:
Sylwan; 2020, 164, 01; 10-15
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jakość drewna sosny zwyczajnej (Pinus sylvestris L.) I. Charakterystyka wybranych cech i właściwości drewna wpływających na jego jakość
Quality of Scots pine [Pinus sylvestris L.] wood. Part I. Characteristics of selected wood traits and properties affecting its quality
Autorzy:
Tomczak, A.
Pazdrowski, W.
Jelonek, T.
Grzywiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1012211.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
jakosc
Pinus sylvestris
drewno pozne
drewno sosnowe
seki
drewno wczesne
gestosc drewna
drewno mlodociane
sloje przyrostu rocznego
sosna zwyczajna
drzewa lesne
wady drewna
wood quality
scots pine
knots
wood density
tree rings
latewood
juvenile wood
Opis:
The study presents the synthetic characteristic of selected wood tissue traits and properties (knots, tree rings, the proportion of latewood, juvenile wood, wood density, dimensions of anatomical elements, cell wall structure), which play significant role in modifications of wood quality. At individual stage of the raw material–product cycle the term "quality" may be interpreted differently, but characteristics determining it remain unchanged. Quality depends on the natural traits and properties of wood.
Źródło:
Sylwan; 2009, 153, 06; 363-372
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmienność wybranych cech makrostruktury i gęstości drewna świerkowego (Picea abies (L.) Karst.) z regla dolnego i górnego
Variability of selected macrostructural features and density of Picea abies (L.) Karst. wood from lower and upper subalpine forest zones
Autorzy:
Michalec, K.
Wąsik, R.
Barszcz, A.
Powiązania:
https://bibliotekanauki.pl/articles/989498.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
wysokosc nad poziomem morza
lesnictwo
lasy gorskie
regiel gorny
regiel dolny
drzewa lesne
swierk pospolity
Picea abies
drewno swierkowe
drewno pozne
gestosc drewna
sloje przyrostu rocznego
szerokosc
czynniki siedliska
tree−ring width
latewood share
height above mean sea level
Opis:
The paper compares the properties of Norway spruce (Picea abies (L.) Karst.) wood from stands growing in the lower and upper subalpine forest zone in terms of the tree−ring width, the share of latewood and the wood density. The investigation concerned material originating from plots established within the boundaries of the south−western incidence of spruce in Poland. Plots were located in the Sudety Mts. and in the Carpathians (tab. 1). On each plot fifteen Norway spruces were chosen and increment cores were sampled using the Pressler borer. The surface of the cores was smoothed and the tree−ring width was measured. The latewood zones were determined and the share of latewood was calculated. Then, the cores were divided into 2 cm sections, for which the relative wood density was determined. Tree−rings were wider in trees growing in the lower when compared with those from the upper subalpine forest zone (tab. 2). Weak negative correlation was revealed between the elevation and the tree−ring width (r=–0.308). The latewood share was slightly higher in trees from the upper than those from the lower subalpine forest zone (tab. 2). However, no statistically significant correlation between the latewood share and elevation was recorded. The wood density was slightly lower in trees from the lower than those from the upper subalpine forest zone (tab. 2), but the difference was not statistically significant. The correlation between the wood density and the elevation turned out to be insignificant.
Źródło:
Sylwan; 2016, 160, 10; 855-860
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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