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Wyszukujesz frazę "sapwood" wg kryterium: Temat


Wyświetlanie 1-5 z 5
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:
Strefa twardzieli w drewnie i proces jej powstawania
Heartwood zone and its formation process
Autorzy:
Bieniasz, A.
Tulik, M.
Powiązania:
https://bibliotekanauki.pl/articles/979188.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
parenchyma cells
programmed cell death
sapwood
tyloses
aspiration
ecstracts
heartwood formation
Opis:
This paper reviews the literature on heartwood and its formation process. The factors involved in the process of heartwood formation are described, with particular attention paid to molecular, intercellular, organismal and environmental ones. The spatial distribution of heartwood along longitudinal and radial axes of the stem as well as biochemical changes in the heartwood and durability of this zone are also presented. Based on the literature data, it turns out that the heart−wood formation is neither clearly studied, nor fully understood. It seems that this part of wood can not only play a significant role from the point of view of tree biomechanics, but also is of great importance in their immune responses. In the era of observed dying processes of forest−forming trees, knowledge about the role of heartwood in these responses seems desirable.
Źródło:
Sylwan; 2020, 164, 06; 474-481
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Udział bielu i twardzieli w strzałach sosen zwyczajnych (Pinus sylvestris L.)
Autorzy:
Pazdrowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1023792.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
warunki siedliskowe
uzytkowanie lasu
sosna zwyczajna
lesnictwo
strzala drzew
drewno bielu
bor mieszany swiezy
drewno twardzieli
Pinus sylvestris
drzewa lesne
pruning
sapwood
heartwood
stem
scots pine
forest site type
Opis:
In this paper the attempt has been made to determine the proportion of sapwood and heartwood in pruned and non−pruned stems of Scots pine growing in the fresh mixed coniferous forest. Research results have shown that the proportion of heartwood in pruned pine stems was higher than in non−pruned ones. This was particularly noticeable after 24 years from the treatment while after 51 years this regularity was less distinct.
Źródło:
Sylwan; 2004, 148, 03; 21-27
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Udzial bielu, twardzieli drewna mlodocianego i dojrzalego w strzalach sosen zwyczajnych [Pinus sylvestris L.] wyroslych w roznych warunkach siedliskowych
Autorzy:
Jakubowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/973595.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
drewno mlodociane
budowa drewna
sosna zwyczajna
typy siedliskowe lasu
drewno bielu
drewno twardzieli
Pinus sylvestris
drewno dojrzałe
drwno młodociane
leśnictwo
strzała drzew
drzewa leśne
sapwood
heartwood
juvenile wood
mature wood
wood macrostructure
Opis:
This paper reports on author's attempts to establish the relationship between forest site type and the proportion of sapwood, heartwood, juvenile wood and mature wood in Scots pine (Pinus sylvestris L.) stems. The experiment was carried out in pine stands representing dry coniferous, fresh coniferous and mixed fresh coniferous forest site types.
Źródło:
Sylwan; 2004, 143, 08; 16-24
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ligninolityczne właściwości izolatów Heterobasidion parviporum w hodowli na drewnie świerka
Ligninolytic activity of Heterobasidion parviporum isolates in cultivation on Norway spruce wood
Autorzy:
Żółciak, A.
Bohacz, J.
Powiązania:
https://bibliotekanauki.pl/articles/989467.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
fitopatologia lesna
grzyby
Heterobasidion parviporum
izolaty grzybowe
aktywnosc lignolityczna
enzymy lignolityczne
lakaza
peroksydaza manganozalezna
peroksydaza ligninowa
peroksydaza "versatile"
rozklad drewna
drewno bielu
drewno twardzieli
drewno swierkowe
biodegradacja
laccase
manganese peroxidase
lignin peroxidase
versatile peroxidase
hydroxy−
methoxyphenols
sapwood
heartwood
norway spruce wood
Opis:
The aim of this preliminary study was to assess the activity of laccase, diverse peroxidases as well as the level of micromolecular compounds in Heterobasidion parviporum isolates grown on pieces of Norway spruce wood (sapwood and heartwood) during 50 days of incubation under the laboratory conditions. H. parviporum isolates secreted extracellular enzymes: laccase, manganese peroxidase (MnP), lignin peroxidase (LiP) and versatile peroxidase (VP). Hydroxy− and methoxyphenols were also released during this process. The above−mentioned enzymes showed low activity in mycelium grown on both sapwood and heartwood. The activity of laccase ranged from 0 to 0.513 mU/mg protein on sapwood, and from 0 to 0.106 mU/mg protein – on heartwood. MnP activity of H. parviporum isolates ranged from 0.024 to 0.667 mU/mg protein on sapwood, and from 0.038 to 1.585 mU/mg protein – on heartwood. LiP activity was small and ranged from 0 to 1.281 mU/mg protein on sapwood, and from 0.013 to 0.166 mU/mg protein – on heartwood. Activity of VP oxidizing manganese ions was low. It ranged from 0 to 3.063 mU/mg protein on sapwood, and from 0.059 to 3.054 mU/mg protein – on heartwood. The activity of VP oxidizing guaiacol ranged from 0.006 to 1.490 mU/mg protein on sapwood and from 0.038 to 1.147 mU/mg protein – on heartwood. The hydroxyphenols produced by H. parviporum isolates ranged from 15.037 to 110.149 mg of protocatechuic acid/ml on sapwood, and from 11.236 to 27.220 mg of protocatechuic acid/ml – on heartwood. Methoxyphenols produced by H. parviporum isolates ranged from 3.393 to 24.253 mg of vanillic acid/ml on sapwood, and from 4.955 to 12.005 mg of vanillic acid/ml – on heartwood.
Źródło:
Sylwan; 2016, 160, 12; 1027-1035
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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