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    Tytuł:
    Znaczenie wspolczynnika zmiennosci w okreslaniu jakosci surowca drzewnego
    Autorzy:
    Barszcz, A
    Rutkowska, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/819428.pdf
    Data publikacji:
    1999
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    surowce drzewne
    drzewostany swierkowe
    drewno swierkowe
    lesnictwo
    wspolczynnik zmiennosci
    jakosc
    pomiary
    wady drewna
    Źródło:
    Sylwan; 1999, 143, 07; 45-55
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Jakość surowca świerkowego pochodzącego z drzewostanów naturalnych (rezerwatowych) i drzewostanów pełniących funkcje gospodarcze
    The quality of spruce timber from natural stands (forest reserves) and managed stands
    Autorzy:
    Michalec, K.
    Barszcz, A.
    Wasik, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/52586.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
    Tematy:
    drzewostany swierkowe
    drzewostany naturalne
    drzewostany gospodarcze
    surowce drzewne
    drzewa lesne
    swierk
    drewno swierkowe
    jakosc
    struktura jakosciowa
    wady drewna
    Opis:
    W artykule przedstawiono wyniki analizy porównawczej jakości surowca świerkowego pochodzącego z drzewostanów naturalnych (rezerwatowych) i drzewostanów pełniących funkcje gospodarcze. W analizach uwzględniono również wady drewna wpływające na wyniki klasyfikacji badanego surowca oraz częstotliwość ich występowania. Wytypowane do badań drzewostany zlokalizowane były w terenach górskich: w Sudetach i Karpatach. W wyniku przeprowadzonych analiz stwierdzono, że nieznacznie lepsze pod względem jakości surowca drzewnego są w porównaniu z drzewostanami naturalnymi (rezerwatowymi) drzewostany pełniące funkcje gospodarcze.
    The aim of this study is to determine the variation in the quality structure of spruce timber and to analyze the frequency of occurrence of trees with defects, including the generic structure of defects in natural stands (forest reserves) and stands serving economic functions. The study was conducted on 20 experimental plots located within the Sudeten and Carpathian Mountains, of which 10 were located in the area of nature reserves or national parks while the other 10 - in the managed stands (table 1). Each experimental plot constituted 5 or 10% of the area of the whole stand, depending on its differentiation. The following tasks were performed on the experimental plots: measurement of the breast-height diameter of each tree with a thickness of at least 7 cm, measurement of the height of each tree, quality assessment of the first section of the tree stem from the base along with its quality-dimensional class or group [Zasady... 2003], recording the types and varieties of wood defects. Analyzing the research material obtained, the stem of each tree growing on an experimental plot underwent simulated division into sections corresponding to the quality-dimensional classes and groups which could theoretically be distinguished over the whole length of a stem up to its top. The starting point was the quality-dimensional class noted in the butt section of the stem (section 1) during the field research. The above tasks included the use of the Radwański tables [Roczniki... 1956], which allowed the determination of the size and volume of each section of the spruce stems on the basis of the breast-height diameter and the tree height; wood defects, noted in field, were also taken into account. The material obtained was divided into 2 groups: data from the reserves and from the managed stands. For the material grouped in this way, juxtapositions were made of the average volumes of individual stem sections in quality-dimensional classes and groups of timber and the percentages of particular timber classes and groups in the two stand types were calculated. The material was also analyzed taking into account the generic structure of defects (percentages of individual trees with particular wood defects in a given group of stands). The next stage consisted in statistical analyses using the U-Mann-Whitney test, examining the significance of differences in the quality-dimensional structure of timber and the share of trees with defects between the two groups of stands. The research showed that trees growing in natural stands (reserves) are characterized by a greater average height, thickness (d1.3 and d1/2) and volume of individual trees as compared with the same characteristics of spruce trees in managed stands (table 2). Also, the average volume of the large-sized timber sections (WA, WB1, WB, WC, WD) of individual trees from natural forests dominated the volume of tree sections in managed stands. Despite that fact, the volume/ha of natural forest stands was lower (355.91 m3/ha) than of managed stands (380.27 m3/ha). By analyzing the quality-dimensional structure of the examined timber it was found that the proportion of higher quality timber classes (WA and WB) prevails in the managed stands, resulting in a lower share of the WC class of timber (fig. 1). Only the share of WB1 class timber prevails in natural stands. The managed stands also showed a larger share of medium-sized timber (groups S1, S2 and S4) as compared to natural forests. TheU-Mann-Whitney statistical test, however, did not show statistically significant differences in the timber quality structure between the natural and the managed stands (U = 49.00, Z = -0.0378, p = 0.9698). Subsequently, it was found that the proportion of trees with quality reduced by defects was higher in the natural stands (70.38%) as compared to the managed stands (67.13%). The main defect, decisive for timber quality, were knots (in both groups of stands). The share of trees with that defect was greater in the stands of natural origin (fig. 2). In those stands, there was also a larger share of trees with rot (external and internal rot) and unilateral curvatures. The managed stands demonstrated a share of injuries (overgrown and open ones) as well as bilateral and multilateral curvatures that was higher than in the natural stands. In conclusion, it should be emphasized that in the managed stands within the research area a higher quality of spruce timber as well as higher volume/ha were noted as compared to the natural stands (forest reserves). Stands in forest reserves are generally located at higher altitudes in the mountains or hardly accessible areas; their main purpose are protective functions, they also serve the purposes of research. In the stands situated in forest reserves there was reported, in comparison with the managed stands, a higher incidence of trees with a large number of knots and highly affected by rot. A frequent presence of such defects is inevitable there because this group does not undergo any management cuts that would improve timber quality. Moreover, the presence of rot is due to the advanced age of these stands. At the same time, what is disturbing is a large share of trees with injuriesin the managed stands. Given that spruce is very sensitive to mechanical damage of the stem, resulting in rapid development of rot, caution is recommended during forest management work and harvesting in spruce stands.
    Źródło:
    Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2013, 56, 189
    1644-3985
    Pojawia się w:
    Drewno. Prace Naukowe. Doniesienia. Komunikaty
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wpływ zgnilizny na jakość drewna w zróżnicowanych wiekowo drzewostanach świerkowych
    The effect of decay on the quality of wood in spruce stands of different age
    Autorzy:
    Dardziński, A.
    Giefing, D.F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1009391.pdf
    Data publikacji:
    2010
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    uzytkowanie lasu
    drzewostany swierkowe
    drzewostany przeszlorebne
    drzewa lesne
    swierk
    Picea
    drewno swierkowe
    degradacja drewna
    wady drewna
    zgnilizna drewna
    mature and overmature spruce stand
    rotation age
    bark stripping
    fungal decay
    Opis:
    The objective of the research was to analyse the level of fungal infection of spruce wood in the mature and overmature stands and determine the age of their technical maturity. Trees from seven stands aged 49−137 were examined. Age was found to have a statistically significant effect on the level of infection of trees caused by wood−rotting fungi. A high infection level was also detected in the bark−stripped spruces of the lower storeys of multi−storeyed stands. The obtained results enabled determination of the age at which spruces are considered mature (technical maturity) for felling at 80−90 years.
    Źródło:
    Sylwan; 2010, 154, 08; 569-576
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Porównanie ilości martwego drewna leżącego w drzewostanach sosnowych i świerkowych Skandynawii przy różnych szerokościach geograficznych
    Comparison of the amount of dead wood resources in Scots pine and Norway spruce stands at different latitudes in Scandinavia
    Autorzy:
    Tomusiak, R.
    Kedziora, W.
    Krzemien, W.
    Moskwa, A.
    Karbownik, O.
    Mazur, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/881703.pdf
    Data publikacji:
    2014
    Wydawca:
    Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
    Tematy:
    lesnictwo
    drzewostany sosnowe
    drzewostany swierkowe
    sosna zwyczajna
    Pinus sylvestris
    swierk pospolity
    Picea abies
    drewno martwe lezace
    ilosc drewna martwego
    gradient szerokosci geograficznej
    Szwecja
    Norwegia
    Źródło:
    Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2014, 16, 4[41]
    1509-1414
    Pojawia się w:
    Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Problem masowego zamierania drzewostanów świerkowych w Leśnym Kompleksie Promocyjnym "Puszcza Białowieska"
    Problem of a massive dying-off of Norway spruce stands in the 'Bialowieza Forest' Forest Promotional Complex
    Autorzy:
    Brzeziecki, B.
    Hilszczański, J.
    Kowalski, T.
    Łakomy, P.
    Małek, S.
    Miścicki, S.
    Modrzyński, J.
    Sowa, J.
    Starzyk, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/985913.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    lesne kompleksy promocyjne
    Lesny Kompleks Promocyjny Puszcza Bialowieska
    drzewostany swierkowe
    stan sanitarny
    zagrozenia drzewostanow
    szkodniki roslin
    kornik drukarz
    Ips typographus
    dynamika populacji
    gradacja
    drewno martwe
    grzyby patogeniczne
    zagrozenie pozarowe
    zamieranie lasow
    norway spruce bark beetle infestation
    białowieża forest
    ecosystem stability
    multifunctional forestry
    natura 2000 plc200004
    natural values
    world heritage site
    Opis:
    The Białowieża Forest (BF) is in many respects an exceptional object, of a great importance for nature protection and forest management, at the international scale. The BF plays also a key role from the point of view of regional development and welfare of local community. In the last period, a big threat for multiple values of the BF has arisen, as a result of enormous bark beetle infestation, which started in 2012 and has killed 1.4 million m3 of spruce trees. In the paper, first, a brief overview of the general history of the BF and an account of long−term human impacts on its functioning and structure is provided. Next, the history of bark beetle infestations in the BF is analysed. It is shown that, in the period 1992−2007, the average volume of spruces killed by bark beetle amounted on average to 20,000 m3 of wood annually. During that period practically all dead trees were removed from the forest by means of salvation cuttings. Starting from 2008, more and more trees infested by European spruce bark beetle were left in the forest, in a result of a pressure exerted by environmental groups. In 2012, Minister of Environment decided to reduce the allowable cut, determined in forest management plans elaborated for the managed part of the BF, from 107,000 to 48,500 m3/year. This decision, along with several other regulations and restrictions, made in practice impossible to stop the development of a current bark beetle infestation, which started in 2011 and intensified during the next 6 years (solely in 2016 bark beetles killed 480,000 m3 of spruce trees). In the paper, the most important implications and consequences of the current situation are briefly summarized and discussed. A special attention is given to the problems concerning: 1) protection of Natura 2000 species and sites (endangered by bark beetle outbreak), 2) a negative influence of large amounts of spruce deadwood on forest soils, 3) threats caused by pathogenic fungi, 4) question of public safety, 5) fire hazard, and 6) economical dimension. The legal and socio−economical foundations of the functioning of Hajnówka, Browsk and Białowieża forest districts comprising the managed part of the BF, as well as their most important environmental and social consequences are discussed too. Among others, it is indicated that, under current conditions of the BF, human intervention plays a key role in maintaining stable and compositionally diverse woodland communities. Finally, several suggestions and recommendations are provided, aimed at, in the short term, breaking off the current bark beetle outbreak, and, in the long term, at maintaining a multifunctional character of the BF and its ability to provide all important ecosystem services on a sustainable basis.
    Źródło:
    Sylwan; 2018, 162, 05; 373-386
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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