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1
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Charakterystyka jakości technicznej drewna paulowni COTE-2

100%
Lachowicz H., Giedrowicz A.
Sylwan
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2020
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tom 164
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nr 05
Seedlings of Paulownia (Paulownia sp.) has increasingly appeared in the merchant offers in Poland. However, the knowledge of the technical characteristics of its wood is still insufficient because comprehensive studies of wood properties for this species have not been performed. The main aim of this study was to determine the selected physical and mechanical properties of Paulownia COTE−2 wood. The wood comes from the plantation of Paulownia COTE−2 located in Granada region in Spain. The investigation were carried on 162 samples, according to Polish standards. We analysed the following physical properties: air−dry density, oven−dry density, basic density, proportion of wood substance, wood porosity, total shrinkage of wood in longitudinal, tangential and radial anatomical directions, volumetric shrinkage, coefficients of each of mentioned shrinkage, the anisotropy index of shrinkage and mechanical properties: compression strength, static bending, modulus of elasticity in static bending, including the coefficients of the mechanical properties mentioned before. The results show that Paulownia wood is very light, with the density of 270 kg/m³ and low shrinking (volumetric shrinkage equaled to 7%). The mechanical properties of Paulownia wood are closely related to its density. Static bending equaled to 38 MPa and compression strength parallel to grain amounted to 24 MPa.
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Dokładność wybranych metod określania miąższości drewna sosnowego wyrabianego w kłodach

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Giedrowicz A., Staniszewski P.
Sylwan
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2017
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tom 161
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nr 11
In 2015, approximately 38.5 million m³ of round wood was harvested in Poland, and this volume is constantly growing. Scots pine (Pinus sylvestris L.) occupies about 58.5% of the forest area in Poland and is the species of the most economic importance. Along with the changes in the timber market, mainly due to the development of technology for the harvesting and processing of wood raw materials, the consumers interest in stem wood has increased. The State Forests in Poland have developed their own system for timber volume calculation that is based on the measurement of the under−bark diameter at the thinner end of the log. The aim of the study was to evaluate the accuracy of three methods of determining the harvested timber volume: Huber's and Smalian's dendrometric formulas and the method currently used by the State Forests. The study was conducted in the Choczewo Forest District (N Poland). In total, 193 logs collected from five forest ranges and from two forest habitats (fresh mixed broadleaved and fresh mixed coniferous forest) were measured. The relative error calculated as the relative difference between log volume obtained by the dendrometric formula and the real volume determined with section−wise method was statistically analysed. Mean errors obtained with all tested methods of volume determination differ significantly from zero, which indicates the systematic error of volume determination. The greatest errors are generated by the method used by the State Forests. The volume obtained with this method is underestimated on average by over 14%.
3
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Dokładność określania struktury dnia roboczego metodą obserwacji migawkowych przy zrywce drewna

81%
Pszenny D., Giedrowicz A., Staniszewski P., Moskalik T.
Sylwan
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2019
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tom 163
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nr 04
One of the most difficult technological operations in forest utilization is wood transport, especially its first stage i.e. extraction. This is related to the fact that the forest operations must be economically effective, but also safe for the forest environment. Difficult terrain conditions require determining and choosing the optimal variant of skidding. The most popular method for optimizing work is the use of working day photography. However, it is time−consuming and labor−intensive, that is why it is possible to use an alternative way of measuring working time, i.e. snapshot observations. It is therefore important to determine which measurement method is appropriate for the complicated and variable production processes in forestry. The aim of the research was to assess the accuracy of snapshots at intervals of 1 and 5 minute in relation to the stopwatch time study (which was a reference measurement), carried out for a two−stage wood logging in quasi−mountain terrain conditions of the Elbląg Upland (N Poland). It’s mountain like characteristics causes some difficulties in the forest works. Data for the study were collected in two periods – summer and winter. We did not prove statistically significant differences between the methods studied.
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Pozyskanie drewna daglezji zielonej (Pseudotsuga menziesii (Mirb.) Franco) w Lasach Państwowych w latach 2006-2018 oraz znaczenie drewna tego gatunku w Polsce i Europie

81%
Giedrowicz A., Zastocki D., Lachowicz H.
Sylwan
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2020
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tom 164
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nr 11
The paper presents an analysis of the assortment structure of Douglas−fir timber harvest in the State Forests, National Forest Holding in 2006−2018 and discusses the role of wood of this species in Poland and Europe. The analyzes were made on according to the division into regional directorates of the State Forests and were the based on the data from the reports created by the State Forests Information System. In years 2006−2018, the total harvest of merchantable timber in the State Forests amounted to 259,215.7 m³, of which large−size wood equaled to 194,306.8 m³ (75%) and medium−size wood – to 64,908.9 m³ (25%). The highest volume of merchantable timber in total, large−size wood and medium−size wood was harvested in the regional directorate in Szczecin (NW Poland). The largest total annual harvest of merchantable timber of Douglas−fir was recorded in Szczecin directorate in 2017 (11,555.44 m³, i.e. 43% of the national production). The harvest of large−size and medium−size assortments also peaked in 2017 amounting to 8953.56 m³ and 2601.88 m³, respectively. The highest harvest of timber of Douglas−fir in Poland show the regional directorates of the State Forests located in the north−western and western Poland.
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Popularyzacja wiedzy o lesie przez studentów Koła Naukowego Leśników Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie

81%
Koc K., Broda D., Giedrowicz A., Gasek A.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
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2018
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tom 20
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nr 2[56]
6
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Wpływ pozyskiwania pędów na wybrane parametry krzewinek borówki czernicy (Vaccinium myrtillus L.)

51%
Giedrowicz A., Sulej J., Jasionowska M., Kopec S., Jerczynski T., Ostromecki K., Tomusiak R., Staniszewski P.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
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2018
|
tom 20
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nr 2[56]
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