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1

Wysokość położenia sęków oraz lokalizacja i wielkość martwic u świerka pospolitego [Picea abies (L.) Karst.] pochodzącego z głównych ośrodków i zasięgów jego występowania w Polsce

100%
Michalec K.
Acta Agraria et Silvestria. Series Silvestris
|
2011
|
tom 49
The research presented below analyses the differences in the location of knots and injuries as well as the size of injuries on the stems of Norway spruce from different regions of Poland. The research was conducted on 32 plots located within two ranges of the occurrence of spruce in Poland: the north-eastern range and the south-western one. On the selected spruce trees, the researchers measured the height of location of knots and injuries as well as injury sizes. The analyses revealed significant differences in: the height of location of knots and overgrown injuries and the size of injuries in trees from different regions and ranges of occurrence while no such differences were found in the height of location of open injuries.
2
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Kształtowanie się jakości surowca świerkowego w zależności od wysokości nad poziomem morza i wystawy

100%
Michalec K.
Sylwan
|
2011
|
tom 155
|
nr 06
3

Jakosc surowca swierkowego [Picea abies [L.] Karst.] pochodzacego z glownych osrodkow i zasiegow jego wystepowania w Polsce

100%
Michalec K.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
|
2007
|
tom 50
|
nr 177
57-78
4

Comparative analysis of spruce timber quality classified according to the Polish standards and the European Union standards

100%
Michalec K.
Zeszyty Naukowe Akademii Rolniczej w Krakowie. Sesja Naukowa
|
2005
|
tom 91
449-455
5
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Zwiazek typu ugalezienia swierka pospolitego [Picea abies [L.] Karst.] z jakoscia surowca drzewnego

100%
Michalec K.
Sylwan
|
2008
|
tom 152
|
nr 06
33-43
6
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Wpływ wskaźnika zadrzewienia drzewostanu na wybrane cechy makrostruktury i gęstość drewna świerkowego (Picea abies (L.) Karst.)

100%
Michalec K.
Sylwan
|
2020
|
tom 164
|
nr 09
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.
7

Comparative analysis of the quality of timber of Norway spruce (Picea abies L. Karst.) from two ranges of this species in Poland in relation to age, stand quality class and site type of forest

100%
Michalec K.
Electronic Journal of Polish Agricultural Universities. Series: Forestry
|
2008
|
tom 11
|
nr 1
8

The dynamics of stem necrosis occurrence in mountain stands of varying forest cover index and ground slope

63%
Michalec K., Wasik R.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2012
|
tom 11
|
nr 3
The aim of this study was to analyse the frequency and extent of mechanical damage of tree stems in mountain spruce stands of varying forest cover index and ground slope, without taking into account the technology used in obtaining wood. The study was conducted in 17 spruce stands located in the Sudetes and the Carpathians. In the stands the 1 ha test surfaces were established. The damage on trees with dbh ≥ 18 cm was measured. As a result of the analysis it was found that the most damaged trees grew in the stand with forest cover ratio of 0.7 and 1.0, while taking into account the decline of the area most damage was found in the stands with a slope of 16 to 25°. The study, however, showed no clear relationship between the position of necrosis on tree stems (its size and height) and forest cover and a decrease of the area.
9

Spruce timber quality in trees with different thickness from the Beskidy Mts

63%
Barszcz A., Michalec K.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2007
|
tom 06
|
nr 3
10

Zmienność wybranych cech morfologicznej budowy drzew daglezji zielonej (Pseudotsuga menziesii var. viridis Franco) w Polsce

63%
Wasik R., Michalec K.
Acta Agraria et Silvestria. Series Silvestris
|
2010
|
tom 48
This paper presents the results of investigation into the variability of selected features of morphological structure of Douglas fir trees in Poland. The research was carried out in 28 Douglas fir stands, which were at least 80 years old. The mean values of studied features amounted: diameter at breast height — 54.8 cm, height — 32.4 m, bark thickness — 3.9 cm, crown length — 13.6 m, relative crown length — 41.6% and crown width — 5.4 m. The significant variability of studied features was stated, especially large diversity bark thickness and crown width was revealed. Four regions were distinguished in Poland. These regions were characterized by some distinction of the studied features.
11

Optimalization of the number and size of sample plots for estimation of the quality structure of standing spruce timber

63%
Barszcz A., Michalec K.
Electronic Journal of Polish Agricultural Universities. Series: Forestry
|
2004
|
tom 07
|
nr 1
12

Comparative analysis of the calorific value of giant fir timber (Abies grandis Lindl.) from various stands in southern Poland

63%
Wasik R., Michalec K.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2012
|
tom 11
|
nr 3
The paper presents a comparative analysis of wood calorific value of grand fir (Abies grandis Lindl.), originating from four stands of the southern Poland. The research material were the samples, collected from the trunks of 30 trees in each stand. The samples were divided into sections, each containing five annual increments. Then each section was measured: annual ring width and the relative wood density, which was converted to dry wood density, taking the total volumetric shrinkage of 11%. It was assumed that the calorific value of 1 kg dry wood of grand fir is 20.15 MJ. On the basis on the analysis it was found that the average calorific value of 1 m3 of grand fir wood was 8021 MJ. It was shown, that a significantly higher calorific value was obtained by the combustion of 1 m3 wood of giant fir trees, growing on the poorer soil in comparison to the more fertile soils. Statistical analysis also showed that with increasing age of the trees the calorific value of 1 m3 grand fir wood increases significantly.
13

Zwiazki miedzy wysokoscia nad poziomem morza i typem ugalezienia a wybranymi cechami drzew i drewna swierka pospolitego [Picea abies /L./Karst.]

63%
Barszcza P., Michalec K.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2003
|
tom 02
|
nr 2
5-15
14
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Zmienność wybranych cech makrostruktury i gęstości drewna dębu czerwonego (Quercus rubra L.) z Polski południowo-wschodniej

63%
Wasik R., Michalec K.
Sylwan
|
2020
|
tom 164
|
nr 10
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.
15
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Zmienność wybranych cech makrostruktury i gęstości drewna świerkowego (Picea abies (L.) Karst.) z regla dolnego i górnego

51%
Michalec K., Wasik R., Barszcz A.
Sylwan
|
2016
|
tom 160
|
nr 10
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.
16
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The variability of certain macrostructural features and the density of grand fir (Abies grandis Lindl.) wood from selected stands in southern Poland

51%
Wasik R., Michalec K., Barszcz A.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
|
2015
|
tom 58
|
nr 195
The paper presents the results of investigations into the variability of certain features of the wood macrostructure, such as the width of the annual ring, the share of late wood, and the relative density of the wood of grand fir, growing in four stands in southern Poland. The trees under investigation were 30-35 years old. The research material consisted of incremental cores sampled from trial trees with the use of a Pressler borer. The examined wood features were analysed in sections, each one comprising five annual rings. The rings were given numbers, sorted in an ascending order from the trunk circumference. The mean values of the analysed features were as follows: the annual ring width – 4.38 mm, the share of late wood - 35.39%, the relative wood density – 0.354g·cm-3. It was established that the wood of grand firs growing on less fertile soils had significantly narrower annual rings and higher wood density than those on more fertile soils.
17
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A comparative analysis of pine and beech wood classification according to Polish and EU norms

51%
Barszcz A., Michalec K., Wasik R.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
|
2014
|
tom 57
|
nr 193
Investigations were carried out at timber storage sites (depots) on large-sized pine (110 pieces) and beech (130 pieces) wood from three forest districts within the territory of the Regional Directorates of the State Forests (RDSF) of Łódź, Lublin and Kraków. As a result of a comparison of both classification systems, it was proved that in the case of pine wood classified according to EU norms, the shares of the number of pieces and volume in classes B and C decreased, whereas they increased in class D when compared with Polish classification. Analogically, in the case of beech wood, a decrease in the share of the number of pieces and volume in classes A, B and D, and an increase in class C were recorded. Among the most common defects that influence the classification of both sorts of wood, open and burl knots as well as curvatures are recognised, while in the case of beech wood, shakes and galls (disease T stains) are encountered. The results of the classification determined differences in the wood value. According to the pricelists for wood standing in forest districts where the raw wood under investigation originated, it was established that the value of the pine wood classified according to the EU norm decreased by ca. 7.6% when compared with the value estimated using the Polish norm. The value of the beech wood was nearly identical in both cases, which was mainly due to the higher share of wood of class C and lower share of class D upon applying the EU standards, in comparison with the Polish classification system.
18
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Zmienność wybranych cech makrostruktury i gęstości drewna świerkowego (Picea abies (L.) Karst.) pochodzącego z drzewostanów rosnących na różnych siedliskowych typach lasu

51%
Michalec K., Wasik R., Barszcz A.
Sylwan
|
2019
|
tom 163
|
nr 03
The aim of the study was to compare the tree−ring width, latewood share and density of spruce wood from the mature stands occupying different forest habitats. 12 study plots were located in the north−eastern Norway spruce range in Poland (lowlands), whereas 16 in the south−western one (mountains). On the lowlands we chose stands growing on fresh mixed coniferous, humid mixed coniferous, fresh mixed deciduous and fresh deciduous habitats, while in the mountains we selected alpine coniferous, mountain coniferous, mountain mixed coniferous, mountain mixed deciduous and mountain deciduous ones. On each study plot we chose 15 trees according to the Draut method and took increment cores with the Pressler borer. We measured tree−ring and latewood width and then divided the cores into 2−cm sections, for which the relative wood density was determined. The tree−rings were the widest in trees from fresh mixed coniferous (lowlands) and mountain mixed deciduous (mountains) sites, whereas the narrowest ones were observed in trees growing on fresh mixed deciduous and mountain mixed coniferous sites. We found statistically significant difference (p<0,0001) between analysed habitats. The latewood propoprtion showed the opposite dependence than the tree−ring width – wood from fresh mixed coniferous and mountain mixed deciduous sites was characterized by the lowest proportion of latewood, whereas the wood from fresh mixed deciduous and mountain mixed coniferous sites had the highest share of latewood. In this case the differences between the two analyzed groups of stands were also statistically significant. As far as the wood density is concerned, the highest values were found for trees occupying fresh mixed deciduous and mountain mixed coniferous sites and the lowest in trees growing on humid mixed coniferous, fresh deciduous and mountain deciduous sites. The differences between them was also statistically significant. Next, the stands were divided into two groups: coniferous and deciduous sites. It was found that trees from lowland coniferous sites have wider rings than the ones from deciduous sites. In the mountainous region the opposite dependence was observed. The latewood share and wood density was lower in lowland coniferous sites in comparison to deciduous ones. The results were reverse in the mountainous sites.
19
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The effect of stand origin on the wood structure of Norway spruce

51%
Michalec K., Wasik R., Barszcz A., Sowa J. M.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
|
2020
|
tom 63
|
nr 206
20
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Obecność martwic na pniach drzew stojących a jakość i wartość surowca dębowego

51%
Michalec K., Wasik R., Gruchala K.
Sylwan
|
2015
|
tom 159
|
nr 09
This paper aimed to evaluate the impact of necroses occurring on trunks of standing oak trees on their wood quality and value. The research was carried out in five study plots situated in the Meszcze Forestry, Piotrków Forest District (central Poland). The investigations covered: measuring the diameter at breast height of every injured tree with diameter ≥7 cm, estimating the length of the trunk fragment that should be cut off to remove the defect, the assessment of the quality and size of the 3−m butt−end fragment of a trunk, excluding the detected damage or rot (classification I), as well as the quality and size assessment of the same trunk fragment, though including the encountered defect (classification II). The theoretical volume of timber within the particular quality classes was computed (WAt, WBt, WCt and WDt). Afterwards, the real volumes (WAr, WBr, WCr and WDr) were compared with those of groups S2r and S4r. Based on the analysis of the quantity of damaged trees in the investigated trial plots, the lowest share of such specimens was recorded in the compartment 2a (1.6% of defective trees). Whereas, the highest share of damaged trees was encountered in the compartment 39a (8.5%). The timber of more valuable large−sized classes 'migrated', due to damages, to the groups of medium−sized timber (S2 or S4). With respect to the total volume of timber within the particular classes and groups, the greatest loss was reported in the WB class. The timber in question 'migrated' mostly to the group S2, though a part of it was classified to the group S4 as well. The established decrease in the timber value, due to damages to trunks, accounted for ca. 26%, which amounted to ca. 5.8 thous. PLN, in relation to the entire investigated material. The obtained results indicated the necessity to reduce the damages occurring in oak stands and remove the injured trees as soon as possible to avoid a significant depreciation and a value loss of raw wood.
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