Wyniki wyszukiwania - BazTech

1

Characterizing Sawdust Fractional Composition from Oak Parquet Woodworking for Briquette and Pellet Production

Warguła Łukasz, Wilczyński Dominik, Wieczorek Bartosz, Palander Teijo, Gierz Lukasz, Nati Carla, Sydor Maciej

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 5

236--247

EN

The particle size distribution of woodworking residues influences the quality of the biofuels made of these materials. Hence, it is essential to investigate the fractional composition of raw materials for pellet production. Tested materials originated from ten parquet manufacturing facilities located in western Poland. The research material consisted of uncontaminated oak (Quercus spp.) wood particles. The tested material had a moisture content ranging from 8.8% to 11.4% and a density of 210.7 ± 1.79 kg/m3. A sieve analysis method segregated the tested material into four distinct size fractions (<1.0 mm, 1.0-2.5 mm, 2.5-5.0 mm, and >5 mm). The average mass shares in these fractions were 53.72 ±0.51%, 35.14 ±0.27%, 9.59 ±0.36%, and 1.55% ±0.11%, respectively. The particle size distributions of wood particles generated in all the facilities demonstrate remarkable similarity. No substantial differences were observed in terms of tilt angle and calorific value. Factors such as variations in raw material species, geographical origins, density, humidity, and technological processes appear to have minimal influence on the sieve-size distributions of the generated sawdust. All these solid wood processing residues can undergo processing into high-quality solid biofuel production.

2

Rozpoznawanie jesiennych faz fenologicznych dębu bezszypułkowego (Quercus petraea Liebl.) na ortomozaikach zdjęć lotniczych uzyskanych z wykorzystaniem drona

Łoziński A., Będkowski K.

Teledetekcja Środowiska

|

2016

|

T. 55

5--14

EN

Changes to beginning and the length of the growing season and the phenological stages can be of great importance for the individual trees, their populations and the populations of other species. The aim of the research described in this paper is to assess the ability to recognize the autumn phenological phases in single trees of the sessile oak, using UAV images. In our study we have examined if we can on this basis rank the trees according to their preparation for winter dormancy. There were 20 observers involved in the research whose objective was to pass each of 114 trees to one of five classes, based on the dominant color of assimilation apparatus observed on an orthomosaic. Distinguished color classes of oaks were: 1 - green, 2 - greenish-yellow, 3 - yellow, 4 - yellowbrown and 5 - brown. The analysis revealed that only 6 of all trees (5 green and one greenish-yellow) were classified by all observers to the same group. Other trees were classified to different colors, and in the case of 25 trees (22%), the number of the same color indicated was less than or at most equal to 12. The applied color scale did not correspond fully to colors perceived by the participants. After completion of the study, all said they ran out of green-brown color, and the crowns of trees that could be assigned to that color, were therefore classified as greenish-yellow, yellow or yellow-brown. In further research it is necessary to explain the causes of green-brown color observed in some trees, as well as its natural meaning and place in a chain of crown colors changes taking place during autumn, using methods of digital image analysis.

3

Competition between sessile oak (Quercus petraea) and black cherry (Padus serotina) : dynamics of seedlings growth

Robakowski P., Bielinis E.

Polish Journal of Ecology

|

2011

|

Vol. 59, nr 2

297-306

EN

Competition is an evolutionary mechanism which exerts a selection pressure on living organisms. Forest trees compete for light, water and nutrients, especially at a young age. It was observed that the Quercus petraea and Padus serotina natural regenerations occupied the same site growing under the canopy of Scots pine (Pinus silvestris L.). To simulate the competition between young sessile oaks and black cherries found in forest, a controlled experiment was conducted using one-year-old seedlings of both species. There were eight treatments of different competition intensity. The treatments were established varying the number of potted seedlings and adding fresh cherry leaves to the substrate to enhance allelopathic effects. It was hypothesized that black cherry would reduce the height growth and diameter at root collar of sessile oak seedlings and this inhibitory effect would be magnified by an increasing number of cherry seedlings and/or fresh leaves. Black cherry as an invasive, fast-growing species was presumed to win the growth competition with oak. However, the differences in growth parameters would not only depend on genetic differences between the species, but also on the number of competing seedlings in pots and an allelopathic effect of cherry leaves. During the whole vegetative season, each two weeks, the growth parameters of seedlings (height, height increment and diameter at root collar) were measured. The results did not support the hypothesis that cherry had an inhibitory effect on oak growth, at least after one vegetative season. Contrary, a presence of cherry seedlings enhanced the oak height increment (F = 8.6, P <0.001) which might be due to either the strong interspecific competition for light or, less plausibly, positive allelopathic effect, or an interaction of both. Our results indicated a negative auto-allelopathic effect of cherry seedlings and/or fresh cherry leaves on height of cherry seedlings (F = 47.7, P <0.001). This invader showed a continuous and steep height increment within the whole vegetative season, whereas oak seedlings grew rapidly only in July. When compared the mean initial heights in April with those after the bud set in September, cherry was four fold and oak only two fold higher. A very intensive height increment gives black cherry an advantage over sessile oak at a young age which can disturb the spontaneous conversion of pine stands into a mixed pine-oak forest with a greater share of oak and other native deciduous tree species.

4

Interrelations among con-generic and co-occurring tree species : asymmetric hybridization and the high success of Quercus petraea (Matt.) Liebl. regeneration in mixed Q. petraea/Q. robur L. stands

Boratyński A., Jasińska A., Iszkuło G., Marcysiak K., Lewandowska A.

Polish Journal of Ecology

|

2010

|

Vol. 58, nr 2

273-283

EN

Hybridisation and introgression are expected to be common in plant populations composed of various species of the same genera. These processes, however, frequently have one direction or are asymmetric, when one of hybridising species is a donor and other recipient of pollen. The asymmetric hybridisation may be also an important manner of migration by pollen. According to the theory of asymmetric hybridisation in mixed oak populations of European white oaks (Quercus robur and Q. petraea) the number of hybrid saplings should be higher under a canopy of Q. robur than under Q. petraea trees. The aim of this study was to determine, which of the two species in the mixed populations has a greater degree of success in regeneration and colonization, measured by the proportion and density of saplings and young individuals higher than 0.3 m. The taxonomic composition of saplings under the crown ranges of trees was analyzed on the basis of morphological characters of leaves in two distantly located mixed oak stands in Poland, in Jamy and Legnica Forests, where young generation to about 17-18 years old was observed under canopy of 125-140 years old mother trees. The first population is located about 100 km of Q. petraea geographic range and covers area of 6 km, the second about 500 km of Q. petraea range and covers more than 10 hectares. The density of 60 and 134 adult trees per hectare, were found in analysed populations, respectively. A significantly higher proportions of Q. petraea than Q. robur saplings were found in both compared stands. A hybrid saplings proportion were higher than hybrid adult trees. The hybrid saplings were observed more frequently under canopy of Q. robur only in the stand closer to the range of Q. petrea. Gene flow from Q. petraea to Q. robur by cross-pollination was found to be likely. The number of hybrid saplings found under crown projections of Q. petraea trees in both populations suggested also reverse gene flow, at least in the stand located close to the north-eastern limit of the Q. petraea range. A higher regeneration success of Q. petraea was observed in both stands suggesting expansion of this species.