WOOD RESEARCH Volume 67, Number 1, 2022
Mengxue Li, Lei Shi, Fuxian Xia, Jiang Deng, Huaijian Liao, Ting Du, and Bingyi Wang

Chemical constituents of the stem in dalbergia sissoo

The chemical constituents of ethyl acetate extracts from heartwood and sapwood of different ages of Dalbergia sissoo were studied by gas chromatography-mass spectrometry. The results showed that the chemical composition of wood heartwood and sapwood is significantly different. In the vertical direction, the type of the ethyl acetate extract from Dalbergia sissoo tends to decrease from the base to the upper portion; in the horizontal direction, the type of extract gradually decreases from the center to the periphery. And it showed an increasing trend with the age of the trees. The experiment also revealed that there were significant differences in chemical components between heartwood and sapwood. We speculated that the main chemical component trismethoxyresveratrol of heartwood extract may be related to the formation of heartwood, and the specific correlation needs to be further verified.

WOOD RESEARCH Volume 61, Number 3, 2016
Robert Kalbarczyk and Monika Ziemiańska

The effect of air temperature, precipitation and humidity on ring widths in the black locust (Robinia pseudoacacia L.) growing in urban conditions

This study characterizes the basic biometric traits of the black locust growing in urban conditions of the city of Wrocław (south-western Poland) and sets out the relationship between annual tree ring widths and air temperature, air humidity and precipitation. Materials consisted of 54 wooden discs taken from felled straight-trunked trees at four sampling sites at a height of 1.3 m from the ground in the area of a defunct garden established at the turn of the 20th century. Meteorological indicators were calculated based on daily data obtained from the Wroclaw meteorological station, part of the national atmospheric monitoring network. Tree ring widths were determined separately in heartwood and sapwood using LINTABTM 6 and TSAP-Win software, to an accuracy of 0.01 mm. Just over 85 % of the analyzed trees were at least 61 years old. In the heartwood layer the average tree ring width of 2.44 mm was about 1.08 mm wider than in the sapwood layer. Results confirmed the significant effect of warm winter and cool July on the ring widths of the black locust. The greatest demand for water was statistically proven in the period June to August in the year preceding the formation of the tree ring, and in the months January and September in the year of the tree ring formation.

WOOD RESEARCH Volume 63, Number 5, 2018
Arkadiusz Tomczak, Karol Tomczak, Natalia Smarul, Krzysztof Rutkowski, Małgorzata Wenda, and Tomasz Jelonek

The gradient of wood moisture within-stem of sessile oak (Quercus petraea (matt.) Liebl.) in summer

In the xylem of growing trees water fills both free spaces in the cell walls and capillary spaces. For this reason its share in the tree mass is very high. As a result transport of logs obtained from fresh-felled trees is mainly equivalent to the transport of contained water. The primary aim of this study was to determine wood moisture content in growing trees in the selected season of the year. Absolute moisture content of tested wood was established at 62.4%. Average moisture content in heartwood was 60.6% and it was lower by approx. 6% from moisture content in sapwood. Moisture content of the oak heartwood is high, similar to central part of the trunk of non – heartwood species. It is an exceptional situation in comparison to heartwood species, particularly conifers.

WOOD RESEARCH Volume 63, Number 1, 2018
Monika Ziemiańska and Robert Kalbarczyk

Biometrics of tree-ring widths of (populus x canadensis moench) and their dependence on precipitation and air temperature in south-western poland

The aim of this study was to explore the structure of the basic biometric characteristics of Canadian poplar (Populus x canadensis Moench) growing on former farmland, and the influence of meteorological elements on the variability of tree-ring widths (TRW). The test was performed on stem discs. Measurements of TRW were made with the use of LINTABTM 6. The impact of meteorological conditions on the TRW of the examined poplars was determined using correlation analysis for the dependent variable – residual chronology and independent variables – rainfall and air temperature in the current year and the year preceding the formation of rings. The average TRW of the Canadian poplar was 6.70 mm, with a coefficient of variation of 45.6%. The average TRW in sapwood was 5.37 mm, 2.11 mm less than in heartwood. The site chronology represented the period 1967-2014 (48 years). Our study demonstrated a significant correlation between rainfall and temperature on TRW in Populus x canadensis. The greatest demand for water by the Canadian poplar was observed in April and September of the current year. In contrast, the effect of air temperature most negatively affected TRW in June-July of the previous year (especially July) and April-May of the current year. In the designated chronology we established 13 pointer years, 7 positive and 6 negative. Negative years were determined in the years in which the shortage of rainfall was up to 50% of the norm, and positive indicator years where precipitation was higher than in the multi-annual period, even >150%. Both the correlation analysis and the analysis of indicator years indicated rainfall as a factor determining the size of the tree-ring width in Canadian poplars. In recent years, Poland has seen a resurging interest in planting poplars, following a long-term global trend in forestry and the paper industry which requires fast-growing tree plantations. The authors of this study attempted to address the gap in knowledge about the impact of meteorological elements on the tree-ring widths of Populus x canadensis in the conditions of south-west Poland.

WOOD RESEARCH Volume 65, Number 6, 2020
Boháček Štefan, Pažitný Andrej, Halaj Michal, Balberčák Jozef, and Kuňa Vladimír

Freeze-thaw pretreatment of poplar sapwood dust

The paper is focused on the effect of freezing and cyclic freezing-thawing pretreatment of poplar sapwood (Populus alba L.). The experimental comparison was carried out by the sawdust fraction 0.7 mm as (a) water-saturated and (b) dry. Monosaccharide yields, as well as an amount of acetic acid, were measured after 6, 24, 48, 72, and 96 hours of enzymatic hydrolysis with 15% load of the enzyme measured to total cellulose content. The influence of freezing rate on total yields was observed on equally prepared samples with different weights (31 g, 25 g, 62.5 g, 125 g, 250 g, 500 g, and 1000 g) by “cubic” tests. To increase the efficiency of pretreatment, a cyclic freezing-thawing experiment at temperatures -20°C and +25°C was performed. The results show that single freezing of grounded poplar sapwood impregnated by water or dry in its matter is not a sufficient pretreatment method, so cyclic freeze-thaw is needed to enhance the yield of monosaccharides. Analysis of cubic test showed that slower freezing process has a positive effect on enzyme accessibility.

WOOD RESEARCH Volume 65, Number 4, 2020
Pažitný Andrej, Albert Russ, Boháček Štefan, Monika Stankovská, VLADIMÍR IHNÁT, and Štefan Šutý

Effect of steam explosion on enzymatic hydrolysis of various parts of poplar tree

The effect of steam explosion on enzymatic hydrolysis of various parts of poplar tree (heartwood, sapwood and 1-year coppice) was investigated. These parts were milled, the obtained sawdust was chemically analysed and then steam explosion of 0.7 mm poplar particles at temperature of 205°C was performed. Concentration of monomers obtained after enzymatic hydrolysis was considered as the main indicator for cellulose accessibility. Analysis of high performance liquid chromatography showed that non-treated poplar sawdust does not enable sufficient cellulose accessibility, while excessively high temperature and rapid pressure release resulted in substantial breakdown of polysaccharides and lignin and formation of inhibitors. The concentration of monomers increased gradually in the order of coppice, sapwood and heartwood. Steam exploded heartwood gave the maximum monosaccharides concentration of 90.0 g.L-1 after 72 hours of enzymatic hydrolysis. However, glucose concentration culminated after 48 hours of this hydrolysis. This corresponds to the best holocellulose accessibility for enzymes. The maximum concentration of inhibitors (9.3 g.L-1) was determined for poplar coppice after 24 hours of enzymatic hydrolysis.

WOOD RESEARCH Volume 66, Number 3, 2021
Tomasz Jelonek, Witold Pazdrowski, Joanna Kopaczyk, Magdalena Arasimowicz-Jelonek, and Arkadiusz Tomczak

Biosocial diversity of scots pine (pinus sylvestris l.) in a tree stand in relation to chosen hydraulic conductivity indicators of the stem

The research focused in determining the lignification indicator of fresh needled springs and the mass of fresh needles in reference to the lignin content in tracheid walls of peripheral area of the stem (MFT/LC and MFN/LC) of Scots pine differentiated as far as its biosocial position within the community expressed by Kraft’s classification. The material for the analysis came from mature pine stands growing on North European Plain, on the territory of Poland. Chemical and structural analyses of wood encompassed the area of mature sapwood, i.e. thickness of the last 10 annual rings located at 1.3 m (DBH). It seems that the noticed differences values of both indicators (MFT/LC and MFN/LC) in pines belonging to the first three Kraft’s biological classes are connected with physiological, physical and structural conditionings of water transport with minerals in xylem and are closely connected with competition for sunlight, water, nutrients and living space.