Important Wood Species Research Articles

Antioxidant activity of knotwood extractives and phenolic compounds of selected tree species.

The antioxidant potency and the radical scavenging capacity of superoxide and peroxyl radicals were assessed for 13 hydrophilic knotwood extracts of commercially important wood species, or fractions thereof, as well as for five pure wood-derived lignans and the flavonoid taxifolin. The chemical composition of the knotwood extracts was determined by gas chromatography combined with mass spectrometry. Most of the investigated wood species were rich in hydrophilic extractives (10-20% of the dry wood) with one or a few compounds dominating in each extract. All extracts had a high antioxidative potency and/or radical scavenging capacity as compared to the well-known antioxidants Trolox and butylated hydroxyanisole. The pure wood-derived lignans and taxifolin also had a high antioxidative potency and/or radical scavenging capacity. However, the antioxidant potency and/or radical scavenging capacity of several of the hydrophilic knotwood extracts were higher than that of the dominating compounds in pure form.

MICRO- AND ULTRASTRUCTURAL ASPECTS OF NORWAY SPRUCE TRACHEIDS: A REVIEW

Norway spruce, Picea abies (L.) Karsten, is one of the most commercially important wood species in northern Europe. Wood from Norway spruce consists mainly (> 90%) of tracheids and the micro- and ultrastructure of these tracheids have a considerable effect on the wood and its manufactured products. This literature review presents current knowledge on some important aspects of the micro- and ultrastructural morphology of Norway spruce tracheids. At the microstructural level, variation and general trends within the tree are given for tracheid length, tracheid diameter and cell wall thickness. At the ultrastructural level, the architecture of the secondary cell wall, and particularly its lamellation and microfibril orientation are considered. Where information on Norway spruce tracheids was lacking, tracheids of other conifers are reviewed. Thus, this review also gives an insight on the structure of other conifer tracheids since there are many similarities in structure between different conifer species.

Properties of Acacia and Eucalyptus woods

In view of limited reserves of fossil fuels and environmental problems associated with their use, increasing attention is currently being directed towards biomass as a renewable energy alternative for iron-making. Most developing countries have limited conventional energy resources, very little money to pay for imported raw energy materials, plenty of wasteland (approximately 60 million ha in India), ample sunshine and cheap labour. Social conditions and economics are therefore thought to be favourable for bioenergy. In India, Acacia, Eucalyptus, subabul and casuarina appear to be the most important wood species for the manufacture of charcoal suitable for iron-making. In this letter, as a part of the search for alternative energy sources for iron-making, we report our studies of the properties of Acacia and Eucalyptus woods. (author).