Comparison of the physical properties of grey alder (Alnus incana (L.) Moench) and black alder (Alnus glutinosa (L.) Gaertn.) wood in Latvia and elsewhere

Warsaw

2008

S. 129-132

2 Tab., 7 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200153261

About 25 species are known in the Alnus genus, whose wild-growing natural habitat embraces the Northern hemisphere's moderate zone and extends to Peru in South America. In Latvia, wild-growing black alder (Alnus glutinosa (L) Gaertn). and grey alder (Alnus incanca (L.) Moench) grow; now and then a hybrid of both species occurs. The traditional fields of the use of alder wood are the production of plywood, joinery products and Containers, as well as production of heat energy (firewood, chips, charcoal). Black alder is used also in the furniture industry. With growing prices for timber and upgrading of wood processability, for wholesome use of the wood of these fast-growing tree species, it is necessary to investigate its physical and mechanical properties. In the present study, the physical properties of the wood of black alder and grey alder grown in Latvia along the stem height and in die radial direction from the centre to bark are investigated. These properties are compared with those of alder wood grown in other world's regions. It has been shown that density in the oven-dry State for alder wood grown in Latvia is similar to that of alder wood grown in other regions, and it is about 450 kg/m3 and about 530 kg/m3 for grey alder and black alder wood, respectively. Both alder species under study are characterised by an increase in density in the direction from the butt-end upwards. The same tendency is observed also in respect to linear swelling, namely, it increases in the direction to the top. Black alder wood is more stable against the form linear changes under the effect of moisture.