Dimensional and quality properties of deciduous trees stem wood | Mīksto lapkoku stumbra koksnes dimensionālais un kvalitatīvai raksturojums
2009
Lipins, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dreska, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sarmulis, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the investigation is to clarify the quantity and quality properties of aspen and gray alder tree species stem-wood timber to be expected from final felling forest stands in Latvia. The tasks to be solved encompass the selection of methods for field works and data processing, the arrangement of sample plots, the preparation of sample tree stems, measuring operations and data collection, data processing, analysis and interpretation of results as the basis for quality indices and numerical values forecast depending on affecting factors. Sample plots location is chosen with the purpose to cover all territory of Latvia. The material for the investigation of aspen tree species is taken from 6 sample plots, and for the investigation of gray alder tree species it has been taken from 5 sample plots. The breath height diameter of every aspen tree or gray alder tree respectively, is measured in each sample plot, and the characteristic of wood quality features has been prepared at the same time. Tree stem length and diameter over and under bark measurements, knot size and location parameters of other wood quality features are the main object for data collection. The standard equipment and methods are used for this reason and the data processing as well. The results of investigation reveal that 25 to 100 % of aspen trees in final felling forest stands (at the age of 50 to 80 years) suffer from tree heart rot. The stem volume portion occupied by this rot depends on stem diameter, stem slenderness, year ring width, and tree crown length. The rot portion decreases with the increase of stem diameter, year ring width and/or tree crown length, but increases at the same time as slenderness does. Affected by heart rot aspen tree forest stand market value diminishes by 25 to 50 % if compared with unattached one Aspen tree stem knots are another kind of wood quality features badly affecting timber value. Aspen tree stem knotless zone length is between 3.5 and 10.0 m, or 7.5 m average (25 % of stem length).
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