Asghar Tarmian; Marjan Ebrahimi; Reza Oladi
Abstract
In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) ...
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In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) were cut from the sapwood and were then dried in laboratory kiln at 50˚C and 50 % relative humidity to final moisture content of 8%. After drying, the severity of casehardening of dried boards was measured using prong test. For anatomical studies and measuring vessel features, white chalk and black marker method was used and scanned sections were analyzed using ImageJ. Pearson correlation was applied between vessel features and drying properties using SPSS software. Results showed that vessel proportion and porosity have more pronounced effect on the drying rate than vessel diameter and the latter feature can be ignored; as drying rate in the free-water domain was lower for oak having larger but fewer vessels than beech. Results also showed that correlation between casehardening and vessel diameter was significantly positive; however, a negative correlation was observed between porosity and casehardening.
Management and Economics wood
Reza Oladi; Saeideh Nasiriani; Afshin Danekar
Abstract
From a long time ago, researchers in the fields of wood science, dendroclimatology and tree physiology were interested in variation of tree-ring width and vessel features within a tree. However, mutual relationship and interplay between these anatomical features were less studied. In this regard, the ...
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From a long time ago, researchers in the fields of wood science, dendroclimatology and tree physiology were interested in variation of tree-ring width and vessel features within a tree. However, mutual relationship and interplay between these anatomical features were less studied. In this regard, the main question is whether the pattern of adjustment in wood anatomical traits (tree-ring width and vessel features) is similar in all hardwoods and in every site? Or may the same species chose different strategies in different sites? To answer these questions, two growing sites of black alder (Alnus glutinosa) with completely different micro-climates (dry and brackish) were selected near Astara city. In each site, a few trees were selected, cut or cored. After preliminary treatments, wood cross sections were prepared from the bark to the pith of each tree. These sections were scanned and by using an image analysis software, tree-ring width (TRW), average vessel lumen area (AVLA), number of vessel in the unite of an area (VF), and the porosity (Porosity) of a tree ring were measured in the last 20 annual rings of each tree. To study the inter-relations between variables at each site, they were analyzed using different statistical tests. The results showed that the inter- and mutual-relations between tree-ring width and vessel features were similar in tow studied sites. In brief, it can be concluded that regardless of site and climatic condition, in alder trees, wider tree rings leads to fewer vessels and these two anatomical traits are controlled by the same component but AVLA is affected by a different component and is not associated with the tree-ring width.
