جستجوی مقالات مرتبط با کلیدواژه "wood identification" در نشریات گروه "جنگلداری"

The art of "Chutashi" or "Lucktarashi" is the manufacture of traditional wooden boxes and containers using forest trees in Mazandaran province, which has a long history. The purpose of this research was to identify the wooden species used in Chutashi and to investigate their distinctive features and technological (physical, mechanical) excellence. Hence, rough or semi-finished wood specimens were collected with different dimensions and shapes from local workshops. The handicraftsmen's reason for preferring these woods and their presumed superior characteristics were also recorded. The moisture content, density, shrinkage, and the swelling of the wood as well as mechanical properties including shear strength perpendicular to grain, cleavage strength, side hardness, and Charpy impact strength (toughness) were measured on seven kinds of selected specimens (maple root, maple trunk, Boissier pear, wych elm, boxwood, yew, and walnut). To further investigate the reason behind the desirability or undesirability of certain woods, their xylem was examined under a microscope and/or a stereomicroscope. Summarizing the views of the craftsmen showed that they prefer the root wood of maple and close-to-bark lumbers of mature, thick trees. Moreover, that part of a tree trunk, which is less exposed to the sun and is covered by moss, is more suitable for Chutashi. Mechanical tests showed that the shear strength perpendicular to the grain in the elm, cleavage in maple and walnut, the toughness of maple and boxwood, and the hardness in the yew had the highest values. Also, boxwood had the highest density, and yew showed the least shrinkage. Microscopic examinations clearly revealed the wider vessels, more homogeneity, and more interlocked grains in the root wood compared with the trunk one. The phenomenon of "Ahanak (ironlet)" in the yew, which causes a sharp drop in its quality, is, in fact, the accumulation of special extractives in several tracheid rows. Finally, the relationship between physical-mechanical characteristics and the views of the craftsmen was discussed and presence of superior properties in the selected timbres were verified.

All imported softwoods are called "Russian wood", in Iran. Despite the existence of domestic Persian terms for naming each individual conifer genius, they are known and traded by Russian names like "Sasna (Сосна)", "Yulka (Ёлка)", and "Leastvinitsa (Лиственница)" in the Iranian market. Although, practically, some wood sellers relate these Russian names to a specific genus or species but no systematic investigation has been done to verify it and there is huge confusion for consumers to obtain the right softwood. According to differences in applicability and end-use of different softwoods, not knowing the genus/species of purchased timber can be problematic. Hence, the aims of this research were to survey the sawn softwood market in Iran, in terms of abundance and identification of different woods.

25 different softwood pieces were collected from the Ports and Maritime Organization of Guilan as well as 10 big lumberyards in Tehran and Karaj. Those wood sellers who did not discriminate between softwood types and sell all of them under the general name of "Russian wood" were excluded. The collected woods were investigated macroscopically and after preparing microscopic slides and picturing, the anatomical features of samples were extracted according to the IAWA list of microscopic features for softwood identification. Then, genus or species of wood was identified based on the combination of proposed methods.

The most abundant softwoods in the Iran market were respectively, Yulka, Sasna, and Leastvinitsa while true fir was remarkably less common. Other than true fir, imported softwoods were in good accordance with the corresponding genus/species attributed to each Russian name. Eight out of ten Yulka samples were identified as Picea sp.; six out of seven Sasna samples were identified as Pinus sylvestris; and all of three Leastvinitsa pieces were of the species Larix sibirica. However, regarding true fir (Abies sp.), considerable discrepancies existed. Some wood sellers entitled all purchasable softwoods as "fir" and did not discriminate between them. Among four sources who acknowledged that fir is an exclusive type of wood, half of the samples were actually pine.

Macroscopic features of softwoods, e.g. color, texture, sheen or luster, size and frequency of resin canals, the transition from earlywood to latewood, and presence of pitch pockets in longitudinal planes are not reliable properties for wood identification and precise identification of these woods entitles a microscopic investigation. On a macroscopic scale, the only decisive feature is the presence/absence of the resin canals in the transverse plane, which can be used to easily isolate true fir from the rest of the softwoods in the Iran market. On a microscopic scale, Scots pine having big cross-field pitting can simply be separated from two other woods also bearing resin canals i.e. spruce and larch. However, two latter softwoods cannot readily be distinguished from each other. Overall, it can be concluded that although Russian names of softwoods in Iran are somewhat correctly applied to the corresponding sawn lumbers but popularizing equivalent long-lasting Persian terms is recommended to avoid confusion and discrepancies.

One of the the challenges of lumber traffic is adulteration in wood kind which is widely spread due to the difficulty or impossibility of wood identification –especially exotic hardwoods- at macroscopic level. The other concern regarding luxury and aesthetic wood market in Iran is trading the colorful wood of some endangered and protected trees species like wild Pistachio in the name of imported tropical wood. The aim of this study was to identify different types of luxury hardwoods in the wood market of Iran and validate their corresponding commercial names.

39 different hardwood pieces were collected from Ports and Maritime Organization of Guilan as well as lumberyards, marquetry and wood mosaic workshops in Tehran and Karaj. First, the scientific names of samples corresponding to commercial names were recorded. Cross-sections of woods were sanded and scanned and microscopic slides were prepared. After extracting the anatomical features of samples, genus or species of wood was identified and compared with those claimed by the seller or handicraftsman.

The results showed that 80 percent of hardwood samples were dealt and used in industry by the correct name. Imported hardwoods were mainly of tropical woods which shared many common features (arrangement of axial parenchyma, presence of banded parenchyma, crystals, and storied structure). According to the similarity of key features, the process of discrimination and identification was not easy and fast. Well-known tropical timbers like okoumé, rosewood, African padauk, and sapele were correctly traded. Almost all timers in warehouses were named correctly; however, in retails and small workshops, discrepancy increased. Among collected samples, the most discrepancy was observed in the case of teak and a wood called "fofel". Teak is one of the few tropical woods in the market that has distinct growth ring boundaries and hence, its identification is comparatively easy. Therefore, we conclude that the incorrect naming of teak woods is partly due to the dishonesty of wood sellers. On the other hand, "fofel" is a wrong labeling of Indian rosewood and there are some cheatings regarding this wood due to its popularity in Iran wood market.

The main conclusion of this study is that due to the similarities, distinguishing common decorative woods in Iran market is impossible in terms of macroscopy and merely based on texture and color. Even on the microscopic level, the wood identification is laborious and can be accomplished only by cautiousness. Having said that, the exotic hardwoods in Iran market –especially at wholesales- are relatively in good accordance with their English commercial names and hence, Iran wood market is relatively verified in this aspect. However, due to the existing discrepancies in the case of some popular luxury woods, it is recommended to trade these exotic hardwoods with certificate or verification of wood anatomists.