Journal of Wood and Forest Science and Technology
Year:2017 | Volume:24 | Issue:1|Papers Count:18

Background and objectives: Common yew (Taxus baccata L.) is one of the most valuable coniferous species in the northern forests of Iran which is shade tolerant and its distribution is from Astara to Ali Abad Katoul (Golestan province). This species additional to having genetic reservation, silvicultural and ecological values, has the special advantage in drug industry. As callus is a primary substance for cell cultures and secondary metabolite's production and indirect organogenesis, therefore, in order to suggest a suitable explant and definite concentration of growth regulators for callus production, the effect of Indole-3-butyric acid (IBA), a-Naphtaleneacetic acid (NAA) and 2, 4- Dichlorophenoxyacetic acid (2, 4- D) on callus production and growth in common yew under in vitro conditions were considered.Materials and methods: In this research, the explants were provided from different parts of the tree such as leaf, young stems and apical buds with 1.5 cm lengths. For sterilization of explants different methods were used. The explants were cultured in Murashige and Skoog medium after sterilization. For callus induction from IBA, NAA and 2, 4- D in 4 levels (0, 0.3, 3 and 6 mg L-1) were used. In order to prevention of auxins decomposition and their better absorption by explants texture, all of the explants were maintained in dark conditions for a week. For each explants of stem, leaf and bud callus growth curve were drawn. Data were analyzed with ANOVA and Duncan tests.Results: The results were shown that the best method for explants sterilization was ethanol 70% (for 1 min), HgCl2 0.2 % and CaCl2 0.2% (for 1 min). The maximum percentage of browning was observed in bud explants at concentration of 6 mg L-1 NAA. The leaf explants were better than other explants in the browning phenomenon, so that there was no evidence of browning in different concentration of IBA and 2, 4- D. The maximum wet and dry weight of callus was belonging to stem and bud explants under treatments of 2, 4- D and NAA at concentration of 3 mg L-1, respectively. In addition, the produced calluses had different texture and color. Most of bud explants at concentration of 0.3 mg L-1 NAA were normal conditions but at concentration of 6 mg L-1 IBA and 2, 4- D, they were converted to callus. The callus growth curves in different explants showed that initiation and callus production and its growth is having a relatively low rate.Conclusion: 2, 4- D at concentration of 3 mg L-1 for callus production from yew stem and leaf explants, NAA at concentration of 3 mg L-1 for callus production from apical bud and NAA at concentration of 0.3 mg L-1 for plantlet production from yew bud are suggested as suitable protocols.

Background and objectives: Riparian forests are one of the unique forest ecosystems, but, there is little information available about these forest ecosystems in the Iran. These forests have an important role in riparian ecosystem protection, but they are in danger. Populus euphratica is one the most common tree species in these ecosystems and is a native species of arid and semiarid sites that spread out in most part of the Iran. Regarding to lack of data about symbiosis of arbuscular mycorrhizal fungi and P. euphratica, this study was done to study of AMF symbiosis with P. euphratica and the effect of distance from river bank on root colonization and spore density. Furthermore, correlation between soil physiochemical properties, root colonization and spore density were investigated to determine the most effective parameters on this symbiosis.Materials and methods: The Maroon riparian forest width was divided to three distances with 200 meter interval. Site one, two and three were located beside water, 200 and 400 meters away from river, respectively. Then, 10 soil samples belonged to P. euphratica rhizosphere were collected in each site. Furthermore, for each selected tree, root samples were collected, and root length colonization and spore density were determined. Also, soil physiochemical properties of each studied distance were determined.Results: The result indicated that the least root length colonization belonged to the distance two and significantly was lower than the other two studied distances. This result might be because of human activity in this distance that could have negative effect on root length colonization.Moreover, although no significant difference was observed for spore density in studied distance, but the highest value of spore density belonged to the distance three. Soil phosphorous, sand and clay were significantly different between studied distances. While, the other studied soil physiochemical parameters showed no significant differences in studied distances. Furthermore, no correlation was observed between root length colonization and spore density. Significant correlation was observed between soil clay, silt and phosphorus. While, root length colonization and spore density showed no significant correlation with studied soil physicochemical parameters.Conclusion: Regarding to the high level of root length colonization and spore density in P.euphratica rhizosphere, we could say that there is high level of symbiosis between P. euphratica and mycorrhizal fungi. Using this symbiosis could be an effective way in protection and expansion of P. euphratica afforestation. Moreover, distance from river bank is an effective parameter on mycorrhizal fungi symbiosis in riparian forest.

Background and objectives: One of the main fields of interest in vegetation ecology is the analysis and understanding of vegetation-site relationships, particularly the response of species to underlying ecological gradients. Many attempts have been done in linking the performance of plant species to environmental variables since last decades. The aim of this study is investigating on the response curve of the beech tree to environmental variables using the generalized additive model.Materials and methods: For this purpose, a stratified sampling method based on landform was used to locate 114 0.1 ha circular sample plots in beech dominated forests in experimental and educational forest of Kheyrud, Nowshar. The mean height of five largest diameter trees within each plot was considered as dominant height. Elevation above sea level, geographical aspect and slope of the ground were also recorded or measured. At the center of plot, soil samples from 0-10 cm depth were taken for analyzing soil texture, bulk density and saturation moisture, pH, lime (%), nitrogen (%), carbon and organic matter (%), potassium, calcium, magnesium and phosphorous. By using generalized additive model and mgcv package in R statistical software, the response curves of the beech tree were individually and simultaneously analyzed. Due to the nature of response variable, Gaussian distribution and identity link function were selected for generalized additive model.Results: The comparison of response curves resulted from GAM for explanatory variables individually and simultaneously showed that there are considerable differences in the shape of the response curve. There are also differences in significance of predictors among these two approaches. By using GAM for each explanatory variable individually indicated that altitude, slope, radiation index, clay, silts, sand, nitrogen, saturation moisture, carbon and organic matter, pH, phosphorous and potassium are significant (P<0.05). Considering all non-collinear predictors showed that altitude, ration index, sand, bulk density, nitrogen, CN, pH and phosphorous are significant variables on beech dominant height in the generalized additive model.Conclusion: The results of this research imply that if the study aims at investigating only the shape of the response curve, considering simultaneously all predictors will present the precise description of species behavior to environmental variables. But if the researcher wants to extract ecological optimum and tolerance for the species besides the shape of the response curve, the behavior of species to predictors individually would be the better choice.

Background and objectives: Unlike forests of North of the country which mainly produce wood, most notable products in the forests of West of the country are non-woody products.These products provide the bulk of the needs of the people in Zagros area. People have acclimated with nature to earn their living needs and have been able to maintain these products and more or less have created and published the methods of preservation, development, restoration, and utilization in these forests, but in some cases, have operated against nature and destroyed the nature either intentionally or unintentionally. Lorestan province comprises 2, 000 plant species and among these, 250 species are medicinal plants. Among these products is myrtle shrub with leaf, fruit, and flower of medicinal value, and this product could be used with correct utilization. Unfortunately, inappropriate and improper utilization practices and excessive use of the species, especially in recent years, has caused serious damages to the habitat of this species, so that in the last ten years, about half of its habitats has been destroyed in Doureh County which its rehabilitation and replacement cost 1, 029, 600, 000 Rials.Materials and methods: The most important factors in the destruction of this species in the viewpoint of experts, farmers and local people have been examined through a questionnaire. A total of 66 were completed by experts and 244 questionnaires were completed by farmers and local people and after extraction and categorization the responses were analyzed by binomial test.Results: In total, 7 factors were identified that have some influences on the habitat destruction, among which weak management and utilization by the company with an average of 4.76 (94% of respondents) and 4.42 (83% of respondents), respectively, were defined as the most important factors causing habitat destruction.Conclusion: However, the current situation of the myrtle sites has been presented as a serious threat, if this situation is defined correctly by adopting the right policies and providing financial and administrative support necessary for the successful implementation, it could be turned into an opportunity causing the economic prosperity and improvement in employment conditions of the province. This opportunity includes encouraging local people to plant myrtle with effective financial support by the government to promotion and development of the man-made plantation of myrtle species.

Background and objectives: Analysis of spatial pattern and association of inter-tree species in the developmental stages in natural stands is a prominent prerequisite for simulating, founding and extending forest ecosystems. This study aimed to obtain appropriate information for extending sustainable development and simulation, and performing close-natural silviculture in a non-protective site using this technique for endemic species including Caspian poplar and Ironwood trees in Nour Forest Park forest.Materials and methods: In the studied site, the developmental stages consisting of initial, optimal and decay stages were determined in each area of one hectare using the specified indices, and coordinates of target species were taken by GPS and trigonometric relationships.To map spatial patterns of each tree species and competition model for inter-tree species, univariate and bivariate function of K-Ripley were used in the study. As such, Monte Carlo simulation was used to test the null Hypothesis of a random distribution and interaction relationships.Results: The findings of univariate function showed that Caspian polar trees were clustered in the distances of 9- 14 m, >7 m and 8- 35 m in the initial, optimal and decay stages, respectively, and this species, however, was randomly distributed in other distances. The results for Ironwood trees showed the random pattern in the initial stage, cluster pattern in distance of 20-39 m and 6- 32 min the optimal and decay stages respectively, and either random or clustered patterns in the other distances. There were no regular patterns for these species in the different stages. Furthermore, the results of bivariate function indicated that there were attraction relationships between Caspian poplar and Ironwood trees in the majority of distances in developmental stages though there were also independent associations in some distances within the different developmental stages.Conclusion: According to the findings, the specified spatial patterns of each tree species would be affected by natural events, and since there were found no inter-species repulsion relationships, high density of Ironwood trees could be in association with density of Caspian poplar trees in the studied forest.

Identify tree species and tree composition mapping are playing an important role in making optimal decisions for the forest's ecosystem management of large areas. Capability investigation of different remote-sensing sources, such as aerial digital images for forest resources is considered as an alternative method for ground surveying in recent years. Remote-sensing data, especially digital aerial images with high spatial and radiometric resolution could be a useful tool to identify tree species. By traditional pixel-based methods, classification the pixels of images can be done the different algorithms. Traditional digital classification methods such as the maximum likelihood algorithm are the most common methods based on pixel-based classification. The use of modern classification algorithms such as a non-parametric support vector machine algorithm is essential to compare their performances.Background and objectives: According to a few studies to examine the capability of these images in the urban forests and reforestations in the northern Iran, and lack of a research about evaluating the capability of Digital aerial images to identify tree species in the Hyrcanian mixed forests, The aim of this research is an investigation of capability of UltraCam-D aerial digital photos to identify tree species in the Hyrcanian mixed hardwood forest, district 1 of Shastkalate forest in Gorgan and comparing two pixel-based algorithm, i.e. the maximum likelihood and support vector machine. There are several ways to extract information from this type of image.Materials and methods: a ground truth map of 128 trees species was provided by registration of their position with DGPS. Identification and classification of tree species were done using original and processed bands s using pixel–based method of maximum likelihood and support vector machine algorithms Accuracy assessment of classified maps was done with use of 25% of the ground truth samples.Results: The accuracy assessment of filtered classified maps showed the classified map of the maximum likelihood algorithm had the overall accuracy and kappa coefficient of 63.63% and 0.51, and support vector machine algorithm had 42.37% and 0.2, respectively.Conclusion: By comparing the results, it is exposed that the pixel-based classification method has not been effective relatively in identifying tree species due to the salt and peppery effect or without using of the auxiliary data (slope, elevation, etc.) in the classification process. The use of other methods such as object classification method based on identify of tree species will be recommended. In addition, the capability of images should be examined in different forest conditions.

Background and objectives: To reveal plants systematic and phylogenetic evolutionary development of the species, wood identification and wood anatomical descriptions were being considered by Biology researchers every so often. From Palaeobotany point of view, there have been done successful researches by studying wood fossils. Petrified woods preserve more extended history of wood habitats comparing to other plant organs. In this study, we identify and introduce fossil woods of Annakhatoon NE of Tabriz region, which were explored from 1: 25000 map preparation operations.Materials and methods: In this study, we put to use stem like pieces to make identifications of the petrified tree stems of the age Pliocene, NE Tabriz. Appearance, size, color and other physical characteristics were recorded and photographs prepared, after transferring the collected samples to the laboratory. We prepared thin sections of all types of transversal, radial and tangential planes, according to specific methods, whereas possible. First of all, we cut 1*2*3 cm pieces with their long axis parallel to the tree longitudinal axis, removed rough areas, planed and finished. After making a polish, the thickness was so lowered around 0.03 mm that the light could pass through the wood thin sections. Thin sections of tangential, radial and cross section were prepared to study microscopically. In the cases where the state of preserving allowed, we studied wood anatomy and the features related to tracheids, ray parenchyma, pits, resin canals and other wood elements employing light microscope. Following IAWA list of microscopic features of Gymnosperms, made the elementary descriptions the identification was completed by comparing data with other petrified woods in collections elsewhere.Results: The results showed that the structure of fossil sample was the same as Gymnosperms.Growth ring boundaries distinct, transition from early wood to latewood abrupt, ground tissue consists of thin walled tracheids, uniseriate rays abundant, unlikely pinoid bordered pits in cross fields and a few solitary resin canals, were common. The material has been referred to Pinuxylon fossil species of Coniferals at this stage.Conclusion: Although lack of proper preservation, solitary resin canals, few axial parenchyma, large bordered pits arranged in single rows at radial walls of early wood tracheids and very likely pinoid pits in the cross fields, show close relation to Pinuxylon genus type. This genus type implies a temperate climate there at that age.

Background and objectives: Wood modification with eco-friendly materials and methods improves the wood properties for many applications. Synthetic polymers are widely used for wood modification via wood impregnation with unsaturated monomers. Results in the fabrication of wood-polymer composites (WPC) through in-situ polymerization within wood pores. In modification with the Acrylonitrile vinyl monomer, the hydroxyl group of the cell wall are free and they could absorb moisture. So, a modifier presence with coupling effect between monomer and cell wall, could increase the wood service life. In this research, the effect of 3- (trimethoxysilyl) propyl methacrylate on mechanical and biological properties of Acrylonitrile wood-polymer was investigated.Material and Methods: Mechanical and biological test samples were prepared from straight grain and no defect timber of dried Poplar wood according to ASTM-D143 and EN113 standards respectively. Test samples were divided in 7 levels: control, modified with silane compound in subgroups of acidified Ethanol at 110 and 150oC, ethanol with and without Benzoyl peroxide as initiator at 150oC, Acrylonitrile/ Benzoyl Peroxide and combined level of silane/Acrylonitrile/ Benzoyl Peroxide. Sample's impregnation was carried out using vacuum-pressure method in the laboratory cylinder. Statistical analyses of mechanical and biological data were conducted using complete randomized design. Means of each treatment were compared according to Duncan multiple range tests.Results: Silane modification and Acrylonitrile presence in the composite were confirmed by infrared spectroscopy. Silane modification led to increase in mechanical strength of wood due to crosslink formation, and also created significant improvement in flexural modulus and hardness at acidic conditions and higher temperature. Adding initiator to silane modification, in addition to the cell wall modification, resulted in more activity in the free radicals and polymerization the part of silane in the lumens. The presence of Acrylonitrile in the lumen enhanced the mechanical properties. Combined modification by modifying the cell walls, filling cavities and linking between lumen polymer and cell wall in the presence of silane coupling agent, caused the more uniform distribution of force and significant improvement in the most mechanical strength compared to single modification with silane and acrylonitrile. Also, presence of monomer improved the biological resistance of the resultant product. In acidic condition, higher temperature with further cell wall modification led to the significant decline of weight loss.Compared to the other single modifications, Silane modification containing initiator, with cell wall modification and physical blocking the entrance path of fungal hyphae and humidity, significantly decreased the decay weight loss. The combined Silan/Acrylonitrile modification showed the lowest weight loss exposed to fungal decay due to the linking between more silanol and hydroxyl groups of wood and acrylonitrile presence in the lumens.Conclusion: Silane compound enhanced the mechanical and biological properties of Acrylonitrile wood polymer, which the improvement was more obvious at the higher temperature and under acidic conditions. Combined Silane/Acrylonitrile modification created maximum improvement in the most mechanical properties. Presence of a initiator with less weight loss exposed to fungal degradation, intensified bio-resistance compared to other silane modifications. Combined Silane/Acrylonitrile modification was presented the less fungal degradation that can be attributed to filling lumen and cell wall pores, less moisture and finally reduction of hyphae development, enzymes transfer and fungal hyphae access through the wood cell wall.

Background and objectives: Development of non-oil exports is one of the pillars of strengthening the country's economic growth. Today furniture industry has a significant share in global trade, so the sustainable development and growth of this industry can have a significant impact on employment, GDP growth and non-oil revenues. Because of the economic, social, and environmental importance of the wooden furniture industry, the need to move toward sustainable development in the industry is felt. The aim of this study was to identifying and assessing the weight of effective criteria on the sustainable development of Iran wood furniture industry and suggesting appropriate solutions using a non-parametric approach of the analytic hierarchy process.Materials and Methods: In this regard, first by comparative studies as well as interviewing relevant experts, the effective criteria were identified. After plotting the hierarchical levels on the decision tree (including goals, criteria, sub-criteria and alternatives), the data needed to determine the weighting value and prioritize each of them were prepared in the form of designing standard questionnaires based on paired comparisons and using the opinions of the industry & university experts of and the relevant institutions and finally, its computational steps were carried out with Expert Choice software.Results: Base on the obtained results, economical and environmental criteria have the highest weighting values at first level as 0.358 and 0.212 weighting values, respectively. At the other hand, an improvement on economical stability (0.168), development of industrial clusters (0.149), reduction and control of volatile organic components (0.121), continuous relationship between university and furniture industry (0.093), Furniture recovery (0.074) and development of outsourcing strategy (0.060), have the highest priorities at the secondary level. Finally, the "Modeling of sustainable development models in developed Countries, " with a weight of 0.340 as the best alternative, was selected to achieve sustainable development in the Iranian furniture industry.Conclusions: Results of this research can be used as a road map for movement to the sustainable development, and appropriate solutions to improve the performance of producers and to introduce structural reforms in various sectors of the Iran's furniture industry with the aim of achieving international markets and sustainable development will be addressed to authorities, practitioners and policy makers.

Background and objectives: One of the requirements of adhesive joints formation is penetration into the wooden substrate. This phenomenon is influenced by multiple factors such as resin viscosity and wooden substrate moisture. There are many studies which were done on adhesive penetration in wood veneers and two strands. In this study, adhesive penetration pattern due to strand moisture and resin concentration in a particulate wood-based composite; OSB, was investigated. For this purpose, micro photographs of cross-section of the produced boards were prepared and parameters of the adhesive penetration pattern were evaluated and compared between treatments.Materials and methods: for this research, oriented strand boards were made with poplar strand and phenol formaldehyde resin. The variables consisted of strand moisture content with three levels; 2%, 6% and 10% and resin concentration with 45%, 50% and 55% levels. After preparation microscopy samples, micro photographs of core layer and middle layer were taken.FFN and FVN as penetration pattern parameters were measured. In order to determine significant effects, one-way ANOVA was used. For grouping the mean amounts, Tukey test was applied.Results: the effects of strand moisture content, resin concentration and position in the board thickness on penetration parameters were significant. Higher strand moisture content increased the penetration especially in fibers. Application of lower resin concentration improved the penetration. The penetration of resin was higher in middle layer that was near to the hot platen of press.Conclusion: As mentioned in previous studies, the existence of moisture in the strand prevents increasing of resin viscosity and causes more penetration. In other words, the more dryness in wooden substrate, the more increasing in resin viscosity and could limit the resin penetration.Generally, the parameter take from fiber counting showed more organized changes with compare to FVN parameter that was taken from vessel counting due to strand moisture and resin concentration effects. Also it was determined that, the penetration patterns in core and middle layers of the board are different.

Background and objectives: Several studies have been conducted to improve the paper properties and this research is for coating process in the converting operations of papers. Improvement of paper properties can cause a variety of its applications. In general, the desirable properties are expressed by barrier, mechanical and optical properties. The aim of this study was to evaluate the effect of the GCC coatings on two types of base papers with two levels of binder.Materials and methods: For this purpose, two different base papers (kraft liner and fluting from Mazandaran pulp and paper mill), immersion and bar coating methods as well as a binder (PVA) at two levels were used. Coating material had 20% solid content, including GCC (100 parts), dispersant (0.3 parts) and PVA (6 and 12 parts). Two suspensions with low and high binder were named no.1 and no.2 combination respectively. Dip coating was performed in the two suspensions for one minute, and the bar coating was carried out by the bench coater with the same combinations. Physical characteristics such as air resistance, thickness, mass, brightness and water absorption (Cobb60) for control and treated paper were determined. After the calculation, the coating weight and grammage was obtained, and then these data were entered to SPSS 16.0 software for analysis of variance.Results: In comparison to the control group, all the treated fluting papers showed significant difference in grammage, thickness and coating weight. The significant effect was observed on air resistance of fluting and kraft liner papers at 5% level. However, there were not any differences in bar coating method on air resistance at 1% level in fluting papers with low PVA and so in the kraft liner papers with high PVA. The amount of water absorption in the treated fluting samples with low and high PVA using bar coating method indicated a significant difference at 5% level compared with treated samples in immersion method and control group. However, the Cobb60 significant reduction at 1% level was seen in the low binder combination with rod coating method. In terms of lower water absorption, rod coating with high PVA was much better than the other treatments. Due to more coating weight in the immersion method, the value of brightness increased in the immersed samples. Except rod method with low PVA, other treatments created significant differences (5%) in brightness between the treated fluting papers and control group. Kraft paper samples showed significant differences in brightness at 1% with both suspensions in immersion method, but kraft samples of bar method with low PVA were significant at 5% level. Correlation coefficients between the coating weight and air resistance, thickness, brightness as well as grammage were 0.549, 0.734, 0.687 and 0.489 in the tested papers respectively.Conclusion: According to information of this research, changes of water absorption in samples were low, but the rod method reduced water absorption and had positive influence on paper barrier properties.Brightness of studied kraft liner was pretty good and the brightness of this brown paper reached to 57.Even in cases such as water absorption and brightness, the first composition (low binder) was better than the other suspension. The air resistance improved in all treatments and increment of this measurement is more evident in the fluting papers and the immersion method. Due to the improvement of physical properties, barrier and brightness in treated paper, made value-added papers in these samples compared to the control groups.

During recent few decades several denderoclimatological studies have been done in different places of the world and researches using denderoclimatology methods extracted the climatic related information from the tree ring and reconstructed past climatic variations. The purpose of this study was to investigate the potential of Siberian elm wood (Zelkova carpinifolia) in reconstruction of precipitation and temperature using tree-ring width and vessel lumen area chronologies.Materials and methods: In this study, we built Zelkova carpinifolia ring width and vessel lumen area chronologies we extracted 20 cores from intact trees using Swedish increment borer.After preparation the samples were scanned using a 4800 DPI scanner. After scanning ring width and vessel lumen area were measured by image j software. Afterwards ring width and vessel lumen area time series were drawn by Excel software. Standardization of time series was performed by Fritt's method (1976). Chronologies characteristics including mean sensitivity, first autocorrelation, express population signal and GLK coefficient were calculated. Correlation coefficient was calculated between ring width and vessel lumen area indexes and neighboring meteorological station precipitation and temperature data. We used Ramian meteorological station data. It was 5 kilometers far from Dland Park. Variations with the most important correlations were used for temperature and precipitation reconstruction. Reconstruction performed by split– sample calibration verification method. For testing validity of reconstruction we used sign test and reduction of error (RE) statistics.Results: Correlation coefficient's analysis indicated that at seasonal scales ring width was significantly, positively correlated with previous year spring and fall precipitation and vessel lumen area was correlated with previous year autumn precipitation. About temperature the only important correlation was observed in August. Ring width and vessel lumen area were negatively correlated with the previous year August temperature. The validity of reconstruction by sign test and reduction of error statistics indicated that reconstruction of previous year spring precipitation using ring width variation and reconstruction of previous year fall precipitation by vessel lumen area variation in this region is the successful, but reconstruction of temperature was not successful.Conclusion: It seems that at low elevation reconstruction of precipitation by ring width and vessel lumen area variation is the successful but reconstruction of temperature perhaps needs other tree ring variables such as maximum late wood density or late wood ring width. Also at this region the effect of previous year climatic condition on ring width and vessel lumen area is more important than current-year climatic conditions.