Journal of Forest and Wood Products
Year:2014 | Volume:67 | Issue:1|Papers Count:14

Rainfall after passes through the biomass and necromass, penetrates into the soil and make large qualitative changes because of rhizospher, microorganisms, horizon thickness and organic matter. This process is the result of atmospheric, hydrological and biogeochemical reactions influenced by seasons. In this study we investigated seasonal variations of base cation leaching (Ca2+, Mg2+, Na+ and K+) in the soil of mixed Hyrcanian beech located in district one of Shastkolate forest, Golestan province. Shallow and deep soil leachate samples (0-10 and 10-50cm) were taken within a year (2008/12/21 to 2009/12/21). Amount of base-cations of shallow and deep soil leaching in different seasons were compared by the one way variance and Duncan test. Results showed the amount of Ca2+, Na+ and Mg2+ contents of shallow soil leaching in seasons are different significantly (P<0.05) so that the most leaching of Sodium and Magnesium were observed in winter. Sodium and Magnesiumin deep soil leaching were different significantly (P<0.05) so that the most leaching of them were observed in winter and spring respectively. With the recognition of chemical properties variations of shallow and deep soil leaching, we can suggest that exploitation programs perform in February to make optimized biogeochemical cycle and maximized base cation leaching.

The aim of this work was to assess the characteristics of Poplar root system. Root Area Ratio (RAR) values were obtained using profile trenching method. First a starting point along the row of trees was randomly selected. Then a ten meters contiguous profile was dug along the row of trees and roots on both trenches (At a distance of 0.5 and 1.0 meter from the trunks) were measured. RAR values of roots were obtained at depth increments of 0.1 m. Also 30 root specimens were analyzed for tensile strength. The results indicated that RAR declined mostly in depth and distance from the stems. This decrease approximated a power function. In most cases the maximum RAR values are located within the first layers, with maximum rooting depth at about 1.0 m. The minimum and maximum RAR values along the profiles were 0.004% and 0.534% for nearer and 0.001% and 0.314% for farther trenches to stem respectively. The results of traction tests revealed that a positive power function existed between tensile force and root diameter. The mean root tensile strength and diameter were 19.92±4.12 MPa and 1.51±0.95 mm respectively. The root tensile strength values showed that root strength decreases with diameter following a power law equation. The data presented in this study expand the knowledge on most important biotechnical properties of Poplar growing in Iran.

Remotely sensed data, especially high spatial and radiometric resolution data can be useful to identify tree species. In this research, the capability of digital aerial images for this purpose was investigated by object-based classification method. About 5.8 ha of Taleghani park in Tehran, including species like platanus orientalis, Morus alba, Cupressus arisonica, Robinia pseudoacacia, Pinus eldarica, Ailanthus altissima, Cedrus atlantica, was studied. Four pan-sharpened multispectral images of UltraCam-D camera with the spatial and radiometric resolution,  0.07×0.07m and 16 bit respectively, were analyzed. These data were geometrically corrected by aero-triangulation method using GCPs and IMU. The images classified using object-based method with the main and synthesic bands of Ratioing, PCA and HIS transformations. Firstly, segmentation was done with different parameters in order to avoid exceeding the maximum allowable number of objects. Finally, the classification was performed using appropriate features and layers by Nearest Neighbor method. In order to assess the accuracy of result, a ground truth map was produced based on field survey. This map has included 688 points, which each represents a tree on the ground. The result of accuracy assessment showed that overall accuracy and Kappa coefficient were 78% and 0.73 respectively. Platanus and Aillan showed the highest and the lowest Kappa 0.81700.2481, respectively. The result of this study showed that the UltraCam-D and object-based method have relatively good capability to recognize tree species. To reach a certainty about this result, it is essential to evaluate UltraCam-D data in other sites with different species.

One of the most important disturbance occurred in beech stand is tree uprooting that creates pit and mound microsite where caused serious change in soil physical and chemical properties. Pit and mounds have different ages in forest. So this research was carried out to investigate the relation of pit and mound dynamics with some physical and chemical properties of soil in a mixed beech forest in Shastkolate forest, Golestan Province. Soil samples were collected from 4 microsites: pit, mound, around the dead woods and closed canopy, in 4 different decay stages. Then soil Organic matter, bulk density and pH were compared in different age and 4 sections using one way ANOVA. Results showed that the amount of soil organic matter, bulk density and pH in 4 sections were significantly different (P<0.05). The most amounts of soil organic matter were found in pit while the most amounts of soil bulk density and pH were found in mound. Also the amount of soil organic matter and bulk density in different ages were significantly different among decay stages except for pH. The greatest amount of soil organic matter and bulk density were found respectively in 10-15 and less than 5 years. It can be concluded that soil organic matter increase while bulk density decreases when time following up and pit become older. However, older pit has richness and fertile soil because litter decomposition well done and microorganisms activities increases. Microsites created by the beginning of change, forest stand development and soil fertility.

Farm tractors are a multipurpose machine in many applications, especially in agriculture and forest logging activity. Short log skidding with farm tractors is one of logging systems in plantation area in north of Iran as in many other areas in the word. In forest logging operation, equipped farm tractor with trailer can be used to skid short logs from stump area to landing. In this study, that has been carried out in Sheikhneshin plantation area of Shafaroud watershed, 69 skidding cycle studied and, after determination of skidding affective factors, the elemental time study method was applied to develop the skidding time predicting model. The efficiency and unit costs of logging were calculation in the operational and scheduled working time for farm tractor operators. Skidding time was most affected by number of log per turn, volume per turn and skidding distance. The logging productivity was 5.66 m3/PH or 5.34m3/SH with an average log number pre turn 59, an average volume per turn 3.81m3, and the average forwarding distance 202m. The cost of skidding using with and without delays was 88196 and 80354 Rials per cubic meter, respectively. Result of this study consistent with the result of research in progress should provide forest manager, planner and logger with detailed and accurate logging cost estimators allow for comparison and selection of equipment.

Basic forest management and planning require appropriate quantitative and qualitative information. This information obtained from forest inventory. So forest inventory have an essential role in estimating present situation and future planning. In this study,  37.2hectares of Daalaab forest of Ilam province were calculated with 1 hectare samples. To analyze quantitative characteristics, “transect with fixed length (50 m)” and “transect with fixed number of tree (5 trees)” were selected for comparison. Measured characteristics were density (number tree per hectare), crown cover and basal area. Based on systematic-random sampling pattern with 100×100m dimension, 37 samples were selected for each sampling method. In each sample, characteristics of trees were recorded and measured. Results this investigation showed that based on precision and cost criteria, transect with fixed number tree sampling method is a more suitable method for analysis of quantitative characteristics in the studied forests.

This study aimed to determine the effect of physiographic factors (slope, aspect and altitude) on quantitative characteristics of Persian Oak (Quercus brantii Lindl) in forests of midlle Zagros. In this study in forests of the Abdanan city if Ilam province and regional functions area were approximately 150 ha, 134 sample plots of rectangular shape with dimensions 40*50 m to the systematic – random method in a network with dimensions 100*100 m using and species characteristics, dbh, crown diameter, heigh of trees and physiographic sample plot (slope, aspect and altitude) were recorded. Results showed that the effect of physiographic factors on dbh of trees was not significant. The aspect and altitude on the characteristics size canopy of tree, basal area per ha and number of ha has a significant impact. Among the physiographic factors aspect have a significant impact on trees height. This study can conserved areas that Oak species with quantitative characteristics better and special attention to areas that are being destroyed, to be effective.

In this research, effects of pre-steaming of fir wood (Abies alba) on the ACC preservative absorption, retention, and depth of penetration were investigated. Pre-steaming was carried out at 120, 140 and 160°C for one hour under 2 to 3 bars pressure. Steaming was carried out for bastard sawn boards with green dimensions of 250×100×50 millimeter and average initial moisture content of 30%. After moisture conditioning of wood samples, they were impregnated with ACC preservative solution with 5% concentration using low pressure process. Then, the impregnation properties were measured. The image J software was also used to determine the wood cross section impregnation. Results showed that pre-steaming at 140 and 160oC significantly increased the absorption, retention, and depth of preservative penetration, however, no significant difference was observed between the control specimens with those pre-steamed at 120oC. Furthermore, the results showed that the wood impregnation properties, including absorption and depth of penetration improved by increasing steaming temperature from 120 to 160o C.

Cellulose, which is the most abundant natural polymer on the earth, has wide variety of applications due to unique physical and mechanical properties. The native crystalline structure of cellulose (cellulose I) is considered to be one of the major factors limiting its potential in terms of cost-competitive variety production. Here the effect of ionic liquid treatment on the cellulose crystalline structure was studied. Two imidazole-based ionic liquids, 1- butyl -3 - methyl -1 - Imidazolium chloride (BMIMCl) and 1, 3 - methyl imidazolium dimethyl sulfate ([BMIM] [MeSO4]), were used to dissolve cellulose. The overall evaluation indicates the inability of ([BMIM] [MeSO4]) in dissolution of cellulose whereas BMIMCl was capable in cellulose dissolution. This was also confirmed by 13CNMR spectrum. Original cellulose crystalline structure was deformed to Cellulose II and the crystallinity rate was decreased during dissolution and regeneration. Also, crystallinity percent, nano crystal thickness and hydrogen bond energy were decreased after dissolution. Moreover, results showed that the crystallinity and crystal thickness were increased through gradual cooling method regeneration compared to immediate cooling method.

In this study, the effect of using cellulose nanofibers and cationic starch on the mechanical properties of soda anthraquinone (Soda-AQ) pulp prepared from un-extracted/ alkaline pre-extracted rice straw using conventional hand sheet paper making system with standard wire was investigated. Cellulose nanofibers were added at three ratios of 2, 5 and 10 wt%, mixed with pulps from un-extracted/ alkaline pre-extracted rice straw over 2, 5 and 10 minutes. The consumption ratio of cationic starch was also tuned at 1.5 percent based on dry weight of pulp. The results show that in spite of using conventional hand sheet paper making system, the mechanical strength of paper containing cellulose nanofibers linearly increased. The use of cationic starch had a positive significant effect on the paper properties due to better retention of cellulose nanofibers. The results indicate the success of using cellulose nanofibers with cationic starch in improving the mechanical characteristics of soda-AQ pulp in conventional hand sheet paper making system.

In paper industry, Twin roll press machines are utilized for recovering the dissolved materials resulting from the process of transforming wood into pulp and it's efficiency has a considerable role in wasting resources and effluent pollution load. This research was performed for the purpose of showing the effective pulp consistency on efficiency of washing by using a mathematical model based on the pattern of simulating the System Engineering Analysis. The press function was analyzed according to the same principle. Based on the data of Mazandaran Wood and Paper Industries, the results show that in a fixed amount of production the washing efficiency of the twin roll press has a direct impact on the pulp consistency coming out of the related press. The consistency rise of about 10% of output pulp, increases 10% washing efficiency and reduces about 35% of not recovered dissolved materials, this represents a decrease in effluent pollution load.

This research was done to evaluate of cellulase potential to improve the physical properties and drainability of OCC pulp. The OCC pulp with 10% consistency was treated enzymatically under constant conditions of temperature 50°C for 60 min and pH range of 5-5.5 by different levels of 0.05, 0.1, 0.2, 0.3 and 0.5% from cellulase (based on oven dry weight of waste paper). Also OCC pulps were separately pre-treated at different times of 30, 90, 120 and 150 min at given cellulase charge (0.3%). In addition, enzyme pre-treated OCC pulps were refined mechanically at constant revolution of 2000 rpm. The results showed that without employing refining, enzymatic pre-treatment caused to improve the pulp freeness by about 22% proportional to control sample (non enzyme treated pulp with 470 ml, CSF). Using 0.3% and 0.5% were resulted as same as the highest freeness (600 ml, CSF). With increase in cellulase charge from 0.05 to 0.3%, the paper with lower calliper and higher density was resulted. Also, in unrefined OCC pulp, use of shorter duration of enzymatic treatment (30-60 min) was resulted in a pulp with higher density and air resistance. Maximum freeness (645 ml, CSF) was attained at 90 min. Increasing the enzyme level followed by refining caused to improve pulp freeness and a range of 0.05-0.1% cellulase is advisable as the best level of enzyme usage.

This study was conducted to investigate the low weight coating (LWC) effects on mechanical and optical properties of printing papers produced by Mazandaran Wood and Paper Industries Co. (MWPI). Two mineral pigments including nanoclay and precipitated calcium carbonate (PCC) were applied by blade coating method in different weight percentages of latex. Surface structure of coated paper was characterized by atomic force microscopy (AFM). Also, mechanical and optical properties of coated paper and control were measured. Comparison of the characteristics showed that surface of coated paper with nanoclay had better uniformity and smoothness than PCC due to higher specific area and plate form shape. There were no significant differences among the paper strength except tensile stiffness. Yellowness of the LWC paper with nanoclay decreased by approximately 20% compared to the control, whereas there were no significant differences among of brightness and opacity of LWC paper and control.

Subsidy reform was an important step for the country economic flourishing. Effect of subsidy reform was not found on the lumber and wood products in Iran. Therefore, their effect manner on the commodities is an important question. The research methodologies are descriptive analytic and survey and also, inflation rate formula, price growth formula, questionnaire statistical and Mann-Whitney U test was used. The results show that the effect of subsidy reform on the economic situation of these workshops and store are weak, but this effect on coast and price of their products more than others such as their competition. Their products orders are increase without change of their income or benefit and also, this effect are case more increase and change in price and consume of some products such as medium density fiber board than others products. Mann-Whitney U test show that the answer producers or marketer in before subsidy reform are similar to after subsidy reform. But consume of interior products and inexpensive such as interior MDF and particle board and also price change of furniture and wooden cupboard are more than before subsidy reform and the difference was significant at the 95% confidence level. Inflation rate of wood and paper products due to subsidy reform have been more growth than before subsidy reform.