فصلنامه جنگل و فرآورده های چوب
سال هفتاد و دوم شماره 1 (بهار 1398)

This experiment was conducted to survey the effect of desiccation and storage temperature on Balkan maple (Acer hyrcanum Fisch & Meyer) seed viability. The seeds were hermetically stored at three moisture content levels (12%, 8% and 4%) and stored in three storage temperatures including -20 °C (freezer), 4 °C (refrigerator) and 25 °C (room) up to 48 weeks in order to record the loss variability in viability. Results showed that effect of seed moisture content, storage temperature and their interaction on seed viability was significant. Seeds were viable (98%) at refrigerator until week 48. Viability at freezer reduced to 80% on week 8 and was constant till week 48. At room temperature, viability sharply reduced from week 24, so that on week 48 all of the seeds (12% and 8% moisture content) were found dead, but the seeds with 4% moisture content had weak viable (18%). This research revealed that Balkan maple seed with 4-12% moisture content can be successfully stored up to 6 months at room temperature and up to a year at refrigerator and freezer. Continuing the experiment in refrigerator and freezer will reveal the storage capability of this seed for longer periods.This research revealed that Balkan maple seed with 4-12% moisture content can be successfully stored up to 6 months at room temperature and up to a year at refrigerator and freezer. Continuing the experiment in refrigerator and freezer will reveal the storage capability of this seed for longer periods.

The purpose of this study was to investigate the ability of Mondell Pine tree) Pinus eldarica (in decreasing heavy metal contaminants within the environment by determining the concentration of heavy metals in the leaves and bark of P. eldarica and comparing their concentrations on falling dust. to reduce the concentrations of heavy metals in the environment compared with the concentration of these pollutants in falling dust. After the preparation of falling dust and plant samples, the heavy elements of them have been extracted by acid digestion method and then measured by flame atomic absorption spectrophotometry. The results showed that the concentration of Iron, Manganese, Zinc, Lead, and Cadmium in falling dust respectively were the highest to the lowest. Concentrations of Cadmium, Iron, Cobalt, and Nickel, increased with increasing distance from the road due to multi-directional winds and the presence of other contaminants. The Pearson correlation analysis between heavy metals found in the falling dust and Mondell Pine tree showed that the input and controlling factors of these elements in the Mondell Pine tree are probably the same as the dust. The results showed that the P. eldarica bark with the amount of accumulation index of 7261 mg/kg has more ability to simultaneously absorb different metals. As a result, since this green belt surrounds the Yazd urban area, it is hoped that a significant amount of heavy metals will be absorbed by these trees.

By determining the environmental factors affecting the plant species in a particular site, the presence of the species in the site can be predicted. The aim of this study was to investigate the response of Buxus to environmental variables individually and to extract its ecological optimum and amplitude in relation to the most important environmental factors using HOF function. This study has been done in the major sites of Buxus hyrcana in the Hyrcanian forests. 834 sample plots (400 m2) were established by systematic-selective method and within each plot, the presence of this species, topographic factors and some soil variables were recorded and measured. Fitting the response curve to the environmental variables with HOF function showed that pH, altitude, and clay were the most important variables on the performance of box tree. The results of this study showed that the response curves of Buxus species relative to the elevation and clay are unimodal and right-skewed, for sand variable is left- skewed, for nitrogen is symmetric and for the remaining variables are monotonically increasing or decreasing. The general conclusion based on the ecological optimum amount for each variable showed that the Buxus tree is lime- and moisture-demanding species, which is present in low altitudes, steep slopes and light soils with high nitrogen content. Since simultaneously more than one factor affects the behavior of species, it is recommended that the shape of the Buxus response curve is studied by taking into account the environmental variables in combination and by using other models.

The aim of this study was to provide a multi-factor ecological power model based on the ecological factors of hydrological response units in order to assessing the ecological potential of different uses in the Zailakirood Basin, northern Iran. First, by employing ArcSWAT 608 units of hydrologic response in 39197 independent polygons were found in the study area. Then, by measuring the hydrological response units by using special ecological capability models, the yield of the studied lands was measured in terms of production, quality of vulnerability and management requirements. In the next step, the final vulnerability of the hydrological response units was assessed against the degradation caused by forest utilization by employing hydrological indicators. In order to evaluate hydrologic indexes, by applying the SWAT model, calibration and sensitivity analysis, the effective parameters in runoff and sediment simulation have been obtained and in each of hydrological response unit, the numerical value of the hydrologic indexes estimated then the hydrological response units which were capable of producing sediments more than the determined limit of the index was changed to protective and supportive usage. So, the usage of potential of utilization 1 of forestry and centralized ecotourism capacity 1 remained without changing the area, potential of utilization 2,3 and 4 of forestry and centralized ecotourism capacity 2 reduced in area. And finally protection and supportive function with an area of 14083 hectares increased. Since slope, soil and land use have the highest variation in the region and cause the most limitation.

The present study aimed to assess the effect of canopy combination of beech trees and associated species (beech-hornbeam- maple, beech-hornbeam, beech- maple and pure beech) on basis of litter and soil characteristics in Mazandaran Province, northern Iran. Litter and soil sampling was made at each beech stand composition, using litter bags and plastic bags (30 × 30 × 30 cm), respectively by five replicates beneath Canopy of central beech trees. Also, in order to effect different seasons on the presence and activity of fanua, were done sampling in addition to summer season in spring, autumn and winter. Characteristics of litter quality (carbon, nitrogen, carbon to nitrogen ratio), Physicochemicaland biological properties of soil (water content, pH, organic carbon, total nitrogen, carbon to nitrogen ratio, earthworm density and biomass, nematodes and microbial respiration) was investigated. The results showed that nitrogen content of soil ( 0.48%), pH (7.43), biomass (56.88 mg m-2) and density (57.05 nm-2) of earthworm, total nematodes (55.02 in 100 gr soil) in beech-hornbeam-maple stand was higher than other studied stands. In all the studied combinations, dansity (45012) and biomass (46.08) of earthworms and nematodes (56.78) had the maximum activities in autumn while the highest of soil microbial respiration (58.5) was recorded in summer season. The based on findings, the stand of beech-hornbeam-maple has significantly impact on the soil organic and mineral characteristics. of the applied results of this research can be to prioritize in the selection of broad-leaved species for revive of degraded areas of the country North.

Today, the development of industrial clusters is considered as one of the successful approaches to industrial development. The cluster development approach, if developed in conjunction with the development of appropriate strategic plans, will not only promote specific industrial development but also regional development. Due to the fact that the furniture industry in Iran is mainly composed of small and medium enterprises, cluster development can be used to develop it. This study aimed to prioritize the furniture industry products for eight known furniture clusters in Iran. In the first stage, criteria and sub-criteria of ANP model were identified, and then the decision model was prepared based on ANP in the Superdecitions software. After weighing the criteria and the sub-criteria, we used the results of the questionnaire to determine the weight of the alternatives for each cluster separately. The results showed that in the furniture clusters of Tehran and Islamabad city, the option of decorative projects is about 0/35 and 334/0, respectively. In furniture clusters of Shandiz, Babolsar, Tabriz and Rudsar, the furniture and office furniture options with the weights of 271/0, 287/0, 284/0 and 293/0 were the first priority, respectively, and in furniture clusters of Qom and Malayer classic furniture with a weight of 0/32 and 0/304 respectively. The prioritized results showed that each of the studied clusters has more competitive ability to produce which products. . The prioritized results showed that each of the studied clusters has more competitive ability to produce

In this study, the effect of alkyd coatings on the color changes and adhesion strength in parallel and perpendicular to fibers of date palm trees was investigated. For this purpose, the boards with the dimensions of 2 × 7 × 15 mm (parallel) and 5 × 5 × 5 (perpendicular) were prepared. Then, acid catalyzed and nitrocellulose lacquers (SC) and polyester (SP) coatings were applied and all specimens were then transferred to conditioning room (20±1 ºC, and 65 ± 1 % RH) for 15 days. Also, the quality coatings was evaluated by colorimetric and adhesion strength with pull-off test in parallel and perpendicular to fibers. The results of colorimetric showed that, after coating with acid catalyzed and nitrocellulose lacquers the . Also, coating in parallel direction caused a greater change in color than the perpendicular direction. Also, by parameter color saturation and hue of coating compared to the control sample increased and decreased, indicating that the transparency and gloss increases and the color tends to red-show have given. The results pull-off test showed that, the adhesion resistance of acid catalyzed and nitrocellulose lacquers (SC) was less than the polyester (SP) coating and the adhesion resistance in the perpendicular to fibers was generally 2 times higher than the parallel to fibers. Increasing adhesion resistance in cross section than the longitudinal section is due to better penetration of the coating into the fibers of palm, but in the longitudinal section it is due to the separation of the palm tissue.

This research was carried out to investigate the possibility of improving the strength properties, especially the impact resistance of plastic wood composites by adding carbon nanoparticles GNPR to using the automotive industry. For this purpose, the nanocomposite must have a low density and high impact resistance. In this research used 40% and 55% of bagasse particles with 40 meshes, four GNPR 0, 0.25, 0.5 and 1%, polypropylene polymer and 2% maleic anhydride polypropylene. in this study Nanocomposites were produced by using an internal mixer and then samples of density test, impact and flexural strength were produced by two-stage hot and cold press. After reviewing the results of physical and mechanical tests, it was found that increasing the consumption of bagasse particles in the composition of nanocomposite increases the density, flexural modulus and water absorption of the product, but decreases the impact resistance and bending strength. Also, Increasing carbon nanoparticles GNPR also increases the impact strength and flexural strength of the nanocomposite. SEM microscopic examination revealed the uniform distribution of carbon nanoparticles GNPR at the fracture surface of the impact specimens and improved bonding between bagasse and PP particles, Also, by increasing the use of carbon nanoparticles GNPR.with increasing carbon nanoparticle consumption, the glass transition temperature of nanocomposites increased. The study of the material modulus in the DMTA test indicated that the value of the modulus increases with increasing bagasse quantity.