فصلنامه پژوهشهای علوم و فناوری چوب و جنگل
سال بیست و یکم شماره 3 (پاییز 1393)

Crataegus from Rosaceae family is a tree which has medical, ornamental and commercial utilizations. In this Study, all stages of Micropropagation of Crataegus pseudoheterophylla Pojark. including sterilization, establishment, proliferation and rooting were evaluated. For disinfection, explants were taken in spring and autumn and rinsed under running tap water for 30 min then dipped in 70% ethanol for 30 s followed by immersion in ClONa 1.5% and 2% for 10, 15 and 20 minutes. MS, WPM and DKW media were used for initial establishment. Proliferation was conducted on MS and WPM medium supplemented with different concentrations of BAP and NAA and rooting of shoots was done in 1/2 MS medium supplemented with different concentrations of IBA. Results indicated that the best method of sterilization was obtained in ClONa 1.5% for 15 minutes in spring and the best medium of establishment was obtained on MS medium with maximum shoot length (3.5 cm) and the survival rate (90.33%). The best treatment for proliferation was 8 mg / l BAP plus 2 mg / l NAA with 39.33 shoot numbers on MS medium and the best treatment for rooting was 1 mg / l IBA with 25% rooting on 1/2 MS medium supplemented with 40 mg / l PG.

In this study, the impact of the selected macroeconomic variables on demand for imports of particleboard and MDF and the existence of long-run and short-run relationships between the variables of import functions for these products investigated applying Johansson – Juselius and Granger causality tests respectively. After making stationary all of the variable and ensure the lack of serial autocorrelation in error terms, the linear functions of import demand in the period of 1986 to 2011 are empirically estimated using an ordinary least squares model. The results indicated that demand for imports of particleboard and MDF have positive relation with national income per capita, the relative price Index and population of the country. Also, the results of Johansen-Juselius test showed that there was one cointegration vector between the related variables for particleboard and MDF. In the imports demand function of particleboard found that there was one-side causal relation from the price per barrel of oil, the relative price Index and population quantity variables to the dependent variable and for MDF are confirmed the one-side causal relation from the relative price index, national income per capita and population quantity at the 95% level and for price per barrel of oil at the 90%level.

In this study, it was evaluated the effect of almond shell powder as extender on the mechanical properties of the medium density fiberboards manufactured from bagasse fibers. Almond shell powder/UF resin ratio at five level (0:100, 5:95, 10:90, 15:85 and 20:80), paraffin content at five levels (0, 0.5, 1, 1.5 and 2%), press temperature at five levels (140, 150, 160, 170 and 180 C) and press time at five levels (5, 6, 7, 8, 9 min) were selected as production variables. The mechanical properties (modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding strength (IB)) of panels were tested and the data was analyzed based on Response surface methodology (RSM). Results showed almond shell powder, significantly influenced the mechanical properties of panels. They in general decreased with increasing almond shell powder content. Although internal bonding of all panels showed a decrease with increasing the extender, but internal bonding strength of all panels were more than recommended standards (EN). Besides, results of this analysis showed during high press temperature, the extender was better efficiency. In general, wax had a negligible reducer effect on mechanical properties. According to RSM analyses, the best results were found on the panels that have been made at 160° C press temperature and 6 min pressing time.

In this study, the effect of foaming agent content (0, 2 and 4%) and the amount of nanoclay (0, 2 and 5%) on cell structure and mechanical properties of high density polyethylene (HDPE)/wheat straw nanocomposites foam was investigated. Also maleic anhydride grafted polyethylene (MAPE) was used as coupling agent on fixed level of 3%. Wheat straw flour, HDPE, nanoclay, foaming agent and MAPE compounded in the internal mixer (HAAKE) and then milled granules were manufactured fiber-plastic foam samples by injection molding method at 180°C. Results show that with increasing foaming agent, average cell size and cell density increased and by adding nanoclay cell size decreased. Also by adding 4% foaming agent, foam density of HDPE/wheat straw composite decreased to 21.7%. The mechanical properties of HPDE/Wheat straw composite were reduced by adding the foaming agent, but tensile strength was improved by adding 2% of nanoclay and impact strength decreased. Further evidences of foaming agent and nanoclay effects on the properties of nanocomposite foams were observed by scanning electron microscopy (SEM).

This research investigated the accuracy and precision of prevalent methods of annual allowable cuts estimation for uneven-aged high forests based on real growth rate in different forest types in district 1 of Dr. Bahramnia forestry plan, shast kalateh of Gorgan. In order to determine volume increment using Mayer method, sampling of increment cores was done in 140 circle plots with an area of 0.1 hectare in a Systematic- Randomize pattern with (300×400 meters) dimention network an intensity of 3.33 %. Based on parcel level forest typing and site classification in similar compartment, study area has been divided to 4 forest types including Fageto-carpinetum, Carpino-parrotiom, Parrotio-carpinetum and mixed type in order to calculate volume growth rate and allowable cut in forest types and whole district. Estimation of allowable cut was carried out using eleven scientific current methods. The statistical comparisons were conducted using paired samples T-Test between the ibserved allowable cut rate (growth) and the estimated allowable cut rate based on eleven methods. Analysis of Variance (ANOVA) and Duncan test were used for determination of differences among suitable allowable cut methods in the various forest types. Results showed that among 11 methods for estimating allowable cut compared to observed growth, 4 formula have significant differences (P0.05), and results shown that one method (Van mantel) was unsuitable because of less or more than real growth in four forest types. Results showed that only Zahiraldin and Kohmian methods were suitable due to estimation of slightly lower than real growth.

Forest road network is the most expensive part of construction, environmentally and economically. For decreasing the environmental and economical bad effects, technical standards for forest road network planning and constructing should be done as a need. In this study, soil volume and costs of the soil operation were investigated along 12.4 Km of second degree Forest Road on Arzefon district in Tajan River Basin and to compare them with standards condition. For this operation slope was classifies into three classes: 0-15, 15-30 and 30 – 45 percent. The length and angle of cutting and filling slopes, width of soil operation were determined by soil texture and slope angles (Based on standards: Guidebook 131 from Budget and Planing Organization). Then operated surface and volume per hectare were calculated using AutoCAD and cross section Profiles were drawn based on three slope classes. Width of clear-cutting and its surface on width of soil operation and volume per hectare were compared with standards. They were analyzed by SPSS and T-student (One sample). Results showed that operated surface from trees for less than 15 percent, 15-30 were 4.49 (ha) and 1.08(ha) respectively and more than standard significantly (1% level). For 30-45 percent class was 0.55 (ha) less than standard and non-significant. Soil operation volume in less than 15 percent was 2.4 times and 15-30 percent was 1.2 times more than standard and 30-45 percent was equal to standard. Along the study Road, adding harvested as volume per hectare was 693 cubic meters more than standard. Finally the cost of soil operation in the study area was calculated 461/700/000 Toman more than standard condition.

Filler materials commonly used to improve interdiction, optical and compensational characteristics of a part of fibrous materials needed in manufacture of paper to reduce production costs. One of the most common materials used in this area is clay and Nano clay. In this study, to enhance the Nano clay potential of improving the features listed and However, to avoid compromising the mechanical properties of paper, This material reprocessed with homogenizer and Turned into stable colloidal Nano clay with nanometer Dimensions. According to the results, Nano clay reprocessed with homogenizer in comparison with raw Nano clay In the presence of preservative had more ash and durability, more Density and resistance to airflow. However, the value of Burst and tear resistance slightly reduced. Finally, high levels of homogenized Nano clay Persisting, Indicates that Effluent Contamination has been reduced and improved the system economically.

Collection of information on the status and distribution of vegetation, is costly and time consuming trough conventional methods. Using of satellite data is considered as a potential way. The objective of this study was capability investigation the different spatial resolution satellites with emphasis on spectral indexes for separation of species of planted pure stands in district 1 of Shastkolate forests in Gorgan. In this study satellite imagery of Quickbird, ASTER and Landsat TM was used. The geometric and atmospheric corrections were implemented on the images and 20 spectral vegetation indexes were created using images. The 80 points in ten pure and dense coniferous and deciduous stands were recorded with GPS. The vegetation spectral indices were extracted in sample plots for each pure stand and were statistically analyzed. The results for the best indexes in separation of all species showed that brightness and greenness indices in Quickbird data, wetness (VNIR) and DVI indices in ASTER data and GNDVI index in TM data could identify and differentiate more species compare to other indices. For separation of coniferous species, the brightness and greenness (VNIR) indices in ASTER data showed the best separation results. For separation of deciduous species, the greenness index in Quickbird data, wetness (VNIR) and DVI indices in ASTER data and GNDVI, MSI and II indices in TM data showed the best separability and are introduced as the best indices.

The present study was conducted to investigate the impact of Maple (Acer velutinum), Ash (Fraxinus excelsior L.), Oak (Quercus castaneifolia) and Pine (Pinus brutia) plantations on soil properties and fine root biomass in Darabkola Forest of Sari. The soil samples were taken from top mineral soil layer (10 cm) with using coring method (8 cm diameter ×10 cm deep soil) in each site randomly (n=4). The litter layer was removed from the soil surface before samplings. Fine roots (< 2 mm diameter) were extracted from each core and dried at 70 °C to a constant mass. The moisture content of soil, soil texture, Organic carbon and total N, pH, EC, available Ca, K and p was measured in the laboratory. Results showed that many soil physical and chemical properties was significantly (P

In this study, for the first time, the possibility of DNA content and ploidy level of species and inter-specific hybrids of walnut for breeding purposes were examined by flow cytometry. In the spring, the young leaves of samples, including of Persian walnut (J. regia), black walnut (J. nigra), J. hindsii and inter-specific hybrids Paradox (J. hindsii × J. nigra) and Royale (J. hindsii × J. regia) in research station of Karaj, Horticulture Research Department of Seed and Plant improvement Institution were selected, Randomly. DNA content of walnut trees were optimized on the base of tree leaves by method of flow cytometry. In order to comparison and determine the ploidy level, mitotic chromosomes of samples with highest and lowest level of DNA, were counted by using squash method. Ranges of mean or mod of DNA content in samples were different from 46.24 to 71.68. However, the samples had equal (2n=2x=32) chromosomes, so the diversity of DNA index among species were not from changes in the number of chromosomes such as Aneuploidy. The use of flow cytometry as an affordable, easy and rapid method for determination of ploidy level and other tree species is recommended Walnut and the other trees.

In this study, The effect of alternative humidity stages on Physical and mechanical properties of Rice stem flour (RSF)-Polypropylene Composites was considered. Panels composites were built in 1g/cm3 nominal density and 25×15×1cm dimension that including, treatment of PP and RSF with 45, 60 and 75% weight ratios. Physical and mechanical properties of composites were measured and data were compared with randomized design. The Results showed that increasing of filler ratio, and passing of humidity stages result in decrease of Physical and Mechanical properties of composites. Adding 2 percent MAPP result in partial improve in Mechanical properties and decrease in water absorption and thickness swelling of composites.

Fungi are the important components of forest ecosystems that influence on the life of other organisms. Macroscopic fungi vary in broadleaf and conifer forests. In order to identify Macrofungi on forest floor in Alnus subcordata and Cupressus sempervirens forested masses Plats 0.6 ha were selected in the Shastkalateh forest, Gorgan (North of Iran). Macrofungi collected in summer and autumn season (2010), they were identified according to macroscopic, microscopic characteristics and reliable sources as well. 11 species consist of: Boletus queletii, Collybia confluens, Coprinus atramentarius, C. Lagopides, C. micaceus, Hygrocybe laeta, Lepiota cristata, L. naucina, Mycena polygramma, M. pura, Psathyrella candolleana Were collect on Cupressus sempervirens in compare 7 species consist of: Collybia sp, Cystoderma amianthinum, Lepiota brunneoincarnata, L. naucina, Mycena abramsii, Macrolepiota gracilenta, Psathyrella candolleana collected in Alnus subcordata mass. In order to find relationship between impact pH and presence macrofungi, pH of soil under each specimen was measured by PH meter paper and PH meter device in lab. PH level in Cupressus sempervirens mass and in Alnus subcordata mass were found between 7-8 and 6.5-7.5 respectively.