نشریه علوم و فنون منابع طبیعی
سال هفتم شماره 1 (بهار 1391)

In this study, the effect of geographical variation on the morphological and anatomical characteristics of beech (Fagus orientalis Lipsky) in Guilan province were investigated. To meet this objective, five watershed include of Astara, Asalem, Fuman, Chere, Shenrud were selected Forty fully expanded leaves (sunned leaves from the middle part of tree crown) were collected from 40 healthy trees in each populations. Some leaf morphological traits including leaf length, leaf width, petiole length, leaf area, leaf dry mass per unit leaf area, leaf thickness, leaf density, stomatal density, and stomatal pore lenght were measured. The results showed that all measured leaf traits were remarkably different among the populations excluding distance between veins at P<0.05. A hierarchical classification (SPSS Version 16) was led to the formation of three major groups: (i) Fuman (ii) Astara & Asalem, and (iii) Chere & Shenrud. Leaf dissimilarities are possibly attributed to the geographical variation, since the majority of the studied leaf traits were statistically (P<0.05) related to the latitude and edafic factors of the studied populations.

For investigation on the effect of relative light intensity on grouah flora variation, thirteen gaps provided from beech deadtrees with an area between <200m2 and 1000m2 were selected in the reserve oriental Beech (Fagus orientalis Lipsky) stand at Langa–Kelardasht, watercatchment 36 in Mazandaran province, north of Iran. Ground flora were assessed in 65 sample plots (within each gap, 5 sample plots 2 m × 2 m). Moreover, hemispherical photos were taken with a fisheye camera over all plot and were then analyzed in order to calculate the herp species diversity and their relationship with entered light on the forest floor in 9 selected gaps out of 13 gaps in all plots. Results indicated that number of herb species, number of individuals and Shannon index increased with increasing of relative light intensity due to increasing of gap area, whereas no statistically significant differences between different decay classes was observed.

Oak (Quercus brantii) is one of the most important tree species in Zagros forest that its natural regeneration has been disturbed specially in recent years. In this research, Oak (Quercus brantii) regeneration and their relation ship with environmental factor in a part (approximately 100 ha) was investigated. A part of Ghalarang protected area located in north of Ilam province (approximately 100 ha). In order to study the vegetation, inventory method of randomsystematic with 100´200 dimensions network and sampling plot area of 20m ´ 20m were selected. Totaly, 50 sampling plots were harvested. In order to analyze of data, multivariate methods of TWINSPAN and CCA were used. Five ecological species groups were found using multivariate methods. The results showed that, there are significant differences in natural regeneration of Quercus brantii (with sprout and seed origin) between the groups. Quercus brantii regeneration (with seed origin) had positive correlation with elevation, aspect, organic materials, nitrogen and SP and, the mentioned species regeneration (with sprout origin) had positive correlation with bulk-density and aspect. The results also showed that elevation and aspect had significant effect on Quercus brantii regeneration. The elevation over 2000 m and north aspect had high Quercus brantii regeneration (with seed origin), whereas the elevatio below 1500 m and south aspect had high Quercus brantii regeneration (with sprout origin).

With a view on the necessity to avoid contamination of the growing pollutions of Tehran, this research was done to determine the appropriate species for afforestation on the border of the city. In order to the study area, watershed Darakeh - located in Velenjak Shemiran and steppe regions of non-forested mountains of Iran was selected: first of all, positioning suitable areas for afforestation studies according to ecological characteristics of the region, gathering and analyzing data in GIS and evaluate multiple criteria evaluation method was performed. Then, the vegetations in area were studied by using land survey, and positioning of suitable units to afforestation and identify all species of trees and shrubs local region were done. Also, the appropriate species list in Alborz range was prepared with regional and library studies. In the final stage, ecological characteristics of the appropriate units were checked by characteristic of suitable species, and eventually the appropraited species were proposed for each unit. Results show that the only 740 ha out of 3240 ha have no absolute limits to afforestation. The 257 ha of studied area can be much better than the other areas that have had significant afforestation. To afforestaion, native trees were proposed to the region, including: (Juniperuss polycarpus), (Amygdalus scoparia), (Amygdalus lycioide), (Celtis caucasica), and (Berberis crataegina) because of indigenous characteristic they are synchronized by successful afforestation principles. Proposed non-native species are (Cupresus arizonaca) and (Robinia pseudoacacia.

Productivity and its increasing reasons have been interested in scientific institute for many years ago. International labour organization, has defined productivity as ratio of output to one of the production factors (land, capital, labour and management). The ratio of production to the each of factors has been used for productivity measurement. In this study, the total productivity and partial productivities were measured in Asalem particleboard factory since 1383 to 1388 by index approach. The results indiated that, the total productivity has been decreased since 1383 to 1385, but increased since 1386 to 1388. Also regression analysis indicates that main effective factors on total productivity in this factory are material productivity, time productivity and personal productivity.

In this study the effect of talc particles (as a mineral material) on mechanical properties of wood flour/polypropylene (PP) hybrid composites was evaluated. Three levels of wood flour/polypropylene compoundes (40:60, 50:50 and 60:40 wt%) were used in fabrication of specimens and two levels of talc particles (10 and 15 phc) were added to mixtures. polypropylene grafted maleic anhydride (PP-g-MA) at 3 phc was mixed to all compounds as a coupling agent. The prepared compounds were milled and then, injectin molded for producing mechanical test samples (according to ASTM) Then, mechanical properties (tensile, flexural and impact) of specimens were measured and the data were statistically analyzed. Results indicated that the tensile modulus, flexural strength, notch impact strength and elongation at the break increased with addition of talc to polypropylene/wood flour composite. However, tensile strength decreased with talc addition. Also, the addition of talc particles to wood flour and polymer matrix had synergic effect on flexural modulus.

Tobacco (Nicotiana tabacum) is one of non-wood species which its stalks after using of leaves for cigarette can be used for production of paper and composites. For better using of this biologic material, the evaluation of anatomical, morphological and chemical components are necessary. many tobacco stalks "PVH" type cultivar 19 which is approximately planted in Guilan province of Iran have been sampled randomized.The anatomical properties in three section of cross, tangential and radial and morphological properties including: fiber length, fiber diameter, cell wall thickness were measured and derived quantities of fiber properties including: slenderness index, runkel index, flexibility ratio in three height of stem (5%, 50% and 75%) was calculated. The chemical components including: cellulose, lignin, ash, alpha cellulose and hemicellulose of stem with bark and without bark were recorded according to related standards and results were analyzed by statistic experimental design. the results showed that the chemical components of tobacco stalk is desirable but the ratio of L/D of fibers are lower than many non-woods and hardwoods and so it is assumed that the papers of tobacco stalks doesnt have suitable tear strength. The runkel index (2 cell wall thickness / fiber diameter) is near to hardwoods range and many non-woods, so it is presumed that papers have appropriate tensile, burst and folding strength.

In this research, the production method for carboxymethylated fibers from waste paper and chemical structure of the product were distinguished by Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectral analysis. The treatment condition for producing carboxymethylated fibers also involved the use of isopropanol, sodium hydroxide solution, and monochloroacetic acid. The product was purified with 70/30 methanol/ water. Then, one sample was neutralized with acetic acid and the other was considered as a sample without having been neutralized. The results of FTIR and XRD analysis indicated that the carboxyl and methyl functional groups had increased in the carboxymethylated fibers and the crystallinity of cellulose had decreased in the carboxymethylated fibers.