نشریه علوم و فنون منابع طبیعی
سال سوم شماره 4 (زمستان 1387)

The effect of conservation intensity on the plant species biodiversity in the protected area of Oshtrankooh in Lorestan in the Zakros mountain ranges was investigated. To this aim, the biodiversity indices between the core and peripheral zones were compared in this study. In order to study the plant biodiversity, 16 plots in an area of 20Í20m2 were selected in order to count the woody species, and 3 sample plots as the microplots in an area of 1Í2m2 and the sum of 48 microplots were randomly selected for studying the herbal species from each of the sample macroplots. The number and list of plant species in the macroplots and the number and list of herbal species in the microplots were recorded. The sample plots were collected from the altitudes betweem 1600- 1800 above the sea level and in the range slopes between 30 to 65 degrees in the spring of 1386 (2009). Due to the data normality, the non-paired t-test was used to compare the two zones. The data showed that the biodiversity indices, based on tree and plant species, are greater in the peripheral zone than in the core zone from the mean evenness indices, and based on the herbal species, the mean indices of the dominant species are greater in the core zone than in the peripheral zone, and the mean indices of diversity and the richness of the herbal species are greater in the peripheral zone than in the core zone. Based on the total species observed (tree, plant and herbal), the means of biodiversity, evenness and richness indices are greater in the peripheral zone than in the core zone.

The Sardabrood river is one of the protected rivers of the central Alborz. It is about 55 kilometers long and located at heights between-27 to 4850 meters above the free-sea level and has various ecosystems. So the study of the flora of the area can be an important measure for the better management of this river. The present study was done for this purpose. At the beginning, four different landscapes were identified, using the landscape ecology method. Then the sample floras of the areas at the river-bed and along the river were identified and collected by the ground survey. The results of the study showed that Chalous landscapes have 63 species from 35 genera and 38 families. The Hemicryptophytes and phanerophytes contain the greatest percentage of life forms in this ecosystem. The forest landscapes have 74 species from 65 genera and 50 families of which the Phanerophytes have the greatest percentage. Kelardasht landscapes have 43 species from 40 genera and 28 families of which the Hemicryptophytes are greater than the other life forms in number. In addition, the Therophytes have a considerable percentage which is an indication of the cold and dry climate in the area. The forest and mountain landscapes also have 76 species from 46 genera and 36 families of which the Hemicryptophytes, Phanerophytes and Chamaephytes have the greatest life forms which indicate the mountainous- forest cover with the cold climate.

In this research, the effect of pulping conditions on the high yield pulp from the corn stalks was studied. The biometric properties and chemical compositions of stalks were measured, and then the stalk pulping was done by injecting sodium sulfate amounting to 8,10,12 and 14 % (Sodium Hydroxide at constant ratio of 8 %) and then the time variables of 30, 45, and 60 minutes were measured at the Pulping temperature of 95 oC . The yield after the impregnation varied from 70.80 to 87.20% and after the defibration varied from 53.10 to 68.70 % . Based on the results of measurements of pulping yield, pulping with different amounts of Sodium Sulfate at a constant ratio of Sodium Hydroxid and the temperature of 95 oC for 30 minutes were selected for measuring the properties the pulp strength. The pulp was purified up to 400 ml degree of Canadian standard, and after producing the hand-sheet, its strength properties were measured. The statistical analysis of strength indexes revealed that the pulping condition with 10% of Sodium Sulfate, 8% of Sodium Hydroxide, the temperature of 95 oC and 30 minutes are the most appropriate. The pulp properties consist of the breaking length, tear index, and tensile index measured at 2.07 km, 8.28 mN.m2/g,and 20.40N.m/g respectively.

In this study, in order to identify the woods of the archeological buildings of Rashvand House located in the province of Ghazvin, the samples were selected from the woods used in the interior and exterior parts and then the microscopic slices were prepared from them and then identified and described according to the IAWA method. The anatomical characteristics of the samples were the diffuse-porouse-wood, distinct growing rings, axil parenchyma in the margins, single, two or three and rarely four and angular vessels, simple perforation plate, alternate intervessel and polygonal and multiple pits, and uniserial and homogeneous wood slices. Among the Iranian forest and garden trees, the woods of solicacea family have the said characteristics of which the poplars (poplus spp) have the procumbent and homogeneous ray cells.

In this study, the effect of chemical modification of Lignocellulosic components on the mechanical properties of some fiber/plastic composites was investigated. Two types of lignocellulosic composites (Beech flour and rice husk fibers) were subjected to four types of chemical components (alkaline, silane, acrylic acid and benzoil chloride), and maleic Anhydride and polypropylene were attended as the coupling agents at two levels of 0 and 3 %. The FTIR spectroscopy was used to be sure of the chemical treatment of fibers. The tensile and impact properties of treated composites were measured and compared with the pure polypropylene and some untreated samples. The morphological changes of fibers and composites were investigated, using the scanning electronic microscope (SEM). The results showed that the chemical fiber modification led to a change of Ho group absorbance of lignocellulosic composites on 3900-4250 cm-1 band. The mechanical properties of composites showed that the chemical treatment of fibers improved the interfacial adhesion and so increased the modulus and tensile but decreased the impact strengths. The coupling agent also had a positive effect and increased the strengths and modulus. In most cases, some composites with beech flour treated by alkaline and coupling agent had more tensile strengths. The impact strength of silane treated composites increased considerably compared with the other treatments. Also, the simultaneous use of chemical components and coupling agent on the mechanical strengths had synergic effects.

In this study, the effect of the filler content on the mechanical properties of wood plastic composite made of wood flour and polypropylene was investigated. For this aim, the wood flour was mixed with polypropylene at 10, 20, 30, 40 and 50 percent by weight and 2 percent of MAPP was also used as the coupling agent in all formulatins. Then the wood plastic composites were manufactured in twin-screw extruder. The mechanical tests such as tensile, bending and notched impact were performed on the samples according to the ASTM standard. The results indicated that the filler content has affected significantly on the mechanical properties of wood polymer composite. The flextural strength, flextural modulus, tensile strength and tensile modulus were increased by increasing the wood flour from 10 to 50 percent by weight. However, the notched impact and elongation were reduced by the addition of the filler content.

In order to assess the quantitative desertification caused by the water erosion and present a regional model, an area with 42969 hectares in the Ghareh Chay was selected. The FAO-UNEP and ICD models were selected after studying the desertification models and methods. Based on the geomorphological studies, 19 working units were identified and the proposed methods (a combination of the said methods) were evaluated in the region under the study. The desertification was evaluated in 4 classes (low, medium and high and very high in the respective region. The classification of desertification in the current (actual) conditions and potential environment, the categorization of human and natural desert ecosystems and also the possibility of special management on each of the working units are the important features of this model. The results show that the areas under the study are located in 3 classes of low, medium and high desertification intensity which inclued 31.59, 52.40, and 16.01 percent of the total region, respectively.

Nowadays, the surface and ground water management is necessary in order to supply the required water for the drinking, industrial and agricultural sectors. The ground water is the most important source of water supply in the areas with surface water resources shortage. Meanwhile, in order to carry out many of the projects, it is essential to be aware of the depth of ground water of the area in question. Another problem is the lack of necessary statistical data regarding the depth of ground water in many areas. In this study, the multivariate regression analysis was used in order to present a linear model for estimating the average ground water depth in the southern coasts of the Caspian sea. So the average water depth, in 94 sites in the southern coasts of the Caspian sea, was regarded as the dependent variable, and the hydraulic conductivity of aqueous formation, height, average rainfall, evaporation and distance from the Caspian sea as the independent variables. The regression analysis was done, using the SPSS software in order to present a linear model. In the next step, the model in question was estimated in sites from which the statistical data were not used to present the model and its efficiency was proved. Finally, the map of the ground water depth of the areas in question was prepared, using the model in the Geographic Information system (GIS).