نشریه حفاظت و بهره برداری از منابع طبیعی
سال سوم شماره 1 (1393)

Nowadays، annual consumption of paper in the world and also in Iran is growing. To provide the present need، finding new ways for optimum usage of lignocellulosic resources and improved production methods are required. One of the common problems in the papermaking industry is existence of undesirable compounds and by-products such as pitch، stickies and external contamination in papermaking process that each of these materials may arise from various sources. Wood، as a raw material for pulping، because of having hydrophobic materials such as waxes، lipids، fatty acids، resin acids، hydrocarbons، etc، can be the origin of such contaminants. The pitch can cause significant problems in papermaking equipment. For example، it can block drainage felt or attach to wire or drying cylinders and cause holes in the paper. Up to now، various methods have been proposed to control and eliminate these problems. Enzymes due to having various applications such as pitch control، reducing the refining time، helping in pulp dewatering، improving bleaching efficiency and increasing pulp yield، have gained a lot of popularity in pulp and paper industry. Enzymes cause hydrolysis of triglycerides and prevent their formation. Furthermore، enzymatic treatments is the basis of pitch and stickies control which can be used to reduce the size of these materials. In this paper، efforts are done to investigate utilization of enzymes as a new and environment friendly method based on biotechnology to control pitch in papermaking process.

Goldfish as an ornamental fish is generally kept in aquarium throughout the world as well as Iran. Therefore more attention should be paid to their nutritional and environmental needs. The present study was carried out based on previous studies done by researchers in Iran and abroad to provide the best procedures for feeding of such valuable species. Researches have demonstrated that selecting a proper nutritional allotment has been ignored in culturing such valuable species. Few studies were done regarding choosing an appropriate nutritional allotment for goldfish. They indicated that feeding goldfish with live food such as Artemia and Nematod has a higher survival at larvae stage. Also, the allotment with an equal live food and pelleted food was considered as a beneficial food for juveniles, because a mixture of live food and pelleted food leads to a higher growth for such fish. In addition, live food (such as Gammarus) supplies the required carotenoid for colored pigmentation. Consequently, researches concerning the nutritional needs of goldfish and the effect of feeding with live food on growth parameters of such fish seem to be of importance.

Acer monspessulanum is one of the important species of the genus Maple that is in danger of extinction due to lack of natural regeneration and the problems caused by drought, pests and diseases. Its propagation by seed is difficult because of the empty seeds, attack insects and seed dormancy (physiological and morphological), so providing the possibility of reproduction through cuttings is very important. The effect of different media (sand, soil greenhouse–30% Litter–20% organic fertilizer –50% loam soil- and sawdust) and cutting diameter (2-6 mm and 6-12 mm) was investigated on rooting percentage, root and stem biomasses. The highest percentage of rooting cuttings (20.83%) obtained in soil of greenhouse with cutting diameter of 6-12 mm and the lowest percentage of rooting cuttings (4.11%) obtained in sawdust in cutting diameter of 2-6 mm. So using of greenhouse soil with 6-12 mm stem cuttings is recommended to propagate through this method.

Rangelands cover over 52 percent area of Iran. These areas require proper management practices to preserve, rehabilitate, and develop and optimal utilization. Thus, identifying the effective factors upon participation of beneficiaries about conservation, rehabilitation and utilization of rangeland is necessary, for this purpose, a survey was undertaken about Roodbar Khoortab watershed in the city of Noor. 40 samples were selected by Cochran formula. Means of research was a questionnaire and its reliability was obtained. /83 through Cronbach's alpha coefficient. Data were analyzed through Friedman non-parametric test along with regression, analysis of Variance and Pearson as well as Spearman correlation coefficients in order to evaluate the effects of independent variables on the level of participation. Results showed that economic and social poverty, lack of financial governmental support, shortage of the knowledge about natural resources, lack of awareness of laws and regulation, poor instruction and lack of applying local knowledge in execution of governmental and rangeland management plans are some effective factors against the participation of beneficiaries. Considering some policies that increase beneficiaries and villagers level of knowledge, as the main utilizers of these lands, will be effective on growing trend in the participation.

Determining the main factors of environmental factors on species richness pattern of birds is one of the most important issues in conservation ecology. Using this information could have a crucial role in implementing the environmental plans, managing and anticipating future situations. A set of 15 factors including environmental factors, land cover, and topographic variable were studied for determine the role of environmental factors on the species richness patterns of birds in Sarakhs. Sampling of birds had been completed at 12 stations during spring and summer of 2012. In total 107 species of birds belong to 11 orders and 32 families were identified, of which Passeriformes with 66% and Ciconiiformes and Caprimulgiformes with 9% showed the highest and lowest level of species richness. The species richness maps were also prepared with GIS software. The most species richness pattern was concentrated on north– west and south- east of the region. The results of the study of environmental factors, using SAM software application, showed that the rain is the most important factor for explaining the species richness patterns of birds in Sarakhs.

Forest roads play a vital role in management, conservation and restoration of forests in mountainous regions. Despite of their costs, forest roads are essential for forest resource management. Recognition of soil properties has a critical role in finding the potential of the ground as base for road construction. Due to expenses of soil analysis, reducing soil samples to its minimum are of great importance in assessment of soil mechanics in forest roads. In this research, based on properties such as soil, slope, aspect, altitude, etc., zonation of study area was done into homogenous units based on landform using GIS. After preparing landform map, one soil sample and totally 32 samples were taken in units from which road passes. Then soil physical properties such as normal moisture (%), bulk density and soil texture were analyzed. According to the soil zonation map, 10 zones were obtained. One sample was taken in each zone and soil mechanic experiments and soil Classification carried out according to USCS method. Results show only 30% of the samples are coarse soil and the others are fine soil. 40% of fine soil have clay fine soil. Hence, in the parts of the road which have Liquidity Index more than one soils have to be drained before road construction and in the parts that soils have high Plasticity Index the road Bed have to be stabilized with lime after excavation. For decreasing costs of road construction and maintenance it is preferable that road cross from areas that are stable and have sustainable soils. To achieve this goal soil mechanical potential mapping has been done.

Iran is one of the most important centers of plant diversity in the old world and nearly 22 percent of its plant species are endemic. Identifying elements of vegetation in an area is considered as a basic study for ecologic, manage mental and conservational researches of plants. Nekaroud basin is located in the north of country between the provinces of Mazandaran and Golestan, 35 km far from Galugah city and is accessible through Galugah to Damghan road. In this research flora, life form, geographical distribution and endemic statvs of species were studied so, the 38 family and 107 species were recognized. The most important families were Poaceae with 16 species, Compositeae with 10 species, Fabaceae with 11 species, Labiateae with 10 species, Rosaceae with 10 species and Brassicaceae with 5 species. Life forms determined by Raunkiaer method were included PHA (21%), Thr 24%, Cha (10%), Geo (5%), Hem (36%), and Cry (1%). The result showed that most species of area are perennial species adapted to the climatic conditions of the region. Due to disturbance and heavy grazing, the conditions were suited for the establishment of unpalatable and invader specie and they occupied a vast area of the study site.

According to important role of soil in relation to feeding the world's population, identification of all soil characteristics is essential. Thus, an investigation some soil quality indicators under two different management system (corporate and joint) was carried out in Chut rangelands of Gonbadekavoos. At first, the study area was determined by satellite images and Google earth software, and then as control field survey was carried out using GPS. After identifying the area and removing the marginal effect, the thickness of surface soil and litter layer were measured. Finally, Statistical data analysis was performed by Spss 16.0 software and T Student test. The results demonstrated that the thickness of surface soil and litter layer in the section of corporate management are higher as compared to parcenary management.