نشریه حفاظت و بهره برداری از منابع طبیعی
سال یکم شماره 4 (1391)

Deterministic interpolation methods are mathematical functions used to create continuous surfaces from measured sample points based on the similarity of nearby points. In this study, the annual precipitation data recorded at 42 climate stations in Golestan province was used to produce precipitation maps of the entire province by deterministic interpolation methods. Accuracy of the interpolation methods were evaluated by cross-validation technique. The evaluation criteria included: Mean Bias Error (MBE), Mean Absolute Error (MAE), Root Mean Squared Error (RMSE) and correlation coefficient between measured and estimated values.The four evaluation criteria consistently identified Spline with tension as the best method for interpolation, followed by Inverse Distance Weighting (IDW), local polynomial functions, regularized spline, thiessen polygons and global polynomial. By visual interpretation of the maps produced through interpolation it can be concluded that the precipitation distribution in Golestan is influenced by the combined effect of topography and distance from sea. The results of this study could serve as spatial input to many spatially distributed models in other disciplines.

Land use planning is a science that determines the optimum use of land, regarding to the land ecological characteristics and socio-economic conditions. In land use planning of Ghurichai watershed with area of 24039 ha, six information layers including elevation classes, slope, aspect, soil type, vegetation type and density were combined using dual method and the final map of environmental unites were obtained. In this processes, 1921 micro ecosystems or environmental units were distinguished in GIS environment using Arc map software. Ecological potential evaluation for agriculture, rangeland use, forestry, extensive and intensive tourism, aquaculture, rural and urban development and conservation were assessed for each unit. Finally 12.3 percent of the area was allocated to agriculture and rangeland use, 0.4 percent to extensive tourism, 52.5 percent to forestry, 1.1 percent to aquaculture, 1.7 percent to rural and urban development and 32 percent were allocated to conservation. Most of the area was allocated for forestry use, due to high capability and potential of this area for forestry. Therefore, it is necessary to implement some basic practices in this area to prevent forest degradation in order to avoid land degradation and to have sustainable utilization of the mentioned watershed resources. In order to prevent irregular use of the forest, some alternative options have to be suggested for the stockholders of the watershed, not to endanger the socio-economic life of inhabitants. Therefore according to result of study, two new land use including aquaculture and extensive tourism suggested for this area.

Forests have been utilized by marginal villagers and local people who live in forests since many years ago and also this process is continued these days thus has caused an increasingly degradation in this ecosystem. Several factors have influenced on over utilization of forest by villagers and local people. Present study has focused on factors affecting on amount of utilization of Galougah forest located in Hezarjarib, Golestan province. People of the three villages of Vezvar, Evard and Aghooz-Darreh have contributed statistical community of this research that 150 families of them were selected randomly as our samples. The instruments for collecting data in this research were questionnaires and interviews with our samples. Alpha Kronbach coefficient was 76 according to questionnaires and experts opinion. Results showed that interviewees have settled total use of forest in average group. Results also showed that education level and income amount of every family have positive correlation with amount of forest utilization. It is concluded that supplying fuel services in comparing with other factors has noticeable role in changing amount of forest utilization.

Natural ecosystems are severely degraded and their productivity is highly reduced due to improper utilization by human (e.g. mining, road construction etc.) and environmental constrains (e.g. drought and salinity). Natural recovery of vegetation cover in these ecosystems is too slow through natural succession process. Furthermore, low soil fertility and harsh microclimate conditions decrease capabilities of traditional restoration methods, in these areas. In the recent decades, researchers have found positive and negative effects of plant-mycorrhiza symbiosis on plants growth and reproduction. In soil polluted with heavy metals also in saline and sodic soils, mycorrhiza increases uptake of low mobile elements and provides ion balance for the coexisting plants. In degraded soil and mined areas, mycorrhiza increases plant establishment, growth and biomass. Accordingly in the recent years, the benefits of plant-mycorrhiza symbiosis are used for restoration of degraded lands, in some developed countries. The main aim of this paper is to describe potentials and limitations of mycorrhiza-plant symbiosis and to provide suggestions for using this interaction as a tool for restoration of degraded ecosystems.

There are a wide range of models that are being used in the field of soil loss and sediment yield and they have variety based on the complexity, the processes they can simulate and concept of the models. SWAT and WetSpa are tow hydrologic models and sediment and erosion simulator that their compatibility with GIS has raised their capability. SWAT is a continuous, semi physically based and semi distributed hydrologic model which HRU is its smallest work unit and all several hydrological processes are simulated for each one of it. WetSpa is a continuous, distributed, physically based hydrologic model that simulates hydrologic processes in pixel size of 1m2. This model uses some relations with physical concepts to simulate erosion and sediment, but in SWAT, this process is estimated with the Modified Universal Soil Loss Equation (MUSLE) model. DEM, land use and soil maps along with weather data are main input parameters of both models. In this study it is attempted to describe the methods for simulation of erosion and sediment in both models and compare their capabilities briefly.

Understanding the current costs and revenues of the utilizer and utilizing units for short and long term planning of rangeland owners and government sector is necessary and unavoidable and owners should know to use rangeland as an economic unite and its income can be used not only to provide livelihood for families but also maintain and preserve the rangeland. For this purpose, three conventional systems of 20 conventional systems in the region of Aliabad were chosen and in each conventional systems current expenses of livestock (hand grass, Shepherd's wages, clip and milking, animal transportation, medication) calculated 429802 Rials and income from livestock (4-6 months sheep to sell, lamb sell) calculated 1432850 Rials. Net income per head of livestock in the region was 1003048 Rials. According to the average of light livestock in the area as 234 animal units, revenue not only can cover costs of utilizer and utilization unites, but also can compensate the costs of household during the year, any excess income and be reserved.

Land use planning is a science that determines the optimum use of land, regarding to the land ecological characteristics and socio-economic conditions. In land use planning of Ghurichai watershed with area of 24039 ha, six information layer including elevation classes, slope, aspect, soil type, vegetation type and density were combined using dual method and the final map of environmental unites were obtained. In this processes 1921 micro ecosystems or environmental units were distinguished in GIS environment using Arc map software. Ecological potential evaluation for agriculture, rangeland use, forestry, extensive and intensive tourism, aquaculture, rural and urban development and conservation were assessed for each unit. Finally 12.3 percent of the area was allocated to agriculture and rangeland use, 0.4 percent to extensive tourism, 52.5 percent to forestry, 1.1 percent to aquaculture, 1.7 percent to rural and urban development and 32 percent were allocated to conservation. Most of the area was allocated for forestry use, due to high capability and potential of this area for forestry. Therefore it is necessary to implement some basic practices in this area to prevent forest degradation in order to avoid land degradation and to have sustainable utilization of the mentioned watershed resources. In order to prevent irregular use of the forest, some alternative options have to be suggested for the stockholders of the watershed, not to endanger the socio-economic life of inhabitants. Therefore According to the result of the study, two new land use including aquaculture and extensive tourism suggested for this area.