نشریه تحقیقات منابع طبیعی تجدید شونده
سال پنجم شماره 2 (پیاپی 16، تابستان 1393)

In this research, the recreational value of the district was determined in order to study the satisfaction value of the recreational district "Chort Lake". The effective elements of willing to pay in Chort Lake's visitors and the average estimation of their willing to pay were determined by conditional evaluation method and two-stage Heckman model. The necessary data were gathered by filling the questionnaire and verbal interview of 274 visitors in spring and summer, 2013. The results show that 85.3% of visitors had the willing to pay for recreation. Using the conditional evaluation method, the willingness to pay per person per visit was estimated 4307.4 Rials. The variables of the recommended cost, monthly revenue of family members, educational level, satisfaction rate, ability of fishing, seasons, satisfaction level and willingness to revisit, are effective elements of the willingness to pay in this method. Based on two-stage Heckman method, the average rate of the willingness to pay was 3843.5 Rials. Monthly revenue, educational level, satisfaction rate, occasions of visiting the competitor places of Chort Lake and satisfaction rate are the effective elements of people's willingness to pay in this method. The optimized method for determining the recreational value of Chort Lake is two-stage Heckman method.

Forage is a main product in Taze-Ghale rangelands of Bojnourd County and herding is of the important jobs in this area, Also utilization of medicinal plant, Glycyrrhiza glabra in a three-month period from late October is done and provides income of the residents in this regions. Therefore, the present study was conducted in order to determine, financial indices of harvest and supply of Glycyrrhiza glabra and the income ratio provided by means of this beneficiary and forage monetary value for animal husbandry in the region. Results showed that, net income per household from forage production was 17.1 million Rials which covers almost 33% of each household income. Beside, net income gained by harvesting Glycyrrhiza glabra was 2,850,000 Rials encompassing 6% of each household income. Royalties also shows that, royalties provided by Glycyrrhiza glabra harvesting and forage production are 327.5 thousands Rials annually and 6.96 million Rials annually, respectively. Also annual employment results also show that: Employment ratio for forage production and Glycyrrhiza glabra utilization are 65 and 35 percent respectively. The employment ratio for Glycyrrhiza glabra harvesting with 35% and noticing 6% of the net income for each household, compared with 65% employment ratio and 33% of the net income for each household for forage production, possesses a higher rank in the employment ratio in the region. Needed to say that mean added value created through the 2-level preparation process of Glycyrrhiza glabra from fresh to dried reaches 59%, defined as 2.5 time more price. Marketing margin of Glycyrrhiza glabra is 50%. Comprehensive study on financial value of seasonal employment resulted from cultivating medicinal plants in low-income rain-fed farms beside primary vocations of herding and farming could considerably enhance locals’ welfare and on top of that impede converting rangelands into rain-feds and degradation of rangelands as well.

Soil ecosystems management for different purposes requires accurate and quantitative understanding of the soil characteristics and their processes. This study was aimed to predict Artemisia aucheri cover though some soil physical and chemical properties in Vavsar rangeland, Kiasar, Mazandaran province. Random systematic sampling was used. Five transects with 100 m length and 10 plots 4 m2 on each transect were established. Then cover (%) of A. aucheri and 50 soil sample from 0- 15 cm depth was estimated in each plot. Soil properties including soil organic carbon, total nitrogen, EC, water percentage, CaCo3 percentage, soil texture, and pH were measured. Data were divided in two series: a series for analysis including 70% of the data for and 30% for evaluation of customized models. Result showed that soil water, silt and sand percentages were the most important soil properties for prediction A. aucheri cover in the study area. Prediction of the statistical models in the study area resulted in mean error and root mean square error values of 0.25, 0.06 for ANN equation and 0.43, 0.12 for MLR, respectively. Therefore, the ANN model could provide superior predictive performance when was compared with MLR model.

This study was conducted to determine the precision returns of range plans of Karhpo range plan, Ilam by engineering economy methods based on the data and information collected. The results showed that the criterion of net present value (NPV) had a positive net value to a discount rate of 26.00%, while its effect was zero at a discount rate 26.56%. Besides, the benefit-cost ratio (BCR) was higher than 1 until the discount rate of 26%, while it was equal to 1 at the discount rate of 26.56%. Internal Rate of Return (IRR) of 26.56% for plan was economically practical during 9-years period. Given the proper financial explanation of the plan, it is better to adopt a method and policy for assigning and implementing the range plans to beneficiaries in order to making ranchers more willing to implement the plans. The government can also participate more actively in range plans with providing parts of the costs and improving economic efficiency (return) of plans.

The purpose of this study was to provide spatial distribution prediction map of Stipa barbata and Agropyron intermedium species using artificial neural network model. For modeling, vegetation data in addition to site condition information including topography, climate, geology and soil were prepared. Within each sampling unit, three parallel transects with 150 m length each containing 15 quadrats were established. Sampling method was randomized-systematic method. Quadrats size determined for each vegetation type using the minimal area and their number were determined according to vegetation variation. Soil samples were taken from 0-30 cm depth along of each transects. Measured soil properties included grovel, texture, pH, EC, organic matter, lime, soluble ions (N+, P+, K+). Geostatistical methods were used for data analysis and preparation of environmental variables maps, while an artificial neural network with back-propagation algorithm applied for maps prediction. The accuracy of the network for habitat of A. intermedium and S. barbata was 98.7% and 97.6%, respectively. This indicates that the soil and climatic parameters used in the final model of this study were able in predicting potential distribution of the species. According to the results of the models assessment using the Kappa coefficient, artificial neural network model has predicted habitat for of A. intermedium and S. barbata species at an excellent and good levels (kappa= 0.95% and 0.70%). It can be concluded that the neural network model have high accuracy in predict the spatial distribution of species in rangeland of central Taleghan.

Ecological study of Ferula ovina characteristics were carried out to find the applicable information in rangeland improvement and development programs. Habitat map was firstly provided by vegetation map and field visiting. Three different stations including Sirch, Modym and Hatkan were selected in these habitats and sampling was done by random-systematic method in every station with 30 plots (4 m²) along transect. In this study, the ecological characteristics (climatic, topographic, edaphic), canopy cover, density, frequency were investigated. Root system, phenology, preference value of the plant and pests were measured. The results showed that habitat elevation for this species was 2600 to 3200 meters above sea level and slopes 30-60%. Besides, average annual precipitation of the habitats was around 130 mm while mean annual temperature ranged between 10 to 16 ºC. The sandy-loamy texture was preferable to this plant. Electrical conductivity of soil and pH were 0.38-0.49 ds/m and 8.0-8.2, respectively. The percent canopy cover, frequency, and density were 9.9%, 93% and 4300 plants per hectare, respectively. Its root system included a main root and a few distributed roots. Stages of plant growth began late March and continued to August. Vegetative growth of plants started from midMarch. Flowering stage of the F. ovina started from the second half of April. This plant can be propagated only by seed with the best seed planting depth of 1 cm. Sheep and goats eat these flowers and leaves. The preference value of F. ovina was 59% higher than other species. Local farmers use this plant for winter forage.