نشریه مرتع و آبخیزداری
سال شصت و هشتم شماره 1 (بهار 1394)

This study aimed to investigate the effects of urban wastewater on some soil physical and chemical properties in Segzi، East Isfahan. Six sites were selected considering the planted species (Haloxylon persicum and Nitraria schoberi) and irrigation types (control or no irrigation، water logged and furrow irrigation methods). The 4 to 12 replications were chosen in each site depending on its'' size. Soil samples were collected in all replications from the 0‒10 and 10‒30 cm layers. Soil properties such as texture، organic matter، acidity، electrical conductivity، total soluble sodium، calcium and magnesium concentrations، and structural stability (dispersible clay) were measured for 94 collected soil samples. One-way ANOVA، Duncan''s mean test and Principal Component Analysis were used to analyze and interpret the data. The results showed that wastewater affected some soil properties by leaching soluble salts into deeper soil horizons and also adding organic matter and some minerals into the soil. Electrical conductivities of the 0‒10 cm layer in control sites (no irrigation) and the 10‒30 cm layer in sites with furrow irrigation method were significantly greater than water-logged irrigated sites (α= 0. 05). Applying wastewater increased soil organic matter content and aggregate stability significantly (α= 0. 05). Irrigating the sites with wastewater decreased soluble sodium contents and dispersible clay of the soil surfaces; hence the soil structural stability was increased. Overall، applying wastewater to irrigate the planted seedlings in rangeland restoration projects has benefits as its use in these areas has lower environmental risk when compared with agricultural fields.

Evaluation of changes present in soil and water resources due to operation implement of floodwater spreading is necessary to assess their positive or negative resultant effect. Rate of the internal sediment to diversion spreader channels، surface sedimentation and aggregation of the spreading field depth are most important effective attributes on the yield of floodwater spreading systems. These factors can change physical and chemical properties of studied field، as، by measuring of the infiltrate depth sedimentation of can achieve influencing depth of floodwater. To determine the effect of flooding spread on the sediment infiltrate rate in the field depth of Gachsaran floodwater spreading، from 0-15، 30-15، 30-45 and 45-60cm of the soil surface of spreading field and control were sampled. Granulometry of all samples was done using dry sieve and hydrometric analysis and then percent of the sediment grains with size of less than two millimeters were subjected to analysis of variance (ANOVA) by Duncan t-student test for 80 sampled samples. Results showed that deep entering of the sediments into drilled profiles to 30-45cm was completely distinct which can affect on the soil physical and mechanical properties. However، after the 30-45cm depth، the impact of floodwater spreading was minimal. The infiltration of each studied layer is the most important feature which will change from surface to the depth of spreading belts، so that by increasing infiltrated fine particles in the depth and blocking pores، the soil layers are clogged and in result reduce the infiltration rate، sharply. This state was more remarkable in the spreader belts surface. Furthermore، by depositing the sediments in the surface (0-15cm depth)، an impermeable and earthen layer is created which prevent from infiltrate the particles and even water into soil depth. Generally، with determine of the deposited sediment level in the spreading belts and also its deep infiltrate rate can provide effective and practical decision to improve efficiency and easy maintenance of the floodwater spreading systems or even not use this method.

Bitter asafetida (Ferula assafoetida L.) is one of the medicinal-rangeland plants belonging to Apiaceae family. The resin which is through incision secreted of the root has medicinal properties. The effect of rain on resin yield of this plant is one of problem of natural resources offices. The main aim of this study was to find out the effects of the irrigation on the resin yield، plants survival and some morphological traits of asafetida plants. Five irrigation treatments consisting of two times at week، one time at week، one time at two week، one time at three week، one time at month and without irrigation (control) were employed. The statistical design was a randomized complete block design، with four replications. The results show that irrigation increased resin yield، leaf length، vegetative growth period، survival plants at during of exploitation and next year significantly. But irrigation decrease essential oil percentage of resin significantly. One time irrigation in each week was the best treatment for increasing resin as it had produced 81. 4 g resin yield per plant. The lowest resin yield was obtained in control and one time irrigation per month. These treatments had no effect on number of plant leafs. So plants irrigation before exploitation from this plant is recommended.

This study Proceeded the Identity of the shackles of Participation pasture manageres about Performance Projects range- Management to Central Part kohkiloie Township. The purpose in this study was to Identity of the shackles of Participation pasture manageres about Performance Projects range- Management to Central Part kohkiloie Township. The present research is applied research by using descriptive and correlational methods and its instrument was questionnaire. The present statistical community consisted of 197 numbers of the pasture manageres which based on the ''Cochran'' formula، by using of Random Sampling، the number of 110 were selected as the statistical sample. Data was analyzed by using SPSS win software. Findings Through Spearman Rnank Correlation Coefficient، Pearson''s Correlation Coefficient and Eta Correlation Coefficient has shown that based on the pasture manageres'' views، the Personal Factors، the Social Factors، Economical Factors، Political Factors and Didactic Factors wouldeffect on the shackles of Participation pasture manageres about Performance Projects range- Management، while the variable of Age، Precedence، Size Land، Literacy and Sexuality don''t effect on the shackles of Participation pasture manageres about Performance Projects range- Management. The result from stepwise regression analysis showed that، the Social Factors and Didactic Factors had positive effects on shackles of Participation pasture manageres about Performance Projects range- Management.

One of the most important preparation steps of co-management projects implementation is recognizing key actors at local community level. These actors can assist managers and planners as local leaders and social powers. By applying social network analysis and centrality index at actors’ level of “Goormomenin” common rangeland، Kalateh region، Daamghan city in this research، social powers and local leaders in co-management procedures were identified. By social network analysis system، in-degree، out-degree centrality and betweenness centrality at actors level were studied based on trust and cooperation matrices and a combination matrix. According to the results، one of the stakeholders “Go-Bi” is a key actor in this rangeland. Based on core-periphery index، central and peripheral actors and density were identified. Having much authority and social influence، actors at central group play key role in rangeland co-management. Before implementing natural resource management projects، recognizing these actors can help governmental organizations to develop trust among villagers so that propel successful co-management procedures. These people create bridging ties between public institutions and stakeholders in rural sustainable development plans.

Social network analysis used to study the relationship between stakeholders and actors in natural resource management has become a scientific approach. The purpose of this study was analysis of Information Exchange Network among organizations engage in the sustainable management of natural resources. Results of Social Network Analysis revealed that there is weak Relationship among organizations about information exchange in sustainable natural resource management and access to information in this network is very hard and there is medium communication potential among organizations. Also in information network of the organizations، Agricultural organization had high power in the whole network. University، Agricultural organization and Research Center for Agriculture and Natural Resources have important role in facilitating of information exchange. Analysis of regularity process and its relationship with information exchange network revealed that forests، range and watershed management organization has more power than other organizations.

Because plant density is often measured by using plots and also in most cases are done by the method of estimation and counting the individuals، so one of the important cases that we have to decide on is the size and shape of plot. In this research، the density of Astragalus verus that it''s one of the dominate species in the area and has separate and recognizable individuals plant from each other،for investigate the effects of different size and shape of plots on sampling precision and accuracy are estimated in Mayan Mashhad area. The shapes of plot are square، wide rectangular، long rectangular، and sizes of plot are 1، 2، 4، and 8 m2 respectively، that we have been investigated in total 3x4 plots (treatments). In this research، the coordinates of individual plants and the boundary of study area are located by using digital camera. Then، with help of R software، the digital map of study area was sketched. The results show that long rectangular 0. 5x4 m plot has the highest accuracy and precision، so it is selected as optimum plot. Finally، it can be concluded that for saving time and expenses in sampling، using of locating coordinates method of individual plants and application of R software can be appropriate approach for estimating the density of shrublands، so for similar shrublands، the optimum plot of this research (4x0. 5 m) can be used.

Nowadays، designing hydraulic structures for flood damage mitigation has a significant importance in water engineering. One of the necessary parameters for the design of flood control measures is the probable maximum 24-hour precipitation in a 1000-year return period. This research was done using Jiroft Halilrud watershed data to evaluate Hershfild methods. Firstly، the maximum annual precipitation data series were used to do a frequency analysis using linear moments method to determine the maximum precipitation in 1000-year return period. Then this parameter was determined using the Hershfild method. The results showed a good agreement between the two methods according to correlation coefficient (0. 87). The results of this research can be used for the monitoring system of the region

Soil is one of the main non-renewable natural resources in the world and its degradation is considered as a major threat around the globe because it reduces the productivity capacity of soil variability and makes the environment instable in the long turn. Soil degradation has three different aspects: Physical، Chemical and Biological degradation. If any of these aspects of the destruction of the soil can be estimated in an equation، assessment and estimation of the soil degradation can be done easily. To achieve this goal extensive efforts have been made in various parts of the world and different methods for assessing soil degradation have been suggested. In this research latest guideline of soil degradation assessment presented by Land Degradation Assessment in Aridlands is used to desert region of the east of Esfahan and different aspects of soil degradation is assessed by that. According to the findings of this research، LADA methodology of soil degradation easily can be used by most users within the country because the method is simple and provides results as fast as possible. Comparing the results of this method and photos of relative the sampling sites has shown the model is reasonably accurate.

Although precipitation is the most important factor which effects rangeland production، but there is little information on the relationship between production and the interactions of climatic factors and specially drought indices.. In this research، the relation between production and climatic factors of rainfall، temperature، evapo- transpiration، and as well as drought indices of Standardized Precipitation Index)SPI) and Reconnaissance Drought Index (RDI) were investigated in Noudoshan Rangelands. Then the data with 33 variables were generated for different time periods of one to four months based the years of available production data. PCA was employed to decrease the number of variable and based on further component analysis، some variable were selected. To find the relation between production and climatic factors، regression analysis was used. Finally، the model with least IPE was selected as preferred model. By comparison equations based on rainfall، temperature، evapo- transpiration، and drought indices، the model resulted from RDI، selected as preferred range production estimator (R=0. 969، MARE=0. 111).

Plants change their environment characteristics and especially soil properties while their growth and adaptation، to develop plant communities. In this study effect of halophyte patches from Urmia lack in a vegetation type of Salsola nitraria and Aeluropus littoralis on chemical and physical properties of soil was investigated. So 4 vegitation patches along 2 transect with the length of 150 meter that was established in parallel position with the slop was selected and the distances between these patches considered as bare soil. Then soil samples were collected with four replication from the patches and inter patches areas from two different depths of 0-15 cm and 15-30cm، then soil samples were air dried and some of their properties were measured. Independent T-test was performed to compare soil properties of patches and inter-patches. Results showed that vegetation patches had significant effect on decrease of electrical conductivity and soluble salts of sodium، potassium and total phosphorus in soil samples of surface profile (0-15cm) but soil acidity، nitrogen content، organic matter، sand، silt and clay percent showed no significant differences in soil samples of patches and inter patches areas. Then comparing these properties in soil samples of second depth (15-30cm) showed that there wasn’t any significant differences between patches and inter-patches، and these results shows effect of vegetation patches and specially their roots on changing properties of surface soil in this study’s experimental field.

Kashan aquifer is adjacent to Salt Lake. Because of this adjacency، the saline water of the lake has moved to the aquifer. In this study groundwater quality of the aquifer was simulated using Artificial Neural Network (ANN) model. For this purpose، the dominant ion of water was first determined by Piper diagram. Results showed that the sodium chloride is the dominant ion of water and so it was selected as the target variable to be simulated So the output variable of the ANN model was the concentration of sodium chloride in current year while the input variables were the water table of groundwater، yearly rainfall and the concentration of sodium chloride in previous year. Result showed that Multilayer Perceptron ANN model has better result in predict of chlorine concentration compared to Radial Basis ANN model. The sensitivity analysis showed that concentration of chloride in previous year and water table of groundwater are the most important variables in the ANN model respectively.

Understanding the relationship between soil and plant is essential for reclamation of degraded lands. In order to investigate the relationship between Atriplex halimus density with carbon sequestration the rangeland of Incheborun was studied. Soil samples were collected randomly by Auger in the depth of 0-30 cm of the soil profile in three different plant densities (<200، 200-400 and >400 stand per hectare) with 30 replications. The data were subjected to ANOVA using statistical software SPSS 21. 0. Means were separated by T-test at P≤0. 5. The results of this research showed that the soil organic carbon have ranging from 0. 48 to 0. 64 (with an average of 0. 56%) in Atriplex plantation areas، while the organic carbon have ranging from 0. 03 to 0. 12 (with an average of 0. 078%) in the control region. Therefore، plantation measures caused significant difference in soil organic carbon contents per unit area in Atriplex plantation areas as compared to that observed in the control area. Sequestered carbon in per unit is 26. 27، 27. 85 and 30. 66 ton/ha respectively for low، medium and high Atriplex density areas. The results indicated that the rate of organic carbon as well as soil carbon sequestration increased with plant density. There were no significant difference among sequestered carbon and soil organic carbon values under those three different levels of densities، while significant difference were observed between three plantation areas and control area.

Land use optimization is one of the suitable methods for soil conservation. The present research with objective of land use optimization for soil erosion minimization and pure income maximization was conducted in the part of Taleghan Watershed which comprises 80427. 23 ha in area. To achieve this propose، area، erosion rate and net income value of each land uses according to requiring standards of each land uses area was extracted. Then، limitations and two objective functions were determined and optimization problem was solved by using ADBASE software. The results revealed that the optimization decrease 6. 99 percent of erosion rate (6. 28 ton/ha/year to 5. 84 ton/ha/year) and 4. 65 percent of pure income (118174. 38 to 112681. 02 million Rials). Also، the results proposed that drylands farming are changed to garden and orchard and rangelands.