amin salehpour jam; Mohsen Mohseni Saravi; Javad Bazrafshan; Shahram Khalighi
Abstract
Investigation of drought event has a great importance in the natural resources management and planning water resources management. In this research, the effect of the climate change on drought characteristics in northwest of Iran was investigated using the HadCM3 model under A2 scenario. The statistical ...
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Investigation of drought event has a great importance in the natural resources management and planning water resources management. In this research, the effect of the climate change on drought characteristics in northwest of Iran was investigated using the HadCM3 model under A2 scenario. The statistical downscaling was executed using SDSM 4.2.9 and observed daily precipitation, observed predictors and large-scale predictors derived from the HadCM3 model. Afterwards the SPI was calculated for different time scales of 3, 12, 24 and 48 months in the observed period of 1977-2006 and three periods of 2007-2036, 2037-2066 and 2067-2096. Obtained results show that the mean annual precipitation at the stations of Ardebil, Khoy and Oroomieh was decreased in the future periods and it was also increased at the station of Tabriz in the future period. The Ardebil station with the depletion of 97 mm (32 %) in the fourth period than the observed period has maximum rate of the depletion. The results also show that the drought occurrence with more intensity, duration and frequency can occur in the future periods. The comparison of the results between different stations shows that the Ardebil station has the most intensity of dry period in time scales of 3, 12 and 24 months based on the maximum cumulative intensity of dry periods among the stations. On the time scale of 48 months, the Oroomieh station with the cumulative intensity of -92.78, has the most intensity of dry period between the different stations.
Gholam Ali Heshmati; vahid karimian
Abstract
To apply scientific and proper management of rangeland ecosystems, having information on health and functions indices of ecosystem is required. Using landscape function analysis, the present study deals with assessing and comparing of ecological indices in northern and southern landscapes, Darehkonari ...
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To apply scientific and proper management of rangeland ecosystems, having information on health and functions indices of ecosystem is required. Using landscape function analysis, the present study deals with assessing and comparing of ecological indices in northern and southern landscapes, Darehkonari Khashab of Gachsaran. Length and width for ecological patches in northern landscapes in species Astragalus fasciculifolius Boiss, Centaurea intricanta Boiss, Cousinia multiloba DC, and inter patches(bare and litter), in southern ones on species Cousinia multiloba DC, Stachys byzantina C. Koch, Stachys byzantina C. Koch and Cousinia multiloba DC and inter patches were recorded along three 50 m transects across both southern and northern aspects. In addition, eleven soil surface indices were measured. These indices belong to three main characteristics of soil stability, infiltration and nutrient cycling. The results showed that the indices of stability and nutrient cycling in both landscapes have a significant difference (p <0.05), but this was not case for infiltration index (p>0.05). The main ecological indicator of northern and southern landscapes are C. intricanta and S. byzantine + C. multiloba, respectively.
Zahra Eslamian; Mehdi Ghorbani; hamed rafiee; tayebe mesbahzadeh
Abstract
In recent years, natural resource economists evaluate and assess the role of natural resources in the welfare of people have put on their agenda. This study, people's willingness to participation in protecting and reviving the desert area NasrAbad, examined the using conditional valuation and tow-dimensional, ...
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In recent years, natural resource economists evaluate and assess the role of natural resources in the welfare of people have put on their agenda. This study, people's willingness to participation in protecting and reviving the desert area NasrAbad, examined the using conditional valuation and tow-dimensional, dual choice questioner. To estimate the willingness to pay logit regression model was used based on the maximum likelihood method, the parameters of the model were estimated. Results suggest that age, occupation, education and horticultural activities, a native of the region, climate change, poor management officials, family income and number of family members, significant positive effect and gender, agricultural activities, overgrazing of livestock , expansion of urban land and Bid a significant negative effect on the bid people are willing to pay. Deontologist people units 0/868 have likely to pay more compared with Cosequentialists people the Marginal effect of these variables to be allocated. the average willingness to pay of the Deontologist and Cosequentialists people in this study to participation in protecting and reviving the deserts of Nasr Abad is estimated to be 32586 and 6524 Rials respectively.
behzad behtari; Zeinab Jafarian; Hossenali Alikhani
Abstract
Soil heterotrophic respiration, which is the result of soil organic matter decomposition, is affected by environmental factors, especially temperature. A variety of models have been proposed to understanding the respiration response of the soil to temperature and respiration sensitivity to temperature ...
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Soil heterotrophic respiration, which is the result of soil organic matter decomposition, is affected by environmental factors, especially temperature. A variety of models have been proposed to understanding the respiration response of the soil to temperature and respiration sensitivity to temperature (Q10). The aim of this study was to evaluate the respiration response of soil to temperature variations using incubation technique and to examine variety of models in two different management systems. For this purpose, Intact soil samples were collected from a grazing and grazing exclosure in Fandoghlo Ardebil, incubated for 4 weeks at 10, 20 and 30 ° C temperature. Soil respiration was measured by alkaline adsorption method. Nonlinear regression method and The Levenberg-Marquardt algorithm were used to determine the parameters of models. Both ecosystem showed an exponential increase in Soil heterotrophic respiration with temperature. The rate of respiration in soil of grazing, at all three temperature levels, was higher than grazing exclosure. Most models describing the relationship between soil respiration and temperature showed a good fit to the experimental data, especially in the grazing exclosure. Q10 in the grazing (1.21) was higher than the grazing exclosure (0.97). In general, based on the coefficients of the models and the Q10 analysis, the Arrhenius model can be better than the others of model for expressing the relationship between soil respiration with temperature, as well as good numerical estimation for Q10 of soil.
hamid barghi; Bahman Shafiei; ahmad hajarian
Abstract
The present study was conducted using analytical-descriptive methods with the aim of investigating the limitations and abilities of using the rangelands of Kermanshah province by Dehyar using AHP and SWOT models. The statistical population consisted of experts from the Natural Resources Bureau of 14 ...
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The present study was conducted using analytical-descriptive methods with the aim of investigating the limitations and abilities of using the rangelands of Kermanshah province by Dehyar using AHP and SWOT models. The statistical population consisted of experts from the Natural Resources Bureau of 14 people. The tool used to collect the data was a questionnaire which was designed according to the review of the field of research and individual interviews with the experts of the Natural Resources Bureau of the region. Data collected using SWOT and AHP model have been investigated. The results indicated that the most important points in the field of exploitation of rangelands in Kermanshah province are determining the appropriate season and grazing time in rangelands with a weight score of 0.96, the most important weakness, non-principled exploitation of rangelands with a weight score of 1.04, the most important opportunity , The beginning of activities for preserving rangelands in Kermanshah, such as seeding of rangeland species proportional to climate, soil and ... with a weight score of 1.02, and the most important threat is the lack of precise monitoring and strong management of the unit in maintaining pasture and inter-system coordination with a weight score of 0.80. Also, in the prioritization of strategic factors based on the AHP model, it was observed that the most important non-principle exploitation of rangelands with a weight of 0.289 and then the beginning of conservation activities in Kermanshah, such as seeding of rangeland species proportional to climatic, soil and
Mohammad Jafari; ِAli Tavili; Yahya Esmaeilpour; Hossein Azarnivand; Mohammad Zare Chahouki; Hamid Reza Asghari
Abstract
Abstract In this study the effects and costs of application of two kinds of super absorbent polymer on the establishment and surviving of seedlings was investigated. Experiments were done in the field and on two kind of soil with different salinity (EC: 4.5 and 8 dsm-1). The results showed: the establishment ...
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Abstract In this study the effects and costs of application of two kinds of super absorbent polymer on the establishment and surviving of seedlings was investigated. Experiments were done in the field and on two kind of soil with different salinity (EC: 4.5 and 8 dsm-1). The results showed: the establishment rate of seedling in control was about 40 percent. The percentage of seedling establishment in the hydrogel treatments significantly increased and statistically is equal to the optimal surviving of the seedling (80%). Soil salinity on seedling establishment in the same treatments did not produce significant differences. The results were compared with a similar project to determine the costs and benefits. Based on the results a 30 percent reduction in water usage per round and 33 to 50 percent reduction in the number of irrigation replicate were recorded. The costs in compare to the normal project varied from -2 to 29 percent respectively for treatment Herbosorb® 0.5% and Aquasorb 1%. The treatments Herbosorb® and Aquasorb with usage level of 0.5% caused about 2.5 percent for each one percent increasing in the cost. There is no significant increase in the percentage of seedling survival by using 1% super-absorbent compared to 0.5 percent.
vahid jafarian; Mohammadreza Yazdani; Mohammad Rahimi; Mehdi Ghorbani
Omid Rahmati; Aliakbar Nazari Samani; Mohammad Mahdavi
Abstract
Determination of groundwater potential in respect to increasing trend of water demand in Iran, is found to be an unavoidable and vital subject. The present research was aimed to assess the efficiency analytical hierarchical process (AHP) to identify potential groundwater zones. Initially, five parameters ...
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Determination of groundwater potential in respect to increasing trend of water demand in Iran, is found to be an unavoidable and vital subject. The present research was aimed to assess the efficiency analytical hierarchical process (AHP) to identify potential groundwater zones. Initially, five parameters (viz., lithology, annual rainfall, drainage density, lineament density and land slope) were used in Ghorveh-Dehgalan plain. Influencing groundwater potential were selected. A questionnaire was prepared to collect ten experts attitudes to paired comparison of such parameters. The normalized weights of criteria/parameters were determined based on Saaty’s 9 point scale and its importance in specifying groundwater potential zones using analytical hierarchy process (AHP) and eigenvector method. To prepare lineament distribution maps, ETM+ Landsat images and PCI Geomatica were applied. Finally, the set of criteria were integrated by weighted linear combination method using ArcGIS 9.3 software to generate groundwater potential prediction map. The pumping test results collected and overlaid with groundwater potential prediction map. The validation of the groundwater potential prediction map was conducted based on frequency ratio and results of pumping 20 wells in study area. Results from comparing predicted potential of groundwater and by the groundwater specific capacity (SPC) showed 85% accuracy. It was established in the study that the AHP technique is promising of make accurate and reliable prediction, specifically in no-data aquifers.
Farhad Zolfaghari; Hossein Azarnivand; Hassan Khosravi; Gholamreza Zehtabian; Shahram Khalighi Sigaroodi
Abstract
Any Changes in a dry land surface ecosystem will be affected by the climate near the ground or microclimate in the vertical plane. In recent decades' wetland drying cause to reduced vegetation significantly. Assessing Zabol synoptic station statistics shown an increased temperature of this place. It ...
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Any Changes in a dry land surface ecosystem will be affected by the climate near the ground or microclimate in the vertical plane. In recent decades' wetland drying cause to reduced vegetation significantly. Assessing Zabol synoptic station statistics shown an increased temperature of this place. It seems that there has a direct relationship between the changes in land surface vegetation and increases the ambient temperature. The situation ground roll on microclimate has been investigated to illustrate this relationship. In this study we compare and assessment temperatures at depth of 5cm and surface and height about 150 cm and heat fluxes and energy in three microsites with different vegetation cover. The distance between the experiment microsites is about 20 km, and the elevation difference is less than 10 meters. Microsite A with the total vegetation average about 65%, B microsites 20% and microsites C with 100% bare soil. It evaluated the equation ρc_p z_a (dT_air)/dt to investigate the role and effects of vegetation on the ground surface. Data analyzes showed temperatures in the period of study at the C microsites were higher than other microsites. It seems the lack of vegetation in microsites C has a major role in the higher air temperature. In micro site C At 00:30 Am (local time) the air temperature was 3.2ºC higher than microsite A and B. The results showed there is a direct relationship between the vegetation cover percentage and air temperature because of different soil heat fluxes and surface temperature.
Shima Javadi; Gholamreza Zehtabian; Mohammad Jafari; Hassan Khosravi; Azam Abolhasani
Abstract
The reduction of soil quality and health due to the lack of proper management or land use change in arid and semi-arid regions of Iran has become a major challenge, which affects the nutritional properties of the soil. Regarding to the importance of nutrients in plant growth, the aim of this study was ...
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The reduction of soil quality and health due to the lack of proper management or land use change in arid and semi-arid regions of Iran has become a major challenge, which affects the nutritional properties of the soil. Regarding to the importance of nutrients in plant growth, the aim of this study was investigation and comparison of soil nutrients under different agricultural land uses in Eshtehard region. At first, different maps of region including soil map, elevation and land use maps were prepared using ArcGIS 9.3. Five land uses including garden lands, monoculture lands, multiple cropping lands, fallow lands and rangelands were recognized as the treatments. After sampling the soil, nutrients including N, Ca, Mg, K, P were measured in two depths of 0-30 cm and 30-60 cm. In addition, the amount of ESP, as a destructive factor, was assessed in order to determine the corrective or destructive role of different land uses. The results of statistical analysis of data using SPSS software showed that there was a significant difference between nutrients average. In addition, the results showed that rangelands and garden lands had the corrective role in surface and deep layers respectively and monoculture lands had destructive role in the deep layer. Follow lands had the most destructive role in both surface and deep layers. Generally, garden lands, rangeland and multiple cropping lands were determined as the most desirable treatments and follow lands and monoculture lands were determined as the most undesirable treatments.
H. Saadati; F. Sharifi; M. Mahdavi; H. Ahmadi; M. Mohseni Saravi
Volume 62, Issue 1 , June 2009
Abstract
The main structure of this study includes; isotopic tracer evaluation and measuring, to identify and origin of groundwater recharge, contributions determine of diffused recharge (DR) and concentrated recharge (CR) as well as determine drought and wet periods in Hashtgerd plain. The hydrochemical study ...
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The main structure of this study includes; isotopic tracer evaluation and measuring, to identify and origin of groundwater recharge, contributions determine of diffused recharge (DR) and concentrated recharge (CR) as well as determine drought and wet periods in Hashtgerd plain. The hydrochemical study which involved collection and analysis of water samples from the deep and dug wells, springs, tap water and rainwater showed that the rainwater is little source of groundwater recharge. The isotopical study aimed to determine the origin of the groundwater bodies and to offer support for the hydrochemical analysis. To achieve this purpose samples analyzed for H2 and O18 and data was quoted from literature about the isotopic composition of precipitation. The study shows that the isotopic composition during the rainy season ranges for ?O18 between -6/05 ‰ and -6/92 ‰ and for ?H2 between-45/92 ‰ and -52/27 ‰. The changes in ?O18 are correlated with those of ?H2 with R2 =0.9 that was similar to GMWL line. proving their meteoric origin. Cluster analysis supported by the Hierarchical Cluster Analyze, Chebychev and Mann-Whitney tests classified the analyzed rivers water samples into two main groups: the first cluster was included Kordan, Aqasht, Sorheh and Khor rivers. Because of the low runoff and high infiltration these rivers are recharged through groundwater. The second cluster was consisted Valian, Fashand and Hiv-shalamzar rivers. Because of the low infiltration these rivers are recharged through runoff. Cluster Analysis shows that the samples of groundwater of Hashtgerd plain were divided into three clusters. The first cluster was included west and north-east of Hashtgerd plain (Nazarabad, Hashtgerd town, Baraghan and Kordan) were recharged through surface water and rainfall. The second cluster was included north and center of Hashtgerd plain were recharged through surface and groundwater. The third cluster was included south-west and south-east of Hashtgerd plain which were recharged through groundwater. The results show that concentrated recharge (CR) supply groundwater more than diffused recharge (CR). Concentrated recharge was performed by watersheds and flood spreading. Using isotopic method, mean values of ? O18 and ? H2 in a mass-balance equation, the relative contributions of diffused recharge (DR) and concentrated recharge (CR), to groundwater were estimated to be 78 درصد and 22 درصد, respectively. According to results of this study, groundwater resource level decrease and there is a drought period in Hashtgerd plain.
khadijeh rahimi balkanlou; Mehdi Ghorbani; mohammad jafari; ali tavili
Abstract
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 ...
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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.
bahram choubin; SHahram KHalighi Sigaroodi; Arash Malekian
Abstract
Predicting climate trends, especially forecasting rainfall, provides managers of different fields withsuitable tools so that considering these predictions; they can devise future-state policies. At thisstudy, after selecting the most effective climate indices applying PCA method, the effects of largescaleclimate ...
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Predicting climate trends, especially forecasting rainfall, provides managers of different fields withsuitable tools so that considering these predictions; they can devise future-state policies. At thisstudy, after selecting the most effective climate indices applying PCA method, the effects of largescaleclimate signals in seasonal rainfall of basin Maharlu - Bakhtegan were investigated bothsimultaneously and by delay through statistical methods (Pearson correlation and cross-correlationcoefficient) and by applying stepwise regression model, regression equation for forecasting rainfallwas offered. The results showed that in cross-correlation between the time series of SPI (dependentvariable) at time (t) and climate signals (independent variable) at time (t-k), only SOI indexconcurrently has a significant relationship with rainfall, whereas, most of indices turned significantwith standardized precipitation index with different lag times. In season to season study of thesignals with the standard precipitation index using Pearson's correlation coefficient it was found thatclimate signals of spring and summer are not significantly correlated with SPI. Representationcoefficients (R2) and standardized regression effect (Beta) in stepwise regression model showed thatsimultaneous and with season to season delays signals (for example: SPI index of autumn with fourprevious seasons indexes) at method Pearson correlation have higher relationship with seasonalstandardized precipitation index than the cross-correlation in time (t-k), (which signals of allseasons given is delay together with than SPI of all seasons) show.
Serveh Darvand; Hassan Khosravi; Hamidreza Keshtkar; Gholamreza Zehtabian; Omid Rahmati
Abstract
The purpose of this study was to compare machine learning models including Support Vector Machine, Classification and Regression Tree, Random Forest, and Multivariate Discriminate Analysis to prioritize susceptible areas to dust production. To determine the dust days, hourly meteorological data of Alborz ...
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The purpose of this study was to compare machine learning models including Support Vector Machine, Classification and Regression Tree, Random Forest, and Multivariate Discriminate Analysis to prioritize susceptible areas to dust production. To determine the dust days, hourly meteorological data of Alborz and Qazvin provinces and satellite images of the same days for the period 2000 to 2019 were used. 420 dust collection points were identified and the map of their distribution was prepared. The maps of factors affecting the occurrence of dust, including landuse map, soil orders map, slope map, slope aspect map, elevation map, vegetation map, topographic surface moisture, topographic surface ratio, and geology mam were prepared. Using the mentioned models, the impact of each of the effective factors of dust was determined and prioritization maps of dust harvesting areas were prepared. Models were evaluated using the ROC curve. According to the results, the elevation factor is more important in all models than the other parameters used in the model. The modeling results also showed that the Random Forest )RF( and Multivariate Discriminate Analysis (MDA) models had the highest values of accuracy (0.96), precision (0.94), Probability of Detection (POD) (0.98), and False Alarm Ratio (FAR) (0.051) compared to the others. The performance of the RF and MDA models is better than the other models, followed by the Support Vector Machine (SVM) and Classification and Regression Tree (CART) models, respectively. Also, in evaluating the models using Receiver Operating Characteristic (ROC), the RF model was selected as the best model.
Gh.A Fallah Ghalhary; M Habibi Nokhandan; J Khoashhal
Volume 63, Issue 1 , June 2010, , Pages 55-74
Abstract
The aim of this research is the assessment of the relation between rainfall and large scale synoptically patterns at Khorasan Razavi province. In this study, using adaptive neuro fuzzy inference system, the rainfall estimation has been done from April to June in the Area under study. Spring rainfall ...
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The aim of this research is the assessment of the relation between rainfall and large scale synoptically patterns at Khorasan Razavi province. In this study, using adaptive neuro fuzzy inference system, the rainfall estimation has been done from April to June in the Area under study. Spring rainfall data including the information of 38 synoptic, Climatologic and rain gauge stations from 1970 to 2007 has been selected from Iranian Meteorological Organization and Ministry of Energy. In this paper, we are analyzed 38 years of rainfall data at Khorasan Razavi province located in northeastern part of Iran at latitude-longitude pairs (34°-38°N, 56°- 62°E). The Adaptive Neuro-Fuzzy Inference system based on synoptically patterns with 38 years of rainfall data was trained. For performance evaluation, network predicted outputs were compared with the actual rainfall data. In this Study, at the first step, the relationship Between synoptically pattern variations including Sea Level Pressure (SLP), Sea Surface Temperature (SST), Sea Surface Pressure Difference (?SLP), Sea Surface Temperature Difference (?SST), air temperature at 700 hpa, thickness between 500 and 1000 hpa level, relative humidity at 300 hpa and precipitable water were investigated .As the second step, the model was calibrated from 1970 to 1997. Finally, rainfall prediction is performed from 1998 to 2007. The model that used in this research has an input layer, one hidden layer and an output layer. The number of neuron for input layer, hidden layer and output layer was 13-28-1, respectively. The results of simulation reveal that adaptive neuro fuzzy inference systems are promising and efficient.
alam cheraghian; Somayyeh Dehdari; mohammad faraji; Ali Ariapour
Abstract
The present study investigates the effect of restoration actions on Mesquite tree planting, the construction Furrow Contour actions and Eucalyptus tree planting on physical and chemical properties of soil in a Chahshirin in 75 km of Behbahan city. In this study, along with each treatment, a non-operational ...
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The present study investigates the effect of restoration actions on Mesquite tree planting, the construction Furrow Contour actions and Eucalyptus tree planting on physical and chemical properties of soil in a Chahshirin in 75 km of Behbahan city. In this study, along with each treatment, a non-operational correction treatment was selected as a control, two of which were adjacent to each other. Systematic random sampling was carried out during 3 transects of 100 meters in two depths of 30-0 and 60-30 cm soil in each site of correction and control. Soil samples were transferred to the laboratory and nitrogen, phosphorus, potassium, organic matter, organic carbon, lime, clay, silt, sand, electrical conductivity and acidity factors were measured. The results of the independent t-test showed that the factors studied had a significant difference at the level of 1% and 5% compared to the control area. Also, the results of analysis of variance ANOVA between correction treatments in the first and second depths for phosphorus, potassium, organic matter, carbon, lime and Ec showed a significant difference at 1% level. Also, for nitrogen at the first depth and the amount of silt and sand in the second depth, a significant difference was observed at 1% level. In other words, it was observed that the three restoration actions carried out had positive effects on the soil properties; the planting of the tree and the construction of the Farrow Contour had better conditions than the Eucalyptus tree plant site.
aboalhasan fathabadi; Ali Salajegheh; hamid pezeshk; Aliakbar Nazari Samani; hamed rouhani
Abstract
In order to manage and implement conservational activities in watershed successfully, it is necessary to determine the sediment sources. In recent years, sediment fingerpering techniques have been used for estimating sediment sources contribution. With respect to small source samples, having many answer ...
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In order to manage and implement conservational activities in watershed successfully, it is necessary to determine the sediment sources. In recent years, sediment fingerpering techniques have been used for estimating sediment sources contribution. With respect to small source samples, having many answer as a result of over fitting, there are some uncertainties in estimated sources contribution. In this study, the uncertainty associated with the multivariate mixing model was estimated using Monte Carlo simulation and GLUE approach in Zidasht-Fashandak sub- watershed. The sediment and source samples were taken in the study area and then, 54 geochemistry and three organic characteristics were measured. 17 elements were also selected as optimum tracer composition using Kruskal–Wallis H-test and multivariate discriminate analysis. Meanwhile, sources contribution were estimated using multivariate mixing models. Results showed higher contribution of sub-surface sources than the surface resources. Also, the distance between lower and upper limits for all sources and resolutely uncertainty bands were high.
Sayed Hamzeh Hosseini; Reza Erfanzadeh; Paria Kamali
Abstract
The study on the livestock dietary and preference value of different species are essential forrangeland management. Therefore, this study was carried out to evaluate the preference indicesof 14 plant species in Kahnuj, during two different phenological stages (vegetative growth andafter-seed-dispersal). ...
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The study on the livestock dietary and preference value of different species are essential forrangeland management. Therefore, this study was carried out to evaluate the preference indicesof 14 plant species in Kahnuj, during two different phenological stages (vegetative growth andafter-seed-dispersal). The close observation method was used to measure the preference indexfor three age classes of Rainian goat (one, three and five years). The results showed that mainand interaction effects of goat age, plant phenological stage and the kind of plant species onpreference values were significant. Older goat consumed a higher time to graze in the studyarea. Stipa capensis had the highest preference index and Rhazya stricta had the lowest. Thepreference index of most plant species was significantly variable between two phenologicalstages. In addition, in each phenological stage, the preference value of plant species wassignificantly different. In the vegetative growth stage that annual plant species were abundant,goats mostly focused on these plant species for grazing. However, in the after-seed-dispersalstage in which the annual cover decreased, goats (particularly older ones) focused on shrubs forbrowsing. As a result, Rainian goat is a grazer in the normal situation and he can be a browserin the hard condition. It was suggested that the cover of Taverniera cuneifolia to be increased inthe study area in order to compensate the deficiency of forage in long term. Artificial foragingis useful to reserve the performance of goats (particularly younger ones) in short term.
Gholamreza Zehtabian; Hassan Khosravi; Ali Azareh
Abstract
Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, ...
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Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, prevention of land degradation is more desirable. This function requires to research on theutilization of land agricultural and how to use. With this aim, the Khatam city was selected as thestudy region and various maps of the region, including soil, land use and height maps was prepared tohelp ArcGIS9.3 and ENVI software. Four dominant land region mention mono cultivated and multicultivated systems under irrigation, garden lands and range lands as control treatments wereconsidered as the treatments. The soil was sampled and soil factors in two corrective factors, includingcorrection factors N, P, K, CO, Caco3, Mg and damaging factors Hco3, Cl, Na, pH, EC and SAR atdepth 0 to 30 cm of the soil surface horizons were studied. Factors the design of split plots showed thatthere are significant differences between treatments in the region and soil of region is relatively poorfrom CO, N, K and P in soils Rdhy. The comparison of treatment means with Duncan MeanComparison indicated that the garden lands as the most suitable treatments and range lands as the mostunsuitable one.
isa Jafari Foutami; Esmaeil Sheidai Karkaj
Abstract
The purpose of this study was to investigate the causes of uncertainty in different methods of estimating soil carbon and also to evaluate the proposed computational method that eliminated the effect of soil bulk density on carbon calculation and the actual soil carbon content for soils with different ...
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The purpose of this study was to investigate the causes of uncertainty in different methods of estimating soil carbon and also to evaluate the proposed computational method that eliminated the effect of soil bulk density on carbon calculation and the actual soil carbon content for soils with different bulk densities in terms of the equivalent depth.Therefore, in order to check the accuracy of this proposed method, the amount of carbon in three types of grazing intensity in Golestan province (light grazing, average grazing intensity and severe grazing) was calculated and various methods were tested and analyzed. The results of mean comparison showed that based on first approach (concentration carbon Parameter), amount of carbon in first depth of light grazing area, moderate grazing and intensity grazing have significant differences, and soil concentration are 31.39, 23.57 and 11.5 gr C/kg soil, respectively, However, contradictory results achieved for first depth in case of present the mass soil in per unit area based on constant depth. So that the first depth of the light and medium grazing intensity have more mass carbon, 89.15 and 74.47 ton C/ ha, respectively, and heavy grazing intensity site has the lowest, 42.93 ton C/ ha. There are also these uncertainties between two different depths for different sites. In order to dissolved this conflict in several studies, mass carbon based on equivalent depth was calculated for study area and result show that light and heavy grazing area have the highest and the lowest amount of carbon.
Morteza Khodagholi; Razieh Saboohi; mina bayat; Javad Motamedi
Abstract
For the experiment, at the beginning of each growing season, an adult Naiini sheep (3-4 years old) was used as representative of the herd and used in annual censuses. Grazing time measurement continued at the beginning of the growing season and during the four growth stages. Census time at each growth ...
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For the experiment, at the beginning of each growing season, an adult Naiini sheep (3-4 years old) was used as representative of the herd and used in annual censuses. Grazing time measurement continued at the beginning of the growing season and during the four growth stages. Census time at each growth stage was performed one hour after daily grazing, and in three continuous 20-min periods (repeat experiment). Considering the time of concentration of the animal and the tendency of the animal to different species, the palatability class of each plant species was determined. The results showed that during all the years under study, grazing concentration of Naiini sheep on annual species (Grass and Forbes), litter, Stachys inflata, Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia was observed. Based on the results, annual and litter species were classified as Class І species, Stachys inflata as Class II plant and Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia as Class Ш species. The results showed that the palatability of the species was not the same as the change in plant composition during the growing season. Therefore, it is incorrect to consider the same palatability class for each species at different stages of development, and it is necessary to pay more attention to the description of pasture design services when calculating grazing capacity.
M.A Hakimzadeh Ardakani; M Esfandiari; A Mosleh Arani; H Malekinezhad
Volume 63, Issue 2 , September 2010, , Pages 197-10
Abstract
The use of saline groundwater resources, in addition to save fresh water, could be used in production of forage in saline soils. In order to do it, the area in northern Ardakan, Yazd province with saline ground water (EC= 11.25ds/m, SAR= 16.7) and saline and alkaline soil (EC=27.3ds/m, ESP= 30.2%) was ...
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The use of saline groundwater resources, in addition to save fresh water, could be used in production of forage in saline soils. In order to do it, the area in northern Ardakan, Yazd province with saline ground water (EC= 11.25ds/m, SAR= 16.7) and saline and alkaline soil (EC=27.3ds/m, ESP= 30.2%) was selected for planting of Atriplelentiformis, Seidlitzia rosemarinus, and Nitraria schoberi. The seeds of plants were collected from different areas of Yazd province, and were planted in nylon pots in greenhouse and transplanted as split plot statistical design in the field after one month. Based on the potential evapotranspiration of the region, the plants were irrigated as furrow design with leaching fraction (LF) = 0.3, and in 10 and 20 days intervals. After six months, plants were cut from near the soil surface and dried in oven at 60 °C for 72 hours. The dry matter of each plant weighted and analyzed statistically. The results indicated that there are some significant differences between dry matter of plants and the irrigation periods. Among plants, Atriplex lentiformis, with ten days period of irrigation had the best yield in this experiment. In addition, LF of 0.3 could decrease the salinity of the surface soil layers. This reduction was higher than in ten days period of irrigation.
S. H. Hosseini; S. Feiznia; H. R. Peyrovan; Gh. R. Zehtabian
Volume 62, Issue 2 , October 2009, , Pages 215-228
Abstract
In Iran, fine grained formations (Neogene's units) are very susceptible to erosion. Also, they are the units producing runoff and causing soil loss in watersheds. The objectives of this study is to assess the effect of physical - chemical and mechanical properties of these formations on sediment and ...
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In Iran, fine grained formations (Neogene's units) are very susceptible to erosion. Also, they are the units producing runoff and causing soil loss in watersheds. The objectives of this study is to assess the effect of physical - chemical and mechanical properties of these formations on sediment and runoff rates at different rainfall intensities, based on using field simulator in Taleghan Basin. For this purpose, Neogene's units were separated into five sub-units including Halite siltstone (NgSiH), Siltstone (NgSi), Mudstone (gy1C), Gypsum mudstone (gy1CG) and Halite clay stone (gy2CH), based on physical and chemical properties. Then, runoff and sediment rates were determined in each sub-units at two different intensities (30 and 60 mm/h) using rainfall simulator. Analysis of variance and Duncan's tests showed that NgSiH sub-unit has produced the highest amount of runoff and sediment rates and then the runoff and sediment rates of other subunits in decreasing order are as follows: NgSi, gy2CH, gy1CG and gy1C are 5% significant level. The trend of induced runoff and sediment rates at different times showed that in NgSiH and NgSi sub-units, runoff amounts were fixed rapidly at second ten minutes. Also, on the other sub-units, runoff amounts were fixed at third ten minutes but sediment yield was increased rapidly at third ten minutes.
Ebrahim Gavili; Mohammadreza Vahhabi; Fazel Amiri; Shiva Rashidi
Abstract
For planning the grazing of rangeland according to difference in body weight and different energy requirements should determine forage requirement of animal unit. In the other hand, daily need of animal in rangeland depends on the quantity and quality of intake forage composition. For this purpose selected ...
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For planning the grazing of rangeland according to difference in body weight and different energy requirements should determine forage requirement of animal unit. In the other hand, daily need of animal in rangeland depends on the quantity and quality of intake forage composition. For this purpose selected part of the rangeland of Fereidunshahr in Isfahan province was classified to vegetation types. In each type of all plant species about 500 grams at flowering stage were collected. Nitrogen (N) and acid detergent fiber (ADF) were measured through chemical analysis. Crude protein, ADF, dry matter digestibility and metabolizable energy either 3 replicates were assessed in the laboratory as indicators of forage quality. The Lori sheep race is user dominant Animal unit. In order to determine the animal unit body weight, from 3 existing herds within 11 unit management with dominant Animal from this race, 10 three and 10 four Dry adult ewes(main structure of the herd), 5 three and 5 four years old rams and 6 month old lambs randomly selected and were weighed in two period. Weighing operation performance once before grazing beginning (first may) and once after the end of grazing season (first September). In conclusion 45 kg body weight as animal unit was calculated and livestock rations of animal requirement in maintenance condition and grazing in rangeland (0.7 times of keeping in a stable) calculated using the MAFF equation. The result showed that animal requirement based on forage quality at flowering stage was 1.09 kg that for grazing session (30% reduction of forage quality) is 1/58 kg in day. Because there are difference in structure of vegetation types and metabolism energy so a permanent quantity of dry forage cannot specify as basic of computation the daily need
Sare Rasekhi; Mahdi Ghorbani; Aliakbar Mehrabi; Seyed Akbar Javadi
Abstract
Cooperation in pastoralism and indigenous knowledge of dairy management had been considered for many years in Iran and had been adapted with culture and environment of every region. This research had illustrated the analysis of indigenous knowledge and social cohesion in dairy management of grazing livestock ...
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Cooperation in pastoralism and indigenous knowledge of dairy management had been considered for many years in Iran and had been adapted with culture and environment of every region. This research had illustrated the analysis of indigenous knowledge and social cohesion in dairy management of grazing livestock in Ghasr e Yaghub village. Research method was a combination of filed studies, direct observation, and cooperative observation and organized interview. The results include functions of cooperative management system of “Ham Shiry” among rural women named “Shir Dan”, different dimensions of indigenous knowledge, mechanism of dairy management among women and related traditions and local cooperation. The results demonstrated that rural women in the study area had been created social institution based on local rules and in order to manage dairy products. This kind of associations had been rooted in indigenous knowledge and has a significant role to save and improve social cohesion and sustainability of economical characteristics of local inhabitants.
