Fatemeh Azariyan; Sara Valizadeh; Pouyan Dehghan; Hassan Khosravi
Abstract
Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work ...
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Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work units’ map was prepared based on which relevant indicators were valued. Then, relevantindices were prepared based on ESAs model using GIS. Finally, ESAI index was calculated foreach work unit. After mapping the risk of desertification, desertification damages were evaluated. Itwas found out that the risk of desertification in Rudab can be classified at three classes i.e. class I,II, and III; and subclass III1 covered the biggest surface of the study area i.e. 44.48%. Based ondesertification damage map, Rudab region is divided into five classes so that class III covering35.20 percent of the area is the biggest area. Active sandy dune faces are prone to the highest risk ofdesertification since they entail significant risk factors and need to be paid due attention for desertgreening programs.
Hossein Arzani; javad Motamedi; Farhad Aghajanlu; Saeid Rashtvand; Azin Zareii
Hossein Piry; Mohammad Ali Zare Chahouki; Hossein Azarnivand
vahid jafarian; Mohammadreza Yazdani; Mohammad Rahimi; Mehdi Ghorbani
asgar hosseinzadeh; Ghodratolah Heidari; Hosein Barani; Hasan Zali; Ehsan Zandi Esfahan
Abstract
Nomadic migration has been a way of living in Iran from ancient times. Although this way of life has changed in different periods, the intensity of these changes has an origin in social, political and security issues in addition to livestock and rangelands. The population of the study area is 70 and ...
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Nomadic migration has been a way of living in Iran from ancient times. Although this way of life has changed in different periods, the intensity of these changes has an origin in social, political and security issues in addition to livestock and rangelands. The population of the study area is 70 and a number of 58 people were selected using Cochran formula. In the present study, questionnaires were used and data collection was performed using interview. To measure social integration, five factors were used which were included in the questionnaire including customary rights, within group-trust, tribal and local trust, confidence and awareness of the projects provided by the government, and legal protection. Cronbach's Alpha coefficient for the social integration was calculated to be 0.88 and the correlation between social integration and the factors including beneficiaries’ literacy, the history of exploitation, annual income from animal husbandry and the number of livestock was analyzed through Pearson test using SPSS software. It was revealed that there was a direct and significant relationship between social integration and annual revenue of animal husbandry and the history of exploitation while social integration had a significant inverse relationship with the number of livestock, indicating a close relationship between the nomadic community and their social integration. Nomadic community needs should be provided in the form of nomad's social integration. Finally, the tribal system of the country should be viewed as a cultural heritage and it should not be measured by modern development indicators.
khabat Khosravi; Edris Marufinia; Ebrahim Nohani; Kamran Chapy
Abstract
In order to prevent any damages which can be caused by flood at Haraz watershed in the Mazandaran province, it is essential to prepare a flood susceptibility map using logistic regression. About 211 flood locations and 211 non-flood locations were first recognized. Ten flood conditioning factors such ...
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In order to prevent any damages which can be caused by flood at Haraz watershed in the Mazandaran province, it is essential to prepare a flood susceptibility map using logistic regression. About 211 flood locations and 211 non-flood locations were first recognized. Ten flood conditioning factors such as Slope, plan curvature, altitude, distance from river, topographic wetness index (TWI), stream power index (SPI), rainfall, landuse and normalized differences vegetative index (NDVI) were then identified. The maps of all affecting factors were prepared using ArcGIS10.1, ENVI 5.1 and SAGA GIS2 software and they were exported to raster formats. Flood locations were randomly divided into two groups: 70% (151 flood locations) and 30% (60 flood locations) for modeling and validation, respectively. Enter method was selected for weighing the 10 factors in SPSS.18. The factors with their corresponding weights were used in the ArcGIS software for generation of flood susceptibility map. The map was divided into 5 classes. ROC curve and area under curve (AUC) are used for the validation of derived map. The results indicated that for prediction rate, the AUC is 78.3%; thus, the logistic regression has a reasonable accuracy for flood susceptibility mapping. The findings of this research are useful and necessary for scholars, the Mazandaran Regional Water Authority (MRWA), Ministry of Energy, and other agriculture and natural resources-related organizations in order for mitigating losses and damages during flooding events.
valiollah Raufirad; Qodratollah Heidari; Hossein Azadi; Jamshid Ghorbani
Abstract
The purpose of this study was to assess socio-economic vulnerability in lowland rangelands of Aran-v-Bidgol County. Accordingly, the most important socio-economic indices were identified using literature review. The sample size was calculated based on Cochran’s formula. Data was collected using ...
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The purpose of this study was to assess socio-economic vulnerability in lowland rangelands of Aran-v-Bidgol County. Accordingly, the most important socio-economic indices were identified using literature review. The sample size was calculated based on Cochran’s formula. Data was collected using a researcher-made questionnaire. A panel of experts and Cronbach’s alpha coefficient approved respectively the content validity and reliability of the questionnaire. Me-Bar and Valdez's vulnerability formula was applied to assess the socio-economic vulnerability. Results showed that “presence of experts in rangelands”, “local problems and the collapse of past utilization systems” and “number of rangeland users” were the most important indices of social vulnerability. Findings further indicated that “life expenses of rangeland users”, “number of livestock of rangeland users”, “economic status of rangeland users”, “livestock type” and “increasing prices” are the most important indices of economic vulnerability. The results also identified that more accuracy can be obtained to assess rangelands vulnerability by integrating social and economic factors at local scale. Therefore, policy-makers and rangeland managers and practitioners should pay more attention to socioeconomic factors at local scales to sustainable rangeland management.
zohre sepehri; Zeinab Jafarian; Ataolah Kavian; ghodratollah heydari
Abstract
Since fire effects on soil properties, awareness about effects of fire on soil is important for fire management. This study was carried out to investigate effects of fire on hydrological, physical and chemical properties of soil in Charat rangeland of Savadkuh. Sampling was performed in two plant types ...
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Since fire effects on soil properties, awareness about effects of fire on soil is important for fire management. This study was carried out to investigate effects of fire on hydrological, physical and chemical properties of soil in Charat rangeland of Savadkuh. Sampling was performed in two plant types Astragalus gossypinus and Artemisia aucheri, 120 soil samples were gathered. Experimental design was factorial design based on complete randomized design with three repeat. Five prepared treatments for Experiment were control soil, burned soil with burner and burned in oven at 100, 300 and 500 °C. Soil characteristics including the texture, saturation moisture, pH, organic matter, field capacity, wilting point, available water and retention capacity were measured in the laboratory. Results showed that percent of sand and pH increased but percent of saturation moisture, silt and clay decreased as temperature increased. On the whole, fire and heat have decreased soil potential of keeping moisture and infiltration considerably. As physical and chemical properties of soil change, especially hydrological ones, living environment of soil microorganisms and plant roots change as well. Besides, amount of runoff and erosion increases.
sahar sabaghzade; Mohammad Zare; Mohamad Hosein Mokhtari
Abstract
Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. ...
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Vegetation is an important component of each global ecosystem. Determining of the biomass of plant is important to assess its impact upon climate, soil erosion, and as well for management of natural resources. The aim of this study was to estimate biomass using vegetation indices based on remote sensing. The Landsat 8 data of May 2013 and field studies coinciding with field imaging in Marac (South Khorasan province) were used. Tamarix plant biomass measured in 30 random plots of 11 vegetation indices including DVI, IPVI, NDVI, PVI, RVI, SAVI, TSAVI, WDVI, and Tasselcap were used to estimate biomass of Tamarix.Then, using cluster analysis, vegetation indices were divided into three groups among which SAVI, RVI , and IPVI were chosen. The results showed that indexes which consider soil factors are more accurate than other measures. In this study, biomass map was prepared using the SAVI index.
Farshad Soleimani; Naser Brumand; ali azareh
Abstract
In recent decades, increasing population growth and development of agriculture have increased groundwater consumption and decreased the quality of groundwater resources of most parts of the country. Given the importance of this issue, present study investigates the spatial and temporal changes in parameters ...
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In recent decades, increasing population growth and development of agriculture have increased groundwater consumption and decreased the quality of groundwater resources of most parts of the country. Given the importance of this issue, present study investigates the spatial and temporal changes in parameters of calcium, magnesium, pH, chloride, sodium sulfate and water in Jiroft plain. The data was obtained from 40 wells in the region of Kerman province over which in 2002-2012 water harvesting and qualitative analysis had been done. In this regard, after normalizing the data, the accuracy of different geo-statistical methods including the Kriging and inverse distance weighted were evaluated and then the map of the spatial zoning was prepared in the software quality parameters ArcGIS9.3 using the best method of interpolation. The results showed that the amount of pH, Sodium, Chlorine, and Sulfate increased but the amount of calcium and magnesium declined. But in general, in 2012the quality of groundwater resources of Jiroft plain decreased compared to 2002 and the trend of changes showed water quality reduces toward the South and West.
Khosro Shahbazi; ali salajagheh; mohammad jafari; hassan ahmadi; ali akbar nazari samani; mohammad khosro shahi
Abstract
Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland ...
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Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland (FR) and poor rangeland (PR) areas in the Qasre-shirin, Kermanshah, Iran. Nine flumes were performed in the field to determine the critical values of hydraulic parameters including flow discharge, velocity, Froude and Reynolds numbers, Darsi resistance coefficient, shear tension, head-cut dimensions as well as vegetation cover. Results showed that respective critical value of discharge as the gulling thresholds for AG,FR and PR was 1.53, 12.0 and 4.49 li/s indicating significantly higher (p<0.05%) in the FR due to higher vegetation cover. In addition, there were no significant differences for flow disturbance based on Froude number, while the respective value of Rinuldze number in the AG, FR and WR were obtained 3113, 26092 and 9525 significantly higher in the FR. Furthermore, the critical level of shear tension for gully formation in the AG, FR and WR were found 12.12, 14.01 and 9.28 Nm-2, respectively showing significant differences among them. Finally, it is concluded that hydraulic flow parameters as the gully triggering are strongly affected by vegetation cover through landue practices so that higher plant cover in the FR was the key factor resulting in significant enhancement of gully.
esmaeil sheida karkaj; javad motamedi; fateme alilu; hamid sirusi
Abstract
Grazing management is one of the basic elements in managing rangeland ecosystems. Proper use of grazing lands in order to achieve optimal efficiency and maintain the sustainability of rangeland ecosystems is the purpose of grazing management. In order to evaluate the response of vegetation to grazing ...
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Grazing management is one of the basic elements in managing rangeland ecosystems. Proper use of grazing lands in order to achieve optimal efficiency and maintain the sustainability of rangeland ecosystems is the purpose of grazing management. In order to evaluate the response of vegetation to grazing in summer rangelands of Chahar Bagh region of Golestan province, vegetation density, vegetation cover and functional properties were measured at five different grazing sites. Thus, using the statistics method of samples and regarding the size of the dominant plants canopy, 20 plots 1*1 meter by using a systematic- random method was considered in order to do sampling in each site and the density, and vegetation cover were recorded within each plot. Finally, parameters were analyzed using Duncan test and analysis of variance and the vegetation compositions of sites were compared using cluster analysis and Jaccard's coefficient of similarity. Results showed that the grazing intensity have significant effect on the vegetation. As grazing intensity increased, the density of desirable species decreased and density of undesirable species increased. So, the enclosure site had the highest desirable species density. Moreover, some functional types such as perennials, Hemicryptophytes, Chamephytes, grasses and decreaser plants significantly reduce with increasing grazing intensity. The greatest increase belongs to grasses with density of 9.8 and class I of palatability with density of 22.8 in enclosure site. Between functional groups, grass life form had the greatest increases in enclosure site with the cover of 19.65 percent. According to results of clustering and similarity index, pen surrounding and watering sites had similar vegetation composition. Enclosure and key area also had similar composition. In general, it can be concluded that increase in grazing intensity has caused negative changes in vegetation in study sites and the changes in watering area, village vicinity and pen area clearly observed. So, using of the management methods in order to improve vegetation indices and pushing it toward balance is recommended.
Seyde maryam Alibakhshi; Alireza Faridhosseini; kamran davari; amin alizadeh; Henry Munyka Gathecha
Abstract
Satellite precipitation products have been used in scientific studies in global and regional scales from several decades ago. The purpose of this research is quantitative comparison between TRMM and GPM precipitation products in Kashafrud basin. The important point about these products is their accuracy ...
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Satellite precipitation products have been used in scientific studies in global and regional scales from several decades ago. The purpose of this research is quantitative comparison between TRMM and GPM precipitation products in Kashafrud basin. The important point about these products is their accuracy and pixel size. GPM satellite launched on 28th February 2014 and there is no research in Iran and few in the world. This research aims to assess GPM and its predecessor i.e. TRMM products in comparison with 34 ground rain gauge stations in the basin. Comparisons are done in basin and gauge spatial scales and each in daily and monthly time scales. For validation, the statistical metrics including RMSE, MAE, CC, BIAS, FAR, POD and CSI are used. The results indicated that generally the 3B42V7 product from TRMM has higher accuracy than IMERG product from GPM in our study region. IMERG product only in monthly and basin scale has better accuracy in comparison to 3B42V7 product. Regarding time scale comparison, monthly analysis showed higher accuracy. RMSE value for TMPA product in daily time scale for rain gauge and basin scale is 1.88 and 1.55 and in monthly scales is 2.87 and 2.77, respectively. Also, RMSE for IMERG product in rain gauge and basin in daily time scale is 2.43 and 2.3 and for monthly time scale 3.64 and 2.56, respectively.
mohamadreza fazelpour aghdaei; hosein maleki nezhad; mohammad reza ekhtesasi; jalal barkhordari; Asghar Zarea Chahooki
Abstract
Given the widespread distribution of flood water spreading areas and variety of main effective parameters in their design and implementation, assessment of the performance of system components located in different areas of the country is necessary so that optimal patterns can be achieved. This research ...
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Given the widespread distribution of flood water spreading areas and variety of main effective parameters in their design and implementation, assessment of the performance of system components located in different areas of the country is necessary so that optimal patterns can be achieved. This research was done to assess the impact of the flood water spreading projects on soil characteristics in Yazd (Bafg, Herat and Mehriz flood spreading projects). To this end, in the first to the third spreading basin of projects and three a control sites were selected. Then, 99 soil samples in profiles were collected at five depths and physical and chemical properties were studied in the laboratory. Statistical analysis was performed by independent t-test. The results showed physical and chemical properties of soil is not significantly different from controls in Bafgh flood water spreading projects. In Herat, some parameters such as Electrical Conductivity, pH, Calcium and Potassium in the limited depths was significantly different but in Mehriz, most chemical parameters showed significant difference and decreasing trend. The results showed water infiltration and leaching of soil in the Mehriz area was more than others, while less in Herat and the least in Bafg.
Mohammad Rahim Forouzeh; gholam ali heshmati; hosein barani
Abstract
Iran is a country with an ancient culture. During a long time, its inhabitants have created various classifications, nominalizations and technologies on the basis of preference and innovation in different fields in order to adapt with the events happening around. These rich sources of knowledge are being ...
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Iran is a country with an ancient culture. During a long time, its inhabitants have created various classifications, nominalizations and technologies on the basis of preference and innovation in different fields in order to adapt with the events happening around. These rich sources of knowledge are being eroded with an unimaginable speed that is in fact a part of the process of local indigenous culture destruction. Accordingly, their data collection and protection are of importance. This study aimed to record the knowledge of nomads of Boirahmad tribe about time and place recognition, playing an important role in forming their various activities in rangeland. The research was done in Dilegan Rangeland that is the summer quarter residence of nomads and located in cold weather regions of Kohgiloie and Boirahmad province. Participatory observation was used for data collection. Regarding the knowledge of experienced sheepherds about temporal and spatial components, interviews were divided in two parts, interview with sheepherds and others. By applying free interviewing and participatory observation, the required data for local calender and rangeland identification were recorded. Finally the interview notes were analyzed via content analysis method. Results show that nomads had local daily and yearly calendar in their knowledge, regulating their activities in accordance with. Daily calendar consists of 12 parts that different parts of a day are named accordingly. Also in their yearly calendar different times of the year are classified in 13 various time units which nomads' annual activities (such as migration, harvesting edible and medicinal plants,…) are set based on this calendar. As it was previously mentioned, it is recommended that the classification and naming patterns of time and place in rural and tribal traditional system be more investigated by rangeland management authorities and researchers of habitat prediction. Thus, it will give the possibility of more realistic analysis of the following research and also offered more practical solutions to advance the goals.
sadat Feiz Nia; Mariam Musavian; Zohreh Abdolahian Dehkordi; Khadijeh Ebrahimi Dorche
Abstract
Physical characteristics of drainage basins suchas geological materials, landuse type and vegetation cover, soil type, surfacepermeability, depth of underground water table, topographical conditions anddrainage are important factors in flood occurrence which affect prevailingequations on water movement ...
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Physical characteristics of drainage basins suchas geological materials, landuse type and vegetation cover, soil type, surfacepermeability, depth of underground water table, topographical conditions anddrainage are important factors in flood occurrence which affect prevailingequations on water movement in drainage and determine storage capacity ofdrainage basins. Geology is one of the most important factors affecting floodoccurrence of drainage basin. In this study it is attempted to investigate theeffect of geology factor on flood occurrence in Joneghan drainage basin,Shahr-e – Koord, using a new method. In this respect, after preparing base mapsconsisting of slope amount , geology , landuse , erodibility of geologicalmaterial , soil depth and drainage pattern , studies were performed in twostages as follows: In the first stage, flood occurrence of hill slopes of eachsub- catchment was investigated. For doing so, work unit map was prepared usingslope and infiltration maps. Then in each sub-catchment, land use, erodibilityof geological materials and soil depth were overlaid with work unit map one byone and dually. In the second stage, flood occurrence of drainage wasinvestigated as follows: First, longitudinal profile of main drainage of eachsubcatchment was prepared using GIS. For investigation of flood occurrence ofdrainages, slope and permeability of geological units were used. The results ofthe first stage showed that permeability, slope, erodibility of geologicalmaterials and soil depth have the greatest effect on flood occurrence,respectively. Also based on this four – factor method, subcatchments weredivided into five flood occurrence classes as follow: low, low to medium,medium, relatively high, and high. The results of the second stage showed thatdrainage flood occurrence belongs to two classes of low to medium and medium.By combining slope and drainage flood occurrence, it can be concluded that thethird subcatchment with medium flood occurrence is more susceptible to floodrelative to other subcatchments. With regard to the results of the presentstudy, it can be concluded that geology has high impact on flood occurrence andpermeability of geological materials decrease flood occurrence in the basin.
yaser ghasemi aryan; yaser Ghasemi aAryan; ali kiani rad
Rasool Ghobadian; Zeynab Bahrami
Abstract
Increased exploitation of groundwater besides recent periods of drought caused a negative balance in Khezel aquifer located in Hamedan province, Iran. From 2000 to 2010, groundwater surface drop was estimated 5.8 meters. With regard to high potential of GMS in using GIS and careful stratification of ...
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Increased exploitation of groundwater besides recent periods of drought caused a negative balance in Khezel aquifer located in Hamedan province, Iran. From 2000 to 2010, groundwater surface drop was estimated 5.8 meters. With regard to high potential of GMS in using GIS and careful stratification of the aquifer, GMS was used in present study to investigate and predict the groundwater table fluctuations in Khezel aquifer. Thus, Quantitative modeling was performed using MODFLOW model. The model was calibrated (using trial and error method) in two conditions: steady state (in september 2009) and transient state (from October 2009 to July 2010). Also, the quantitative model validated for August 2010. The impact of groundwater artificial recharge (within 31 injection wells for 5 months from October to March) was evaluated by calibrated model. Results showed maximum rise of water level was 19 cm in April. Next, in the same flow simulation stress periods, qualitative modeling was carried out by MT3DMS model. Optimum values of longitudinal dispersion and distribution coefficient were achieved by trial and error method and the qualitative model was calibrated. Statistical results of qualitative modeling are as follow: R2=0.98, slope of regresion line (y=1.0079x), mean error (ME=4.56 ppm) and RMSE=3.36%. Finally, dispersion of point source pollution (leaching pit) was investigated as a scenario. The result indicated that the radius of influence of leaching pits varies from 150 to 200 m in different areas. In continue, in the same flow simulation stress periods , qualitative modeling was carried out by MT3DMS model. Optimimum valuse of longitudinal dispersion and distribution coefficient were achived By trial and error method and the qualitative model was calibrated. Statistical results of qualitative modelling including: R2=0.98, slope of regresion line (y=1.0079x), mean erroe(ME=4.56 ppm) and RMSE=3.36%. Finally, dispersion of point source pollution (leaching pit) was investigated as a scenario. The result indicated that, the radius impact of leaching pit varying from 150 to 200 m.
sedigheh mohamadi
Abstract
This research was done to investigate the effects of change in land use on chemical soil properties in Jamalabad region of Baft county of Kerman province. The experiment was conducted in six sites with the same ecological condition as non grazed site (NG) for 10 years, a moderately grazed site ...
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This research was done to investigate the effects of change in land use on chemical soil properties in Jamalabad region of Baft county of Kerman province. The experiment was conducted in six sites with the same ecological condition as non grazed site (NG) for 10 years, a moderately grazed site (MG) and a heavily grazed site (HG), a dry farming site of barley and wheat (D), a long time fallow site for 5 years (F) and a plowed Glycyrrhiza glabra site (Gl T). Soil samples were collected from two soil horizons (0-15 and 15-30 centimeters) based on a randomized complete blocked design with six replications from each horizon in 2013. Samples were sent to laboratory for soil chemical properties as organic carbon, total nitrogen, available phosphorus, available potassium, PH and electrical conductivity. The results indicated that Land use change significantly decreased organic carbon, potassium content, available phosphorous and nitrogen content as 58.2, 21, 23.5 and 71 percent in dry farming site and 58, 17.3, 19 and 60 percent in plowed Glycyrrhiza glabra site compared to non grazed site. A decreasing trend of organic carbon was seen in moderately and heavily grazed sites in comparison to non grazed site as 42 and 56 percent, respectively. Available potassium of moderately and non grazed sites were maximum. Total nitrogen of soil in moderately and heavily grazed sites was decreased in comparison to non grazed site as 0.035 and 0.04 percent. PH of soil was significantly changed only between non grazed and plowed Glycyrrhiza glabra site (Gl T). Electrical conductivity of soil was increased in dry farming site (165 percent) and heavily grazed site (140 percent) in comparison to non grazed site. According to negative effects of land use change on soil quality and remaining this harmful effect after release of dry farming lands, our recommendation to natural resources offices are programs preventing rangeland occupying, minimizing giving off rangelands, rehabilitation of released dry farming by pioneer plants and improvement of soil qualities in root collection designs of Glycyrrhiza glabra.
fatemeh maghsoud; Arash Malekian; Mohsen Mohseni Saravi; Omolbanin Bazrafshan
