حمید ترنج زر

In order to determine the potential habitat of plant species, it is essential to know the ecological needs of the species as well as climatic and edaphic characteristics to apply management in accordance with the ecological conditions of the studied area. In this research, in order to develop model for the distribution of Astragalus Sp., using different statistical methods in part of the pastures of the Savar-Abad Basin, at first by producing using topographic, slop, aspect maps, types of vegetation in study area were determined. In the specified types, a number of sampling sites with dimensions of 2 to 10 square meters were selected. Information related to the presence and absence of Astragalus sp as dependent variable and other environmental information as independent variables was measured. In each homogenous unit, three transects of 750 meters, two transects along the most gradients (height, direction and slope), And another transect established perpendicular to those two transects. Along each transect, 15 plots were placed at a distance of 50 meters, thus 47 plots were established in each homogeneous unit. (Total 2 units, 94 plots). The size of sampling plots was determined according to the type and distribution of plant species using the Minimum Surface Method. In each plot, the type and number of plant species and their coverage percentage were recorded. For soil sampling, At the beginning and end of each transect, the soil profile was dug and soil sampling was done according to existing standards, and soil variables including gravel, clay, sand, silt, lime, organic matter, acidity and electrical conductivity were measured in the laboratory. Also, in each sampling unit, latitude, longitude, slope, direction and height from the sea level were also determined. In this study, the dependent variables are the data of the presence and absence of vegetation types, and the independent variables include soil and topography characteristics. The best distribution model was determined using statistical analysis. The results showed that the MaxEnt model has a better performance than the logistic regression and genetic algorithm models. However, the findings of the research show that altitude, acidity and salinity have a greater effect on the distribution of different species in the study area.

The values of rangeland vary, and there are significant temporal and spatial changes. Since rangeland are constantly changing, they play a crucial role in the economy and in the protecting the land and water. So it is crucial to grasp them and manage them properly. The middle "Kashkan" watershed in the "Lorestan" province was chosen in order to assess the capability of multi-spectral pictures from Sentinel 2 and Spot 5 satellites in creating rangeland density maps. Using ground control points and the region's digital height model, the photos were geometrically adjusted with an accuracy of less than 0.21 pixels. On the primary multispectral image of each satellite as well as the integrated image of Spot 5 and the rangeland density map, supervised classification utilizing the parallelepiped, minimum distance, maximum likelihood, and neural network classification techniques was carried out. Three density classes—5–25, 25–50, and 50% and above—were prepared for it. 117 ground control points were located on the topographic map of the area in question in order to measure the classification's accuracy. The global positioning system (GPS) was then used to pinpoint the locations of the points in the study area, and the ground reality map of the region was created using the determined coordinates. The Spot 5 image with PCA-3-1 band composition and a neural network classification algorithm, which had an overall accuracy of 70.53% and a Kappa coefficient of 0.65 compared to the Sentinel 2 image with PCA-8-2 band composition and a neural network classification algorithm, which had an overall accuracy of 65.72 and a Kappa coefficient of 0.08, produced better results, according to a study that examined the accuracy of classified images. This study showed that Spot 5 satellite photos outperform Sentinel 2 satellite images when creating rangeland coverage maps with three different densities. It is possible to use satellite images with spatial and spectral resolution suitable for creating a map of rangeland density and regulating and trying to prevent the destruction of rangeland in the west of the country over a certain period of time because the distances for aerial photography of rangeland areas in Iran are great.

Fire as a frequent phenomenon in rangelands and because of its complicated and different effects on natural ecosystems, has great importance. Awareness of such fire effects on vegetation cover in point of rangeland management after fire is important and helps better Understanding and sustainable management of rangelands. Changing in plant structure and composition and site  situations is on of the most clear effects of fire on natural ecosystems especially in arid and semi-arid areas. Fire effects on soil seed bank is a fundamental subject in ecology and phytosociology. These seeds have a vital role in maintenance and reclamation of deteriorated rangelands and also in plant composition improvement in plant communities. This study was conducted to evaluate the effect of fire on vegetation and soil seed bank in Sarkhalaj rangelands of Kangavar (middle Zagros).

In current research, one year after the fire, in two areas of the control (Grazing exclosure) and fire, percentage of canopy cover and soil seed bank were sampled on transects with a systematic-random approach. Soil was sampled on these transects in two depths of 0-5 cm and 5-10 cm. After greenhouse cultivation, germinated seeds were identified and the composition and density of soil seed bank were determined. In order to comparing of biodiversity, we used species richness index, species diversity index (Shannon- Wischmeier) And evenness index (Pielou). Also similarity index (Jacard) between ground and underground vegetation cover in exclosure and fire area using formula. Mean comparison of biodiversity indices performed by LSD test. Also, biodiversity indices calculation of plant communities based on two viewpoints: ground and soil seed bank plant composition was done andsignificancy of differences of functions of biodiversity of ground and soil seed bank under treatments (fire and control area) compared via T-test. Raunkiaer life-form system was used to Plant categorizing.

The results of this study indicated that after one year fire the diversity, richness and evenness indexes were significantly reduced. Assessment of soil seed bank in depth of 0 – 5 cm showed that fire decreased the diversity and species richness indexes. However, it did not significantly affect the evenness index. Moreover, in depth of 5-10 cm fire had no significant effect on diversity indexes. Plants life form classification changed after fire and Cryptophytes  and Hemicryptophytes species decreased 8% and 6 %, respectively which resulted in domination of annuals in plant composition. Also, seed amounts decreased greatly in soil surface layer (0-5 cm.).

Overall, considering the results of this study, it could be said that by changing the site conditions, both in terms of the space required for the establishment of new species and by changing the soil properties, the fire has caused a change in the composition and diversity of species and finally the life form of existing species in the area.

Overgrazing, imbalance between stocking rate and range capacity, premature enterance of livestock to range and forests, are among the main factors in range and forest destruction and changes in composition, structure and species diversity. In this study, the changes in composition, structure and species diversity under different intensity of livestock Grazing: ungrazed (UG), moderate grazing (MG), and heavy grazing (HG), after one year grazing in Sarkhalaj Deteriorated Forests (Kangavar), was investigated.

Sampling was done along 100 m transects, with 90 plots (2 m2) based on Brown blanke method to record vegetation cover of species. Whereas Sarkhalaj area, are numbered as summer woody rangelands, sampling of soil seed bank was done before seed growth season. Then after field observation of area, three site were selected that in each site, ecological characteristics such as topography (slope, aspect, height), soil type and average rainfall were the same and only differed in grazing intrnsity. The distance among sites was considered as 500 m. Then these sites treated uvder heavy and moderate grazing and in one of sites, no grazing was performed (control). Also sampling from soil seed bank in the study area, was collected in two soil depth: 0-5 and 5-10 cm in each plot. The composition and amount of seed bank were determined by seeding method in greenhouse.

 The results showed that MG and HG caused change in species diversity by decreasing of cryptophytes and trophytes and increasing of hemi-cryptophytes, chaemophytes and phanerophytes in the study area. Also, diversity indices of vegetation and seed bank in HG, were very lesser compared to UG area which indicats the severe changes of species diversty due to overgrazing. The results of this study showed that, livestoch grazing could be applayed as a management tool to enrichment of phanerophytes (shrubs) in woody rangeland.The results showed that MG and HG led to change in species diversity, so that by increasing of graze intensity cryptophytes and trophytes species were decreased, wherease hemi-cryptophytes, chaemophytes and phanerophytes spesies were increased.Also, diversity indices in HG area were lesser than ungrazing area, wherese diversity indices of MG was more than HG.

 Overally, results of this study showed that annual exclosure oprations can increase the diversity indexes and when exclosure is not possible (because of rural and nomad's needs for rangeland forage and impossibility of exerting rangeland exclosure in such vasst area, MG can be a higher priority.

Anzali, Ajigol, Almagol and Alagol international wetlands are important global ecosystems. In this study, the trend of land use changes in these wetlands and its impacts on the distribution of waterfowl and shorebirds. One of the common methods in studying the ecosystem changes of wetlands is the diversity evaluation of waterfowl and shorebirds. Because of the ease of observing birds in nature, it is possible to find any possible changes in the wetlands by continuously studying the species diversity, population changes, and the habitat quality.

Satellite images and field information of wetlands and their land changes were prepared based on available data and field surveys. In order to prepare the vegetation map based on the wetland index, 6 bands of Landsat satellite TM sensor were used to calculate the NVIDA index. Also, using field survey and sampling of plants and wetland index, the predominance of plants in the region was determined. Then, land-use maps in different periods of 20 years (1998-2019) were prepared based on satellite image processing and image classification using the maximum likelihood method. The data obtained during 8 years census and field surveys, the Shannon-Wiener species diversity indices and inversely the Simpson index, Margalf and Manhink indices has been calculated and were used to determine the species richness and Pilo and Simson indices were used to determine the species evenness.

The results showed that the water area in Alagol, Ajigol and Almagol international wetlands has decreased by 1050.8 hectares (53.7%) and in Anzali wetland by 1541 hectares (18.9%). According to the results, in Alagol, Ajigol and Almagol international wetlands, the most changes are related to vegetation of medium density with 273% increase and in Anzali wetland, the most changes are related to increase in herbaceous plants with 270.3%. According to Margalf species richness index, the highest species richness was observed in Abchelikian. Also, the highest species diversity was observed in the genus Murghabian based on Shannon-Wiener index and the reverse of Simpson index. Also, the highest amount of species evennessbased on Pilo index and Simpson index was observed in the Baklanian genus.

The water extent of the wetlands has generally decreased and due to the increase of man-made land uses in the margins of the wetlands, adverse effects on the wetland ecosystem have been caused to vulnerability of wetlands to degradation. As a result of declining water levels in wetlands and the uncontrolled growth of non-native plants and the reduction of dissolved oxygen, the rate of habitat destruction of migratory aquatic animals and birds will increase. Due to the declining trend in biodiversity indicators in recent years as a result of declining water levels and land-use change, increasing the ecological protection of the wetland through management projects such as habitat protection, poaching control and pollution control, is recommended.

The purpose of current study was to study the physiological and phonological traits of Salivia eremophila Boiss. As a native and medicinal species in three rangeland sites in Yazd province (Iran). For this perpose three ares (Damaghan, Tange-Chenar and Ghavam Abad) and three sites in each area, were investigated in terms of Soulobe carbohydrates, Proline, Chlorophyll and Carotenoids in aerial parts of Salivia eremophila in two phonological stages: Flowering and seeding. Plant sampling was done based on randomized-systematic method in 1M2 plots, along with 50 m2 transects. Also, phenolocical diagram of Salivia eremophila was figured based on consecutive field investigations. Data were analyzed at level of 5%. The results showed that there are significant differences in interaction effects among phonological stage, site and area. site No.1 of Tange-Chenar had significant difference in Chlorophyll (a & b) with the other sites (p<0.05). As for Carotenoids, There were significant difference between sites and areas, in which site No.3 of Damgahan in seeding stage, and site No.1 of Tange-Chenar had the higher rates. Also, the rate of Proline in site No.1 of Damgahan (in flowering stage) was higher than the other sites and areas and it showed significant difference. The amount of Soulobe carbohydrates had significant difference in sites and phonological stages in general (except flowering stage). In overall, the climatic conditions of the sites of studied areas are almost similar in terms of annual rainfall, as well as rangelans type and altitude, and this can affect the occurrence of low changes in plant nutrients

This study aimed to evaluate and zoning the status of metal contamination using the Nemro integrated pollution index (NIPI) in the vineyards of Malayer county. For the study, 286 geolocated soil samples were excerpted based on a random systematic method; each with a weight of 1 kg collected both from a depth of 0-20 cm and a surface of 20 × 20 cm, and then stored in the polyethylene bags to be transferred to the laboratory getting further analyzed. The concentrations of Mn, Zn, Cu, Ni, Cr, As, and Hg were measured using a spectrophotometer; the average concentrations of the sampled metals were respectively 597, 109, 87.86, 84.32, 67.12, 47.1, and 0.344 mg/kg. Based on the results, the measured values were below the NIPI index thresholds for each element remarking the relatively unpolluted condition of the study area. Having evaluated the NIPI-based map in line with low concentrations of the heavy metals in the soil of the study area and a semi-homogeneous distribution of the heavy metals concentration, unfold that the geological processes are the governing factors in controlling the concentration of measured metals. By contrast, human-made changes are mostly responsible for the heterogeneous distribution of metal concentrations in small parts of the region.

Most of the vertebrate species populations affected by the main threatening factors like habitat destruction and fragmentation are experiencing rapid and worse destruction and decrease. Identification of potential and suitable habitats trough modeling tools and methods as well as survey on population relationship and contacts through genetic studies, provides needed knowledge and understanding to define the conservation status and needs for different species. For these purpose, Maximum Entropy (Maxent) and mitochondrial cytb sequencing with 704 bp were deployed. Based on the results, northern part of Iran followed by Semnan, Tehran, Qom and Alborz provinces, as well as western part including Khuzestan consisted the most suitable habitats for the species. Haplotype diversity of h= 0.894 as the main index, showed high genetic diversity for the populations of the species in Iran. Populations of Stripped Hyena, in Iran, are losing their main and suitable habitats due to habitats destruction and degradation, illegal hunting and lack of proper genetic connections. Decreasing populations and worse conservation status of the species convince us to prepare and conduct urgent conservation actions to prevent more loss. The study, using the habitat modeling and genetic surveys, as well as data gained from the field works, gives new vision on the conservation actions needed to protect stripped hyena in Iran

Rangelands rehabilitation have a high priority for improving the environment and mitigating climate changes in comparison to natural rangelands. This study was conducted to compare carbon sequestration in soil and phytomass between land uses of rangeland and irrigated agricultural farms in Mahallat, Markazi province, Iran. The soil was sampled by setting profiles (17 Land uses) in two depths of 0-15 cm and 15-30 cm. In the both land uses, three 50 m transects were established with four 2×2m plots sampled in each transect with random distances. Soil samples were taken from center of each transect. The contents of aboveground and underground biomass carbon, litter carbon and soil organic carbon were determined (in summer 2017). Percentage of organic carbon of plants and soil samples was measured in the laboratory. Soil bulk density, texture, acidity and electrical conductivity were determined. The carbon sequestration in phytomass and soil between rangeland and cropland was compared using independent t-test. Result showed significant effect of carbon sequestration in phytomass, Litter (P<0.01) and soil (not Significant) between rangeland and cropland land uses. Total carbon sequestration in rangeland ecosystem (59471 kg/ha) was higher than carbon sequestration in cropland (53314 kg/ha). Therefore, despite the lack of irrigation and fertilizer inputs, the amount of carbon sequestration in rangeland was higher than the cropland in the region.

Awareness of climate change impacts on suitable habitats of wildlife species is a prerequisite for long-term management of wildlife populations. In this research, we applied maxent approach to investigate the consequences of climate change on climatic habitat suitability for sand cat (Felis margarita) for present, the best, and the worst greenhouse gas emission scenarios for 2050 and 2070, throughout the country.  Modeling results indicated that nearly 18 percent of area of the country is currently suitable for the sand cat. However, only 15 percent of suitable habitats are conserved inside the protected area network. Sand cat avoids areas with high annual precipitation and prefers areas with high mean annual temperature. Under influence of climate change in lowest emission scenario in 2070, the area of suitable habitats and conserved habitats increases. In other scenarios, there are negligible decrease of suitable habitats. Therefore, it could be concluded that sand cat is the winner of climate change.

There have been few studies conducted in Iran regarding immigrant fowl especially European turtle dove and its incubation.‌ Considering the stated issues, this study was carried out with the aim of investigating the effect of land use change on the incubation of European turtle dove in national parks of Dez and Karkheh.‌ In this case study, the studied bird was European turtle dove.‌ Given the space of regions and the amount of access to the nests, the regions have been divided into various parts and they were selected based on the importance of issue in each region regarding the information provided before.‌ The results of the current research indicated 75% decrease in the number of chickens, 15% success of flight in the periphery inside the fence; and regarding outside of the fence, it showed 83% decrease in the number of chickens all over the region and 5.‌18% success of flight for all chickens during 2019 as compared to 2012.‌ Moreover, the results indicated that there was a significant difference between the chickens inside the fence and those outside the fence and the amount of chickens’ success inside the fence was higher in both 2019 and 2012 due to protected conditions.

Oil pollution is an inevitable consequence of rapid population growth. Increasingly, large scale use of petroleum resources is one of the major causes of pollution. This study investigates contamination of petroleum hydrocarbons and single metals (lead, cadmium) in wastewater of Golestan Oil Company. Three stations were constructed at the effluent outlet of Oil Company. For each station, 20 bivalves were assigned to the net section. Atomic absorption spectroscopy was used to measure cadmium and lead metals and GC-Mass was used to measure total petroleum hydrocarbons. The results show that the annual mean total hydrocarbon concentration was 2.94 mg/l and the highest oil content in spring was 20.1 mg/l below market saturation which was several times higher. The global standard for the highest concentration of petroleum in the autumn has been measured at 0.01 mg/liter. Average annual heavy metal concentrations in the first station for cadmium in spring, summer, fall and winter were equal to 0.750, 0.556, 0.265 and 0.279, respectively, in the second station for cadmium in spring, summer, autumn and winter. At the third station, the levels of cadmium were 0.317, 0.2284, 0.192 and 0.179 at the third station. Also, the mean concentration of lead in spring, summer, fall and winter were 0.860, 0.721, 0.383 and 0.221, respectively, at the second station of cadmium concentration in spring, summer, fall and winter, respectively. In the third station, the amount of cadmium was 0.392, 0.436, 0.342 and 0.194, respectively. The output effluent of oil depots in Golestan province Petroleum Products Distribution Company is higher than international standards in terms of total petroleum hydrocarbons and heavy metals distribution.

High population growth rate has led to excessive use of capacity and double pressure on natural resources, resulting in rapid land use changes. Therefore, quick and accurate identification of types of land cover can play an effective role in planning and management. Satellite data because of vast and integrated sight covering with different electromagnetic spectrums and updated images are very suitable for making applicable Land use maps. The aim of this study is preparation of land use map using ETM+ landsat (a Case Study in Hendodar Watershed)

The Landsat 7 satellite images were used to determine the land use changes of Hendodar watershed in Markazi province. The GPS was used to determine the position of land use and land cover types on the basis of taking test and ground control points on field investigation. Obtained samples were used for supervised classification with four different algorithms including maximum Likelihood, minimum distance, Minimum Mahalanobis Distance and Box Classification. 

The optimum index factor (OIF) for the main bands and PCA (principal coordinate analysis) were used to select the optimum combination of three bands in a satellite image to create a color composite, sample set and other operation and classification. Among the algorithms, the maximum likelihood classification algorithm had better results from the types of coverage and lands use on the images.

The maximum likelihood classification algorithm with combination of b7, b4, b1 bands with 81.25% accuracy is the best algorithms of land use determination and classification comparing with real ground map of the area.

This study aims to quantitatively model the utility of low-lying Pelican habitats using the MAXENT model in Iran. The bird's presence points were obtained from data recorded by the EPA and the World Report on its presence. The environmental data used were also obtained from the climate database www.worldclim.org. The results of VIF test were used to examine the correlation between variables including 7 variables mean annual temperature (Bio1), mean daily values ​​(Bio2), isothermality (Bio3), seasonal temperature changes (Bio4), annual precipitation (Bio12), seasonal variations. Precipitation (Bio15), mean precipitation in the driest season of the year (Bio17) had the lowest co-linearity and were used as climate variables. The model's AUC index was 0.953. According to the Jack-Nieff graph, the mean daily temperature (Bio2) and seasonal temperature (Bio4) variables have the highest percentage of participation and importance, respectively, and the mean precipitation variables in the driest season (Bio17) and isothermal (Bio3), respectively. They were important in mapping the habitat suitability of pecans in the Maxent model. In this study, the MAXENT modeling results show that only 77838% of the total country (5%) is favorable for the presence of thick pelicans.

The hawksbill turtle (Eretmochelys imbricate) is important species and a critically endangered species. In present study reproductive ecology and biology of hawksbill turtle from Ommolgorm Island in Mond Protected Area investigated in 2017. During monitoring period, 110 turtles were biometry that 41 of them have been successful nesting.  The results showed that mean of nest length, width and depth were recorded 110.76±16.65, 99.45±11.90 and 55.3±8.5cm. Carapace curved length and width were 70.25±3.75 and 64.72±3.08cm, mean of total number eggs was 108±11.5, mean of normal and abnormal eggs number, diameter and weight were 74±3.9, 37.9 ±2.1 mm and 28.85±3.82gr, and 26.9±6.25, 20.6±2.6mm and 11.1±3.85gr, respectively. Mean of hatchling length, width and weight were recorded 38.1±1.97mm, 29.95±1.45mm and 12.4±0.97gr. Incubation period, egg hatching percentage and death embryos were calculated 62.5±14.9 days, 52.45±14.9% and 19.4±6.4 embryo, respectively. Results showed that the hawksbill turtles in ommolgorm Island are similar to other area of the Persian Gulf in some reproduction characters, while they are smaller than other hawksbill turtles in the world. The mean of total number eggs in this island was more than other coastal in the Persian Gulf and close to global mean.

Salinity is one of the most destructive processes in soils, particularly in arid and semi-arid areas. In order to use and exploitation of such soils, the soil monitoring and mapping are necessary. In this study, in order to zoning and mapping of soils, sampling was collected based on network method from Bolagh (Saveh) saline lands and the electrical conductivity of saturated soil extract was determined. Then the data had been transferred to the ArcGIS 10 software and soil mapping had been drawn. The exponential model of Semivariogram showed the best cross-validation and efficiency than the other models (spherical, linear and gussian). Also, the amount of nugget effect to the threshold was 84/43% which indicates that the medium spatial correlation for soil EC amounts in the study area. Also, the variogram effect range was calculated about 261 meters. Assessment of the resultant index indicates that the geostatistical has been able to soil salinity mapping with moderate accuracy and precision. The results showed that among five soil salinity classes, the soils of study area classifying in four Classes (including non-salinity, low salinity, medium salinity and high salinity) which highest quantities are related to middle southern regions. These results show that soil salinity in this area has high variability.

Cations of sodium, potassium, magnesium and calcium play important roles in adaptation of plant species to arid conditions. The research in 93 years to evaluate the uptake of cations of sodium, potassium , magnesium and calcium cations such Halocnemum Strobilaceum in Meghan and compared to the depth ( 0 to 30 cm ) soil samples were analyzed and plant feet in three season ( winter, spring , summer ) was performed . For this purpose, 10 samples from the aboveground plant parts Ha. Strobilaceum and the soil under the plant in three seasons to just completely random sampling was conducted . By transferring the samples to the lab, cations of sodium, potassium, magnesium and calcium were measured. Finally, using one-way ANOVA was used to examine the significant difference values between samples. Results showed, The results showed that the highest amount of 4 cations starting in the spring than in winter and summer growing season plants there and vice versa least the same amount of cations in the soil in the spring event , which shows high absorption and herbal Ha. Strobilaceum at the start of the growing season , as well as the cations accumulation of soil in direct connection with the distribution of the species Ha. Strobilaceum there .

Remediation of soils polluted to heavy metals especially in industrial cities is very important in environmental pollution studies. This research was performed to investigate the effect of rubber ash enriched urban waste vermi-compost on decreasing Cadmium (Cd) availability in lettuce plant in Cd-polluted soil. Treatments consisted of applying urban waste vermi-compost (0, 20, and 40 t/ha) enriched with 0 and 200 kg/ha rubber ash in a polluted soil with 0, 20, 30, and 40 mg Cd per kg, and plant in this experiment was lettuce. Soil and plant Cd concentration was measured by atomic absorption spectroscopy (AAS). Findings: Increasing the use of urban waste vermi-compost from 0 to 20 and 40 t/ha in a Cd-polluted soil (20 mg Cd per kg soil) caused a significant decrease in soil Cd availability by 1.3 and 2.4 times, respectively. Cd concentration in plant aerial organ was also decreased by 1.1 and 1.8 times, respectively. Applying 20 and 40 t/ha rubber ash enriched urban waste vermi-compost in a Cd-polluted soil (30 mg Cd/kg soil) caused a significant decrease in Cd concentration of plant aerial organ by 1.2 and 1.9 times, respectively. Applying urban waste vermi-compost causes a decrease in Cd availability in soil and plants and meanwhile, enrichment of this organic compound with rubber ash also decreases Cd sorption by plant

Haloxylon sp. and Atriplex sp. are among aridity and salt tolerant species which have been planted extensively in practices of combat desertification and arid and semi-arid rangelands reclamation, in recent decades. This study was performed in order to assessment of saxaul and saltbush planting on soil properties in a part of desert rangelands of Mallard Zarandiyeh. Three sites included: control (natural rangeland), Atriplex canescens plantation and Haloxylon persicum plantation types with an area of five hectares for each of them. In each area, 20 plots along six 500 meters transects were located by randomized-sysematic methods for sampling. Soil samples were collected from two depth (0-30 and 30-60 cm) in control and treatment areas (Atriplex and Haloxylon planting) and Soil samples were physically and chemically analyzed in the laboratory for some variables such as: texture, EC, pH, organic carbon, Caco3, P, CA, Mg, N, K, Cl, Na and HCO3-. Data were analyzed by ANOVA. The results showed that except for acidity and silt (%), there were significant differences between Control area and treated areas (planted sites with Atriplex and Haloxylon) in soil variables. Also, Haloxylon pesicum has been caused the salinization and alkalization and calcification of surface soil, more than Atriplex canesces; but regarding to more adaptation, white saxaul seems to be more suitable plant to reclamation of such arid rangelands, as a native species.

Saline areas and marginal rangelands of some playas in Iran have important role to supply forage for livestock. This study was conducted to compare forage quality of four native halophyte and salt tolerant species including: Atriplex verruciferum, Halocnemum strobilaceum, Haloxylon persicum and Nitraria schoberi, collected from Meighan saline rangelands near Arak (Markazi province). Edible parts of aerial biomass of the species were collected in three phonological stages (vegetative growth, full flowering and seed ripening). Forage quality indices such as Crude Protein (CP), Dry Matter Digestibility (DMD), Dry Matter Intake (DMI), Metabolizable Energy (ME), Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF) and Phosphorus (P) contents of the plant samples were measured. The results showed that the forage quality were different significantly between the species and various phonological stages (p

Nebkhas, which are formed by shrubs, are a common phenomenon in arid and semiarid landscapes and play important roles in preventing soil erosion and nutrient loss. Halocnemum strobilaceum is one of the important indigenous plant species of Mighan playa that can not only protects itself against wind erosion but also reduces sediment removal and can forms Nebkha phenomenon. This study aims at examining the role of Ha strobilaceum in controlling wind erosion (Nebkha formation), and its morphometric relation with the accumulated sand in marginal dune land of Mighan playa, Arak, Iran. This study performed at an area of 1000 square meter. In order to analyze the morphometric characteristics of Nebkhas and the amount of accumulated sand in this Vegetative type, parameters including length, width and height of the Nebkhas and canopy cover of Ha strobilaceum were measured separately. The results reveal that Ha strobilaceum can stabilize 74.1m3h-1 equal to 118/56 ton/ha that average is a remarkable number considering the dimensions of the Nebkhas and can prevent soil erosion. So there are correlation among Nebkha volume and large diameter and canopy area, (r=0.68*). and There was no significant relationship between Nebkha volume and plant height (from the top Nabka).

Annually, 200 ha of Agh Ghala rangelands in Golestan, Iran are under Alkaligrass Puccinella distans''s cultivation but the failure in the identification of appropriate sites for seed sowing may result in high costs of cultivation. The current study aims to reduce such costs through the examination of apt sites to grow P. distans in northern rangelands of Agh Ghala Golestan, Iran. Because of the same topography and climate of the study area and Gomishan rangeland in closure where the plant grows and seeds are collected, a map of photomorphic units was first prepared using satellite images of Landsat 5 (28.05.2011) and Google Earth. Then, some soil physical and chemical properties including texture, EC, pH and organic matter were measured in three photomorphic units. In each photmorphic unit, three transects (length of 150 m and intervals of 50 m) were set up. Along each transect, three soil samples at the depth of 0–10 cm (9 samples in each photomorphic unit) were taken and transferred to the laboratory. In order to verify the suitability of the predicted photomorphic unit, the seeds had been sown in the above mentioned key area of each photomorphic unit and P. distans cover percent was estimated. Data were analyzed and means comparison was done between the units using Tukey method. Incorporating all the obtained data led to predict the location of appropriate photomorphic unit for the seed sowing of this plant. Despite the initial prediction of suitable seeding location (photomorphic unit 3), results indicated that the photomorphic unit 1 was the most successful area which had a lower depth of underground water table and higher EC and vegetation cover percent as compared to two other units. Based on the findings of current study, it is recommended that seeding operation should be concentrated on photomorphic unit 1.

Geostatistical approaches have great importance because they include spatial correlation of geographic data. Present study evaluated the efficiency of geostatistical techniques and demonstrated their capabilities in studying the soil variables(soil texture (sand percent), EC and So4-2) in the important plant community of Nitraria schoberi in Meighan desert, Arak. A regular grid on the map comprising rectangular cells was designed and situated over the experimental area with 98 points for vegetation type. The grid was laid out in the field using the global positioning system. Soil samples were taken between 0-20 and 20-100 cm layers for each point. Analysis using the best view at semivariogram model were applied to select the Gaussian models of soil characteristics with R2 higher than 0.95. Among ordinary Kriging, simple Kriging and Inverse distance weighting methods, ordinary kriging method showed the best cross-validation criteria (mean square error and average error) and had higher prediction accuracy than others. Finally, spatial estimates of the soil characteristics were performed using ordinary kriging.

This study was conducted to compare forage quality of two native halophytespecies Camphorosma monspeliaca and Limonium iranicum collected from Meighansaline rangelands near Arak city in center of Iran. Edible biomass of both species wassampled on three phonological stages (vegetative growth, full flowering and seedripening). Forage quality indices such as Crude Protein (CP), Dry Matter Digestibility(DMD), Dry Matter Intake (DMI), Metabolizable Energy (ME), Acid Detergent Fiber(ADF), Neutral Detergent Fiber (NDF) and Phosphorus (P) were evaluated. The resultsindicated there were significant differences (p<0.01) between species and phenologicalstages. L. iranicum had the highest CP (14.62%) in vegetative stage while C. monspeliacahad the lowest CP (5.39%) in flowering stage. C. monspeliaca also exhibited the highestRelative Feeding Values (RFV=135.9), which was significantly different from those of L.iranicum. In both species, the CP, DMD and ME were decreased with progressingphonological stages while ADF and NDF, increased. Our findings showed that thesehalophyte species contain reasonable CP level which could provide N requirements ofgrazing animals whereas Phosphorus was deficient for sheep, suggesting supplementaryfeeding. The results support the good potential of halophytes and salt tolerant plants assource of livestock fodders and arid and semi-arid rangelands improvement.

Several studies have been performed to evaluate the desertification in Iran and other countries which led to present national and regional models. One of them is IMDPA model. This model was used as a case study in Taraz Nahid, Saveh, Iran. In this study, five factors including climate, soil, vegetation, irrigation, and socioeconomic ones were evaluated. According to the region conditions for each criterion, several indices were considered. Based on the selected indices for each criterion, the qualitative maps were developed from geometric mean of indices for each criterion and finally, the desertification intensity map was prepared from the geometric mean. The final desertification map shows the balanced (moderate) and intense (severe) classes of desertification process in the region. According to the performed evaluations, the soil texture index with the average value of 3.75 (very severe class) and vegetation conditions with the average value of 2.9 were more effective indices in the region desertification. Also, the desertification quantitative intensity value (DM=2.31) was calculated for the entire study region that showed the moderate class for this region.