Desert
Year:2006 | Volume:11 | Issue:1|Papers Count:31

Prosopis koeiziana is a native and indicative species for Saharo – Sindian flora of Iran. It is distributed from the coasts of Boshehr, Hormozgan, Baluchestan Provinces to south of Kerman (kahnoj, Jirouft, Bam, Farraj and shahdad) province. The area contains a rich diversity of floristic, climatic and soil characteristics.The area is classified as hot and hypearid in which, mean annual precipitation varies between 25 to 200mm and the absolute temperature is – 1 centigerade.

The kind of land use and intensity of its change is considered as important desertification indices in different models. Land use change is one of the main anthropogenic factors in the desertification. The current research was carried out around Imam Khomeini airport, with an area of 32000 km2, in order to evaluate mentioned area's land use changes effects during 1955-2003 on desertification. To study the changes, aerial photos of 1955 (1:55000) and 2003 (1:40000), in addition to IRS (Pan and LISS III) and ETM images of 2003 were used. Boundaries of different land uses were determined based on aerial photos and satellite images. In the next stage, boundaries were controlled in the field. Five kinds of land uses including agricultural land, abandoned agricultural lands, rangelands, industrial regions and complex, were distinguished in the study area. The extent of land uses areas, except to complex, has been changed during the 48 years. Rangeland has least change (1.5%), while 14% of agricultural areas have been changed into abandoned and industrial areas. This research showed that biomass has been decreased to 24355.6 ton during the last 48 years. This leads to the decrease of organic matter and decline of soil quality, which in turn causes a 32.9% increase of area regions with severe and very severe desertification intensities.

This study determined some spectral characteristics and relationship between Landsat spectral reflectance and soil surface color in the arid region of Iran (Kashan). The study carried out in the kashan area that covers 90000 ha. consisting of mountain, hills and flood plain. Enhanced Thematic Mapper (ETM+) data collected on July 2002 were used for this research. The color composite images produced from ETM+7, ETM+4 and ETM+2 as red, green and blue respectively used in order to choose sample sites. The twelve sample sites were chosen based on resampled 3*3 pixels (90*90 m). In each site, the soil surface conditions and the munsell color of the soil surface were investigated in the field. Some physico-chemical properties of soil samples were also determined in the laboratory. Soil surface particle sizes were categorized into three classes: bare soil <2 mm in diameter, coarse fragment >2mm in diameter and vegetated soil. The results of this study indicates that munsell notation of hue, value and chroma are significantly correlated to the visible bands of Landsat (ETM+) data. From this study it may be concluded that visible reflectance of Landsat can be used to estimate soil color, if very precise result is not expected. More investigation are necessary in order to improve the obtained results.

Local surface winds are affected by different features of such as surface roughness and local topography. As surface winds affects the human activities such as agricultural, economical and safety of transportation, their investigations from the point of view of forecasting is important. In desert area such as Lut, strong surface wind is a major factor in surface erosion and sands transport. Lut valley in the south east of Iran with north- south direction and its continuation to the Jazmorian dry lake towards the Coast of Oman Sea can affect the surface winds (i.e. channeling).In this study using surface wind data the dynamic properties of these surface winds have been investigated. It includes statistical, synoptical and numerical methods. Statistically, there is a good correlation between the strong northerly surface winds and latitudinal pressure gradient. Cold air advection from the north and the latitudinal pressure gradient are the two major factors enhancing the northerly surface wind. A numerical case study for February 2004 also indicates that these are the two important factors intensifying the surface winds, while the mountain ranges on both sides of the Lut valley are important in channeling the surface winds and generating gap winds which are observed in other part of the world.

re are many medicinal plants in Iran but there is lack of information about plants' growth condition and application. Autecology is a science which can help us to investigate seasonal and morphological changes and condition that effect on plant distribution. In this study, the autecology and phonological studies for P.abrotanoides were done. At first, vegetation habitats of this plant were chosen in different regions of Kashan and six sites were selected. The observation and recording of plant in dormancy and activity periods were done every 15 and 7 days, respectively. All samples for measurement were selected randomly. This research revealed the temperature, air humidity and soil condition necessary for plant growth and development. During the two years of study, no pest or diseases were seen. This can be attributed to the existence of high amounts of plant essence. No ecological study has been done on this plant yet in Iran. Regarding to its vast distribution in Iran, other autecology studies are needed for comparing different habitats of this plant species.

The high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas. The objective of this study was to determine the effects of different pruning height on saxual seed production. The study was carried out in an obviously wilted saxual forest located in Ashkezar desert in Yazd in 1994. The experiment was carried out in a split-plot design with 3 replications, with saxual density (250 and 125 shrubs/ha) as the main plots, and pruning height (10, 35, 70 cm, and a no-cut check) as the sub-plots. Pruning was done on autumn 1994. The forest was protected completely and the quality and quantity of seed production of marked shrubs were investigated on autumn 1999 and 2000. The 2-year results showed that saxual density did not have any significant effect on quality and quantity of saxual seed production (P<0.05). Pruning height had significant effect on percent seed longevity and net saxual seed production (P<0.05). Although no significant difference was observed in viable net seed production under different pruning height, the amount of viable net seed production at 35cm pruning height was 9.7 kg/ha, which seems adequate for saxual regeneration.

Drawing isohyet maps is one of the main steps in preparation of depth-area-duration (DAD) curves. To draw these maps different methods are used such as using rainfall gradient, simple classic statistical methods and complicated Geostatistical methods like Kriging method. For this purpose, after collection of data and information related to 59 rainfall gauging stations in the study area, the dominant and maximum rainfall for duration of one to three days were selected. Then, the relationship between rainfall and the elevation were investigated for drawing the isohyets maps, but due to insignificant difference of this relationship, two methods of Geostatistical Kriging and inverse distance with powers of  1 to 3, were evaluated to draw the isohyets maps and determination of the average rainfall. To evaluate the above two methods, mean absolute error (MAE) was used in this research. The results of this evaluation showed that the Kriging method is better than inverse distance method for determination of average rainfall of the region. Then, using kriging method, the isohyets maps of one to three-day duration and DAD curves were drawn. By using this method, conversion of point rainfall to average rainfall for an area of up to 20000 Km2 of the area under study is possible. Also, the investigation of the curves shows that the ratio of the amount of rainfall at the center to the amount of rainfall at an area of 20000 Km2 is 1.98, 1.74 and 1.48 for duration of 1, 2 and 3- day, respectively.

Laboratory studies were conducted to examine the effects of different concentrations of wild barley (Hordeum spontaneum Koch.) shoot and seed extracts on germination and seedling growth of wheat (Triticum aestivum L.) and wild barley. In this study, all wild barley shoot extract concentrations (with exception of lowest concentration) significantly reduced wheat seed germination after 7 days. Shoot extract concentrations of 60 and 120 g / L significantly reduced shoot and root lengths, shoot fresh and dry weights, and, root fresh and dry weights of wheat. Seed germination of wheat was not affected by intermediate wild barley seed extracts. Considerably, some extracts of wild barley seeds stimulated the germination and growth of wheat. Wild barley shoot and seed extracts at low level stimulated the growth of its own plant, however, its germination and seedling growth were inhibited at higher shoot extract concentrations. The results of this investigation show that wild barley shoot extracts exert more allelopathic effects on germination and growth of wheat and its own plant than those of seed extracts.

Biological soil crusts occur as assemblage of lichens, mosses, liverworts, and cyanobacteria. Lichens and mosses are the two important components of biological soil crusts, especially in arid and semiarid rangeland environments, where vascular plants vegetation is poor. Available information indicates that biological soil crusts contribute to a variety of ecological functions such as soil stabilization and vascular plants establishment, but their role in infiltration is not well understood and results of reported researches have been conflicting.Current study was conducted to show possible effects of biological crusts on soil infiltaration rate and moisture condition on Qara Qir rangelands, with an area of 8560 ha, in Turkmen steppe. For this, double ring, core and tensionmeter were used to determine infiltration rate, moisture condition (weight and volume percentage) and matric potential, respectively. Since research was performed at one site with the same climate, topography, vascular plants, and soil texture, the difference of the study points in soil – hydrologic properties, was related to the absence or presence of cryptogamic crust. Comparing means using t- test showed a significant difference between above-mentioned factors in crusted and uncrusted soils. Crusted soil had better condition in view point of infiltration and moisture. Therefore, one can conclude that presence of lichens and mosses in Qara Qir rangelands is important for soil-water relations.

The majority of Iran's area is covered by arid and semiarid climates. In these areas, wind causes more erosion compared to water. Therefore, determination of wind characteristics especially its velocity is very important. One of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photographs or satellite images. The main purpose of this research was to find the relationship of soil drift potential. Sand rose is a diagram that shows not only the direction of wind transportation but also the wind erosion potential. Using a formula, soil ablation potentials were determined for drawing sand rose. A computer program was used to simplify and speed up the computations and increase the accuracy. Two stations in Sistan – Balochestan province, namely Zabaol and Zahak were selected. These two stations are located on flat lands and are naturally faced with higher wind erosions. The two stations are faced with the 120 days winds of Sistan and have very high drift potential.The results of this study show a south- southeast direction of drift potential, which exactly matches the direction of 120 days Sistan winds. Interpretation of aerial photographs and satellite images confirmed the sand rose study results because most of sand dunes showed a south – southeast direction of wind. Considering the location of sand dunes result drift direction, and the distance that sand can be transported, the locations of sand ablation was identified to be waterways and pediments of Sistan and also agricultural lands around Zabaol and zahak.

Estimation of the magnitude and frequency of maximum instantaneous discharges and hydrographs are used for a variety of purposes, such as the design of bridges, culverts, flood-control structures; and the management and regulation of floodplains. Fuller (1914), developed a flood-frequency formula based on analysis of flood peaks in hundred of streams to provide simple methods of estimating maximum instantaneous discharges, and sought to link maximum instantaneous discharges having various average return periods to the mean of the maximum annual discharges with a factor calibrated for different catchments. The aim of this study is the evaluation of the mentioned method in order to estimate maximum instantaneous discharge and calibrating its considered coefficients in Kaal Shour Sabzevar region. Therefore, the collected data from 10 hydrometric stations in the region were used in analysis and regional coefficient was obtained 0.041 and regional inundation coefficient is from 0.88 to 2.23 in 5 to 200-year return periods. The results showed that the discharge calculated by Fuller's empirical formula is less than values calculated by statistical distributions.

This experiment was conducted to evaluate the competition relationship of corn (Zea mays) and Lambsquarter (Chenopodium album) at the Research Farm of Agricultural Faculty, University of Tehran in 2002. Two considered factors were:1) seven lambsquarter densities of 0, 5, 10, 15, 20, 25 and 30 plant /m2 and 2) two different planting patterns of corn including one row (conventional) and double row sowing methods. Linear reciprocal and yield loss models were fitted to collected data’s and calculated coefficients of those fitted models were used to compare the competitive relationship of those two species as affected by two different planting patterns. The result revealed that applied double row spacing planting pattern enhanced the competitiveness of corn against lambsquarter for grain yield but not for the biological yield. Coefficients of hyperbolic model (yield loss) I (yield loss as weed density approaches zero) and A (asymptotic value of yield loss at high weed density) were lower for double row planting pattern in compare with conventional one. The coefficients of A and I were 6.7, 44.5 in conventional pattern and 3.5, 41.6 in double row, respectively. Therefore according to these results it would be possible to obtain higher corn grain yield by sowing corn in double rows pattern in fields infested by lambsquarter weeds.

Soil organic matters are considered as the animal and plant residues and active components of soils. The cultivation practices will cause the quick removal of organic matters in soils even in those which are not affected by erosion. This study was carried out to assess the level of soil humus in the pilot area, to investigate the positive or negative effect of humus level on soil and to introduce the most appropriate farming system The area is 12409 hectare located on the eastern north of Khodabandeh city. In order to identify land uses, aerial photos and topographical maps were used and supported by field surveys. Four stages were followed in Khodabandeh in order to investigate on humus status in the regions. The results were compared using MSTAT statistical soft wares. In order to compare treatments, Duncan test was applied.The results obtained from the studying surface and sub-surface layers of the area show that rangelands which have not been disturbed by anthropogenic activities are classified between irrigated and drylands. It can be said that the irrigated farming, especially alfalfa farming, enhances soil humus content due to nitrogen fixation done in the roots. But, the drylands especially those with high slope cause degradation of soil organic matters, fertility and production yield and also increase soil erodability.

This study was conducted to evaluate the role of effective parameters of MPSIAC and EPM models in sediment yield estimation in Taleghan watershed. Different parameters of models and watershed charactristics were extracted through 400 random points via GIS. Statistical analyses were done using stochastic softwares to achieve correlation and stepwise regression. The results showed that annual temprature has a negative significant relation with MPSIAC sediment yield but, not with EPM. Rain and also slope are important factors which had positive significant relation with sediment yield of both models. MPSIAC sediment yield was increased in higher elevations because of their higher slopes while this was negliable in EPM model. As runoff and pick discharge were increased, sediment yield was increased. Considering geology rating, EPM had significat relation with both model ranking methods. The results of multiple regression indicated that canopy and geology rating have the most important role in MPSIAC and EPM models, respectively. Slope and runoff also were important agents in both models.

In experiment 1, the effects of electerical conductivities of irrigation water (ECiws) of 0.5 upto 16 desisimens/meter(dSm-1) on growth indices in seedlings of eight pistachio cultivars (cvs.), (Pistacia vera L., P. mutica) were studied. This experiment was done in the form of split plot based on RCBD. In experiment 1 the source of salt was NaCl. Whereas in experiments 2 and 3 were NaCl+CaCl2+MgCl2, such as the ratios of Na: Ca: Mg in splits 1, 2 and 3 were 5:1:1, 1:5:1 and 1:1:5, respectively. In experiment 2, main plots were ECiws of 0.5 upto 16.5 dSm-1. The same seeds of eight cvs. Which have previously been used in experiment 1 was put in subplots. According to results obtained from experiments 1 and 2, third experiment carried out. ECiws of 0.5 upto 8.5 dSm-1 and also cvs. Badami-riz, Owhadi and Momtaz were selected as main plots and subplots, respectively. In experiment 1, total dry weight (TDW) of seedlings in higher ECiws (up to 8 dSm-1 and more) was reduced, significantly. In experiment 2 where the ratio of Na:Ca:Mg was 5:1:1, in regard to growth characters (e.g. TDW), the results showed significant differences between ECiws. Where dominant salts were CaCl2 and/or MgCl2, the differences were meaningful but with changes in comparison to 5:1:1 ratio. In experiments 1 and 2 Badami-riz was selected as tolerant cv. to salinity whereas Owhadi and Momtaz were moderate sensitive cvs. In experiment 3 while the source of seeds was different, in comparison to previous experiments, salt tolerance in seedlings of cv. Owhadi increased whereas in cv. Badami-riz decreased. With considering the results which obtained from this and the other researches, for selecting of the most resistant and/or tolerant seedlings to salinity, we introduce the different sources of more resistant and/or tolerant genotype (mostly cv. Badami-riz).

Application of compost from solid waste refuses is common in agricultural lands, but, solid waste has high moisture percentage. During the process of composting, it produces considerable amount of leachate and if not properly collected, it can cause environmental problems. Therefore, a greenhouse experiment was conducted to study the effects of municipal waste leachate and solid waste compost on yield and yield components of wheat. Treatments were four irrigations with different leachate to water ratios (T0=water, T2= 20%, T4=40%, T6= 60% V/V basis) and a loamy soil with 15 ton per hectare solid waste compost in a completely randomized design with three replications. Results indicate that different leachate to water ratios and solid waste compost had significant effects on yield and yield components of wheat. Yield and yield components were decreased with increasing ratios of leachate to water more than 20/80 ratio. The highest yield and yield components were obtained in 20/80 leachate to water ratio and in soil with compost. Furthermore, the comparison of control soil with and without compost revealed a positive effect of compost on number of grain per spike, spike length, grain weight per spike, grain and straw yield per pot, probably. Due to increase in organic matter content and more availability of nutrient elements in soil and soil physical improvement. leachate to water ratio of 20/80 (T2) showed a more positive effects with respect to plant height, number of grain per spike, grain weight per spike, 1000 grain weight, grain and straw yields per pot than the addition of compost effects.

Seed priming could be as a way to improve seed germination behavior and seedling establishment in moisture limitation and low temperature conditions. This experiment was carried out, therefore, to determine the best duration of hydropriming as well as its effect on various growth traits in barley cultivars (Kermanshah, Gorgan and Zarjo). A lab experiment was conducted at seed laboratory of faculty of Agricultural, University of Tehran in 2004. A 3- replicated factorial experiment based on CRD was carried out. The seed were primed by exposing them to distilled water for different duration of 5, 10 and 15 hours. At the end of hydropriing duration standard seed germination test was carried out. The studied traits were: germination percentage and rate, length of coleoptiles and of the longest root, dry weight of root and shoot as well as seed vigor index. Analysis of variance indicated that cultivars were differed in all characteristics with exception of the longest root length. Effects of hydropriming for all studied characteristics were significant, so that in optimal duration of hydropriming, it improved all studied characteristics. Also the interaction between hydropriming and cultivars was significant, so that in Zarjo cultivar 10 hr hydropriming and in Kermanshah and Gorgan cultivars, 15 hr hydropriming were the best. The result of this experiment is consistent with the hypothesis that under undesirable condition such as dry land areas, hydropriming of barley seeds could be one possible way of enhancing seed germination performance and seedling establishment.

Coordinate of Kohdasht watershed is about 47˚ 27’ to 47˚ 49’E and 32º 25’ to 33˚ 40’ N as one of the sub catchments of Karkheh basin .Area of this catchment is about 46370 ha, average annual precipitation equal to 418.5 mm and average of temperature is about 17˚C .In this study for selection suitable area in the case of aquifer management using runoff control in the Quaternary area, five effective agents as slope, infiltration, transition  ability  and depth of alluvium and quality of alluvium were considered. By using the Landsat TM images, Quaternary area was selected and separated and then assessed. Also by using the topography map in 1:50000 Scale, the slope map was prepared in four different classes. For assessing the infiltration on Quaternary area 48, profile and sample set in depth of 50 cm of ground surface were estimated. Equation between texture and infiltration was compared to F.A.O. tables and correction was done for these amounts with double ring exercise and by GIS software.For estimation of transform ability, depth of alluvium and quality of alluvium, isohital map of Lorestan  was used and interpolated using GIS software and classified to prepare the geomorphology map of the area using TM images, arial photography, 1:50000 scale map and also field surveying. By using Feiznia method, sustainable map for sedimentation of upper landsat was prepared by using the 5 information layers and run of different model. The best model was selected and crossed with geomorphology map to prepare the classification map of the area for aquifer management.

The adaptation of 19 plant species were studied for 5 years (1985-1989) in Aghelah of Gorgan Station. The annual mean rainfall at the station is about 350 mm  and the soil texture is clay-loam with electric conductivity about 9-22.5 desi zimense per meter and PH about 8. The seed of the non- shrub species were planted on 2 m length lines aparted 70 cm and the seedling of shrubs  cultivated on 25 meter lines apparted 2.5 meter each other. A completely randomised design with 4 replications was applied for analyses. 160 plants of each species were studied. The percent of survived plants in fifth year were compared. Results showed that the species of Puccinelia distans was established successfully and it was more vigor and productive than others. Atriplex canescens, Atriplex halimus Agropyron elongatum, Atriplex lentiformis, Atriplex simibacata, Artemisia sieberi, established and survived upto fifth year but were less vigor and productive than Puccinelia distans.

Salinity of water sources and soil is one of the most important agriculture problems in Iran. Nutrient availability is decreased in saline conditions because of high concentration of sodium, chloride and sometimes calcium ions in soil solution and plant nutrient balance is changed. Then under these conditions, proper and adequate nutrition play an important role in nutrient balance and crop improvement. A greenhouse experiment was conducted to investigate the effect of 4 different irrigation water salinities (0, 4, 8 and 12 ds m-1, prepared with 1:1 molar ratio of chlorides of calcium and sodium and magnesium sulphate salts.) and 5 different zinc applications (0, 10, 20, 30 mg kg-1 soil and foliar application of salt of zinc sulphate) on yield and chemical compositions of wheat, using a completely randomized design, factorial with three replications. The results indicated that irrigation water salinity decreased grains and straw yield; however zinc application improved these parameters in all salinity treatments (except S12 treatment). Saline water decreased nitrogen, phosphorus, zinc, iron concentrations in straw and grain, manganese and copper in grain and potassium in straw. However concentration of nitrogen, zinc, and iron in straw and grain, potassium in straw and copper in grain was increased by zinc sulphate application. Results of this study showed that the addition of zinc under low to medium salinity conditions may cause an improvement in growth and increases the relative yield of wheat due to improving the overall nutrient status of plant and decreasing the impacts of salinity.

In order to investigate the effects of sorghum densities and different interference periods on corn growth analysis, a factorial experiment was conducted based on randomized complete block design with three replications in 2003 at the Research Farm of Agriculture, Tabriz University, Tabriz, Iran. The sorghum densities (4, 8, 12 plants M-2 and interferences at different periods periods (0, 14, 28, 42 days after corn seedling emergence and also during plant life) were measured. Optimum corn density was 7.8 plants M-2. The results showed that with increasing sorghum density and interference decreased corn total biomass, crop growth rate, relative growth rate, net growth rate and leaf area index. It may be due to decreasing of leaf area index, shading and competition between bushes for light. The highest shading (60%) and maximum corn leaf area index loss 38% were occurred at the highest sorghum density with complete interference.

The determination of effective parameters on Atriplex lentiformis vigority is essential for sustainable development of planted shrub areas. In fact, the experiment was carried out on limitary and planted shrub area (4.5 ha) in kavir-e- Siah koh for 10 year period (1992-2001). Experiment was conducted in split split plot design with main-plot that row space was 2, 4, 6 meter and sub-plot (1) was as 3 period of cutting (every, two and three time years of cutting) and sub plot (2) was 5 types of cutting height 0,20,40,60 cm and control. Vigority index analyzed on harvested forage production on autumn 1993 and continued to 2001. Results showed that effect of row space treatments on vigority was not significant (p<0.05). Also effect of cutting period treatment on plant vigority was significant in 6 years period (p<0.05), whereas this effect was not significant in 9th period. The cutting level has significant effect (p<0.05), and maximum effect is in the 60 cm height. The plant vigority was decreased, when cutting intensity increased. The 0 cutting height destroyed most of the plants in the field. Vigority index in the best treatment (2 meters row space and 60 cm height in every year cutting) were 0.63 and 1.21 in 6th and 9th cutting period respectively.

The recognition of the vegetation effects on soil and selecting the appropriate plant species are necessary to rehabilitate and stabilize shifting sand dunes. The successfulness of fixation of sand dunes and prevention of sand encroachment to the villages and cities is completely related to have knowledge on soil and plant relationship. In this study, the effects of two plant species including Haloxylon aphyllum and Calligonum commosum on physico-chemical soil properties and sand dune fixation of Reza-abad region were assessed.In this regard, two large pilot areas including eight plots (100 m2) were  selected. In each one, plant species diversity was estimated and soil sampling was done from soil surface (top 10 cm) and sub surface (10 to100 cm) layers. All relevant soil samples were tested in physio-chemical factors like soil texture, pH, EC, N.P.K, lime and organic matter and finally the results were analyzed using statistical software into split split plot design. These plant species were shown to increase content of organic matter and N.P.K levels and improve soil structure in ling term periods. These provide better environment for activity of micro-organisms and accelerate soil formations processes. Moreover, these plants absorb sand particles by their aerial organs and increase the clay and silt percentage of sand dunes in long-term.

For sand dune types including simple, compound and complex ones, an  infinite number of varieties occur which represent transitions and change from one basic type to another. The result is differences in the direction and strength of wind, the amount of available sand, physical obstructions and other factors that control dune types development. In this research, role of wind system and dynamic has been discussed based on erosion and deposition form in creation of these varieties. Data have been prepared  using the satellite images Landsat (1/250000 scale), aerial pictures (1/55000), topography map (1/250000), and using of three major system of wind effect theory, ability of wind erosion theory , ability soil erosion theory and Bernoly low and field observations. At present in Lout plain, wind transfers the sand particles and prohibits vegetation formation. This is accompanied with a complex mechanism.The 60% of Lout basin is affected by wind (deposition and erosion). Rearly permanent wind in lout plain will be distinguished by lack of vegetation. Of course present winds in Lout plain aren’t severe. In this research, wind mechanisms which are part of denudating Lout materials and dynamic system of winds were ranked based on erosion and deposition forms

Effects of salinity stress on seed germination of Haloxylon aphyllum, Hammada salicornica and Seidlitzia rosmarinus were studied. At present study Salinity treatments were (0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500 Mm) NaCl. Percentage of germination, plumule and radicle length and germination rate was measured. Statistical analysis showed significant difference germination, seed germination rate and plumule and radicle length (P<0.05) parameters. Salinity level had significant effect on percentage of germination, germination rate and plumule and radicle length (P<0.05). Percent of germination, germination rate and plumule and radicle length were decreased with increasing of salinity. Hammada salicornica is the most resistant species.

Salinity has affected about 10% of world lands and damages due to salinity are recorded as 3 ha per minutes. Due to geographic and climate conditions which is arid and semi arid, Iran is 5th among Asian countries. The central part of Iran and specially Yazd province is one of the major centers of salinity and dust damage and desertification. Salinity which is caused by human activities, especially agriculture & irrigation activities (secondary salinity) is differ from normal salinity and is the most important factor for desert developing in arid and semi arid lands.An area in north of Ardakan was studied to find the irrigation effect on Yazd-Ardakan desert salinity. At first, we collected the information about area, such as geology, topography, climate, water sources and agriculture. Then 8 study areas in three types (barren, agricultural and garden land) were sampled in 0-30 / 30-60 / 60-90 cm.We repeated for 3 times to collect more precious results and sent samples to laboratory. Results show that irrigation with salty water in area has caused salinity. But in general, the comparison between rate of electrical conductivity of saturation extract (ECe) in barren, garden and agricultural lands showed that irrigation decrease salinity in that area and its EC is very low. On the other hand the rate of EC in depth is more. This matter shows the effect of leaching and drainage factors by irrigation on depth which lead to decrease salinity and so in that area which the elementary salinity is high, irrigation can have a good effect on salinity.

One of characteristics studied in many researches on desert and arid zone such as study of ergs, Aeolian erosion, moving of sand dune, etc is grain size and morphoscopy. This study, as first step, is done in Iran for recognition of many regions especially in different ergs but, there is still a necessity of comprehensive research on Iran ergs and calculation of correlation among this characteristic with the others such as transition distance, sorting, etc. In this research, the mean of diameters of particles, the mean of mode of particles, the mean of skew ness in normal charts of particle diameters and the mean of distance moving of internal and coastal ergs were compared. There were no significant differences in the mean of diameter, the mean of skew ness, the mean of distance moving in internal and coastal ergs. But the mode of particles diameter was shown to have difference. The mean of diameter in internal ergs is varied from 74 µ to 689 µ and in coastal ergs is from 100 µ to 744 µ. 31% of mode of diameter in internal ergs is classified in class of 75 µ, 63% in 150 µ, 2% in 300 µ and 4% in 600 µ. These amounts are different in coastal ergs as 18% for class of 75 µ, 73% for 150 µ and 9% for 300 µ. The skew ness in internal ergs is varied from -0.2 to 2.95 and in coastal ergs from 1.31 to 2.71. The mean of moving distance has 4 classes consisting of 3, 12.5, 35, and 125 Km for internal ergs are 4, 2, 63 and 31% and for coastal ergs are 0, 9, 73 and 18%

Common landforms of Iranian desert zones landscapes are sandy deserts and sand dunes, which cover considerable area of Iranian deserts. These are called ergs. One of these ergs is Kharturan Erg with an area of about 200000 hectares that is located in North East of Iran. The geomorphology studies have been done on Kharturan Erg with morphological view points on sand dunes and the prevailing wind direction. These studies have shown that Kharturan Erg has the active depositional dunes structure and it has two types of sand dunes:1- Crescent and transverse chains, 2- Linear or elongate dunes. The first type contains: a) "prebarchanic landform", b) "barchans", c) "transverse dunes" and the second type contains a) "simple linear dunes (Seif)" and b) "composite forms (silk)".From the view point of spatial distribution, the simple sand dunes are located in the marginal parts of Erg including prebarchanic, barchanic and Seif. The composite sand dunes have occupied the central part of mentioned Erg.