Desert Management
Year:2018 | Volume:6 | Issue:11 |Papers Count:8

Salt domes are one of the most interesting geomorphologic landforms that have great potential in attracting tourists and developing the geotourism industry. Due to the existence of various salty geomorphosites in Semnan, there are not systematic researches for estimating these geomorphosites for developing tourism and creating its infrastructures. Therefore, it is necessary to estimating the capability of salty diapirism landforms in developing tourism in the study region. In the present study, we try to estimate the data of field observation and questionnaire information about geamorphosite value of salty domes in the south of Semnan by using Reynard and Pereira methods. The present research is quantitative in terms of research paradigm, field, library and questionnaire in terms of collecting data, and in terms of purpose is applied, which is based on descriptive-analytical method. First, the results of literature were studied, field measurements and interpreting the satellite images have presented in the form of recognition sheet, then have given scores to each criteria and sub-criteria in Reynard and Pereira method, according to experts opinion and field observations. The results indicated that in the Reynard method, the scientific value (0. 785) and combination value (0. 547) and in the Pereira method, Geomorphological value (6. 74) and Managerial value (4. 66) have obtained the highest and lowest scores, respectively. The high scientific and geomorphological values in geomorphosite is due to the aesthetic values and educational capability of geomorphologic processes, and then the virginal of the landforms in the area due to the unfamiliar of these geomorphosites to tourists and the lack of attention of the officials to these tourist attractions. In contrast, low values of combination and management, indicates poor management and lack of support equipment and services in the region. In general, geomorphosite obtained a good final score based on two methods, which indicates the high capability of geomorphosite in the attraction of tourism. The results of present research can be used by decision makers to develop the salt geotourism in the province.

This study investigated the vegetative and physiological characteristics of Hammada salicornica Syn.: Haloxylon salicornicum under sand burial. Experiment conducted in completely randomised design with five replicates. One year-old seedlings of Hammada salicornica in the same size assigned to one of the following five burial treatments, control, buried to 33% of plant height, buried to 50% of plant height, buried to 75% of plant height and buried to complete plant height. After 6 months watering under glasshouse conditions, some of vegetative and physiological characteristics of Hammada salicornica were measured. Results showed the highest amounts of leave proline equal to 20. 8 mg/gfw observed in 33% burial treatment. Root proline in all burial treatments were significantly more than two times compared to control. The root proline in 33% burial traetment was equal to 22. 72 mg/gfw that was two times more than control. The amount of oxine significantly increased in 33% and 50% burial treatments compared to control. The amount of oxine in 33% burial treatment was equal to 0. 64 mg/gfw that was two times more compared to the control. The amounts of stem sugar were deacreased in all burial treatment while heighest amounts of root sugar were measured in 33% burial treatment. Stem and root sodium, 22 meq/l, significantly increased in 33% and 50% compared to control and 75% burial treatment. The amount of root and stem potassium content in 75% of burial treatment was significantly lower than other burial treatment. The amounts of stem phosphorus, 0. 73 meq/L, and root phosphorous, 1. 9 meq/L, observed in 33 % of burial treatment. The amounts of root phosphorus significantly increased in all burial treatment compared to the control. Moreover, the stem hieght in 75% burial treatment, 40 cm, were more than two times compared to the control. The highest amount of stem and root dry and wet weight in 33% of burial treatment was significantly more than other burial treatments. It is concluded that Hammada salicornica tolerate not only 33%of burial treatment but also the burial stimulates the growth.

Declining condition of water resources cannot be shown by single-variable drought indices because of changes in precipitation and temperature due to climate change. Accordingly, multivariate drought indices are considered such as the Standardized Precipitation-Evapotranspiration Index (SPEI). In order to study the trend of changes in the severity of meteorological drought in the geographical zone of Iran, the SPEI global network data was used over a 30-year statistical period, and trend detection test and Sen's slope estimator were performed on their seasonal series. Then, their results were mapped in the GIS and the results showed that the highest drought trend is in the winter between seasons, and more than 94 percent of the country's area shows a declining slope in the drought index time series. The trend of this slope in the west and north-east of the country is statistically significant. Also, the eastern half of the country shows a drought trend in the summer, but a better situation prevailing in Iran in spring and autumn, and a small percentage of the country's area indicates a significant drought trend. So that in the spring and autumn, the slope of the trend line in 85 and 91 percent of the country is less than and equal to 2 percent, respectively. Generally speaking, the result of the Standardized Precipitation-Evapotranspiration Index showed that climatic changes are occurred in Iran and the country is going towards more dry periods in future years.

Astragalus squarrosus is a species of shrub without spine and palatable. This plant distributes in sandy dunes of arid and hyper arid regions in central, south-eastern and north-eastern desert of Iran. In this study the effect of rain harvesting treatments including furrow, pitting and crescent pond and planting season on initial establishment of A. squarrosus in Kalmand Bahadoran was evaluated. This region in terms of soil type, condition of rainfall and temperature is similar of the main habitat of this species. The seeds were planted at two season late fall as autumn sowing and late winter as spring sowing season. Also, the seeds were scratch according to germination studies in the lab. The scratched seeds were compared in split plot design with main treatment of planting season in the autumn of 2013 and 2014 and winter of 2013 and 2014. Subsequent treatments of pitting, furrow, crescent pond in three blocks were compared. In the spring, the number of established plants in each plot was counted and analyzed. Based on the results, fall planting been more successful than spring planting. Also, furrow treatment with 11. 5% seed establishment had better results in seed establishment than other treatments. Also, the results of season and treatment interaction showed that 27% of seeds were planted in furrow during autumn 2013. But seeds in any of the treatments were not grown in winter 2014. Generally, low seed establishment suggests that rain storage combined with seeding in areas with average rainfall less than 100 mmfaces with a high risk. In these areas, methods of potted seedlings combined with rain harvesting should be examined.

Present study was conducted to find out the effect of arbuscular mycorrhizal fungi Glomus intraradices and the plant growth promotion rhizobacterium Pseudomonas putida inoculant on the concentration of macro and micro elements and seedling quality indices of Calotropis procera seedlings in a completely randomized design with three replications. The results of one way ANOVA showed that measured parameters of nutrients and seedlings quality index have been significantly influenced by the inoculation fungi and bacteria. The Duncan’ s comparison of mycorrhizal inoculum than control in total root nitrogen concentration was 26%, iron concentration in leaves and root were 70% and 52% as well as potassium and zinc concentration in the leaf as of 5% and 45%, respectively that compared to the control has increased. Mean comparison of Rhizobacterial inoculation with control showed that total nitrogen, iron and manganese concentrations in the leaf were 57%, 450% and 225% respectively, and iron and zinc concentrations in the root increased 58% and 84%, respectively. According to thehe mean comparison of Duncan’ s, mycorrhizal treatment with Rhizobacterial had increase in total nitrogen, potassium, iron and zinc concentrations in leaf by 51%, 48%, 450% and 31%. Nitrogen and potassium in the root were observed at 48% and 300%, respectively. Comparing seedlings quality indices, inoculated seedlings of the Rhizobacteria with the index of 0. 85 were highest rate, which was 66% higher than the control. The results of this study indicated that inoculation of mycorrhizal and Rhizobacterial has increased in nutrient content and quality of seedlings. Despite the slight differences between inoculations, it is recommended to use both types of mycorrhizal and Rhizobacterial inoculum in order to replace the fertilization in the culture media in nursery.

In the present study, four supervised classification algorithms including Maximum Likelihood, Mahalanobis Distance, Minimum Distance and Neural Network with and without TIR1 were used to mapping land use of southern Khorasan province. Based on the results, the highest of overall accuracy and Kappa coefficient were calculated for the Maximum Likelihood algorithm with and without of TIR1. Using of TIR1 increased classification accuracy byMaximum Likelihood and Mahalanobis Distance algorithms; but using of TIR1 decreased classification accuracy byMinimum Distance and Neural Network algorithms, remarkably. Using of thermal data along with other spectral bands caused facilitation of discriminating classes with similar spectral characteristics. According to the land use map, bare land covered about 60% area of southern Khorasan province, generally more than 90% of the area of the province is involved by sparse land or weak vegetation cover which is prone to wind erosion.

Identification of the origin of sand dunes and determining their sensitivity are very important for combating wind erosion. The main aim of this research is investigating sediment characteristics and classification of sand dunes created at the western margin of Lake Urmia. At the first, geomorphological unit map was prepared, then 21 and 12 surface samples were selected from detachment wind sediments areas and sand dunes, respectively. The results of morphometry showed that frequencies of particle size are 125-500 micron indicated the short distance transport of particles and close to the site of the deposit. Also, sorting index is poor in detachment wind sediments areas and moderate to good in sand dunes. The index of particle skewness is very fine, fine, symmetrical, coarse, and very coarse and the kurtosis index is classified in categories of Platykurtic, Mesokurtic, Leptokurtic and Very Platykurtic. The results of morphoscopic analysis of quartz beads in 250-micron mesh sieve showed that around 53%, 14. 4% and 40% segments of the sediment in sand dune were corona, brilliant carried by water and opaque carried by wind, respectively. Based on Besler classification, sand dunes located in saline and extremely saline classes showed that local winds carrying fine salt particles from the Urmia Lake toward sand dunes.

Climatic variables are considered as one of the most important factors affecting the spatialtemporal dynamic of vegetation. Nowadays, satellite images are widely used for monitoring the effect of climatic variables fluctuations on vegetation changes. The purpose of this study is to investigate the relationship between two climatic variables of precipitation and temperature with vegetation dynamic in one of the world’ s dry plains i. e. Sistan plain in eastern Iran by using satellite data. In the present study, the data generated in NDVI related toMODIS sensor of Terra satellite for 3 months of April, May, and June over 2000 to 2014, data of temperature andmonthly precipitation (October-September) in Zabol meteorological station were used for the same time period of 2000-2014. Pearson product moment correlation was used to study the relationship between climatic variables with NDVI. The results showed no correlation between MODIS NDVI of April, May, and June with the average temperature of previous months in terms of monthly scale. In case of precipitation, it was observed that the precipitation of May with MODIS NDVI of May 0. 603 and June 0. 542 had a normal positive correlation. But due to the very low amount of precipitation and high evaporation in this month, this correlation cannot be trusted a lot. Thus, by recognizing no correlation between climatic variables and vegetation dynamic in Sistan plain, the correlation between the average annual discharges of Hirmand river was considered as the only river in this plain with MODIS NDVI of April, May, and June. The results of correlation showed a strong positive correlation of 0. 75 between the average annual discharges of Hirmand river and MODIS NDVI of April. Thus, it is obvious that the critical vein of Sistan plain is Hirmand river and the life in this land and its vegetation dynamic depends not only on temperature fluctuations and precipitation but also on the water of this life-giving river.