فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و نهم شماره 1 (پیاپی 86، بهار 1401)

Salsola laricina is one of the main elements of vegetation communities in the steppe rangelands of the dryland region, which protects it from disturbances and provides conditions that can preserve its ability to rehabilitate after chest, is one of the basic requirements of rangeland management in such fields. Therefore, in the present study, the variability of structural and functional traits and morphological characteristics and seed germination were tested under supportive grazing. For this purpose, by establishing a sampling system inside and outside of the 10 year old Khoshkerood detention, the vegetation cover and structural and functional traits of Salsola laricina species, such as crown cover, density and forage production in the field were measured. Seed of healthy and healthy rootstocks, morphological characteristics and seed germination, such as; 1000 seed weight, germination percentage, germination rate, root length, stem, seedling, and finally vigor index (straw) Seed) was measured in laboratory conditions. The results showed that the values of structural and functional traits, inside the enclosure, are more than outside the enclosure. In this regard, the percentage of crown cover, density, and amount of production of Salsola laricina species were respectively in the enclosure relative to the outcrop, 5.46 and 3.6%, 21600 and 17000 bases per hectare and 161.4 and 12.71 kg respectively hectare. The average of morphological and germination characteristics of the seeds collected from the intruder was also greater than the outside grazing. So that the highest index of seed vigor as a sum of outcomes of morphological and germinating properties in inoculated and outcroped seeds is 389.88 and 1037.37, respectively. The increase of these values in the enclosure relative to the outcrop; indicates the effect of supportive grazing on the improvement of structural and functional characteristics and the morphological and seed germination characteristics of rangeland species in vulnerable ecosystems in arid areas.

The increasing popularity and trade of medicinal plants on the one hand, and the expansion of polluting water, soil and air resources on the other hand, have made the health, safety and quality of medicinal plants raw materials and their processed products a major concern of world organizations. Become more and more diverse and implement various research projects in this field. The present study aimed to investigate the effect of cadmium heavy metal on the phytochemical properties of licorice in a completely randomized design with cadmium treatment at 6 concentrations (0, 10, 20, 40, 80 and 160 (ppm)) and 4 replications. Potted cultivation (24 pots in total) was performed. After planting substrate and spraying cadmium heavy metal nitrate with above mentioned concentrations, licorice rhizomes were cultured in pots and kept in greenhouse for 7 months. Finally, dried and powdered plant samples (in two sections of aerial parts) were transferred to laboratory for measurement of phytochemical properties. The measured variables in the underground organs were glycyrrhizic acid, glabridine, liquoritin and in the aerial parts of routine and catechin flavonoids. Extraction was performed by ultrasonic and solvent methods. The best solvent for extraction of active substances in aerial and ground organs was determined after ethanol: water (70:30) tests and the measurements were performed by high performance liquid chromatography (HPLC). Comparison of mean cadmium concentrations in the studied concentrations showed that increasing the concentration of this element in soil had a significant effect on glycerolic acid, glabridine and liquoritin levels in groundwater and routine flavonoids and catechins in aerial parts of licorice. In this regard, glyceric acid and liquoritin were the most additive effects at concentration of 10 (ppm), 70.12 and 56.44%, and glabridine at concentration of 20 (ppm) at 51.70%, respectively. It also showed that the amount of active substances in licorice underground increased initially with cadmium treatment and then decreased with increasing concentration of heavy metal.

The aim of this study was to investigate the effect of conversion of rangeland into agricultural and horticultural land uses on important soil properties including aggregate stability in Salavatabad watershed in Eastern Sanandaj. For this purpose, simultaneously with the predominant growth of plants, four land uses including 1) rangeland 2) orchard 3) chickpea field 4) wheat field were selected as the study area and 42 soil samples were random-systematically collected. Then soil physico-chemical properties including aggregate stability, total nitrogen, total carbon and particulate organic carbon of each sample were measured in the laboratory. One-way ANOVA of the data showed that due to the conversion of rangeland into three uses of orchard, chickpea and wheat fields, aggregate stability, particulate organic carbon at the level of 5%, total organic carbon and total nitrogen in all three uses at the level 1% decreased significantly. As the aggregate stability in orchard, chickpeas and wheat 35.51, 25.94 and 19.56% respectively, particulate organic carbon in orchard, chickpeas and wheat 62.5%, 79.16 and 75%, respectively, total organic carbon in orchard, chickpea and wheat use decreased by 23.63%, 50% and 49.09%, respectively, and total nitrogen decreased by 31.25% in orchard, 62.5% in chickpea use and 75% in wheat use. According to the results of this study, the conversion of rangelands to any of the agricultural and horticultural uses is unacceptable, but in case of forced conversion, the use of the orchard is recommended because the orchard has less negative effects on soil quality factors than wheat and chickpeas. It is also emphasized in converting rangeland use to cropland, as much as possible to maintain the balance between the input and output of the plant residual into the soil bed, it should be prevented the exit or fire of remaining straw, or grazing livestock after harvest.

The importance of paying attention to sustainable development and biosafety in areas that effected by an environmental disaster such as dust storms has increased the need for new methods to find coping strategies. For this purpose, cross-structural analysis is an effective tool for studying system behavior. Based on the results of structural analysis and future study approaches, stability strategies can be proposed in the affected area by high-risk dust. The method of the research is according to the applied and future study approach. The sample population of this research was composed of 22 experts and managers in the field of agriculture and dust. Based on collecting data through expert interview and brainstorming method, the effective drivers were identified. According to the opinion of experts, the final drivers were extracted as a 26 × 26 matrix. Then, the cross-impact matrix was scored by experts. To determine the key drivers affecting the resilience of farming communities affected by dust in Ahvaz County, the future research approach was performed using MICMAC software in three groups of economic, social, and natural-physical components and 26 indicators. Research variables were divided into three categories »key, Independent and Regulative« based on the degree of relationship between influence and dependence. Key drivers include »Change of Quality and Quantity of Agricultural Products, Income Risk, Unemployment and Poverty Rise, Access to Financial Credits, Alternative livelihood and Immigration«. The results showed that the system of this study is unstable and in order to make management decisions and increase sustainability, it is necessary to develop strategies based on key drivers affecting farmer’s resilience.

Desertification has been considered as a serious threat to arid, semi-arid and even semi-humid climate in recent decades and it is a major obstacle to sustainable global development, so monitoring its changes is urgent. Using remote sensing and GIS is one of the cost-effective, often free and accessible method to monitor changes in these areas. In this study, change vector analysis method was used for evaluation and analysis of desertification change in a part of Ghalehganj county in south of Kerman province. For this purpose, Landsat 8 image bands in two time periods of 2014 (first period) and 2020 period (second period) for March and April was used in Google Earth Engine. Image pre-processing were applied and averaging was done separately for both periods which was followed by calculation of EVI and BSI indices. For the next step, using these two indicators and the change vector analysis method in the GIS software, the magnitude and direction of desertification change trends were determined. The results of the present research indicated the dominance of the reclamation process in the region during the years studied and the overall results indicate that development of cultivated lands and land use change have the greatest impact on monitoring indicators and desertification trends in the region. Thus, degradation of lands around residential areas are witnessed and on the other hand, there is a significant relationship between agricultural activities and rehabilitation areas in the region.

Taverniera spartea is one of the most important species in the Gulf and Omani rangelands. In this study, some ecological needs of Taverniera spartea and their response to soil and topographic factors in three main habitats in Hormozgan province (Siahoo, Ahmadi and Bashagard) were determined. The results showed that the percentage of cover was significant at the level of 1% and the percentage of bare soil and the percentage of rocks and pebbles at the level of 5% was significant. Applying the generalized collective model for each of the environmental variables showed that the variables of soil lime percentage, clay percentage, acidity, soil organic carbon content, soil nitrogen and bare soil percentage on species yield are significant. Increasing the percentage of soil clay from the Monotonic decrease, increasing the acidity of the soil, from the Bimodal distribution, increasing the amount of soil lime and also the percentage of bare soil from the Unimodal and increasing the percentage of organic carbon and soil nitrogen from the Monotonic increase followed. The phenological study of the species showed that the growth of this plant starts from the second decade of November and from the third decade of May, enters a stage of stagnation. Considering the nutritional value of the species and its role in the protection of rangeland soil, it is recommended to plant this species in the degraded rangeland areas that have the conditions for its establishment.

Desert ecosystems have substantial economic potentials that paying attention to them to attain sustainable development and to get rid of the one-product economy is essential. According to the growing demand for ecotourism, calculating the recreational value of recreational areas seems to be necessary for efficient and effective management. The purpose of this study is to determine the factors affecting the willingness of tourists to pay in the Qaleh-Bala area of Biarjamand city in Semnan province. To examine the factors affecting the willingness to pay, the Logit model was estimated by the maximum likelihood method. To measure the willingness to pay off the Qaleh-Bala Double-bounded Dichotomous Choice, it was used. The required data were prepared and collected by completing a questionnaire and face-to-face interviews with visitors from the area. The tourist samples were selected by a simple random sampling method for 207 people, and then the questionnaires were completed by them. The results of the Logit model showed that the coefficients of the variables number of visits, final destination, and distance from residence, monthly household expenses, and offered price were significant at the level of 1% and 5%. Finally, the average willingness to pay for the use of the area by visitors was 48,220 Rials and the annual recreation value of Qaleh-Bala village was estimated at 434 million Rials

Measuring the diversity and identifying plant vegetation traits and functional groups and classifying them, in addition to helping to accurately identify the vegetative capacity of the area, helps us to understand the vegetation response of the area to disturbances and presence. Potentially resistant species with similar or invasive traits help. The purpose of this study was to investigate and evaluate the vegetative status of the region, the trend of changes and evaluation of the second sequence of dust centers in Khuzestan after planting seedlings in different ways. Functional groups (PFTs) were used. To evaluate the changes in the vegetation of the area by field survey, 15 transects of 100 meters with distances of 50 meters were systematically randomly selected (the first transect was randomly selected and the rest with a defined distance of 50 meters). Due to the uniformity of plant species composition and the absence of environmental effects, a total of 180 fixed plots with dimensions of 1 square meter (location recording with GPS device) were installed. The results of a recent study in three areas of the dust center in the southeast of Ahvaz showed that in selected areas, various irrigation methods along with rainfall will cause significant changes in the percentage of cover (frequency) and the number of species from 2017 to 2020. Functional groups in the Tovayel region with surface irrigation (Faro) In 2020, nine groups were identified, in Bagan region with tanker irrigation and hole digging with seven excavators, and in Hanitieh region with tanker irrigation and hole digging seven functional groups. The results of T-test analysis also showed that there is a significant difference between the average of the two values of all indicators, including the diversity of Shannon and Simpson in March 2017 and March 2020 for all three regions so diversity indicators raised since number of species and cover increased.

Changes in different solute compounds in edaphic factors affect the spatial distribution of plant species, especially hemicryptophytes.Soil salinity is one of the most common desertification factors in arid and semi-arid regions that contributes to the degradation of the soils of regions susceptible to desertification and eventually leads to a decreased soil ecological potential which is considered as one of the most significant factors that intensifies desertification. In order to explore the impact of principal components of soil on the diversity of plant types in the forest regions scattered along the coastal belt of the Persian Gulf and Oman Sea, current research was conducted on saline soils in Hasan Langi Village. Analysis of correlation coefficient between different traits of the plants in the respective vegetation (percentage of coverage, height and density and diversity) and the soil parameters of the habitats indicated that these vegetative parameters were mostly correlated with acidity, texture, and total calcium and magnesium. Principal component analysis (PCA) demonstrated that components 1 and 2 explained a total of 85% variance suggesting the largest impact of soil factors on differentiation of vegetation. In total, the factor of diversity was most correlated with calcium and magnesium in the second depth while other vegetative characteristics were directly correlated with the amount of sodium and potassium as well as electrical conduction in the first depth and the amount of calcium in the second depth.

The various services that we obtain directly and indirectly from the natural environment are referred to as ecosystem services. The purpose of these services is to communicate with human welfare in four categories of services: provision, support, regulation and culture. The purpose of this study was to investigate the supply of soil conservation services at different land uses and also to compare their amount. InVEST model was used for this research. To calculate soil retention, this model estimates soil erosion potential using the Modified Soil Erosion Equation (RUSLE) and sediment retention rate based on sediment delivery ratio. Therefore, the required input information of the model including biophysical table and maps of digital elevation model, rain erosion, soil erodibility, vegetation and land use were prepared with the help of ArcGIS 10.4 software and entered into the model in the form of raster maps. The results of this study showed that among different land uses, forests and rangeland with good and average condition had the highest soil conservation and the lowest amount was related to barren lands, residential areas and poor pastures. The results also showed that the highest rate of soil conservation occurs in the east and southeast and upstream of the basin and factors such as reduced vegetation and soil type have contributed to the intensification of erosion in this area. The results of this research can be useful in land management programs and appropriate decision making for rangeland management.