فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و هفتم شماره 1 (پیاپی 78، بهار 1399)

Rangeland capacity depends on forage produced in the rangeland, the permitted range of plant species, forage quality and rangeland health. Range species have a certain production in months and years. Without recognize properties production plants and the rate consumption forage rangeland cannot programming and management at during a period of grazing. This study was conducted at 2009-2013 years, and rate forage production and utilization was measured. The rate of precipitation annual at 3 years were 138, 200 and 330 millimeter respectively. The results showed that total forage production was significantly different between years (p<0.01). Forage production were 485.7, 1372 and 1844.4 Kg per hectare respectively. The amount of production in the months of growing season (March to August) were significantly different, so 94.7 of pasture growth in the first 2 months (March and April) and three fifths% by feed-in last 4 months. The annual consumption of respectively 400 and 751 and 490 kg per hectare. Although not statistically significant, But in the dry year of 2008, 83% and in the wet year of 1389, 26.6% were used of pasture production. Therefore, in drought, at the same time as the reduction in forage production, the livestock utilization rate increased by 83%, which is not proportional to the rangeland capacity. Therefore, in order to achieve sustainable production, proper management of rangeland and the use of indigenous species such as Onosma bulbotrichum, Ankyropetalum gypsophiloides, Convolvulus reticulatus and Salvia compressa are recommended.

Determining grazing capacity of rangelands is one of the main factors in range management so that, regarding this important factor, is one the main causes of range degradation in Iran. Middle Taleghan rangelands have utilized for many years thus, there aren’t preserved from degradation. The aim of this research was to determine the short term grazing capacity of these rangelands to show factors affecting grazing capacity and both preserve and improve the condition of them. During the field work was done in June 2013, sampling performed by random- systematic method using four 150 meters transects and 10 plots along each one randomly and current forage production was harvested in separation of each species form all three palatability classes. Then proper use factor was determined. Finally, short term grazing capacity was calculated through the computing daily requirement energy method and attending to forage quality for each type. The results are shown that grazing capacity range from 0 to 1534 Fashandi race adult sheeps for grazing period. Least required area for a sheep grazing range from 1.92 to 8.63 hectares for grazing period. Grazing capacity for all of studied rangelands is equal to 6802 Fashandi race adult sheep by 60.7 kg weight and least required area for a sheep grazing is 3.76 hectares in average, Whereas the actual grazing capacity in these rangeland is mostly 159 Fashandi race adult sheeps  per hectar  for good condition ranges ang 19 for poor condition ranges. So, For calculating grazing capacity it is also necessary to consider palatability, proper use factor, forage quality, animal weight and its daily requirement and its movment rate in addition to rangeland yield. Thus, current research is emphasizing on to pay attention toward all effective factors in evaluating rangeland grazing capacity.

Rainfall storage with plant species planting is used for rehabilitation and improvement of rangelands, especially in arid areas. In this study the effect of rainfall storage treatments furrow, pitting and crescent pond on the establishment of Ferula tabasensis in Kalmand Bahadoran area of Yazd province was evaluated. This area is one of the habitats of the species studied. Seeds were planted at two season, early fall as autumn sowing and late winter as spring sowing. The research was a split plot design, based on randomized complete blocks with three replications. The main plot was planting time (spring and autumn) and sub plot was planting method (farrow, pitting and crescent pond). The seeds were planted in 2013 and 2014. The results showed that seed emergence rate in autumn were significantly higher than spring planting. Among the planting methods, the impact of the crescent pond method was slightly more than the other two methods. In general, planting methods caused more than 50% seed emergence. Although some of these seedlings were destroyed for various reasons, however, the establishment of about 30% of seedlings shows that the methods of rainwater harvesting in the establishment of cultivated plants have had a positive effect.

To manage an animal species effectively, it is necessary to identify habitats with high suitability for it; So its population can be preserved by conserving those habitats and planning to manage them properly. For this purpose, the study was done to determine Relationship between rangeland species and habitat suitability of Gazella subgutrrosa in different seasons on the basis of dung groups in Kalmand plain of Yazd province. So, sampling was done using random steady plots with 200 meters long and 2 meters wide and with 2 replications during five field investigation in summer and autumn. Random and control plots were put in different directions and were investigated every 45 days. Finally, all maps needed and information incorporation were prepared and done in ArcGIS9.3. The results showed that there is no difference in two seasons related to dung groups' density. In terms of canopy cover percentage, Artemisia species had a significant increase in presence points compared to random points; Astragalus sp. had also a significant increase in presence points compared to control points. Onopordon sp. canopy cover in absent points and Acanthophyllum sp. in random points were higher than in presence points (p<0.01).according to the prepared map, 23% of the region has topnotch suitability and 47% has second best suitability. Rocks and the regions under human activities were identified as unsuitable habitats. According to the results, it is seems that from habitat variables, species richness, Artemisia cover percent and distance from road are effective on deer habitat.

Plant litter is one of the best factors in the protection and stability of soil and by decomposition of litters, the percentage of organic matter could be increased which also improves the chemical properties of soil and plant production. The aim of this study was to compare the litter quality accumulated beneath three shrub species (Amygdalus scoparia, Ebenus stelata, Daphne mezerum) by measuring the soil chemical (carbon, calcium, magnesium, nitrogen, phosphorus, and potassium) and physical (Electrical conductivity and acidity) properties in Marvast rangelands, Yazd province, Iran. At the end of growth season, fifteen sites were selected and soil samples containing litter material was done randomly taken beneath and outside of the shrub canopy covers. Then, the chemical and physical characteristics of litter were measured in the laboratory. In order to compare the litter characteristics, one-way ANOVA were made between species and, between outside and beneath the shrubs. Mean comparisons were made using Duncan method. The results showed that the litter samples under E. stelata and D. mezerum shrubs had the highest values for calcium, magnesium and nitrogen contents. In contrast, the litter samples collected from outside shrubs had the highest values carbon content and electrical conductivity. The phosphorus contents between the species and between under and outside shrub of litters were statistically equal. Generally, the results of this study showed that the woody species in dry regions had different capacity in litter quality and soil improvement. It should be considered in the activity of rangeland improvement and development.

In the past four decades, land use changes in Iran, have become more frequent as a human desertification factor, which has led to an intensification of land degradation in all types of land uses. In this research, due to the wide range of these changes, we used remote sensing technology to assess land use and vegetation changes in Damghan plain. The area of the study region was classified into three classes including unutilized land, lands with vegetation cover (agriculture and pasture) and urban areas using supervised classification strategy and the changes of the land uses were compared over four periods. The results indicated an increase of 184% and 1.07% respectively in urban land use and unutilized land use and a 15.7% reduction in lands with vegetation (agriculture and pasture). Using the Normalized Difference Vegetation Index(NDVI), the results of classification of vegetation in the region were such that class 1 (index less than zero), from 93.3 to 99.5 percent increase, class II( Between 0 and 0.2), from 5.6 to 0.38 percent, and the third class (index ranging from 0.2 to 0.5), from 1.1 to 0.01 percent, and class four (index ranging from 0.5 to 1) has changed from 0.03 to 0%, which indicates the validity of the findings from the review of the changes in land use, both of which indicate an increase in dry land and a decrease in vegetation. Also by using the Iranian model's climatic indices, the potential of desertification, the results of the 17-year calculations during the period of 1997 to 2013 indicated that desertification had decreasing trend in three classes: weak, severe and very severe, and increasing trend in the middle class. Finally, by combining the findings from the Iranian model and the results of remote sensing method, a weak trend in desertification based on climate criteria in the region was confirmed.

Times and methods of seed harvesting and seed storage have important effects on seedling viability and establishment. Effects of seed harvesting times and storage duration were tested on seed germination of Krashninkoviaceratoides in the Shahrak-Imam Seed Production Station in Neyshabur Iran. Experiment treatments were: 1) two methods of cultivation for seed producing stands (rainfed or irrigation), 2) two methods of seed storage (cold room and normal condition), 3) seed scarification and coat removal in 6 times of seed harvesting, and 8 periods of seed storage. All treatments were designed as three independent experiments, and statistical analysis were performed accordingly. For each experiment, four replicates (25 seeds each) were located in a germinator with 14:10 hours light and dark periods. Methods of seed storage (cold room or ambient) did not affected seed germination rate. Rainfed grown stands led to higher germination percent as compared to those growing under irrigation. Seed coat removing significantly reduced germination rate. Under both cold and ambient storage conditions, seed germination rates did not significantly change till 242 days after harvesting; it gradually reduced and reached to zero at 271 days after seed harvest. According to the results of this research, the best time for seed collection is early October, seeds do not need coat removing or cold treatments, as they are able to germinate till 6 months after the ripening stage under the normal room storage conditions.

This study was was don to investigate the interaction  of fire and grazing effects on index of vegetation diversity in Semi-steppe rangelands in Chaharmahal - Bakhtiari Province.Therefore, 16 sites was selected with different periods of fire and grazing intensity and 18 quadrates along transects at each site were determined and then a systematic -random sampling method was don. Then, species diversity and Beta diversity indices were calculated. To determine the effects of fire, grazing, number of year and their interactions on the diversity indices, the method of General Linear Model (GML) and for determining the significant effect between fire site and unfired site the method of T- Test was used. The results showed that in areas with moderate grazing intensity and with different periods time of fire, Diversity, Simpson, Shannon and species richness indices, compared to control areas significantly increased. But beta diversity has decreased. Simpson's and Shannon Index compared to control areas significantly increased, in areas with high grazing and different time periods of fire, and in areas with 1-3 and 3-5 years fire, Species Richness was increased and decreased respectively. Also with different time periods of fire, beta diversity was decreased. Despite the restoration of some shrub species with the passage of time at burned areas, Compared to control, the grazing intensities was significantly decreased and the highest percentage of perennial grasses coverage was observed in fire areas in places with moderate grazing intensity. After the fire, appropriate management methods in Semi-Steppe Rangelands, can increase the Forage quality and also cause an increase in species richness.

The Identification of the affecting factors for establishment of native vegetation in area can help to manage rangelands correctly. Desirable habitat will have a significant impact on the survival and reproduction of species. The development of science of statistics and geographic information systems has been made to determine of the habitat prediction of plant species using modeling approaches. So, this study has been done by the purpose of prediction of habitat Artemisia aucheri map using Ecological Niche Factor Analysis in summer rangelands of Balade, Nour city in the Mazandaran province. For achieving to this purpose, the map of environmental variables (physiographic, soil and climate parameters), was prepared after sampling soil profiles and collecting climate variables information from the meteorological organization of Mazandaran province and physiographic maps, via GIS techniques in cell size of 10 x 10. Also; 30 sites were recorded as the presence of species with sampling classified – random. Ecological niche factor analysis counted as a profile model and it is one of the most frequently used techniques to generate species distribution map which uses species “presence-only” data. According to this results A.m.p, Aspect, Ec, TNV were used as influential environmental variables. Also, the evaluation of the model indicates a high accuracy model of the Ecological Niche Factor Analysis of the Artemisia aucheri by using Boyce index in the study area. Furthermore, the results of this study showed that Artemisia aucheri has sort of limited study area and tends to live in its own special habitat conditions.

Invasive species are the major threats to natural ecosystems worldwide. Pteridium aquilinum has the widest distribution of any pteridophyta in the world. This study aimed at investigating the impact of Pteridium aquilinum invasion on species composition, richness and diversity, and forage production in summer rangelands of Bandpay Babol, Mazandaran province, Iran. Vegetation was sampled in four invaded vegetation types including Fagus orientalist forest, Crataegus shrubland, Crataegus+Berberis shrubland, and rangeland. Also, vegetation sampling was done in surrounding uninvaded rangelands. The cover of species was estimated in 1 m2 plot for herbaceous and 25 m2 for shrubs. In all plots, the cover of P. aquilinum was estimated and then all fronds were cut at ground level, counted and frond length was measured. The forage of palatable species was measured by clipping and weighing. Findings showed different species composition among invaded and uninvaded areas. A total of 25 species were found only in invaded areas whereas only 11 species were detected in surrounding uninvaded rangelands. Cover, density and height of P. aquilinum fronds significantly influenced the species composition. Annuals significantly decreased by Pteridium aquilinum invasion. Except for Crataegus+Berberis shrubland, in other invaded areas the forage production was not significantly different from that in surrounding uninvaded rangeland. There was a reduction of desirable rangeland species due to P. aquilinum invasion. Also, we found that species richness significantly increased when invaded by Pteridium, while the diversity significantly decreased. The current understory floristic composition showed a low potential to support future restoration after P. aquilinum control. This result emphasizes the need for adding the seeds of desirable species

 The aim of this study was to investigate the best planting time and method of A. podolobus</em>. The experiment was conducted as a split plot design based on a completely randomized block design with three replications at Hana Semirom station, Isfahan Agricultural and Natural Resources Research Center during 2013 to 2015. Main factor was sowing date (fall and spring) and sub plot was sowing method (linear seeding and crescent shaped bounds). The results showed a significant effect of planting time, planting method, and its interactions on the percentage of establishment. The percentage of establishment of fall cultivation was 14.28% and spring planting was 27.78%. The lowest percentage of establishment was observed with 6.35% in sowing method and the highest with 35.71% in crescent banquet method. The interaction of this trait showed that the lowest percentage of establishment was observed in spring cultivation treatment and seeding method (4.76%) and the highest percentage was observed in crescent and spring cultivation methods (47.61%). The results indicated that crescent-shaped bounds were more appropriate in both spring and fall cultivation. Forage yield was strongly affected by the planting season and in fall and spring cultivation and were 7 and 15.6 grams per plant, respectively. Forage yield was 9.5 g in seeding method and 13.16 g in crescent bounds. The range of changes in this trait ranged from 6 g in fall cultivation and seeding method to 18.33 g per plant in spring cultivation and crescent bounds method. In general, the results showed that for planting this species in semi-steppe areas, spring planting in the form of crescent bounds and non-coating seeds is suitable for maximum establishment.

In order to achieve a suitable cultivation method and season of Sanguisorba minor</em> in rangelands, the present study was carried out during 2013-2016 in Homand Absard research station. The design was conducted in the form of split plots based on the randomized complete block design with three replications. Factor A was cultivation time (in two levels of fall and spring rangeland) in the main plots and factor B was cultivation method (in two levels of seeding and seeding combined with rainfall storage using crescent bounds) were located in the sub-plots. The percentage of plant establishment was recorded at the end of the growing season in each year. Analysis of variance was performed using SPSS 22 software and the means were compared by Duncan method. The results showed that season and cultivation method had a significant effect on species establishment. Fall cultivation was better than spring and sowing with rainfall storage was better than regular sowing. Last year's results showed that the highest percentage of establishment was related to fall cultivation with rainfall storage with 45% establishment that the seedlings reached flowers and seeds.

The most important structural factor that contributes to desertification is the appearance of salt domes. Due to its solubility and also the effect it can have on the quality of water and soil resources in the surrounding areas, its study is of special importance in agricultural projects and natural resources because it will reduce soil fertility and expand deserts. In this study, it has been tried to determine the quality of surface and groundwater and also to study the factors of geology, morphology, salt dynamics, and tectonic fractures around the Dashti salt dome and its relationship in desertification. The thickness of the salt column in the Dashti salt dome has been estimated at approximately 2,800 meters, and salt glaciers are affected by the topography of the dome (northeastern-southwest) from both sides and laid on the surrounding rocks. For this reason, low sediment is constantly threatened with contamination. Examining the dynamics of the dome, it was found that the balance between the amount of supply and the lack of salt in the desired salt dome is always established and plays an active and permanent role in the expansion of the desert around it. The flow of groundwater in the aquifers of the region is mainly controlled by the permeability of tectonic joints and faults around the dome and confirms the effect of the dome on the salinity of groundwater. Close activity to the surface of the Dashti salt diapir before the orogeny of Zagros is an important and fundamental factor in the destruction of the Kangan anticline soils and the expansion of desertification.

Due to the limitations of field measurements of vegetation, the application of plant indexes to estimate rangeland biomass using satellite data can be very useful in rangeland studies. For this purpose, it is necessary to identify appropriate vegetation indices. The aim of this study is to investigate the possibility of estimating rangeland biomass using plant indices obtained from digital data of Landsat 8 satellite and determining the most appropriate ones in semi-arid regions of the northeast of the country. For this purpose, the average values of plant indices NDVI, TDVI, SAVI, ARVI, EVI, OSAVI, IPVI, GRVI, and GNDVI within each unit of one hectare of the studied basin network were calculated. Then, the correlation of these values with the average measured field values of these units was examined by linear regression, and the regression model of each index was determined to estimate biomass. Finally, the results were validated and a field biomass map was prepared for each index. The results showed that all indexes had a high and acceptable correlation with real biomass data. Based on the validation results, the SAVI plant index with a coefficient 0.79 and root-mean-square error of 14.73% was the most suitable plant index for estimating biomass in the region. By using the wavelengths located in the blue band, these indicators modify the effect of dust in the calculations, which reduces the atmospheric effect and improves the results of calculating the NDVI index, and it can be called the modified NDVI index. According to the results, plant indices obtained from the ratio of near and visible infrared bands are highly correlated with biomass. In general, the shorter the wavelengths used by plant indices, the lower the accuracy of estimates in arid and semi-arid regions.

In the 3 last decades, there were efforts to consider the economic value of ecosystems in the framework of virtual markets, in order to have a better recognition and protection toward them. Therefore, the authors of current study tried to use conditional valuation and mutual 2-dimensional technique, since they have a good knowledge about the valuable services of forest ecosystem of Sheikh mousa in Babol city. 157 questionnaires were distributed among the population (eastern banpey region in Babol) in 2017-2018 period. The factors effective on propensity to pay to stakeholders based on Protective valuation scheme had been investigated. In addition, sampling was performed according to Michel & Carson’s method. The current study is quantitative and results were analyzed in maple 18, shazam 11 & excel 2016 software. The consistency and reliability of information resulted from logit pattern showed that proposed price, age, not being the head of family, visiting the area and environmental ethics are the main effective factors on the propensity to payment for protecting the forest ecosystem of sheikh mousa region. In addition, the annual propensity toward individual payment is equal to 7892.92 Rials (1.87 dollars), and the overall protective value of mentioned ecosystem is more than 2276 million Rials (66096 dollars). In addition, the minimum voluntary investment (available capital) to protect the forest ecosystem of sheikh mousa, from the preference perspective of stakeholders of related society is around 1289 million Rials. According to the obtained results, it can be argued that protecting from this forest ecosystem because of its valuable services from stakeholders perspective is very important. Therefore it is suggested that by establishment of NGO and workshops in the city by corresponding authorities, the environmental ethics and tendencies of people toward protection of such ecosystem get changed. In addition, performing more studies about other applications and services of these type of ecosystems is proposed, in order to have a higher and better understanding in public community and responsible managers about these ecosystems.