فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و ششم شماره 2 (پیاپی 75، تابستان 1398)

To determine the phenological stages and plant height of three important range species Aeluropus lagopoides, Desmostachya bipinnata and Halocnemum strobilaceum, this investigation was carried out for four years starting in 2007 in Zaminsang Rangelands of Hormozgan province. In this study, the information about the phenology and plant height for 10 individuals of each species in 10-day intervals was measured and recorded. The results showed that phenological stages of three species were different in the study years, so that plant growth started 2-3 weeks earlier in wet years and later in dry years, while the duration of vegetative and reproductive activity of plants was different. The results showed that vegetative growth started with cooling of air and the onset of rainfall. The growth period of A. lagopoides, D. bipinnata and H. strobilaceum was 6, 6.5, and 10 months, respectively. The vegetative growth of A. lagopoides started from 22 December, whereas the vegetative growth of D. bipinnata and H. strobilaceum started from 20 February. The flowering stage started from April, June, and September, and the seeding stage from 22 April, 22 July, and 15 October, respectively. The dormancy period of plants started in 22 May, 1 September, and 22 December, respectively. Since Aeluropus lagopoides is a palatable and dominant species in the Zaminsang region, the time of arrival and departure of livestock is recommended to be late November to late May.

This research was carried out to determine the nutritive value of Stipa capensis in various growth stages at three rangeland areas during November 2011 to April 2012. The samples of S. capensis were taken randomly in three stages including vegetative, flowering and maturity (seed production). Samples from each stage of each area were determined for DM, CP, Ash, EE, NDF, ADF, ADL, GE, Ca, P, K, Mg, Na, Fe, Mn, Zn, Cu, DMD, OMD and DOMD. Data were statistically analyzed in a Randomized Complete Blocks Design with three treatments (growth stages) and three blocks (rangeland areas). Results showed that CP, Ash, NDF, ADF and ADL content of S. capensis at different growth stages were significantly different (P<0.05) and CP content of S. capensis decreased with growth advancement but its NDF, ADF and ADL content increased. DM, EE and GE content of S. capensis at three growth stages were not different significantly (P<0.05). Also, P, K, Mg, Zn, Cu, DMD, OMD and DOMD content of S. capensis decreased with growth advancement but its Na increased significantly (P<0.05). This plant in vegetative and flowering stages can supply a great part of protein and energy requirement of different groups of sheep and goat at rangeland areas. Ca, K, Mg, Na, Fe and Mn content of S. capensis at different growth stages were higher than those of  critical limits for sheep and goat; however, the P and Cu content at three stages, and Zn concentration at flowering and maturity stages were less than those of critical limits. Totally, this plant species is suitable for livestock grazing specially at vegetative and flowering stages and could be recommended in similar rangelands.

Modeling and prediction of groundwater level is one of the basic tasks to achieve optimal management of water resources. One way to predict the groundwater level is using artificial intelligence techniques such as neural networks and gene expression planning. The aim of this study was to evaluate the effectiveness of artificial neural network (ANN) and gene expression methods in predicting groundwater level of Jiroft plain aquifer. For this purpose, the data from 65 piezometric wells in the Jiroft plain aquifer was used for a period of eleven years. The level of piezometric wells by each of the techniques of gene expression and neural network were simulated separately and at the end, the root mean square, mean absolute error, and R2 were used to determine the accuracy of the predictions of each of the methods.The results of this study showed the higher efficiency and accuracy of both neural network techniques and gene expression in predicting the groundwater level region. The correlation coefficient in the artificial neural network method gene expression method was equal to 0.96 and 0.72, respectively, indicating the higher efficiency of artificial neural network in the simulation of Jiroft plain groundwater data over the period studied.

Land use change, land abandonment, overgrazing, expansion and spread of exotic species are of the most important challenges in the rangelands of the country. For this reason, in this research, it has been attempted to address the challenges by presenting a single improvement solution. Therefore, the perennial rainfedd alfalfa was used for cultivation in degraded rangelands or abandoned lands for both goals of rangeland reclamation and carbon sequestration. Three rangelands were studied in the protected area of Lashgardar-Malayer reclaimed rangeland via alfalfa, medium grazing, and degraded rangelands. In each of these rangelands, sites were selected for sampling. The size and number of plots were determined by the minimal area and statistical method. In each plot, the aboveground and underground biomass and litter were collected. Soil sampling was performed in the plots and the measurement of carbon sequestration was conducted in the laboratory. Soil samples were collected from two layers of 0-15 and 15-30 cm and their carbon was measured. The three study rangelands were compared using a One-Way ANOVA analysis, and the results showed that the amount of carbon sequestration in the rangeland reclaimed  with perennial rainfed alfalfa (36.8 ton / ha) after 4 years was around 1.25 fold higher than the medium grazing rangeland (29.27 ton / ha) and 1.71 fold as compared with the degraded rangeland (21.54 ton / ha). These results indicate that reclamation of degraded rangelands causes to achieve land conservation goals and increase the ability of the ecosystem for carbon sequestration.

In recent years, drought, industrial and mining activities have increased the amount of dust deposits in the suburbs of Isfahan. The aim of the present study was to investigate the chemical and physical properties of dust particles in the suburbs of Isfahan and to compare it with previous years. In total, 80 dust sediment samples were collected with Marble Dust Collector (MDCO) at 20 stations across the study area during July 2014 to July 2015. The physicochemical characteristics of the collected samples were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP_MS), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP_OES), X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM) methods. The results indicated that the main element composition of dust sediment was Ca, Al, Fe, Mg, Na, K, Ti, Sr, Zn, P, Mn, and Ba. The study also found that concentrations of most heavy metals in the study area were up to five times higher than in previous studies. The northeast part of the study area had the highest amount of dust deposits; However, the highest concentrations of chemicals, especially heavy metals, were observed in the southwest. Considering the highest mean concentration of dust sediments across the study area, the index elements are grouped as Mg, Na, Sr, Mo, Cs and U in the north-east, Mn, Cr, Zr, Pb, Cd and V in the south-west, Hg in the north-western, and Ca in the south-east. According to the mineralogy and morphology analysis, dust sediments in north-east part contained Quartz, Calcite and Gypsum, coated with Dolomite and Muscovite. Angular and semi-rounded morphologies of dust sediment indicate their local source contribution.

The effects of human activities on the land use and landscape and its subsequent effects on the natural environment have always been considered. Therefore, to have a sustainable landscape planning, knowing about such changes would be essential. Satellite images of TM sensor in 1990, ETM+ Sensor in 2002 as well as OLI Landsat 8 in 2013 were used to investigate the trend of changes and preparation of cover maps. The executive phase of the study included the analysis of the gradient of land use structure in eight geographical directions for class area (CA), number of patch (NP), and mean patch size (MPS) in seven classes such as woodland) low-density forest and garden), water zone, agriculture, bare land,  rangeland, urban and sand dunes. The results showed that the land use of woodland, urban, and sand dunes had an increasing trend, while the bare land showed a decreasing trend. The results of gradient analysis of land use structure in eight geographical directions indicated that the most changes were in the west and center of the region. Based on the analysis of changes rate of metrics, the most changes were recorded for rangeland, bare land, and urban during 1990 to 2002; the woodland, agriculture, and urban during 2002 to 2013; and rangeland, woodland and urban during 1990 to 2013. Therefore, given that some aspects of land use change depend on human aspects, the relationship between these quantitative indicators can be used to determine the sustainability level as well as the future trend of land use change to identify the critical affected areas. Metrics of area, number of patches and mean patch size were recognized as the important indices in discussions of monitoring land use and mosaic changes.

The present study was aimed to determine the potential of bioethanol production in three halophytes: Suaeda</em> vermiculata</em>, Halocnemum</em> strobilaceum</em> and Seidlitzia</em> rosmarinus</em>. The plant sampling was performed in three vegetative, flowering and seeding stages to measure the content of  cellulose, hemicellulose and lignin. Their biomass production was calculated at the end of annual growth. The results were analyzed in a randomized complete block design with three replications. The results showed that the content of lignin in the Ha.strobilaceum</em> was more than cellulose and hemicellulose at seedling stage; therefore, it does not have the potential to produce ethanol. However, in the vegetative and flowering stages, the amount of hemicellulose increased, indicating a little potential for ethanol production.In Se.rosmarinus</em>, due to an increase in cellulose and hemicellulose percentage compared to lignin, it has high potential for bioethanol production; however, its biomass production is less than the other two. In Su.vermiculata</em>, the percentage of cellulose and hemicellulose is higher than lignin percentage, so it has the greatest potential for bioethanol production. The best harvesting time for bio-ethanol extraction is before flowering stage. Its biomass production is higher than the two other species (1174 kg / h); thus, following some basic principles of agriculture, it could be established on a large scale for massive production. Therefore, Su.vermiculata</em> is a suitable species for bioethanol extraction in saline and low-yielding lands. Due to its presence on the margins of farms and rangelands of arid and saline areas such as southern Garmsar and south of Varamin, it is recommended to be introduced to farmers and experts in the field of agriculture and natural resources.

Fire in rangelands has significant effects on plant and soil factors. In this research, the effects of fire on plant factors were investigated in semi-steppe rangelands of Sirachal for three years (2015-2017). The two selected rangelands were similar in terms of vegetation type (before the fire) were next to each other. The treatments included control rangelands and burned rangelands, and sampling was performed using transects and quadrates (30 plots) for three consecutive years. Vegetation factors included canopy cover, production, density, species richness, and life form. The statistical analysis of the treatments was carried out using the independent t-test. Comparison of different years, in each of the burned or control rangelands, was done using analysis of variance and the means were compared with Duncan's test. The results showed that fire during the years of the project did not have a significant effect on the canopy percentage and the production of all rangeland species, but it had a positive and significant effect on the density of all rangeland species. High difference in density compared to the cover and production could be due to the low canopy cover and production of new seedlings. In other words, new seedlings of plants had a low canopy cover, low production, and a high density. In terms of species richness, the highest difference is related to the absence of shrub species in the burned rangeland; however, according to the Sorenson index, the two treatments were similar in terms of plant species. Also, in terms of life form, fire had a positive and significant effect on the cover percentage, density and production of forbs, a positive and significant effect on the cover percentage and density of grasses, and a significant negative effect on the shrubs.

Rangelands, as one of the world's largest terrestrial ecosystems, are the source of millions of lives. Over the past decades in Iran, these ecosystems have been suffered from degradation and lack of productivity for many reasons and hence there is an urgent need to seek alternative livelihoods for rangeland locals and stakeholders. An alternative livelihood is community based tourism. Rangeland ecotourism should be in accordance with the potential of the area. In this study, a set of criteria was considered regarding land conservation for suitability analysis. These criteria were standardized, weighed and integrated using fuzzy logic based multi-criteria model. The results showed that attractiveness and conservation criteria, characterized with weights of 0.444 and 0.222, were the most important criteria for suitability analysis. The results of suitability analysis in the rangelands of Jahan Nama Protected Area showed that Festuca</em>-Bromus</em> vegetation type, located around village of Jahan Nama, had the highest suitability. As a whole, of 15361 hectares rangeland area, 1516.5 ha are suitable for rangeland land use. This can be attributed to beautiful landscapes, topographic diversity, and proximity to the Jahan Nama village as the service center, access road and favorable climate. The fuzzy logic based multi-criteria model, used in this study, showed high flexibility in weight of criteria. The criteria suggested here could be promising as a base for suitability analysis in other rangelands of Iran.

Given the importance of rangelands for livestock grazing and conservation of the natural ecosystem, it is important to consider the factors contributing in the conservation and development of rangelands to achieve sustainable development goals. Therefore, beneficiaries’ participation in rangeland improvement and reclamation plans as a new approach to natural resource management is essential. Accordingly, the purpose of this study was to investigate the factors affecting the participation of beneficiaries in the implementation of rangeland plans in the rangelands of Savadkouh watershed. Using Cochran formula and random sampling method, 111 beneficiaries were selected as the sample and economic and social factors influencing beneficiaries ' participation such as age, level of education, number of rachers, awareness of range management plans, number of livestock and income level were investigated. The results showed that age had a significant negative effect on participation in the implementation of range management plans. It seems that, despite background and experience, the poor physical ability as well as the type of thinking have contributed to the lower participation of aged beneficiaries. Also, the most elasticity was related to the income level, so that by increasing one percent in the income of beneficiaries, the likelihood of increased participation in the implementation of range management plans would increase 5.612 percent and with the increase of income, the likelihood of beneficiaries’ participation would increase by 0.325 units

Capparis spinosa plays an important role in the ecosystem dynamics of arid and semi-arid regions. The development of cultivation of this plant requires optimal conditions to produce seedlings in simple, practical and inexpensive ways. Low germination percentage is one of the most important barriers to the mass production of Capparis spinosa. In this study, the best strategies for increasing seed germination were investigated using inexpensive and simple scientific methods. For this purpose, after seed collection from local accessions of different areas in Bushehr province, seed preparation treatments were applied for germination. The treatments included scarification with sandpaper, potassium nitrate, hot water, and concentrated sulfuric acid, compared to the control. Seed germination was done by Petri dish in incubator and culture tray in greenhouse. The results showed that potassium nitrate treatment caused the highest germination percentage in Talheh local accession (86.7%) by culture tray method, which showed more than 41% increase compared to control. The highest germination was obtained to be 68.3% in the scarification with sandpaper in the Konari local accession. The germination rate in potassium nitrate treatment in both tray and Petri dish treatments increased significantly compared to other methods. In addition, application of concentrated sulfuric acid and hot water decreased germination percentage and rate compared to the control. Therefore, potassium nitrate solution was the best treatment for increasing the seed germination of the study species.

Vegetation is the most important factor affecting the stability of ecosystems. Therefore, the study of the factors causing the establishment and distribution of plants as well as the effect of plant species on the characteristics of ecosystem is important. The aim of the present study was to evaluate the effect of canopy cover of four rangeland plants (Hertia angustifolia (DC.) Kuntze, Pyrethrum roseum, Astragalus gossypinus Fischer. and Artemisia sieberi Besser) on some of soil quality indices. Thus, this study was conducted in a rangeland of Sardoie – Jiroft. Soil sampling was carried out in three parts of this rangeland in- and out of the plants (depth < 30cm), and calcium carbonate equivalent (CCE), salinity (EC), acidity (pH), soil texture (sand, silt, clay), microbial respiration (MR), organic carbon content (OC), and water repellency of the soils were measured. The results showed that OC, EC, CCE, and water repellency in-side the plant canopy were significantly higher than those out-side the plant canopy (P<0.05). Also, more OC in-side the plant canopy and their decomposition could cause more microbial respiration as well as more salinity and more water repellency. The results also showed that the amount of silt as the most sensitive particle to erosion out-side plants was less than in-side but it was opposite for sand particles that it may show more water erosion in the bare land, especially sheet erosion, indicating the positive effect of plant canopy on the stability of soil.

The aim of this study was to investigate the factors affecting the beneficiaries' economic recession in the BolbanAbad Rangelands. The statistical population of this study was 400 beneficiaries in the BolbanAbad Rangelands. The sample size of this study was determined to be 196 rangeland beneficiaries by using Krejcie and Morgan table. A random sampling method was used to select the samples. The tool used to collect data and information was a questionnaire. The validity of the questionnaire was confirmed by rangeland experts and its reliability was confirmed by Cronbach's alpha coefficient. Data were analyzed by SPSS software version 22. The results of Spearman correlation test showed that economic factors had the highest correlation with the beneficiaries' economic recession. In addition, the results of factor analysis showed that among the economic factors, the lack of job diversification with a coefficient of 0.912; among the management factors, the limitation of credit transfer to low-income beneficiaries to reduce the income dependency with a coefficient of 0.885; among the environmental factors, the traditional livestock vulnerability due to drought and forage deficiency with a coefficient of 0.893; and among the social factors, the distrust between the beneficiaries in collaborative activities with a coefficient of 0.910 had the most impact on the beneficiaries' economic recession. Also, the results of the path analysis showed that the most direct and total effects were related to economic factors and the most indirect effect was related to management factors.

The cultivation of plants that are resistant in difficult environmental conditions is an effective solution for reclamation of lands; thus, recognizing the effects of cultivation of different plants on soil and vegetation cover could be a suitable guide to select proper species by experts. The aim of this research was to investigate the effects of range improvement and reclamation practices on soil and vegetation cover characteristics in Jannat Abad rangeland. For this purpose, four transects of 100-m length and two transects of 100-m length were established with 100-m intervals in the seedling area (Atriplex canescens and Haloxylon aphyllum) and the control area (natural vegetation), respectively. Along each transect, 10 plots of 4m2 were sampled. In each plot, the vegetation data including canopy cover percentage, litter, gravel, bare soil, dominant species, and plant density were measured. Soil profiles were dug at the beginning and end of each transect. Soil sampling was performed from 0-30, 30-60 and 60-90 cm depths. Then, soil chemical and physical properties including electrical conductivity, pH, organic matter, phosphorus, potassium, nitrogen, bulk density, clay, silt, and sand percentage. The collected data were analyzed by independent t-test with SPSS software. Results showed that the cultivation of Atriplex canescens caused an increase in canopy cover percentage, density, and potassium content in the first and second depths (P<0.01), and caused an increase in the nitrogen content of the first depth, organic matter of the second depth, electrical conductivity of the first and second depths, and silt percentage in the first and third depths (P<0.05). It also caused a decrease in soil pH and sand percentage of the second and third depths (P<0.05). The cultivation of Haloxylon aphyllum caused an increase in density, electrical conductivity of the first depth, and a decrease in clay percentage in the third depth (P<0.05), compared to the control area.

Clematis ispahanica is a rare, palatable, and endangered species of Iran. In this research, the distribution of this species was investigated in rangelands of Bavanat and Mehriz cities in Fars and Yazd provinces. For vegetation sampling, the study areas were classified and 30 plots (2 × 3 m) were established using random- systematic sampling method in key areas. Soil samples were taken at the depth of 0-30 cm (based on the depth of rooting). Independent t-test was used to compare soil chemical properties of the two regions. Principal component analysis (PCA) was used to determine the most effective factors affecting soil properties of the two regions.The effect of phenological stage, area, and interaction between phenological stage and area on forage quality indices (CP, DMD, ME and ADF) was determined using a General Linear Model (GLM). The interaction of area × phenological stage on forage quality was investigated using a completely randomized design. The results demonstrated that the best spatial distribution pattern of this species was the northern slopes and relatively flat topography. Our results revealed that this species was found in non-saline soil (EC<2), sandy loam, loamy sand and sandy textures with a pH of 8.6-8.9, %0.4-%0.7 organic carbon, %0.09-% 0.13 nitrogen, 13.9-22.1 ppm phosphorus, %42-%59 calcium carbonate, and 2-2.45 mg/lit potassium. The results of PCA indicated that soil organic carbon (OC), electrical conductivity (EC), and acidity (pH) were the most effective components of the soil in two study areas. The results demonstrated that in the growth and flowering stages, forage quality indices of this species in Bavanat area were significantly higher than those of Mehriz area, but in the seeding stage, the study indices in Mehriz area was higher as compared with Bavanat area. No significant correlation was found between soil chemical properties and forage quality indices. Thus, it can be concluded that the effect of climate on forage quality indices is higher than edaphic factors. In general, it can be stated that the high forage quality of C. isphanica can be one of the reasons putting this species at risk of extinction.

This research was conducted to evaluate the environmental factors affecting functional characteristics (biomass, density, regeneration, cover%, basal area and species richness) of Ferula haussknechtii in Saral rangelands of Kurdistan. After determining three altitude classes (1850, 2250 and 2650 m), a systematic-random sampling was performed to measure aboveground biomass, cover percentage, height, basal area, and density of Ferula haussknechtii with 1.5-m2 plots along transects. In each plot, a soil sample was taken from 0-30 cm soil depth. Soil texture, CaCo3, acidity, electrical conductivity, nitrogen, potassium, phosphorus, and sodium were measured in the laboratory. Analysis of variance of data was done using a randomized complete design with R software, and also CCA was used to compare the relationship between species and environmental factors. The results showed that aboveground biomass, vegetation percentage, height and density of Ferula haussknechtii increased with increasing altitude, while the basal area of this species decreased. The green biomass, cover percentage, basal area and height of this species were positively correlated with nitrogen, carbon, potassium, silt and clay and negatively correlated with acidity, phosphorus and sand. The results also showed that due to the impact of this valuable species on the soil stabilization, forage supply and production of active ingredients, altitude, nitrogen, carbon, clay and silt were the most effective factors in establishing this species.

Resilience is one of the strategies to reduce the vulnerability of communities in dealing with natural hazards. The present study examines the role of livelihood diversity as a strategic approach for adaptation and coping with drought risk in Hablehroud watershed. In this research, the research method was quantitative and survey based, and descriptive, analytical and correlation methods were used. To this end, 9 villages from different areas of the province with different degrees of drought and development were selected by simple random sampling method. Then, based on the Cochran formula, 271 households were selected as the sample size. The validity of the questionnaire was confirmed through a panel of experts, and the reliability of the research tool was confirmed by a Cronbach's alpha of 0.842 at a very good level. The results showed that the level of resilience in the area was undesirable and lower than the average level, and the average of the human, social and physical capital index of the area was higher than the average value of the financial (economic) and natural capital. Based on the findings, adoption of a livelihood diversity strategy in promoting the resilience of rural households in Hablehroud area had a significant effect on drought risk.

In Golestan National Park Steppe Rangelands, a variety of shrub plants such as Artemisia are sporadic, and terrestrial surfaces between these plants are covered by biological soil crusts (including moss and cyanobacteria). These crusts are known as a critical factor in arid and semi-arid areas. The effects of them on the moisture and temperature of soil, which play a very important role in ecological and hydrological processes, are still not well-known. In order to know more about this, the effects of moss and cyanobacteria on moisture and temperature regimes and the effect of Artemisia shrub on moisture regimes were investigated. The soil moisture content was measured at four times: first winter, last winter, spring, and summer using a moisture meter (TDR), and soil temperature was recorded in three different seasons: last winter, spring ,and summer using a thermometer for 117 days with two-hour intervals. The most important factor affecting soil moisture and soil temperature was the season, which was determined using a general linear mixed model. Based on the results, the ability to maintain the cyanobacteria moisture content is higher than that of moss and Artemisia shrubs treatments, as well as the daily fluctuation of soil temperature under cyanobacteria (4/3 °- 35 ° C), more than moss (4/25 ° -26 ° C).

Researchers and target groups studying the vegetation are seeking to answer the question “what ground indicators determine the establishment and distribution of vegetation types and vegetation communities of a basin and which landforms can best determine the boundaries of each plant type or community?”. In this regard, the Gardaneh-Ghooshchi basin, overlooking the Urmia Lake in West Azarbaijan Province was selected. Vegetation cover map, land capability evaluation map, geology map, soil map, geomorphology map, and land units map, were precisely and accurately generated based on the technical methods and field surveys. The multinomial logistic regression method was used to compare, describe and accurately predict vegetation types with different landforms. The results showed that homogeneous units with a quantitative value of 0.432 had the highest impact, followed by geomorphology, geology, and soil with quantitative values of 0.389, 0.351 and 0.156, respectively, in the next rank. Therefore, slope, aspect, and elevation (physiographic characteristics of the basin) have a more effective role in the distribution of vegetation, which could be used before ground monitoring as a baseline map in mountainous areas.

In the present study, the severity and extent of desertification in Iran was evaluated using Landsat satellite images with spatial resolution of 30 m during 1984 and 2015. In this regard, new remote sensing techniques (spectral mixture analysis methods) were used. Spectral Mixture Analysis (SMA) is a technique for estimating the proportion of each pixel that is covered by a series of known cover types in mixed pixels. In this regard, changes in vegetation, soil, water, and salt marshes of the entire country were studied. Results showed that about 227000 km2 of Iran included dsertification with low intensity over the past 32 years. In addition, the areas most affected by the desertification and dried water bodies were about 33000 and 5000 km2, respectively. This indicates the occurrence of desertification with varying intensities in 15.6% of the country. Results showed that the contribution of southwest provinces (Ilam, Kermanshah, Lorestan and Khozestan) and southern provinces (Boushehr, Fars and Hormozgan provinces) were much more than other provinces.However, in the eastern and southeastern provinces of the country, due to the dominance of desert and semi-desert climate, the lowest desertification intensity was observed.