Journal of Rangeland Science
Volume:12 Issue: 4, Autumn 2022

The object of this study was to compare predictive accuracy of some individual modeling methods versus ensemble modeling approach in estimating the spatial potential distribution and identifying ecological requirements of Artemisia sieberi in desert rangelands of Yazd province, Central Iran. For this purpose, the species presence data were collected using the random systematic sampling method in 2019. Individual modeling of the species distribution was performed using Random Forest, Classification and Regression Tree and Generalized Additive Model after preparing environmental variable maps using GIS and geostatistics. Predictive performance of individual models was evaluated using Area Under Curve and Root Mean Square Error statistics. Furthermore, the Ensemble model was used based on the weighted average AUC. The appropriate threshold limit value was calculated based on True Skill Statistic for conversion of continuous maps to binary ones of habitat suitability. Comparison of the performance of individual models showed that the RF model had a more accurate prediction compared to the other models (AUC= 0.971 and RMSE= 0.256). Evaluation of the models implemented using threshold-dependent metrics such as Sensitivity, Specificity, and Kappa index also confirmed this finding. The overall comparison of the results from the three models versus the Ensemble model also indicates the high performance of this model compared to the individual models. Based on Ensemble model results, 45.38% of the study area had a high suitability for the establishment of A. sieberi. Based on the analysis of the importance of variables in the RF model, elevation (42%), Clay (40.02%) and pH (38.97%) in 0-30 cm soil depth had the highest effect on the presence of species. In general, Ensemble modeling can reduce the uncertainty and provide more reliable results by combining the results of the different algorithms of individual modeling.

The purpose of this study was to investigate the effect of environmental factors on the plant composition and diversity in QezelOzan - Kosar rangelands of Ardabil province, Iran in 2016. Eight sites with elevation ranging from 900 to 2100 meters above sea level were selected, and three 100-m transects with 10 plots of 1 m2 were established along each one. Species were collected from the plots and their vegetative forms were determined and the factors related to the frequency of species were recorded. Forbs frequency were determined as 2.1% to 33.3%, shrubs 0.4% to 29.2% and grasses 0.4% to 46.7%. Along each transect, a soil sample was collected from depths of 0 to 30 cm. Then, some soil properties such as pH, Electrical Conductivity, Calcium, Sodium, Potassium, Phosphorus, Nitrogen, Magnesium, Calcium Carbonate equivalent, Organic carbon and Soil texture were determined. Vegetation ordination analysis including Principal Component Analysis (PCA), Detrended Correspondence Analysis (DCA), redundancy analysis (RDA) and Canonical Correspondence Analysis (CCA) were performed in Canoco4.5 and PC-ORD5 software. Results of PCA showed organic carbon with eigenvector values of (0.42), nitrogen (0.41) and elevation (0.37) were important factors influencing the distribution of plants. CCA showed that elevation with eigenvector values of (0.37), potassium (0.35) and clay (0.44) were the most effective ones in forbs and grass distribution, potassium with eigenvector values of (0.35), pH (0.58) and organic carbon (0.42) were the most important factors. RDA in shrubs distribution also showed slope with eigenvector values of (0.44), elevation (0.37) and sand percent (0.46) were the most important factors. By doing this research, the basic knowledge of the ecological requirements in the rangelands of these areas was obtained. Thus, by the increase of technical knowledge, some activities can be done to protect, systematically exploit and restore the degraded areas.

Rangelands supply many benefits to society as forage and non-forage goods and services. While some of these can be valued in monetary terms, but it is not possible for some products and services such as recreational use of rangelands. So, the present study was conducted for the purpose of the recreational value of Mazandaran Badab-e Surt GeoPark summer rangelands using the Contingent Valuation Method (CVM) based on the maximum likelihood logit regression model. Data were collected from 311 sample visitors randomly by face-to-face interview and Double-Bounded Dichotomous Choice (DB-DC) questionnaire in 2016- 2017. The results showed that majority of the visitors (96.34%) were Willingness-To-Pay (WTP) for ecotourism in the region. The average WTP for an entrance fee was found to be about $0.4 per visitor, and $2.17 for each family. The total annual recreation value of the region estimated at $39.84 per hectare. Logit regression model indicated that the involved variables, bid, income, number of family members, education, and regional quality were significant. However, based on research findings, the economic value of the recreational function of Badab-e Surt is very low, but other benefits such as environmental culture, job creation for the local community, alternative livelihoods and increased economic prosperity in the region will also be available using a nature tour in addition to the calculated amounts.

This research aimed to determine the potential habitats of Vaccinium arctostaphylos as a rare species using the MaxEnt method. For this purpose, sampling was performed from the areas of V. arctostaphylos at eight habitats in Namin rangelands, Ardabil, Iran in 2020. Also, latitude and longitude as well as physiographic factors were recorded using GPS. Soil samples were collected from depth of 0-30 cm. Then, some physicochemical properties of soil such as pH, electrical conductivity, soil texture, lime, soluble potassium, magnesium, soluble sodium, particulate organic matter, absorbable phosphorus, soluble bicarbonate and clay, silt and sand percentage were measured in the laboratory. The MaxEnt model was used to determine the relationship between environmental factors and the distribution of V. arctostaphylos. The map of environmental factors affecting the distribution of the species was prepared using IDW geostatistical method in Arc-GISver.10.8 software. Kappa index was used to evaluate the conformity of the forecast map with the actual map. Results of the Jackknife efficiency index showed the variables of elevation, rainfall and temperature were the most important variables in the distribution of V. arctostaphylos, respectively. Results of response curves showed this species is likely to be present in the altitude range of 1500-1900 m. Also, the precipitation range in the presence habitats of species is 350-450 mm and the average annual temperature range is about 7-10 °C. Results showed that the accuracy of maximum entropy modeling with a Kappa index of 0.64 is acceptable and this model has good accuracy in predicting the presence of species with main habitat. Generally, results showed MaxEnt model could be used as a prediction tool to determine the distribution area of V. arctostaphylos. Moreover, the prepared forecast map can be used for better conservation of species and rangelands management and improvement of the regions and similar areas.

Al-Baja area, in White Nile State is considered one of the most important rangelands in Sudan as a rainy season grazing area, it used intensively by the herders. The study was conducted in the end of rainy season, November 2019. The study aimed to assess the impacts of intensive use of rangeland on the vegetation attributes and the soil seed bank of Al-Baja area. Parker loop and quadrate were used to determine the vegetation attributes. The number of samples was distributed systematically along line transects. Soil sample was taken from three depths (0-5, 6-10 and 11-15 cm) to assess soil seed bank. The data were analyzed using SAS statistical program, Duncan procedure for mean separation. There were significant differences between the ground cover components. The litters and bare soil recorded high percentage of 40 and 31%, respectively. The species Schoenefeldia gracilis recorded high plant composition 93% with density of 75 plant/m². The study showed that the biomass and carrying capacity of Al-Baja area was very low. The results found that Schoenefeldia gracilis recorded highest presence of seed in the soil (live 68.2% and dead 70.4%). The study revealed that the soil depth had a significant impact on the seed number and density in the study area and the highest values of both live and dead seed were observed in the upper soil layer (0-5 cm). The natural rangelands in Al-Baja area have been severely degraded as a result of intensive use by the herders and their animals.

Now a day, due to climate change and deforestation, the density of Acacia species are decreasing in the pastoral areas. Therefore, the research was conducted with the objective to assess the existing management, utilization practices and density of Acacia species in Mio District in the year 2019. Five representative kebeles (the smallest administrative unit below District) were purposively selected, and from each kebeles, 15 representatives were purposively selected with the assumption that they had sufficient knowledge about the area to collect surveying data. The major livestock feed resources available in the study area were natural pasture, browse species, crop residues and hay. The purpose of keeping livestock in the study area varied based on the species of livestock kept. The primary purpose of keeping cattle and camel were for milk, while it was for meat and income generation in case of small ruminants. Shortage of feed was the first production constraint for cattle followed by shortage of grazing lands. Moreover, the major constraints for small ruminant were health problem followed by predators. Pods, twigs and flowers of Acacia Spp. were utilized by livestock as a source of feed. However, the leaves were the most available feed resources in the study area. Acacia species were grown on grazing land, crop land, in the house compounds or shelter belts between crop plots. Acacia tortilis is the highest in relative density, relative cover (43.3%) and important value (100%). In general, Acacia species pod could be used to improve animal performance through improving the nutritive value of low-quality feed resources. Conserving nutritionally important Acacia species like Acacia tortilis are paramount important for the environment and animal feed. Further study is suggested to assess the nutritive value of Acacia pods and leaves which are consumed by livestock but not considered here.

Camel's grazing in dry areas is of great importance so that in accordance with the nutritional value of the available forage for the livestock, damage to rangelands could be prevented. The objective of this study was to identify and to determine the quality of the most preferred forage species using camels in Aran and Bidgol desert rangelands, Iran. Grazing behavior of camels and their calves were observed during dry and wet seasons for a period of 84 days (August to November, 2020). The forage species were ranked based on the camels bite count. The most browsed forage was identified through observation, then they were sampled for identification of the local and scientific names. The forage quality parameters such as Crude Protein (CP), Ether Extract (EE), Calcium (Ca), Phosphorus (P), Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF), Acid Detergent Lignin (ADL) and Dry matter digestibility (DMD) were determined in the laboratory. The most browsed forage species involving Smirnovia iranica, Astragalus squarrosus, Nitraria schoberi, Haloxylon persicum, Seidlitzia rosmarinus in the wet season and Stipa barbata, Artemisia sieberi, Zygophyllum eichwaldii, Stipagrostis plumosa, Alhaji persarum were observed in the dry season. For CP, the highest values of 25.7 and 17.9% were obtained in Stipagrostis plumose and Astragalus squarrosus, respectively, and for DMD%, the highest values of 72.0, 81.6 and 76.6 were obtained in Artemisia sieberi (leaves), Stipa plumose and Haloxylon persicum, respectively. The results of this study showed that forage quality in the wet season was much higher than dry season and camels fed on different types of forage species; the forage nutritive values could affect their selection.

Semi-arid mountainous areas are of special importance in terms of ecological function i.e. vegetation dynamics and its evaluation under environmental- managerial factors is a necessity for their sustainable use. Due to the highly variable environmental characteristics in these areas, proper land management and utilization can severely affect the Range Condition (RC). Here, the relationship between topography, soil characteristics and management (RC) under grazing] was investigated through multivariate analysis in mountain areas of Golestan’s Chahar Bagh, northeastern Iran in 2019. The RCs were assessed by scoring vegetation and soil characteristics in areas under livestock grazing areas. The preliminary findings of this research showed that environmental factors i.e. clay, P, EC, slope, aspect, Soil Moisture (SM) and K had the most effect on the formation of five different vegetation types (Cum.% of Var.=80.4%). The results showed that RC changes had more significant relationships with managerial factor/grazing than environmental factors. In general, the effect of environmental and management factors and their common effect in changing RC were equal to 1.84%, 74.1 and 21.04%, respectively. The change of soil physical properties was more than soil chemical properties under RC changes. Factors of Organic Matter (OM), Bulk Density (BD), porosity and SM showed significant changes under excellent, good, fair, poor and very poor conditions (P<0.05). In general, excellent and good rangelands were related to more OM and porosity and less slope and K. Moreover, poor/very poor rangelands were related to more SM, BD, P and slope. Overall, managing grazing can significantly decline/improve RC in mountainous area.

The indigenous knowledge of shepherds about the different components of the plant fuel, ways of their classification and their contribution to fire behavior helps range managers to understand fire and effective management of the rangelands. The present research aims to document the indigenous knowledge of shepherds in this regard. For this purpose, a semi-structured interview in 2020 with 17 shepherds of semi-steppe rangelands of Khalkhal in northwestern Iran was performed and data were analyzed by the note-taking method and the categorization method. Given the knowledge of shepherds, plants were categorized into three groups of carriers, retardant, and burnable. They consider the morphological traits, type and composition of vegetation, climatic factors and physiography to be effective in creation and spread of fire. Shepherds' controlled fires are carried out with the aim of removing thorny plants to increase the length of the green period of the plants, to graze more livestock, to increase the income, to destroy the old seedlings and to rejuvenate the rangeland. Uncontrolled and deliberate fires are conducted with the aim of destroying state property, protesting against fines, unhealthy competition and conflicts between individuals, which reduce the winter forage of livestock and land grabbing. The time required for the rehabilitation of the rangelands was expressed after 6-7 years after fire. Practical suggestions could be used in participatory management system (shepherds and officials from natural resources management) for controlling fuel density using different grazing systems.