JOURNAL OF RANGELAND SCIENCE
Year:2016 | Volume:6 | Issue:2|Papers Count:10

Water harvesting is the collection of runoff for productivity purposes, instead of runoff being left to cause erosion. In arid and semi-arid drought-prone areas, microcatchments are widely used as a water harvesting method to improve rangeland condition.The aim of present study was to investigate the effects of micro-catchment on ecological indices of rangeland health in Ghick-Sheikhha, Jiroft, Iran using LFA (Landscape Function Analysis) method. A free micro-catchment area (as control) was selected to compare the effects of micro-catchment on the soil and vegetation cover. In this method 11 soil parameters were assessed (transects of 100 m length) to recognize three functional properties, including stability, infiltration and nutrient cycling. Statistical data analyses were done using analysis of landscape function and paird t test to compare the performance indicators in the control and micro-catchment. To determine the best factors affecting the health of the range, multivariate regression model was used. The results showed that in the micro-catchment treatment, the length of patches was more than that in the control area.Significant differenceswere observed between the areas in terms of three indices (p≤0.05).Regression models suggested that the parameters of soil sedimentation, soil resistance to humidity, soil surface roughness and canopy cover in the micro-catchment area, and soil surface roughness, litter cover and surface resistance to disturb in the control area had respectively, the higher impact on rangeland health indices. Generally, the present study suggested the effectiveness of micro-catchment compared to the control area.

Predictive modeling of habitat distribution of range plant species and identification of their potential habitats play important roles in the restoration of disturbed rangelands. This study aimed to predict the geographical distribution of Artemisia sieberi and find the influential variables in the distribution ofA. sieberi in the desert rangelands of central Iran. Maps of environmental variables were generated by GIS software (version 9.3). Predictive distribution maps of A. sieberi were produced with Maximum Entropy Method (MaxEnt) and the existing data regarding this species. The agreement of predictive map with the actual map was checked by calculating Kappa coefficient value.Accuracy of predictive models was evaluated using the Area Under the Curve (AUC).Results showed that soil pH and lime content in the surface layer (0-30 cm) and silt percent in both surface and sub-surface soil depths (0-30 and 30-60) had the greatest impacts on the distribution of A. sieberi in the study area. Correspondence of actual map with the predictive one was assessed at a satisfactory level (Kappa coefficient=0.70).MaxEnt is widely used as compared with the other standard methodssince it only requires thepresence data of a specific plant species to draw the distribution map of its habitat.Additionally, MaxEnt is a generative methodand its output can be easily understood by the field practitioners.

Adverse changes in rangeland vegetation can be considered as one of the criteria for land degradation. Some of these changes can be evaluated through monitoring the spatial changes of landscape parameters. This study aimed to investigate the landscape changes in Kezab rangelands of Yazd province, central Iran. Landsat satellite images of 1990, 2002, and 2013, and landscape metrics including Total Edge, Edge Density, Mean Shape Index, Number of Patches, Mean Patch Size, and Median Patch Size were used in this study. Landscape fragmentation was analyzed through calculating various metrics of landscape patterns using the FRAGSTATS software. This study was performed with a focus on landscape elements in poor and very poor rangelands. Results indicated a reduction in the area of rangelands with poor conditions and an increase in the size of rangelands with very poor conditions. The results showed that perimeter sum of spots in rangelands increased From 51.6 km in 1990 to 62 km in 2013. This increase in the perimeter showed further destruction of poor rangelands. This process was considerably seen in very poor rangelands and increased from 48.9 km in 1990 to 56 km in 2013. The process of Edge Density index changes confirmed the intensification of desertification in the region. Also, the number of patches in poor and very poor rangelands increased from 23 to 11 and from 4 to 10, respectively. The intensification of destruction has been shown in very poor rangelands. Rangelands were also changed in terms of other landscape parameters, eventually leading to the deformation of rangeland patches and the degradation process has been intensified in this region. According to the results of these studies, landscape changes of rangelands could be assessed at various time intervals to detect the factors affecting rangelands.

FAO and World Bank promote livestock rearing as a way of poverty alleviation and food security especially among rural poor. Villagers are usually involved in mixed crop-livestock farming. Interviews with villagers in the HableRud basin revealed that some changes have happened and comparing with past decades, fewer villagers keep livestock.They believed that number of villagers who kept livestock in pen has also drastically increased. This study was conducted to understand if natural capital holdings have any impact on villagers' dependence on rangeland or not and also to identify the important natural capitals contributing to villagers' dependency on rangeland, some unstructured and structured interviews with local people were conducted. Comparisons between the two groups of villagers namely, dependent and independent on rangeland in terms of the identified indicators, the independent samples T-test and Mann Whitney U were applied for parametric and nonparametric data, respectively. Then in order to predict likelihood of dependency of a villager on rangeland based on holding of or access to independent variables, binary logistic regression was applied using SPSS. Descriptive data analysis showed that just 177 villagers out of 380 samples were dependent on rangeland and the rest did not rely on rangeland at all. The results revealed that there was a significant difference between the two groups of dependent and independent villagers on rangelands in terms of grazing right, size of farm and orchard holding, number of small livestock, total livestock and total natural capital. But the best indicators to predict a villager's dependence on rangeland was decided to be grazing right, number of small livestock and size of farm.The study revealed that independent variables predict the odds (61% - 82%) that a villager will decide to keep livestock dependent on rangeland.

Improving seed germination rate accelerates the early seedling establishment which in turn, enhances the plant growth and forage production in rangelands and pastures.Rapid and simultaneous germination of seeds leads to successful plant establishment. The ingoing research aims to deal with the effects of SiO2 nanoparticles at the concentrations of 0, 5, 20, 40, 60 and 80 mg/l on seed germination rate in Astragalus squarrosus. The experiment was conducted for 15 days under constant temperature of 20oC for 16 and 8 hours at light and dark, respectively. The treatments were arranged as factorial ones based on a completely randomized design with four replicates in Department of Natural Resources at Ferdowsi University of Mashhad, Iran. The results of experiment showed that the germination percent of scarified seeds treated with SiO2 nanoparticles with 40ppm concentration was improved as compared to control seeds and non-scarified ones treated with nanoparticles. At the same time, some other positive effects of other nanoparticle concentrations on germination rate and percent were obvious so that the effects of different concentrations of nanoparticles on seed germination traits of Astragalus squarrosus were found to be significant. The highest and lowest germination percent was recorded under the concentrations of 40 ppm and 80 ppm for those seeds treated with nanoparticles, respectively. As SiO2 concentration increased, no enhancing positive effect on seed germination attributes of Astragalus squarrosus was found. In this experiment, it was found that seeds scarified and treated with 40 or 60 mg/l of SiO2 nanoparticles showed the improved germination in Astragalus squarrosus; so, this treatment can be promising for the establishment and colonization of this species in natural landscapes.

The aim of this study was to investigate the members’ opinions regarding the influencing factors contributing the success of range management cooperatives in three provinces as Markazi, Tehran and Isfahan of Iran in 2014. The study populations were board and ordinary members of cooperatives (N=750) and the samples were selected using Krejcie and Morgan method through stratified and random sampling (n=98). Data of questionnaires were collected using scaling method. Statistical tests of Chronbach's alpha coefficient indicated high validity and reliability of data. The results demonstrated that the unofficial range management cooperatives were more successful compared to the official ones, but in overall, both cooperatives were not successful in achieving the given goals in the system and satisfying the expectations of members. To study the effects of independent variables on the success of both cooperatives, path analysis and multivariate regression were used. The results showed that the factors of education, technical skills of managers, social participation, financial elements, performance of public departments and knowledge of members as the promotion factors had the most impact on the success of the official cooperatives. For unofficial cooperatives, education, financial fairness, comprehension skills of managers, experience and skills of members and performance of public departments had the highest effects on the success of these cooperatives.

Soil carbon and nitrogen contents play an important role in sustaining soil physical and chemical quality and lead to healthy environments. Conversion of rangelands to arable lands might change carbon and nitrogen sequestration. In order to evaluate the effects of land use changes on soil Organic Carbon (OC) and Nitrogen stock (N), forty soil samples were collected from four depths in two sites of rangelands (Astragalus parrowianus and Acantholimon erinaceum) and one site of walnut garden in north west of Shahmirzad, Semnan province, Iran. The soil properties were measured as gravel percent, particle size distribution, bulk density, OC and N. Results of analysis of variance showed no significant difference of soil OC among garden and rangelands but there was a significant difference for N and higher values were obtained in the garden site. The C/N ratios were similar in both rangelands and they were significantly higher than that for garden. Moreover, the values of OC, N stock and C/N ratio were lower in subsurface layer of soils. The correlation between traits indicated that the values of OC, N and C/N ratio had a significant correlation with soil particle size distribution. Both N and OC stock were positively correlated with clay, soil N content, soil OC and negatively correlated with sand%, silt%, gravel and bulk density. It was concluded that by land use changes from rangeland to garden, the OC values were constant; the C/N ratio were decreased whereas the soil N values were dramatically increased.

There is a different function between rangeland management cooperatives in which effectiveness is also affected. The aim of this research was to identify and analyze the effectiveness of rangeland management cooperatives in Gonbad, Iran in 2015. The research was performed using a descriptive statistical method. The statistical populations include all the members of rangeland management cooperative in Gonbad. The sample size was determined by Cochran (n=200). For sampling, the random cluster method was used.The questioner was provided with 40 variables. Validity and reliability of questionnaire were confirmed according to the experts of Department of Natural Resources and Watershed Management, Golestan province and Cronbach's alpha was given as 0.97.Factor analysis was conducted based on principal components and varimax rotation for recognizing the function of cooperatives of rangeland management using SPSS software.Factor analysis considers 40 variables for five manageable and understandable factors.Five extracted factors were information and extension services, technical support services, collaboration and social interaction, rangeland rehabilitation and supply of inputs accounted for 74% of total variation for range management cooperatives. Therefore, it is important for successful cooperatives to pay attention to these five factors.

This is the second of series on the impact of dust. It focuses on the physical, chemical and physiological effects of dust particles and aerosols. Plants of all types and classes (from algae to forest trees and everything in between) are adversely affected either directly through abrasion by airborne particles or through interference with plant physiology or indirectly through the impact on soil as particles are deposited in the soil surface with effects on the soil chemistry, soil texture and soil structure. The literature that is reviewed spans decades and the biomes from which examples are drawn cover regions from the Arctic Circle to the equator, from deserts to tropical rainforests. The physiological responses of plants underlie and precede ecological changes at the community level and these changes have implications for such important relationships as predator-prey as shelter food supply and other essential ecosystem services either cease to be provided or are severely curtailed. It was found that all species have maximum dust deposition in the winter season followed by summer and rainy seasons. Chlorophyll content decreased and ascorbic acid content increased with the increase of dust deposition. There was significant negative and positive correlation between dust deposition and chlorophyll and ascorbic acid content, respectively.