Journal of Rangeland
Year:2015 | Volume:9 | Issue:3 |Papers Count:10

The objective of the present study was to assess the ecological potential of Tragacanth Gum production and harvesting based on soil characteristics of Tiran and Karvan rangelands in Isfahan province. Scariolia orientalis-Astragalus gossypinus, Hordeum fragile-Astragalus gossypinus and Cousinia bachtiarica-Astragalus gossypinus vegetation types with relatively homogenious topography conditions were selected, and four transects with 100 meters distance were esatbished obliquely to the general and the lateral slope of the site in each vegetation type. The produced Tragacanth Gum from studied Astragalus individuals along the transects were measured based on their ages ad harvesting stages. Soil samples from two depths of soil surface were collected from the start and end point of each transect and their physical and chemical characteristics were measured. STAT Plus(2009) and SPSS software were used to analyze the data. According to the results, the potential of gum production in Sc. or-As. go vegetation type was more than the two other vegetation types. Soil depth, organic matter, electrical conductivity and soil potassium content in Sc. or-As. go vegetation type were also higher then the two other types. Tragacanth Gum can be harvested from the utilized species after a two years resting period. The estmiated required time for collecting Tragacanth from the utilized species in Ho. fr-As. go and Co.ba-As. go vegetation types was three years. Soil lime and gypsum content in these two vegetation types were more than Sc. or-As. go vegetation type.

This study was conducted to evaluate the ability of logistic regression to specify the environmental condition affecting the presence of selected plant species, and identifying suitable areas for the establishment of these species. Some sites with relatively homogeneous ecological conditions were identified by overlaying slope, aspect, elevation and geology maps (1: 25000 scales). Vegetation sampling was carried out using random- systematic method, and 60 plots were established along four transects with 200-1000 meters length in each site. The appropriate plot sizes were determined from 2 to 25 m2 using Minimal Area Method. Soil samples were collected from eight soil profiles in each site from 0-30 cm and 30-80 cm depths from soil surface. Predictive maps of plant species habitats were produced using Logistic regression method. Optimal environmental condition of selected plant species were determined and predictive performance of the produced potential maps were assessed using kappa coefficient and the True skill Static. According to the results, geological formation, percent gravel, soil texture, acidity and lime contents were identified as the most important factors controlling distribution of plant communities in the study area. The accuracy of produced predictive maps for Amygdalus scoparia was very good, for Scariola orientalis- Stipa barbata and Pteropyrum olivieri- Stipa barbata were good and for Artemisia aucheri- Astragalus glaucacanthus vegetation habitats was moderate. The results showed that the logistic regression models, provides high accuracy predictive model for Amygdalus scopariahabitat due to its exclusive habitat conditions. The accuracies of the produced maps for other vegetation habitats were lower than Amygdalus scoparia because they had more wider ecological spectrum.

For good management in rangeland, information of Chemical composite is essential which is influenced by various factors. The main objective of this research was investigation on effects of species and phenological stages on values of chemical composite of five rangeland species. Species were three grasses (Bromus persicus and Dactylis glomerata, Poa alpine), two forbs (Thymus vulgari, Onobrychis cornota). Samples were collected from highland rangelands of Ramiyan. They were dried, grained and analyzed in Laboratory. The results showed that chemical composite values including crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME) were significantly differed among phenological stages (P<0.01). For all species CP, DMD, and Me decreased and ADF increased with plant growth development. Considering chemical composite values among five species, Onobrychis cornota had highest chemical composite. Among species, Onobrychis cornuta the maximum amount of crude protein (24.3), metabolizable energy (10.1) and dry matter digestibility (69.0) and, Dactylis glomerata has a minimum crude protein (13.2), energy metabolism (9.7) and dry matter digestibility (62.4), respectively.

Regarding to the importance of rangelands in ecosystem maintenance, investigating the effective factors for rangeland conservation and development toward sustainability is vital. Pressure on natural resources for utilization purposes are resulted in increasing environmental degradation and conflicts as well as decreasing local stakeholders' participation. In recent decades, social aspects in natural resources governance especially application of social networks for facilitating successful participatory management are emphasized. In this research with the aim of recognizing challenges and handicaps of planning and implementation of successful rangeland participatory management, analysis of trust and collaboration networks among stakeholders of Takor village, Noor, Mazandaran Province was investigated. In this study, Social Network Analysis using UCINET Software was used to evaluate three important indicators including density, whole network centrality, and reciprocity at macro scale and core-periphery at median scale. According to the results, core and marginal actors which indicate stakeholders' network based on trust and collaboration links have middle to high sustainability and middle to low cohesion. Therefore, it is recommended to apply Social Network Analysis as a new approach for rangeland participatory management and create rangeland co-management information system, using monitoring and evaluation of indices and indicators.

Evaluating plant diversity in various ecological conditions is required to develop appropriate conservation plans and enhance natural ecosystem conditions. This study aimed to identify the most influential factors on variations of plant diversity in Valuyeh of Kiyasar summer rangeland in Mazandaran province. Random-systematic sampling approach was used to collect vegetation and soil data along with LFA indices from the sites located 1600 to 2200 meters from sea level with north and south aspect. The plant diversity was determined using entropy Shanon, Sympson, Jini and Sympson indices and plant richness were determined by counting plant species. Multivariate analysis was used to identify the major ecological groups and explore the effects of topographical features and LFA indices on plant diversity in the study area. According to the results, the elevation from sea level and soil stability parameters in the sites located in north aspect, and elevation from sea level, soil infiltration and soil texture in the sites located in south aspect were identified as the most influential factors on plant diversity in this region. Secale montanium-Festuca ovina ecological group with 116 species and Lolium perene- Medicago sativa ecological groups with 119 species had the highest species richness in north and south aspect sites, respectively.

Vetiver grass (Chrysopogon zizanioides) is an exotic multifunctional plant species that has been experimentally planted in Kechik station, Maraveh tappeh, northern Iran. Evaluating the possible negative impacts of introduced species on environment is required to prevent vast ecological hazards. This study aimed to evaluate the effects of this species on some soil physical and chemical characteristics. Soil samples from 0-15 and 15-30 cm depth (totally 20 soil samples) were collected from Vetiver grass planted site and control site. Soil texture, bulk density, porosity, saturated humidity, aggregate stability, EC, pH, organic carbon, total nitrogen, lime, absorbable phosphorous, exchangeable sodium, potassium, calcium, and magnesium were measured. According to the results, soil aggregate stability and lime content of soil were decreased significantly after six years from the establishment of Vetiver (p> 0.05), but soil organic carbon, absorbable phosphorous, exchangeable sodium and potassium were increased significantly. Although carbon, phosphorus and potassium contents of soil were increased as a result of Vetiver grass cultivation, extensive cultivation of this plant in the study area should be treated with caution. More research is required to evaluate the effects of this introduced species on native species in this region.

Range management plans are as one of the best tools to rangeland management and utilization. This study aimed to identify the success and failure causes of range management plans in Golestan province. Questionnaire method was used to collect data from supervising experts in range management plans. Multivariate analysis and Spearman rank correlation were used to data analysis at PC-ORD 5 and SPSS 16 softwares. Common traditional use of rangelands, lack of penalties for uncommitted users, not distinguish between committed and uncommitted utilizers, preparation of the plans without attention to utilizers viewpoint and preparing plans without economic justification were identified as the most important failure reasons of these plans (each of them 24 percent correlation with others). Undesirable plans and lack of distinguish between professional offenders were among other important failure reasons of the plans (each of these 23 percent correlation). These mentioned factors have high and significant correlation (above 70 percent) with lack of ownership, lack of disincentive laws, unsuitable proposed projects in economic and ecological issues and up-down policy making. Insurance of range managers, financial supports of plans supervisors, distinguish between committed and uncommitted utilizers (approximately 34 percent) and proposing plans with economy justification, and utilizing of short return were identified as the most important success factors of these plans (32 percent). The identified success factors had 81 percent correlation with offending range managers, 70 percent correlation with give the plans to the experienced experts and 52 percent correlation with preparing the plans with participating of utilizers.

In order to identify the most important ecological factors affecting distribution of Daphne mucronata, some sites dominated with this species, including Dezli, Naran and Morvarid saddle were selected in Kurdistan province. Systematic random sampling method was used to collect vegetation data. Coverage percentage, density, height and diameter of each plant individual was studied using nested quadrates (15×15 square-meters plots to collect D. mucronata data and 1 m2 plots to study understory species) Three soil samples were collected at depth of 50 cm in each 15×15 plot from below (understory) and between (interspace) shrub canopies. Clay, silt, sand, gypsum, lime, electrical conductivity, pH, phosophorus, calcium, magnesium, percentage of stones, nitrogen, carbon and potassium contents of soil samples were measured in laboratory. Analysis of variance and multivariate regression technique were used to analyze the data. According to the results, soil organic carbon, potassium, pH, magnesium, phosphorus, calcium, lime, nitrogen, clay, sand, average annual rainfall, canopy cover and plant density were different significantly in the identified habitats (&alpha= 1%). Soil silt contents were different in various identified habitats (&alpha =5%) but no significant difference were observed in soil gypsum and electrical conductivity of the identified habitats. Results indicated that D. mucronata preferred northern and western directions and its highest density and cover percentage were found in these directions. According to the regression analysis, 59 percent of the variation in Daphne densities (from 400 to 1600 individuals per a hectare) could be justified by lime percentage (ranged from 9.5 to 32.5 in different habitats). A positive correlation between Daphne vegetation cover with soil nitrogen content was found (r= 0.58).