REZA SHAHBAZI; Sadat Feiznia; Razieh Lak; Hasan Ahmadi
Abstract
Study of surface sediments of southern Khuzestan plain in Shadegan marshes surroundings was made to understand the nature of the sediments, their classification and determining the most effective physical and chemical characteristics of sediments change. Samples were taken from 27 points inside the work ...
Read More
Study of surface sediments of southern Khuzestan plain in Shadegan marshes surroundings was made to understand the nature of the sediments, their classification and determining the most effective physical and chemical characteristics of sediments change. Samples were taken from 27 points inside the work units. The chemical characteristics of sediment samples containing calcium carbonate, calcium sulfate, sodium chloride, sodium, magnesium, calcium, electrical conductivity, pH and sodium absorption ratio, was measured. After removal all carbonates and evaporates materials, the portion of carbonates-evaporates and terrigenous parts, was specified. Granulometry for terrigenous part was done for terrigenous materials. The new method of classification was performed for these fine sediments containing solutes, which considers the portion of the chemical and terrigenous parts, was performed. In order to specify the most effective factors and variables in the sediment variability, factor analysis and cluster analysis were used consequently. Classification results showed that the sediments are marl, with similar components with Iran tertiary marls. Two main factors, the components of the new classification and the chemical characteristics were controlled sediments variability, while the chemical characteristics had more effective roles. According to the results of cluster analysis, Sodium was the most effective variable which its value varies up to more than 20 in different work units. The results of this study show that the use of the new method of classification together with statistical analysis led to extract more details from flat and broad playa and sabkha environments.
Bahram Gholinejad; Mohammad Jaffari; Mohammad Ali Zarechahuki; Hossein Azarniuand; Hassan Pourbabaei
Abstract
This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters ...
Read More
This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. Various environmental factors such as topographic factors (slope, slope direction and elevation), soil physical factors (depths, soil texture, gravel and saturation moisture) and various chemical factors such as acidity, electrical conductivity, lime, gypsum percentage, organic material, nitrogen, phosphor and potassium) were measured and grazing intensity were considered as managerial factors. After collecting data, the Principal Component Analysis (PCA) was used to determine relationship between vegetation cover and environmental factors by PC-ORD software. The results showed that among various environmental and managerial factors affecting in plant distribution, soil depth, grazing intensity, elevation, sand, gravel and silt percentage have the highest correlation with Principal Component Analyses. These factors are the most effective factors on plants type distribution in rangeland ecosystems. Among effective soil factors on distribution of plant communities in this study, soil physical factors have greater impact than soil chemical properties. Physiographic factors including elevation and managerial factors including grazing intensity have considering effect on distribution of plant communities.
