Determination of the Contribution of Some Soil Characteristics on Distribution of Vegetation in the Summer Rangelands of Balade, Nour

Understanding the relationships between vegetation and environmental factors would be essential for rangeland restoration and management. So the current study determines the relationship between indicator plant species and soil in the summer rangelands of Balade, Nour. After determining the vegetation types using topography, the sampling was done with systematic-random method. The plots size was determined using the minimum area method. Soil samples were collected in each vegetation type from 0 – 50 cm depth (effective root depth). In addition, Samples to determine some of the factors such as the percentage of sand, silt, clay, pH, Ec, T.N.V, CO, saturation moisture content and sodium absorption ratio were transferred to laboratory. In this research, relationship between the soil's characteristics and vegetation's parameters were analyzed after data providing about soil and plant by ordination method which is a method to determine the relationship between plant communities and environmental factors. Therefore, to determine the type of ordination method, firstly, the gradient Length was measured by DCCA method. Finally, the gradient length data were analyzed by CANOCO software. The results showed that the types of Astragalus gossypinus and Acontholimon pterostegium have had negative and positive correlation with saturation moisture content and sand, respectively. Furthermore, herbaceous species of Bromus tomentellus and Coronilla varia had positive correlation with saturation moisture content and organic carbon. Therefore, such results could be useful to improve and restore vegetation in areas with similar conditions.