An investigation on the effects of soil factors on the distribution and density of two unwanted species of Rosa persica and Euphorbia macroclada in Lashgardar rangelands of Hamedan province

In the nature, different vegetative mass emergence and develop because of the interaction between plants and environmental factors. In this study the relationship between some soil factors and the distribution and density of two unwanted species (Rosa persica and Euphorbia macroclada) was studied and the most effective soil factors were determined. Sampling was performed by Systematic–randomize method in 4 key areas and totally 45 plots were established (The key areas were identified by field survey and each plot had 3m2 area). In each plot, the percent of canopy cover and density of studied species were measured and two soil samples were taken from depths of 0-10 and 10-30 cm. Soil factors including pH, EC, percentage of nitrogen, percentage of organic matter, and soil texture were determined in laboratory. Data were analyzed by using Canonical Analysis (CCA) via Canoco software version 4.5. The results demonstrated that the acidity, the percent of clay in soil texture, organic matter and nitrogen are more important in distribution of studied species and their distribution has higher correlation with acidity and organic matter. The results demonstrated that density of studied species has higher correlation with acidity and nitrogen, either.