The effect of several soil and topographical factors on the distribution of medicinal species (A case study: Kachik catchment of Maravetappe)

The knowledge of the effect of ecological factors on establishment of vegetation distribution is crucial in the management of rangeland ecosystem. The purpose of this study is to understand the relationship of some environmental factors such as soil and topography features to the distribution of important medicinal plant species in Kachik Watershed. The percentage of vegetation cover and density were measured by random-systematic sampling method in indicator points from each land unit which is developed from overlaying of rangeland use map on the geographical aspect map. The soil samples were collected from the depth of 0-30 cm of soil surface on the basis of the zigzag method along 70 until 100 cm. The percentage of clay, silt, sand and the amount of Ca, pH and EC were analyzed for each sample. The environmental factors and plant features were analyzed by using regression, DCA and CCA analysis from PC-ORD 5, MINITAB 15 and Canoco 4.0 softwares. The results showed that plant species distribution of this area could be affected by %29.4 of soil, %25.3 of topographical parameters and %45.25 by these two environmental factors together. Among the topographic features aspect and slope with the regression value of 0.86 and 0.57 and among the soil features pH and texture parameters with 0.56 and 0.43 were the most influential features on the plant species distribution for this area.