بررسي روابط پوشش گياهي مراتع پشتكوه استان يزد با خصوصيات فيزيكي و شيميايي خاك با استفاده از روش هاي تجزيه و تحليل چندمتغيره

Relationships Between Poshtkouh Rangeland Vegetative of Yazd Province and Soil Physical and Chemical Charateristics using Multivariate Analysis Methods

The aim of this research was to study the relationships between soil characteristics and vegetation in order to find the most important characteristics for classifying of the vegetation types in Poshtkouh rangelands of Yazd province. After delimitation of the study area, sampling of soil and vegetation were performed using randomized-systematic method. Vegetation data including density and cover percentage were estimated quantitatively in each plot; and with the help of two-way indicator species analysis (TWINSPAN), vegetation was classified into different groups. The topographical conditions were recorded for plot locations. Soil samples were taken at 0-30 cm and 30-60 cm depths in each plot. The measured soil variables included texture, lime, saturation moisture, gypsum, acidity (pH), EC, SAR, and soluble ions (Na^+, KC, Mg^2+, C1^-, C03^2-, HC03^- and SO4^2-). Multivariate methods, including principal component analysis (PCA) and canonical correspondence analysis (CCA), were used to analyze the collected data. The results showed that the vegetation distribution pattern was mainly related to such soil characteristics as salinity, texture, soluble potassium, gypsum and lime. Generally, each plant species depending on the habitat conditions, ecological needs and tolerance shows a significant relation with some soil properties.