Spatial distribution modeling for Agropyron intermedium and Stipa barbata species habitat using binary logistic regression (case study: rangeland of Taleghan miany)

The Purpose of this study is to predict the spatial distribution modeling of habitat potential of Agropyron intermedium and Stipa barbata species in area with the size of 37977.12 hectares in Miany (mideal) Taleghan. For modeling, vegetation data and site condition including topography, climate, geology and soil were prepared by satellite images, digital elevation model (DEM), geology map and climatology data (from related stations) were obtained. Within each plant type, three parallel transects with 150m length, each containing 15 quadrats were established. Sampling method was randomized-systematic method. Quadrats size determined for each vegetation type using the minimal area and their number were determined according to statistical method. Soil samples were taken from 0-30 cm in along of each transects. The soil properties included grovel, texture, pH, EC, organic matter, lime, soluble ions (N, P, K) were measured in the lab. Data analysis and prediction maps were done by geo-statistical and logistic regression methods. The results showed that direction habitat (N) and lime increasing soil (to 27.5 percent) had the greatest effect in the appearance and distribution of S. barbata species. Increasing height (to 2550 m) had the most important role in the appearance of A. intermedium species. Assessment of models using Kappa coefficient indicated that logistic regression models ability to predict habitat for both species was very good With the exception that kappa for A. intermedium (k =0.83) is slightly more than S. barbata (k =0/79).