Determination of the Potential Habitat of Range Plant Species Using Maximum Entropy Method

This study aimed to identify the most important physical variables affecting the distribution of four range plant species (Tamarix aphylla, Calligonum comosum, Prosopis spicigera and Salsola rigida) habitats and to prepare potential habitat map of the species using Maximum Entropy (MaxEnt) method in rangelands of Jiroft city, Kerman province, Iran. To this end, sampling of vegetation including species type and percent cover was conducted with a randomized-systematic method in 2015. Sample size was determined as 60 plots with a quadrat size of 25-100 m². For soil sampling, eight profiles were dug in each habitat and samples were taken at two depths, i.e., 0–30 and 30–60 cm. Results indicated that the classification accuracy of the model was acceptable and soil variables including EC, percentage of lime, organic matter, moisture content and texture had the greatest effect on the distribution of the studied plant species habitats. Correlations between the actual and predicted maps for Tamarix aphylla and Calligonum comosum habitats were at a very good level, Kappa= 0.81 and 0.79, respectively; for Prosopis spicigera habitat, it was at a good level, Kappa= 0.75, and finally for Salsola rigida, it was at a moderate level, Kappa = 0.53. These results indicate that the MaxEnt method can provide valuable information about the physical conditions of plant habitats in arid rangeland. Knowledge on physical characteristics of plant habitats can be useful in determination of potential habitats and rangeland improvement projects.