Habitat distribution modeling of some halophyte plant species using Maximum Entropy Method (Maxent) in Hoze Soltan rangelands Of Qum Province

The objectives of this study were to estimate geographical distribution of some halophyte plant species, identifying the most important environmental factors affecting the species distribution and understanding tolerance range of the species to some edaphic factors in Hoze soltan rangelands of Qom province. Vegetation, topography, temperature, rainfall, geology and soil characteristics of the study area were studied. Homogeneous units were identified and 4 parallel 200 to 1000 meters transects were established in each unite and vegetation attributes were measured in 60 quadrates. Appropriate quadrate size was determined for each vegetation type (2- 50 square meters) using the minimal area method. Soil samples were collected from 0-30 and 30-80 cm in start and end points of each transect. GIS and Geostatistics methods were used to map the environmental variables. The species distribution models were produced using the species presence data and Maximum Entropy Method (Maxent). The Kappa coefficient index and the area under curve (AUC) were used to evaluate the accuracy of the distribution maps. According to the results, electrical conductivity, moisture saturation percentage, lime content, soil texture and acidity were identified as the most determinant factors for distribution of the plant species in the study area. The agreements (Compliance) of actual and predicted maps for Tamarix passerinoides and Seidlitzia rosmarinus species was moderate but it was acceptable for Halocnemum strobilaceum and Artemisia sieberi.