Habitat suitability modelling of Eurotia ceratoides (L.) C.A.M. in North East of Semnan, using Ecological Niche Factor Analysis

Eurotia ceratoides (L.) C.A.M. is a perennial and palatable range plant species with high grazing value. This species rarely dominate the rangelands and is mostly growing with other species. Ecological-niche factor analysis (ENFA) is a multivariate approach to study geographic distribution of species on a large scale using “presence” data of the species. This method was used to map potential habitat of E. ceratoides in North East of Semnan province. The presence points of the species were considered as appropriate places for its growth. Habitat characteristics of the species such as Soil & Physiography were identified. Fifteen quadrates were placed at an interval of 50 m along three 750 m transects in each vegetation type. Soil samples were taken from 0-20 cm and 20-80 cm in starting and ending points of each transect. The exact geogerafic position of E. ceratoides plants along the transects were recorded by global position system (GPS) then actual vegetation map of the studied area was produced. The essential data layers were imported to appropriate model and statistical analysis were performed by Biomapper software to map potential habitat of this species. According to the results, 15000 hectares (about 20 percent of the study area) was recognized as potential habitat of E. ceratoides. Accuracy of the model was tested using Boyce index which was about 93.2 percent. The model was verified using kappa statistics and the calculated kappa index was about 0.85. Habitat characteristics of the species revealed that E. ceratoides, is distributed in sites with 7.8-8 pH, 0.17-0.26 EC ds/m, silty-sandy texture and in 1600-2200 meters elevation from sea level.