Comparing Discriminant Analysis, Ecological Niche Factor Analysis and Logistic Regression Methods for Geographic Distribution Modelling of Eurotia ceratoides (L.) C. A. Mey

Abstract. Eurotia ceratoides (L.) C. A. Mey is an important plant species in semi-arid lands in Iran. New approaches are required to determine the distribution of this plant species. For this reason, geographical distributions of Eurotia ceratoides were assessed using three different models including: Multiple Discriminant Analysis (MDA), Ecological Niche Factor Analysis (ENFA) and Logistic Regression (LR). The study area was located in northeast rangelands of Semnan, Iran. Sampling was performed in each vegetation type using randomized-systematic method. Vegetation data in addition to environmental factor's data such as topography and soil were prepared. The MDA and LR methods were performed with SPSS software as predictive modelling methods based on presence and absence data. The ENFA model was performed by the means of necessary statistical analysis in Biomapper (Version 4.0) software only by presence data. The plant predictive mapping needs the maps of all effective factors based on model parameters. Mapping of soil characteristics was done by geo-statistical method. The accuracy of the predicted map was tested with the actual vegetation map. Predictive maps of E. ceratoides (based on the LR and MDA methods) with Kappa coefficients as 0.56 and 0.64 had a good accordance with actual vegetation map prepared for the study area. Kappa coefficient of potential habitat map (based on ENFA method) of E. ceratoides was 0.85; hence, it had a very good accordance. The results obtained by all methods showed that this species is distributed in the rangeland with pH as 7.8-8, EC as 0.17-0.26 dc/m and silty-sandy texture in 1600-2200 m elevation. Organic matter in the depth of 20-80 cm and pH in the depth of 0-20 cm did not significantly influence the differences. Minimum sampling is needed using these methods which provide worth while data about the presence of the plant species in the other places.