Background: Predicting the potential habitat of plants in arid regions, especially for medicinal ones, is very
important. Although Pergularia tomentosa is a key species for medicinal purposes, it appears in very low density in
the arid rangelands of Iran, needing an urgent ecological attention. In this study, we modeled and predicted the
potential habitat of P. tomentosa using maximum entropy, and the effects of environmental factors (geology,
geomorphology, altitude, and soil properties) on some characteristics of the species were determined.
Results: The results showed that P. tomentosa was absent in igneous formation while it appeared in conglomerate
formation. In addition, among geomorphological units, the best quantitative characteristics of P. tomentosa was
belonged to the conglomerate formation-small hill area (plant aerial parts = 57.63 and root length = 30.68 cm) with
the highest electrical conductivity, silt, and CaCO3 content. Conversely, the species was not found in the
mountainous area with igneous formation. Moreover, plant density, length of roots, and aerial parts of the species
were negatively correlated with soil sand, while positive correlation was observed with CaCO3, EC, potassium, and
silt content. The maximum entropy was found to be a reliable method (ROC = 0.91) for predicting suitable habitats
for P. tomentosa.
Conclusion: These results suggest that in evaluating the plant’s habitat suitability in arid regions, contrary to the
importance of the topography, some environmental variables such as geomorphology and geology can play the
main role in rangeland plants’ habitat suitability.