Determination of the distribution of Calotropis gigantea (L.) in Sri Lanka using MaxEnt modelling technique

Abstract

Calotropis gigantea is a drought-resistant, salt-tolerant, native plant in Sri Lanka with ayurvedic medicinal values. The plant is used for fiber, fodder and fuel, as well as a fertilizer. Despite its benefits, C. gigantea has become an emerging problem in countries where it has been introduced because of its invasiveness. Although C. gigantea is widely distributed in Sri Lanka, precise information on its distribution is lacking. Therefore, the present study was aimed at determining the distribution of C. gigantea in Sri Lanka. Field surveys were conducted in 120 sites covering all provinces in Sri Lanka from December 2014 to June 2015 to record the occurrence of C. gigantea. C. gigantea was distributed in all provinces except the Central province. It was more widespread along coastal regions, but its occurrence was low in the Western and Sabaragamuwa provinces. MaxEnt modelling predicted that the entire coast of Northern, North-Central and Eastern provinces contain the highest probability of C. gigantea distribution whereas the low probability was in North-Western, Western, Southern, Uva, Central, and Sabaragamuwa provinces. No occurrence probability was predicted in certain regions of Southern, Sabaragamuwa, Uva, and Central provinces of Sri Lanka. The study provides information on the current and potential distribution range of C. gigantea in Sri Lanka.