The Comparison of Modeling Techniques for Selected Genus Shorea in Peninsular Malaysia

Forests cover about a half of Malaysia's land area. In Malaysia, the forests are mostly dominated by dipterocarps forest where most of the largest trees in forest type belong to the family Dipterocarpaceae. Peninsular Malaysia is a part of Malaysia has a rich flora and fauna. However, many populations of dipterocarps are on the decline mainly as a result of deforestation and timber as source of economic. There are about 155 dipterocarps species recorded and some of the species are endemic in Peninsular Malaysia. Hence, ecological niche modeling (ENM) is used to predict the distribution of selected Shorea species which were Shorea dasyphylla, Shorea gratissima and Shorea ochrophloia in this study. ENM is a method that widely used in rapid conservation assessment tool either for plant or animal. ENM uses presence-only data and environmental data. Generate by MAXENT tool, ENM constructed by using bioclimatic variables, slope and altitude from SRTM database and soil from HWSD dataset. In this study, each species will construct two models which were with HWSD and without HWSD. Next, three different techniques, the extent of occurrence (EOO), area of occupancy (AOO) and ecological niche models (ENM) derived using MAXENT were projected to make a comparison of modeling technique. EOO shows that its technique fall into overestimates because the at least three point of localities species must occur to create polygon. AOO shows that the technique fall into underestimate. Lastly, ENM produce a good assumption when the model falls at the middle of habitat range. Besides that, the used of soil data as one of the environmental layer in conducting MAXENT give the greater effect to predict the present of dipterocarps species in this study.