**Acknowledgements**

This research is supported by Ministry of Higher Education, Malaysia research grant (FRGS/1-2014- STWN06/UPM//02/1) with vote number 5524502 and University Putra Malaysia research grant (GP- 1/2014/943200). The authors like to thank Professor Dr Manfred Buchroithner for joint terrestrial laser-scanning expedition funded by the National Geographic Society.
