Diversity of Limestone Orchids in Central and Northern Padawan, Kuching, Sarawak

Sarawak is situated in the north-west of Borneo, which is the largest state in Malaysia. Limestone hills and mountains are a natural landmark in parts of Sarawak and Padawan Formation is the largest outcrop in Sarawak. Padawan area is located at the south-west part of Kuching District and limestone...

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Bibliographic Details
Main Author: Lim, Michael Yee Liang
Format: Thesis
Language:English
English
Published: 2008
Online Access:http://psasir.upm.edu.my/id/eprint/5113/1/FS_2008_14.pdf
http://psasir.upm.edu.my/id/eprint/5113/
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Summary:Sarawak is situated in the north-west of Borneo, which is the largest state in Malaysia. Limestone hills and mountains are a natural landmark in parts of Sarawak and Padawan Formation is the largest outcrop in Sarawak. Padawan area is located at the south-west part of Kuching District and limestone hills are mostly of the wet type. The favourable climate and various forms of microhabitat strongly enhance the richness and diversity in the composition of limestone orchids in Padawan, especially rare and endemic species. Nonetheless, the Padawan orchid is poorly known due to the very few specific literature made and most of the documentations in field have not been published. This study is an attempt to document the orchid diversity in limestone areas not covered in the previous study by Phoon (2004). From this study, a total of 94 taxa in 36 genera from 4 subfamilies of orchids on 14 limestone hills and one riverbank from northern to central part of Padawan Limestone Area were recorded and botanized. A total of 25 taxa and one genus are new records for Padawan Formation. Out of these, eight taxa are new records for Sarawak and one taxon is a new record for Malaysia. Bulbophyllum reticulatum and Paphiopedilum stonei are endemic to Sarawak; whilst, B. longiflorum, B. reticulatum, Cleisostoma discolor, C. nieuwenhuisii, Dossinia marmorata, P. stonei, Phalaenopsis cochlearis, Trichoglottis winkleri var. minor and Vanda scandens are limestone endemic species. Discussions were based upon two main aspects: (i) floristic diversity significance, for analyzing species diversity and morphological diversity of Padawan orchids; and (ii) the geographical significance, for conferring the diversity patterns of Padawan limestone orchids distributed in different places and endemism. The Orchidaceae of Padawan principally comprised the Bornean element at the generic and species level given its geographical, geological, climatic and floristic proximity. Gunung Bekap, Gunung Mentawa and Gunung Timurang covered the most diverse amount of orchid species together with those rare and endangered species. Therefore, they have to be conserved broadly by implementing in situ conservation techniques.