Plants of peninsular Thailand

Botanical Diversity and Biogeography of Peninsular Thailand


Plants of peninsular Thailand

Plants of peninsular Thailand (clockwise from upper left)
Hedychium longicornutum (Zingiberaceae), Reevesia pubescens (Sterculiaceae), Argyreia roseopurpurea (Convolvulaceae), Paphiopedilum callosum (Orchidaceae)

Thailand is one of the most botanically diverse countries in the world with an estimated 12,000 vascular plant species. The southern peninsula of Thailand spans nearly eight degrees of latitude (about 5 degrees N to 13 degrees N) and includes the transition zone between the Indo-Burmese and Sundaland floristic regions, two of the six most diverse and threatened biodiversity hotspots in the world. It has been estimated that over 500 genera of plants have their northern or southern distributional limits within the transition between these floristic regions.

Several explanations for why these floras became and remain distinct have been proposed, including the role of great variations in length of dry season that occurs within the peninsula. However, analyses of species distributional patterns have not been possible due to a dearth of plant collections from the peninsula. Thailand’s average of only 50 herbarium specimens per100 km2 pales in comparison to countries such as the United Kingdom (1,720 specimens per100 km2) and is even low compared to other areas of Southeast Asia (e.g., Java and the Malay Peninsula each average nearly 200 specimens per 100 km2).

From 2003-04, Stuart Davies and David Middleton (Arnold Arboretum of Harvard University, Co-PI’s), Kyle Williams (Harvard University, post-doctoral fellow), Kongkanda Chayamarit (Forest Herbarium Bangkok), Rachun Pooma (Forest Herbarium Bangkok), and Somran Suddee (Forest Herbarium Bangkok) worked to create an inventory of the plants of peninsular Thailand through intensive field collection and collation of existing records. Plant inventory data derived from this project has been contributed to the broader Flora of Thailand project and is an important resource for critical conservation initiatives in the peninsula.

Map of collecting localities in 2004 Close-up of collecting localities map
Map of Thailand showing collecting localities in 2004. Over 1000 specimens were collected. Close-up map of peninsular Thailand showing collecting localities in 2004. Collections were made in seven provinces and spanned the length of the peninsula.
Researchers and staff collecting in Yala Collecting plants in the field
Researchers David Middleton (far left), Kyle Williams (second from left), and Rachun Pooma (far right) collecting in Yala with staff from the Chulaporn Pattana 7 project in Yala province. Collecting plants in the field in southern Thailand. Researchers Somran Sudee (standing, blue hat), David Middleton (seated, blue shirt), and Kyle Williams (seated, gray shirt) collecting plants in Prachuap Kiri Khan province. Staff from the Forest Herbarium Bangkok and the National Parks and Wildlife Department assist in collecting.