Distribution and conservation status of Water Onion (Crinum thaianum J. Schulze) in Thailand Nirunrut Pomoim1 Yongyut Trisurat2 Duangjai Sukchalerm3 Faculty of Forestry, Kasetsart University, Bangkok, Thailand E-mail: kekek_r@hotmail.com1, fforyyt@ku.ac.th2, ffordcs@ku.ac.th3 Abstract-Water Onion (Crinum thaianum J. Schulze) is an endemic plant species found in southern Thailand. It’s natural habitat is severely fragmented due to deforestation and dredging and it has been extinct in some streams. The objectives of this research were to investigate the current extent of occurrence and to assess the conservation status of Water Onion in Thailand using species distribution models and the IUCN Red List categories and criteria version 3.1, respectively. The results revealed that the distributions of Water Onion generated by the maximum entropy (MaxEnt) model had overall prediction accuracy of 94%, which was greater than the map generated by the logistic regression (accuracy of 86%). Environmental factors contributing to the distributions were annual precipitation, mean temperature of driest quarter, maximum temperature of warmest month, elevation, alluvium soil, land use type and distance to dredging. The predicted extent of occurrence covered 126 km2 in Ranong and Phang-Nga provinces. As compared to previous studies, the extent of occurrence of Water Onion is to continuing decline and shows extreme fluctuation. Therefore, Water Onion is categorized as endangered species. Essential measures for long-term conservation include in-situ conservation in suitable habitats and propagation for domestic and international trading rather than collection from natural habitat. Keywords: Crinum thaianum, Water Onion, Species distribution model, Conservation status I. INTRODUCTION The Water Onion (Crinum thaianum J. Schulze) is an aquatic plant in Amaryllidaceae family listed as endemic species found only in southern Thailand, especially Ranong and Phang-Nga provinces. Water Onion prefers wet. area, riverside or the flat plain in running stream and having wet-dry climate seasonal cycle. Its growth increases in wet. season and declines in dry season. Water Onion plays important roles in sediment retention, reducing the rate of water flow and providing food for caterpillar stages of some insects. In addition, Water Onion is an important commercial plant for domestic and international trading 30 Proceedings of the International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals (SDGs): Policy and Practice 27-29 June 2016, Cha-am, Phetchaburi, Thailand
Proceedings of International Conference on Climate Change, Biodiversity and Ecosystem Services for the Sustainable Development Goals : Policy and Practice 27-29 June 2016 at the Sirindhorn International Environmental Park, Cha-am, Phetchaburi, Thailand
To see the actual publication please follow the link above