For many people conservation brings to mind endangered animals. But unfortunately, endangered plants don’t share the same spotlight — even if they are equally important to the balance of ecology in their habitats. While Thailand may be most famous for its orchids, it is also home to a number of endemic and endangered plant species that are not widely known, yet which make up an important part of this country’s rich natural heritage.
Water onion.
In Surat Thani province there is a type of critically endangered tropical pitcher plant called Nepenthes suratensis. This fascinating plant is carnivorous, and feeds on insects such as flies which are attracted to the cavity formed by the cupped leaf. The rim of the pitcher is slippery, causing insects to fall into the trap, and a waxy coating on the inner surface of the pitcher wall makes it difficult for them to climb out again. Small bodies of liquid contained within the pitcher traps drown the insect, and its body is gradually dissolved. The only remaining wild population of Nepenthese suratensis is scattered in a small area of only about 60 hectares and is decreasing due to a variety of threats.
Ranong and Phangnga provinces are the only places where the endangered Thai water onion Crinum thaianum can be found in small scattered populations. The Water Onion is a keystone species that provides important habitat for native freshwater fish species such as the Soro Brook Carp which uses it as a habitat to lay eggs, while other fish eat the young leaves. Snails and frogs also use it as breeding habitat. The population is severely fragmented by habitat loss related to dredging of rivers and streams and their diversion for agricultural purposes, and there have been rapid population declines in some areas as a result.
Pitcher plant. Ornyupa Sangkamarn
Last but not least, the unusual and threatened Cryprocoryne loeiensis has so far only ever been found in a single place in the world — on the banks of the Mekong River in Chiang Khan district of Loei province.
Only identified as a new species in 2006 this unusual plant grows on the lower river bank, spending half the year submerged as the water rises in the rainy season, and half the year exposed on dry land as the waters recede in the dry hot season. Its dry season flowers attract insects which it traps and holds captive for a day or so until they are thoroughly covered in pollen, before releasing them to carry the pollen to the next plant.
Unfortunately the only site where it has so far been found has already been destroyed by a project to create a rock and concrete embankment authorised by the Department of Public Works, Town and Country Planning. While it is likely that C loeiensis could be found on other parts of the river bank further upstream or downstream from the original site, so far no surveys are planned and there are no proposed mitigation measures being put forward by the department, the local authorities or the building contractor to ensure the continued survival of this species.
Worryingly it seems the department ultimately intends to create an embankment along the entire length of the Mekong River in Chiang Khan district — which would destroy any remaining C loeiensis habitat and could push the species to extinction in the wild.
All three of these unique plant species appear on the IUCN Red List of Threatened Species. And while the Thai government, like many others, has signed on to the Convention on Biological Diversity, it is one thing to sign on to an aspirational commitment on the global stage and often another matter entirely to ensure these commitments are met on the ground in the real world at home.
In some cases, the inescapable irony is that while the government makes international commitments to species conservation, it may be construction projects of government agencies themselves that are actually threatening species with extinction.
The actions of concerned and engaged local citizens and other civil-society groups will play an important role in saving these unique treasures of nature for future generations. But people will often only fight to save what they value. And people are more likely to value something that they know and understand.
For this reason education about threatened plants is also vital for their long-term survival. HRH Princess Maha Chakri Sirindhorn has for a long time been a keen supporter of conservation of endangered plants and of youth education about these species. The Princess's "Botany in School" programme is a model example of how this can be done.
It would be a shame if critically endangered plant species that existed only in Thailand became extinct. And it will be a bigger shame if they became extinct not because of collection by lawless poachers or over-harvesting by poor villagers with no other source of income — but because of legally authorised government infrastructure projects. By doing so the Thai government itself is pulling the plug on endangered species, contravening their commitment and moral responsibility to preserve the country’s unique natural heritage.
Robert Mather is Head of Southeast Asia Group, IUCN (International Union for Conservation of Nature).