With about 25,000 species, orchids are the largest plant family on earth. In that sense, orchids have been quite successful. At the same time, we often hear that orchids are rare and endangered in the wild. This is not a myth. Many orchid species really are rare and endangered. Why is that?
To be classified as ‘endangered’ a species should not only be rare, but there should also be a clear threat to its continued existence. In most cases this means the right kind of habitat is disappearing, or people collect the species in too large numbers.
For orchids both factors apply. Those 25,000 species are not evenly distributed across the planet. On the contrary, there is a huge concentration of species in the wet tropics, where the annual rainfall is in the order of thousands of mm. In the drier parts of the tropics or in the temperate zones of the world we find relatively few orchids. There are some 55 orchid species in Great Britain. Compare this with Ecuador, where about 3,500 orchid species have been recorded.
The great majority of orchid species are found in tropical forests, where they usually grow on trees. If you cut down the forests they have nowhere to go.
Below is a tree with Dendrobium chrysotoxum and other orchids, felled to make way for agriculture, North Laos.
Deforestation still occurs on a massive scale in most tropical countries. As the forests disappear, so do the orchids.
To make things worse, numerous orchid species are targeted by commercial collectors, who often take truck-loads of plants from the wild. These orchids are not only chosen for their pretty flowers. In large parts of Asia many orchid species are collected almost to extinction for traditional medicine. This is a particular concern for various species of Dendrobium.
Below is a picture of Dendrobium fimbriatum, collected for Chinese medicine.
One of the sad things is that many of those disappearing forests have barely been explored by scientists. What we are doing is destroying a treasure chest which we know must contain antique works of art - but without even looking inside first.
This is an Orchid-rich forest being logged in North Laos.
Looking inside is one of the things the Royal Botanic Gardens, Kew is aiming to do by sending expert botanists to remote places. Not to gain any sort of commercial benefit, but to record what is there before it is gone and to preserve specimens for study by future generations.
Always working closely with local counterparts and with support of the government, Kew staff often collect plants and seed samples to aid ex situ conservation, that is, conservation by cultivation and seed-banking. Demonstrating that a particular area is home to endangered species also provides solid arguments to protect that area, which is in situ conservation.
The Orchid Team at Kew are concentrating their fieldwork on two parts of the world where plant (especially orchid) diversity is extremely high but where our botanical knowledge is still sketchy at best. These are Indochina (Laos, Cambodia and Vietnam) and New Guinea. Unfortunately, it is far from easy to obtain adequate funding for this work.
Recently, in November-December 2013, Christopher Ryan, manager of the Tropical Nursery, and I teamed up with Mr. Menghor Nut from the Cambodia Forestry Administration for an expedition to the Cardamom Mountains in south-western Cambodia. The next blog posts in this series will tell you something about this trip and its outcomes.