International Rhododendron Experts Meet to Develop an Action Plan for Threatened Species
Above: Rhododendron simsii flowering in Cangshan, Yunnan Province, China
The Royal Botanic Gardens Edinburgh, the Rhododendron Species Conservation Group and BGCI jointly hosted a two-day conference with the aim to develop a coordinated action plan to save threatened Rhododendron species from extinction in the wild.
The Royal Botanic Garden Edinburgh played host on 20th & 21st April to the most knowledgeable and influential group of international Rhododendron experts ever assembled under one roof. Although common in cultivation, research by Botanic Gardens Conservation International (BGCI) and the Royal Botanic Garden Edinburgh (RBGE), which led to the publication of The Red List of Rhododendrons in 2011, showed that a quarter of the more than 1,000 known species of Rhododendron are under threat in their native habitats.
One particular species (Rhododendron kanehirae) would be extinct but for collections in botanic gardens such as RBGE.
Famous for their flowers, Rhododendrons (including azaleas) have long drawn plant hunters to their centres of diversity in the Himalayas and mountains of Southeast Asia. In their native habitats, Rhododendrons are valued for their medicinal properties, and in some communities they have a wide range of other uses, including firewood, timber, teas, jams, narcotics and also as a source of insecticide. Rhododendrons grow in areas of high rainfall and high humidity on acidic soils; conditions under which few plants would survive. They stabilize slopes and protect watersheds, notably in the Himalayas where five of Asia’s major rivers start. Deforestation on a massive scale, for timber, mining, clearance for grazing, road construction, or to make way for development of towns and tourist infrastructure, is having major impact on the native habitat of Rhododendrons.
Time is of the essence, and the concerns raised by the BGCI publication are beyond the sphere of control of taxonomists and scientists alone to resolve. In seeking a way forward, the conference aimed to assess and recommend what opportunities exist for implementing a practical approach through the involvement of garden curators, head gardeners, horticulturalists, nurserymen and enthusiasts from around the world, who have the knowledge, expertise and ability to work together and make a difference.
The Red List of Rhododendrons was a major step forward in recording the data available to taxonomists and scientists. The publication is available on the BGCI website and will enable the conference delegates, and other knowledgeable individuals, to make an input to verify the data and add further details from their findings during expeditions in the field. In this way the 290 species which were classified as ‘Data Deficient’ will each be targeted with the aim of making a viable assessment, wherever this is practicable. Taxonomists and scientists residing in the Himalayas and Southeast Asia will also seek to establish the numbers and locations of these plants in the wild. Educating people in the local communities and developing their horticultural skills to care for threatened plants in the wild, and encouraging them to take an active role as custodians of their plant heritage, is a vitally important component of the plan.
BGCI’s 2011 report highlighted the urgent need for conservation of 75 of the most threatened Rhododendrons - species that were considered to be on the verge of extinction in the wild. Furthermore, the internationally adopted Global Strategy for Plant Conservation, calls for 75 per cent of all threatened plants to be conserved in ex situ collections (e.g. botanic gardens) by 2020. In the case of Rhododendrons this equates to 238 species.
In 2012, BGCI carried out a global ex situ survey to see how many of the threatened Rhododendrons were already in the collections of botanic gardens and arboreta around the world. Worryingly, only 48 such species were identified. This means that many of the Critically Endangered and Endangered species are currently not known in cultivation and therefore at great risk of extinction if the threats that they are facing in the wild are not addressed. It is likely that some specimens may still exist in private gardens, some of which contain old collections of plants dating back to the days of the great plant-hunters, however, many of these collections have received little maintenance and care as a result of the harsh economic climate that dates back to the cessation of WWII. These private collections will be gradually surveyed with the aims of locating and propagating threatened species, and establishing conservation collections in botanic gardens, arboreta, parks and woodland gardens where climatic, geographic and environmental conditions enable the various types of species to flourish. In this way we can work together to secure these distinctive and beloved plants for future generations to enjoy.
The presentations from the conference are now available on the BGCI website at the following link: Rhododendron Conference 2013 presentations
To visit BGCI's Rhododendron pages and download The Rhododendron Red List and the global ex situ survey, click here.
To find out more about the Rhododendron Species Conservation Group, click here.