Curatorial staff from the National Pinetum at Bedgebury have broken new ground by achieving the first ever successful propagation of a rare and critically endangered Vietnamese conifer.

In 2008 Chris Reynolds and Dan Luscombe from Bedgebury National Pinetum in Kent (the world’s leading conifer collection, managed by the Forestry Commission) travelled to Vietnam as part of Fauna & Flora International’s Global Trees Campaign*, which works to save threatened trees from extinction. Their task was to offer advice and expertise to the Centre for Plant Conservation (CPC) in Hanoi on measures to conserve five rare and highly endangered conifer species, all of which have been seriously affected by logging and habitat loss, and are likely to be further threatened by climate change.

Amongst these was the Vietnamese Golden Cypress (Xanthocyparis vietnamensis), which in 1999 became the world’s most recently discovered conifer genus (its predecessor was Australia’s Wollemi Pine in 1994 – only three or four new conifer species have been discovered in the last fifty years).

Basing themselves at the Bat Dai Son Nature Reserve in Northern Vietnam and accompanied by staff from CPC, Chris and Dan scaled the remote limestone karst mountains to where the few remaining known Golden Cypresses are still growing (fewer than 500 individual trees in two small pockets – making it a very high priority for conservation).

Field surveys by CPC, supported by the Global Trees Campaign, had established that low reproduction in the wild was one of the problems facing the species and attempts by CPC to produce seedlings in a special tree nursery at Bat Dai Son to supplement the wild population had met with no long-term success. In 2009 Matt Parratt from the Alice Holt Forest Research centre in Surrey made a follow-up trip to Vietnam to try and establish why the Vietnamese Golden Cypress was not reproducing from seed. He was able to advise on the optimum time to collect seed from the species and on identifying which cones might potentially provide viable seed. During the following year Nguyen Quang Hieu from CPC visited Bedgebury Pinetum with seed from the Golden Cypress. Using X ray equipment from Alice Holt, they identified which seeds appeared to contain embryos. These were sown in seed trays in the nursery at Bedgebury in May 2011.

On October 19th six seedlings geminated successfully for the first time ever (since then this has increased to 18). In four years time they will hopefully have matured enough to be planted out in the Pinetum, joining nine other Golden Cypresses grown from cuttings donated by Royal Botanic Gardens Edinburgh and planted in 2005 – possibly the first ever planted outside Vietnam. Despite the much colder British climate, these specimens are doing well. The lessons learnt on how to germinate and grow these rare trees from seed will be shared with CPC in Vietnam to enable them to produce seedlings to reinforce populations in Vietnam and support the conservation of the species in the wild.

While the successful germination was taking place, CPC discovered a new stand of just 11 Golden Cypresses. Although most of them were dead or badly damaged, one surviving tree stood at 20 metres tall (60 ft), with a diameter of 1.2m, making it much the largest specimen yet discovered. The Bedgebury team hopes to have the chance to collect seed from this new source, which would give a more diverse – and therefore robust – gene bank of material for future propagation.

* The Global Trees Campaign, a joint initiative between Fauna & Flora International (FFI) and Botanic Gardens Conservation International (BGCI), works to secure the future of the world’s threatened tree species and their benefits for humans and the wider environment. As well as working to save rare conifers in Vietnam, the Global Trees Campaign and its local partners are also saving baobabs in Madagascar, magnolias in China and other highly threatened trees around the world.