Share This

HomeResearchResearch impactConserving biodiversity hotspots

Conserving biodiversity hotspots

Oxford Botanic Garden and Arboretum (OBGA) carries out conservation work in Japan as part of a wider programme of research into biodiversity hotspots around the world.

Survey work in HokkaidoRapid Botanic Survey work in Hokkaido.

(Credit: OBGA 2019)

Thirty-six areas qualify as biodiversity hotspots, which are places with at least 1,500 plants that are found nowhere else on the planet (‘endemic’), and 30% or less of their original natural vegetation. Together, they represent just 2.3% of Earth’s land surface, but they support more than half of the world’s endemic plant species, including many that are threatened with extinction. One of the aims of the research into biodiversity carried out at OBGA is to combine the Rapid Botanical Survey methodology, to establish a feasible and effective means of enhancing the conservation value of wild origin plant material, its utilisation within plant collections, and the long-term safeguarding of plant diversity. Working in collaboration with botanists at the Department of Plant Sciences, this approach has enabled researchers to identify high conservation elements of the Japanese flora, and at a scale suitable for local conservation management.

OBGA’s Director Professor Simon Hiscock, Deputy Director and Head of Science Dr Chris Thorogood, and Arboretum Curator Ben Jones travelled to Japan in the summer of 2018 to sign a Memorandum of Understanding with the Botanical Gardens of Toyama and to meet with the Japanese Ministry for Environment to discuss their existing work and future collaborations. The collaboration with Toyama is helping OBGA to augment its Japanese plant collection with threatened tree species and other plants. New, seed-raised plants, collected as part of the Japan biodiversity hotspot project, have been incorporated throughout the Arboretum, and within the Japan Border on the west axis of Oxford Botanic Garden’s Walled Garden, to be enjoyed by visitors as part of OBGA’s extensive conservation, research, and teaching collections.

A flagship species in this wider conservation effort is the Chichibu birch (Betula chichibuensis), one of the rarest trees in the world. The tree grows only in the Chichibu region of the island of Honshu, Japan and is exceptionally rare in cultivation. Small numbers of trees spread over a small area make the Chichibu birch particularly vulnerable to natural disaster and disease, exacerbated by deforestation. In 2014, only 21 mature individuals were identified, and the International Union for Conservation of Nature’s (IUCN) Red List categorises the tree as Critically Endangered. Oxford researchers are part of the efforts to save the Chichibu birch, in collaboration with the Bedgebury National Pinetum and the University of Tokyo Forest Chichibu. To date, work has included Rapid Botanical Surveys, the collection of plant samples, the development of germination protocols, and the establishment of living ex-situ conservation plantings at the Arboretum, Bedgebury and other sites, which are vital to the tree’s continued existence. Seed has been banked at the Millennium Seed Bank, RBG Kew, and shared with partners in Japan for reintroduction.

The Chichibu birch has been at the centre of collaborative Anglo-Japanese conservation efforts, with the use of seed banking and ‘in situ’ and ‘ex situ’ conservation. Since 2012, the Japan Project has seen the collection and ex situ conservation of over 400 woody and herbaceous plant species, and generated 4,500 herbarium specimens and 45 rapid botanic surveys of the flora, which will help inform the setting of conservation priorities. In addition to helping increase the chances of the survival of rare species such as the Chichibu birch and other endangered species collected as part of this project, staff at OBGA hope that this work will raise awareness about the plight of rare plants in general, at a time when two in five of the world’s plant species are threatened with extinction.
Related websites
Find out more about the Chichibu birch
OBGA’s botanical surveys of Japan
Oxford Botanical Gardens
Professor Simon Hiscock

"Oxford Botanic Garden and Arboretum have worked with the Botanic Gardens of Toyama to collect and conserve rare Japanese flora for almost a decade. This work has seen the collection and seed banking of over 100 plant species across Toyama Prefecture, many of which feature in the living collections on public display. The long-term importance of this conservation project was recognised by the signing of a Memorandum of Understanding between the two gardens in June 2018."

Oxford Botanic Garden and Arboretum