Survey of Japanese threatened plants in UK gardens
Japan is home to a greatly diverse and unique flora that is increasingly under threat of extinction. As centres for plant conservation, research, education and recreation, botanic gardens play an important role in the conservation and rehabilitation of threatened species.
In the latest cooperation between BGCI and the Japanese Association of Botanic Gardens (JABG) towards conserving Japanese plant diversity, BGCI has undertaken a survey of gardens and parks in the UK with the support of the Daiwa Anglo-Japanese Foundation.
The objective of this survey was to establish if any Japanese plants considered under threat of extinction in their natural habitat could be found in cultivation in the UK. The results and recommendations presented in this report are expected to stimulate and help prioritise collaborative actions between Japanese and UK botanic gardens towards achieving Target 8 of the Global Strategy for Plant Conservation (GSPC) through information-sharing on ex situ conservation of threatened plants cultivated in botanic garden collections.
The information-gathering process for this survey was carried out in stages and followed two main approaches:
- Garden focus: Recognised UK parks and gardens known to follow a Japanese style or cultivate Japanese plants were identified using the Internet and specialised garden databases, including BGCI’s GardenSearch database.
- Plant focus: Japanese plant collections and their location were identified by cross-referencing the 2007 Red List of Japanese vascular plants with the extensive plant collection registers of BGCI’s PlantSearch and the Tree Register.
The survey targeted a total of 229 gardens. Of these, 168 were found to have at least one accession of threatened Japanese plants in their collection. The survey identified a total of 1,028 records of threatened Japanese plants cultivated in the UK, representing 356 individual species (about 18%) of the 2,018 registered on the Red List of Japanese vascular plants across all IUCN threat categories, including a small but significant proportion of plants that are considered Extinct in the Wild or Extinct. The survey identified 106 threatened Japanese plant species in UK collections but which are not known in Japanese collections, including two species (Flemingia strobilifera and Hypolepis tenuifolia) which are considered to be extinct in Japan.
As the conservation security of species is increased by wider representation in ex situ collections, the study also looked at the number of different gardens cultivating individual species. The survey revealed that whilst some threatened Japanese plant species exist in several collections, the majority of species are only found in one or two gardens. The survey showed that about 70% of the threatened Japanese species in UK collections of are in the care of only 11 (albeit significant botanic) gardens, This indicates that high species diversity of threatened Japanese plants is not necessarily characteristic to Japanese-themed gardens, but is primarily found in botanic gardens.
Download the report here: