3. Biodiversity and the Museums
3-1 Research and Conserve Organisms in Japan
The role of museums and botanical gardens is not only to display preserved specimens or live plants and animals, but also to survey and research them. Survey research using an exhaustive collection has the potential to extract various valuable information regarding the properties of an organism species, and which can be used in situations to conserve threatened species.
Some examples from the National Museum of Nature and Science and Tsukuba Botanical Garden are introduced here. It is likely that facilities in your local area also carry out research on biodiversity conservation as well.
▼Research activities at the National Museum of Nature and Science and Tsukuba Botanical Garden
・Living collection of Japanese threatened plants
・Propagation of Japanese threatened plants by in vitro culture
・Animal specimens preserved in spirit
・Non-destructive extraction of DNA from insect specimens
・Ultra-low temperature freezer at -80°C
3-2 Specimens of endangered species are a valuable source of information
Many endangered species have lost their habitats and finding a new individual is usually difficult. Specimens are useful in analyzing changes in distribution, habitat environment, and phenology and life history, as well as to examine morphology and substances in the body of such rare species.
The National Museum of Nature and Science has surveyed collections of specimens of endangered species in Japan (endangered Class IB and above) in search of potential research material. As a result, at least one specimen of 95.9% of all endangered species in Japan are confirmed to be deposited at museums in Japan. At the National Museum of Nature and Science, specimens of 75.6% of the endangered species are deposited.
Japanese extinct species for which the specimens are preserved in museums
Lutra nippon
Eriocaulon cauliferum
Albatrellus cantharellus
Present status of specimens of endangered species (endangered Class IB and higher in the Red List 2019, Ministry of the Environment) which are held by the National Museum of Nature and Science and other museums in Japan.
Vertebrates
Land plants
Insects
Fungi and algae
Invertebrates excluding insects
Total
□Species for which specimens are held by the National Museum of Nature and Science.
□Species for which specimens are not held by the National Museum of Nature and Science, but are deposited at other museums in Japan.
□Species for which specimens are not deposited at any museums in Japan.
3-3 Contribution of a staffed specimen for reintroduction plans for Japanese rock ptarmigan
Lagopus muta japonica (Japanese rock ptarmigan) is an alpine endangered species which population has declined to almost half over the past 30 years. Causes for this decline include the encroachment of predators such as foxes, martens and crows into alpine zones, and the effect of global warming is also of concern. Isolated groups remain in the Kubiki, Northern Alps, Norikura, Ontake and Southern Alps Mountains, but it is extinct in the Hakusan, Central Alps and Yatsugatake Mountains. For reintroduction to the Central Alps in 2020, the Norikura population, which has the same genotype as the Central Alps population, was selected. Utilizing stuffed specimens of the Central Alps population, its genotype was identified by museum researchers.
□Extinct
□Extant
Japanese rock ptarmigan, female
3-4 Discovery of a rare species hidden among a wide-ranging salamander species
Onychodactylus tsukubaensis (Tsukuba clawed salamander) is a species endemic to Tsukuba Mountains, Ibaraki Prefecture, and was described as a new species in 2013.
Previously considered to be the same species as the Japanese clawed salamander which is widely distributed throughout Honshu, the Tsukuba clawed salamander was determined to be an independent species with unique genetic and morphological characteristics according to analysis of specimens in the museum’s collection and a new field survey. Its habitat range is only approximately 10 km from north to south and faces extinction due to habitat loss and the effects of global warming.
Currently, in addition to designation as critically endangered species in the Red List of Japan, survey of its habitat status and genetic diversity are underway in order to conserve this species.
▲The habitat of the Onychodactylus tsukubaensis is limited to higher elevations around Mount Tsukuba and Mount Kaba.
The distribution range of Onychodactylus tsukubaensis
▲Onychodactylus tsukubaensis, female
▲Onychodactylus tsukubaensis, larval stage
3-5 How to conserve biodiversity
There are two ways to conserve biodiversity- Protecting them in their native habitat (in situ conservation) and protecting them in facilities, etc. (ex situ conservation). Ex-situ conservation is conducted when the native environment has been significantly altered due to natural disaster or development, or wild individuals have become extinct due to diseases and pests. There are advantages and disadvantages to both in situ conservation and ex situ conservation. Therefore, to conserve biodiversity, the integrated use of both of these methods is needed. Moreover, for ex-situ conservation, since the genetic diversity of the rehabilitated population may differ from that of the original population, precaution is needed.
Two methods to conserve biodiversity
In-situ conservation- Eriocaulon heleocharioides is conserved in its original habitat within an area in Sanuma Pond, Shimotsuma City.
[Advantages]
●The original ecosystem can be preserved undisturbed.
● Evolution is not interrupted.
[Disadvantages]
◆The number of species that can be conserved is limited due to significant cost.
◆Large areas and multiple sites are needed to conserve the genetic diversity of one species.
◆If a part of the ecosystem is missing, sustainable reproduction will not function
Ex-situ conservation- Eriocaulon heleocharioides is conserved at Tsukuba Botanical Garden
[Advantages]
●Many species can be effectively conserved.
●Protection from natural and man-made disasters is possible
[Disadvantages]
◆The ecosystem involving the relevant species cannot be protected.
◆Species which are difficult to grow or propagate cannot be conserved.
◆ Evolution is interrupted.
Complementary relationship
3-6 Rediscovery and successful propagation of an endangered orchid, Liparis hostifolia
Liparis hostifolia (Orchidaceae) was considered to most likely be extinct, but was rediscovered after 79 years in Minami-iwo-to Island, Ogasawara Islands in 2017.
This orchid was successfully cultivated by Tsukuba Botanical Garden and subsequently bloomed. DNA analysis using specimens from approx. 100 years ago and the rediscovered material showed that Liparis hostifolia is an unique, evolved species in the Ogasawara Islands.
Artificial pollination was made and the seeds were collected. The seeds were then successfully germinated in a medium containing symbiotic fungi which had been isolated from this orchid. Hundreds of individuals have been steadily grown, and this orchid could be brought back from the verge of extinction.
Liparis hostifolia has bloomed at Tsukuba Botanical Garden. On the left, fruits from successful artificial pollination in the previous year can be seen.
▼Liparis hostifolia growing in shrub forest on Minami-iwo-to Island at an altitude of approx. 700 m.
▼Artificially pollinated Liparis hostifolia seeds are cultured in a medium containing symbiotic fungi. Optimal culture conditions are examined.
3-7 Ex-situ conservation of Eriocaulon heleocharioides
Eriocaulon heleocharioides is extinct in the wild, and can only be found in cultivation facilities such as botanical gardens. Tsukuba Botanical Garden has continued to study this species to prevent its extinction, to ensure propagation and conservation, and for its reintroduction into the wild.
The cultivation method suitable for in situ propagation of the plants and the suitable environment for them to be returned to the wild (the last native habitat where this species once grew) have been clarified. Currently, predation by non-native aquatic organisms, etc. are still a threat, but creating an environment where the plants can continue to inhabit has progressed.
▲Inflorescence of Eriocaulon heleocharioides, male flower, female flower
▲Eriocaulon heleocharioides conserved at Tsukuba Botanical Garden
3-8 Conclusion
Japan’s diverse natural environment has resulted in the birth and nurture of many endemic species. However, in exchange for the very comfortable and convenient life we humans enjoy, the habitats of other organisms have definitely been lost and the number of species at risk of extinction has continued to rise.
Revitalizing a species which at one time has declined to the verge of extinction and restoring it to its original condition is a task more difficult than we imagine, and successful cases are still rare. Precise technology and thorough planning are required, and many collections which include extant individuals and accurate information collected over the years are invaluable. Facilities such as museums which have a wealth of data, specimens and materials related to Japanese biota, bear an important role in the preservation of biodiversity in Japan.
Acknowledgment
We would like to express our thanks to all the people and institutions involved in the production of this touring exhibition for their cooperation.
With our sincerest appreciation.