The Multi-Dimensional Approaches of Botanic Gardens, especially in comparing Japanese and other Asian Botanic Gardens

Kunio Iwatsuki

Botanical Gardens, University of Tokyo,
3-7-1 Hakusan, Bunkyo-ku, Tokyo 112, Japan


Botanic gardens are urged to respond to global changes in multi-dimensional approaches. Asian botanic gardens generally suffer from their poor research facilities, though various trials are made to fulfil necessary contributions expected at the moment.

Biodiversity from genes to biosphere is the most attractive subject to be analysed in biology in the next century, as we are able to apply a variety of biological techniques in the levels from molecular to biospherical. Basic surveys of biodiversity, especially in the tropics, is another subject to be promoted urgently. We have established an Asian Regional Division of the International Association of Botanic Gardens, which is expected to promote a variety of collaborative efforts between Asian botanic gardens: actually we have been carrying out collaborative projects with our colleagues in Kunming, Nanjing, Bangkok and Bogor for some years.

Conservation of plant diversity is an urgent task to be done in botanic gardens, including basic research into it, and actual projects to protect it in nature, as well as to restore destroyed sites.

Basic surveys of the endangered plants in Japan were carried out in collaboration with local natural historians and botanists in botanic gardens and universities. A Red Data Book of the vascular plants was issued in 1989, and one for the non-vascular plants is to be published. Both the Japan Society of Plant Taxonomists and the Japan Association of Botanic Gardens are contributing to this project in collaboration with the Environmental Agency. We have also succeeded in having an Endangered Species Act passed this year.

The same kind of projects are also under way in China. As plant diversity is more prominent in China, basic floristic surveys should be carried out before we will know the effect of artificial changes in flora. Some of the endangered plants were enumerated from China, though many theatened species still seem to be unknown. There is a still worse situation in south east Asia, where destruction of the forests continues and they are in a dangerous condition.

Some of the endangered species are preserved by ex situ conservation. The Bonin Islands in Japan are oceanic and many of their endemic species are threatened. Some results of the successful efforts made by the University of Tokyo Botanical Gardens will be shown. These included basic research on native sites, ex situ propagation, and restoration of endangered species in the native sites. This work is connected with public education, collaborating with the people on the Islands.


It is generally recognised that botanic gardens now play a multi-dimensional role. Some of the aspects to be promoted may be summarized as:

a) Basic research in botanic gardens to elucidate the biodiversity of plants and its correlation with plant resources;

b) Conservation biology in relation to general surveys of threatened species and to aid in averting environmental crises;

c) Horticulture and landscaping to provide recreational areas, parks, and aesthetically pleasing surroundings in big cities;

d) Social education programmes for citizens to call attention to the importance of the activities cited above, and so on.

Japan is now one of the leading industrialized countries and is generally recognised as one of the richest countries in the world. Although it is true that some of the largest companies in Japan are very rich, the government itself is not rich and Japanese universities and botanic gardens generally suffer because of poor and antiquated research facilities. Since we are obligated to play a variety of important roles in botanic gardens, we cannot be content, however, to sit idly by complaining of the poor facilities in our institutions. In the past few years we have made various attempts to establish mutual collaborative arrangements among Asian botanic gardens, and I would like to summarize here some results of our efforts towards developing these activities.

Activities of the Japan Association of Botanic gardens

Botanical research in biodiversity

There are now some 120 botanic gardens in the Japan Association of Botanic Gardens (JABG). Only a few are research botanic gardens, and the largest amongst them is the Botanic Garden of the University of Tokyo. Our Gardens were established at their present site in 1684 and now have a history of over 300 years. At one time in the past our Gardens were the centre for botanical research in Japan, but now we have a research staff of only six members to contribute to basic research in systematic botany in relation to university education. Although our own staff is limited in number, postgraduate students, including some from Asian countries outside Japan, are contributing significantly to scientific research. In the past few years we have published over 20 original papers including contributions ranging from the molecular to the biospheric level and covering all land plants and applying a variety of modern biological techniques. One of the results of molecular systematics was to elucidate the monophyly of the gymnosperms as well as of the Gnetales. Contributions to the flora have been made in the Malesian region, especially on Kalimantan and Seram, in Thailand, and in southwest China, in addition to those made in Japan. The major work in Japan is actually resulting in a Flora of Japan in English edited by us in collaboration with most of the leading plant taxonomists working on the Japanese flora. Biosystematic analyses are various, including studies of the speciation of rheophytic taxa and the evolution of agamosporous as well as agamospermous species. We have observed the origin of variation in agamosporous ferns and elucidated:

a) Evolution through recurrent hybridization in Asplenium and Pteris;

b) Evolution by natural hybridization between diploid sexual and tetraploid sexual species, mostly worked out by an Indonesian botanist;

c) The origin of diploid agamosporous forms directly from triploid agamosprous forms, mostly determined by a Chinese colleague.

Through these efforts we are certain that we are contributing to various plant biodiversity studies.

Most other Japanese botanic gardens are still poorer in the size of their research staffs, and scientific contributions from other botanic gardens are far fewer in number. During the latter half of this century, when molecular genetics is the leading topic in biology, most biological research is taking place in universities and research institutions, not in botanic gardens. Most Japanese botanic gardens were established during this period to provide recreational facilities for busy citizens. Thus botanical research is ignored in most Japanese botanic gardens.

Endangered plants in Japan

The so-called environmental crisis has also confronted industrialized societies. In Japan we had serious pollution problems during the 1960s, and numerous attempts were made to overcome this crisis introduced by ourselves. Japan is now one of the leading developed countries where pollution has been reduced in comparison with the level of industrialization.

Our headache at the moment in relation to the environmental crisis is the increasing number of wild species seriously threatened with extinction. Our botanical gardens took a leadership position in compiling the Red Data Book of vascular plants, published in 1989, enumerating some 900 extinct, endangered, vulnerable, and indeterminate species. There are some 5500 species of vascular plant in the Japanese archipelago, and therefore 16 percent of the total flora, or one in six of existing species, is seriously threatened. Among them are: one of the seven popular autumn flowers, Eupatorium japonicum; a flower famous in Japanese classics published one thousand years ago, Lithospermum officinale ssp. erythrorhizon; familiar horticultural species such as Primula sieboldii, Adonis ramosa, Magnolia tomentosa; many beautiful species of orchids; and so on.

Of the factors suspected as threatening our flora, roughly one third of all species are seriously affected by land development, another third are threatened by over-collecting, especially by collectors hired by traders, and the remainder are species becoming rarer because of deteriorating environmental conditions such as increasing levels of CO2 and NOx, warmer temperatures globally, less green cover, and so on.

Conservation biology on threatened plants in Japan

Detailed research in the area of conservation biology has been carried out only in particular cases. One particular habitat for Primula sieboldii, where more than a thousand individuals bloom beautifully every year, has been conserved for more than 60 years. This is often cited as one of the most successful examples of a conserved area. In spite of such an interpretation, we are pessimistic about the future of this site. Although P. sieboldii blooms heavily every year, it is important to note that there are no juvenile plants of this perennial species within the conserved area. The species is typically outbreeding because of the heterostylous morphology of its flowers. The four-hectare conserved area is surrounded by industry, residential areas, schools, and even by a golf course, and is in the midst of a large metropolitan area. Insect-pollinated species require numerous visits by insects in order to set seeds, but no fertile seeds are produced by P. sieboldii at this site. In fact no other insect-pollinated species grow at this site. Although these plants occupy a four-hectare conserved area, their reproductive biology is essentially the same as for plants cultivated in pots. Although growing in a natural site and rooted in the earth where they germinated, populations without a complete natural life cycle are living only under artificial controls.

Another case is that of an endemic species native in natural forests. Farfugium (Compositae) is represented on the island of Yakushima by two species, F. japonicum, and F. hiberniflorum. F. japonicum is widespread in open areas. On Yakushima it originally occurred only along the coastal zone, for the island is heavily covered by forests to its summit nearly 2000 m above sea-level. In the dense forests is F. hiberniflorum, a species endemic to Yakushima. The majority of the island is now within a national park and forests are not allowed to be cut, except in some residential areas near the coast. However, logging of the expensive Yaku-sugi, a special ecotype of Cryptomeria japonica prized for its wood, was historically carried out, and passable roads extend to the higher elevations of the island. Farfugium japonicum now extends to higher elevations along these roads and hybridization has been observed between the two species of this genus. Dispersal of the genetic material of F. japonicum into the F. hiberniflorum population is seriously affecting the identity of the latter species. Thus complete green cover over developed areas on this valuable natural resource area is highly recommended.

We also have oceanic island groups, such as the Ryukyus and the Ogasawara Islands, and the floras of these islands are also seriously endangered. The Ogasawara Islands, or Bonins, have a unique flora of which 30 percent of the species are endemic. More than 80 species on these islands are seriously threatened. Rhododendron boninense is known only from one stock at its native site, and Calanthe hoshii appears to have become extinct on these islands. Melastoma tetramerum is another example of a plant surviving on these islands by only one stock. As this species is inbreeding, mature seeds are available by the thousands every year. Although it was said to be difficult to germinate them, a method for artificial reproduction was established and restoration at its natural site is under way with good results. Hundreds of stocks of Melastoma tetramerum are now on Chichi-jima, and are being carefully monitored by the local government officers. The local people now collaborate with us and are expecting to witness the natural regeneration of this endangered species. The people on the island understand that it is rather easy to damage the natural environment, thereby endangering many species, but quite difficult to restore a population of endangered species at its native site.

Activities of the JABG in plant conservation

Through the activities of our own botanic gardens, we recommended that JABG members join with us in confronting this serious environmental problem. Most of the gardens are suffering because of reduced research staffs, but they have found their own ways to collaborate with us. When the Tokyo Metropolitan Jindai Botanical Park celebrated its 30th anniversary, it prepared a special exhibition of endangered species. Through this example of social education they were successful in giving information on this crisis to the general public. The Yomiuri-land Botanical Garden is privately funded and asks as many visitors as possible to contribute an entrance fee, using this to prepare a variety of interesting species for exhibition. Moreover, a native site of Asarum tamaense, an endemic species in their area, is carefully conserved within their garden as an example of in situ conservation of an endangered species. The Medicinal Garden of Kyoto Pharmaceutical College has a good collection of various races of Paeonia. The Kyoto Prefectural Botanic Garden, which recently established a very good glasshouse, is also famous for preparing a series of special exhibitions through which they encourage the local people to contribute to genetic resource conservation by cultivating local races of particular species that are abundant in the Kyoto area but are seriously endangered.

In harmony with nature

These conservation efforts are now recognised by the mass media, and the crisis in endangered species has become better understood in Japan generally. We were therefore successful in passing an Endangered Species Act which will become effective next year after careful analysis of its various conditions. Such Acts are usually not perfect and are not a final focus of our activities. We need to carry out more careful research to protect nature to save our potential genetic resources as well as to conserve our global environment.

In 1990 we held the successful Expo '90 in Osaka, focussing on flowers and greenery. After this big event, we now have an Expo '90 Foundation which has contributing towards promoting the harmonious coexistence of human beings and nature. The botanic gardens of Japan are collaborating in establishing more opportunities for citizens to be close to flowers and greenery. In conjunction with this new awareness, we will establish a large international prize to be awarded every year to a person or group who contributes significantly towards increasing man's harmony with nature. To promote this idea, we will also have an information journal and an international network sponsored by the Expo '90 Foundation.

Asian Division of Botanic Gardens Association

The collaborative activities in the JABG developed the idea that this type of collaboration should be extended. There are popular botanic gardens in Asia, particularly in Calcutta, Peradinya, Singapore, Penang, and Bogor, and some of them have made major botanical contributions in the past. But most Asian countries are still developing and their botanic gardens are suffering from inadequate facilities. Yet the environmental crisis is more serious in those areas.

Thus the JABG proposed the establishment of an Asian Regional Division of the JABG to promote collaboration amongst Asian botanic gardens. This organization was formally established in May 1991. The JABG-AD is still in its juvenile stage and we need to nurture it carefully to maturity. We now have information exchange by means of newsletters through which some bilateral collaborative projects have actually been started. National associations of botanic gardens have been formed in various countries, particularly in China and South Korea, and the exchange of information can now take place much more easily among Asian botanic gardens. If we can collaborate with each other to fulfil our role in the future, we will be better able to develop ex situ conservation of plants and carry out research, and to protect threatened plants in the gardens most suitable for the species concerned. In Asia there botanic gardens in areas of various ecological conditions: in the moist tropics, in cold to warm temperate regions, near the sea coast, in high mountains, in dry areas, and so on. If we can establish perfect collaboration between our members, we will not require specially constructed, expensive, climatically controlled facilities for the preservation of endangered resources. Such collaboration would be convenient for Asian botanic gardens that cannot expect substantial financial support at the moment and yet bear a heavy obligation to address critical social issues.

Endangered plants and restoration

As to the present crisis of threatened plants, we need to develop a much better understanding within the general public. The JABG and the Japanese Society of Plant Taxonomy have formed a special committee to treat the endangered species crisis in collaboration with the Environmental Agency. The mass media, TV and newspapers, are supportive of our efforts and we have published and are preparing popular books to provide information on the problem. This crisis is better recognised by the botanic garden people in Asia, but mostly by specialists. Attempts to inform the local populations on this subject are under way in various countries, and the JABG-AD will aid these efforts.

The dynamics of the flora have not been surveyed in most parts of Asia. In Japan, where we have more information, conservation biological analyses will be carried out. This type of basic study should be increased to provide a sounder foundation for the conservation of nature.

The role of botanic gardens is multi-dimensional, and we, the botanic gardens in Asia, are undertaking a complicated task, even though our facilities are insufficient. Collaboration of the botanic gardens in Japan, as well as in Asia, will promote such a course to fulfil the duty of botanic gardens to provide a glorious life for mankind in harmony with nature.

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