Botanic Gardens and Plant Science: a Changing Relationship

Ghillean T. Prance

Royal Botanic Gardens, Kew,
Richmond, Surrey, TW9 3AB, UK.

Abstract

A mark of a good botanic garden is its ability to adapt to changing circumstances but at the same time provide a high quality amenity and a good science programme. Science in botanic gardens is changing today because of the environmental crisis and so they are much more involved in the conservation of endangered species and the promotion of sustainable use of plants. There are many new opportunities in molecular studies and micropropagation techniques but the basic inventory of the plants of the world is not yet complete and so there is now an even greater urgency for systematics to provide the basic framework of knowledge about plants. There is need for more precise information about evolutionary relationships between species in order to make more rational choices about which species are most important to save. Data basing is becoming progressively more important to a modern botanic garden both for catalogues of living and herbarium collections and as a research tool for systematics. Botanic gardens can address environmental problems both through in-situ work on conservation and sustainable use of ecosystems and the ex-situ conservation of living plants and seeds. It is important to interpret the work of botanic garden science through active education programmes.

Introduction

Adapting to change is nothing new to the research programmes of the major botanic gardens of the world. The earliest ones were founded to grow medicinal plants and later in the nineteenth century many gardens were created to promote what we would today call economic botany. For example, the Royal Botanic Gardens, Kew, in its early days was deeply involved in the interests of the British Empire moving such crops as breadfruit Artocarpus altilis and quinine Cinchona around the world. The British moved rubber Hevea from the New World to the Old World and the Dutch took coffee Coffea from the Old World to the New, in both cases via botanic gardens. However, in spite of this leading motivation for the support of botanic garden science, many gardens also established herbaria and supported taxonomists to collect, identify and classify the plants of the world. Fortunately this activity has continued over time. Botanic gardens offer a unique opportunity for long-term research projects that require stability. Floras and monographs remain a vital and basic need today and they can only be brought to completion if the research programmes of botanical gardens offer the necessary continuity without letting the necessary changes in research emphasis diminish the importance of inventory and documentation of the plants of the world. Science in botanical gardens requires both an adaptability and a stability if it is to fulfil its mission. Today, as we face a serious environmental crisis, botanic garden science is deeply involved in matters of conservation and sustainable use of ecosystems, but the basic inventory still continues.

Global Change

The environmental crisis of today is real and botanic gardens must be prepared to be involved. We cannot ignore the consequences of increasing population and poverty and the resultant destruction of natural habitats and loss of the species which we study. The rise in atmospheric carbon dioxide is already causing a small rise in the average temperature of the world and more drastic local climate changes are occurring. The developed world is putting great pressure on the developing world by its unbridled consumerism which is causing pollution everywhere. There is no need to elaborate further on the global changes to which our research must adapt because the media are now doing a good job of making us aware of all the aspects of global change.

Whether or not the freak storm that blew down a thousand trees at Kew in 1987 or the storms that have recently devastated the Fairchild Garden in Florida and the US National Tropical Garden in Hawaii are related to climate change, these events demonstrate the need for gardens to be ready for change. In the case of the storm at Kew our scientists made great use of the opportunity of having the roots of 200 species of trees upturned. The result of the storm has been books and papers on root biology and anatomy, analysis of tree rings and tree growth through periods of pollution such as the time of the London smogs, and extensive chemical work on roots (Cutler et al. 1989; Gasson and Cutler 1990; Hooper et al. 1990). Many gardens sent teams to the Fairchild Garden to collect data for science and for propagation of the rare species that were devastated by the recent storm there.

For botanic gardens it is essential that we develop a mission which addresses some of these problems and so the contemporary mission of Kew is summed up in our mission statement:

The mission of the Royal Botanic Gardens, Kew is to ensure better management of the Earth's environment by increasing knowledge and understanding of the plant kingdom - the basis of life on Earth . . . we will endeavour to reduce and reverse the rate of destruction of the world's plant species and their habitats.

This is quite different from the emphasis of our mission a few years ago. To fulfil this mission we need new programmes in ethnobotany and economic botany, but at the same time we are continuing the basic research on taxonomy and inventory at the same pace as before.

Living Collections

The greatest asset of botanic gardens that differentiates them from research museums or many university botany departments, is their large collections of living plants. When those are mainly collections of fully documented species from the wild they become an essential part of both research and conservation. The collections are no longer just curiosities for our visitors to see or for use in education programmes, they have again become a more vital part of our research because of the environmental crisis. Botanic gardens house many rare and endangered species and even species which are extinct in the wild. At Kew our living collection of 33 000 taxa contains 15 species that are extinct in the wild and 2500 that are included in national lists of threatened and endangered species. It is not surprising that our research work now has a micropropagation unit that does much work to multiply these rarities and that we are deeply involved in programmes of reintroduction to the wild of many species both within the United Kingdom and around the world. Many other gardens are involved in similar programmes, for example, the Tokyo University Botanical Garden is propagating and reintroducing plants into the southern islands of Japan.

The advent of modern molecular techniques enables us to look at the genetic variation and population structures of the species that we are seeking to conserve or reintroduce into the wild. At Kew we are striving to save the last remaining individual of the lady's slipper orchid in Britain Cypripedium calceolus. Our micropropagation unit is carrying out research on germination and establishment of seedlings and our molecular systematics department has a Ph.D student doing his thesis on the fingerprinting of this orchid to find out which of the known wild source individuals known in cultivation are the best to cross with each other.

Some gardens have space to grow viable populations of certain species. This approach is being encouraged in North America by the US Center for Plant Conservation in St Louis, and in this conference we have heard about the recently formed Australian Network for Plant Conservation Richardson and Meredith, this volume. Many gardens are developing satellite gardens to enable them to grow larger numbers of native species, for example, the Royal Botanic Gardens in Sydney. At Kew we are able to conserve a sample of the Sussex Wealden vegetation at our satellite Wakehurst Place. The active management of these collections for the conservation of certain species has become an important part of botanical garden science. In situ conservation, whether it is in our own properties or through helping to manage other areas, has become an integral part of the programme of many contemporary botanic gardens.

Adapting Research to Global Change

I have already stressed the importance of allowing basic research on systematic botany to continue as we seek to expand our research programmes into many other fields. However, systematics can now do much more than produce the essential taxonomic framework for knowledge about plants. Much greater use is being made of the data that tended to remain hidden in monographs and floras. An important change in systematics is the greater use of research information to define centres of endemism, centres of diversity, biogeographic regions such as phytochoria and other phytogeographic subdivisions. These are now being used to select conservation areas in many parts of the world, for example, the work of Wetterberg in Brasil (Wetterberg et al. 1976) which incorporates much basic phytogeographic data. Botanic gardens must continue to encourage their systematists to produce the types of analyses of their data that are useful for conservation planning. The study of population variation from molecular systematics and data about animal-plant interactions are also offshoots of taxonomic work that are useful for conservation planners.

An aspect of systematic research that is becoming more important for conservation is the knowledge of evolutionary relationships between species. Unfortunately we are losing species, and sometimes hard choices between which species to save and which to allow to become extinct have to be made. Much more rational decisions can be made when adequate cladistic work has been done. From the position on the cladogram it is possible to see which species will contribute the greatest diversity for the future (Williams et al. 1991).

The herbarium is not only a resource for taxonomy but it is also a wealth of information about plant uses. Modern computer database methods allow us to compile the information that is lost on herbarium labels into a readily usable system. At Kew we continue to build up the SEPASAL database of information on the useful plants of arid regions. This database contains far more than herbarium label data and it is a useful resource for field work on the establishment of sustainable land use in arid regions (Lucas and Wickens 1988). The data has been taken largely from the herbarium and library of a botanic garden.

The basic phytogeographic data is a resource for conservation planning and databases such as SEPASAL are resources for developing sustainable land use. The global changes today are leading botanical garden science into this field of sustainable land use because our solid base of information means that we have much to contribute to this area if we collaborate with other disciplines. In the long run we will conserve many more species if we maintain a good balance between conservation and utilisation in our research programmes following the recommendations of the World Conservation strategy recently updated (IUCN, UNCP, WWF, 1991), the Bruntland Report World Commission on Environment and Development (1987) and of the recent UNCED conference here in Rio de Janeiro. The Institute of Economic Botany of the New York Botanical Garden is meeting this new challenge to botanical science with its work on indigenous agroforestry, extractive reserves and new crops for rainforest regions. Kew is doing similar work in the arid regions of the world especially in our Projeto Nordeste here in Northeastern Brazil. Significant results from both these groups and also from the research programmes of other botanical gardens are now being published (for example Wickens et al. 1985.)

Work on quantitative ethnobotany of the Amazon Indians (Prance et al. 1987; Boom 1985, 1990) is providing data for the establishment of extractive reserves in Amazonia. The study of the indigeous agroforestry of the Bora Indians of Peru (Denevan & Padoch 1988; Denevan et al. 1984) and of the Kayapó in Brazil (Posey 1984a;b; Hecht and Posey 1979) is providing leads towards sustainable agroforestry in Amazonia. Work on the babassu palm Orbignya phalerata (Balick 1987; May 1990; May et al. 1985) is helping us to understand how this multi-use palm, which grows in natural clusters, can be used much more effectively as a source of oil and fuel, and a germplasm bank has been set up for species of the genus Orbignya. Botanic gardens are the ideal institutions to search for new crops because of the vast bank of information which they contain about plants. They also have the growing capacity for experiment with the plants which they indicate as potential crops. To be faithful to the mission of botanic gardens they will work on plants that will contribute to the sustainable use of land rather than to new crops that will destroy natural habitats further.

For many years annual seed lists produced by many botanic gardens have played an important part in the distribution of plant material around the world from one garden to another. Today seed banking, where the seeds are stored permanently for the purpose of conservation, is becoming much more important. At Kew we have put considerable emphasis and resources into this aspect of science. We have a seed bank of our 5000 wild species stored at reduced temperature and humidity (Smith 1985). The seed bank concentrates on seeds of arid regions, especially of those species that are in the SEPASAL database, threatened species from other regions and on the British Flora. Accompanying the seed bank is a team of researchers working on aspects of seed conservation, especially on how to cope with recalcitrant species. This year we are installing a cryogenic storage capacity so that we can experiment with the storage of tissue. The direct application of seed storage and seed research to the global change is obvious and so this is the area of botanic garden research that is increasing and already 144 gardens world-wide have some sort of low temperature seed storage facility.

Other areas of our research which might seem to be unlikely contributors to address environmental problems include our wood anatomy department. With its database on wood properties for the purpose of identification it has now become involved in fuel wood programmes in Africa and Brazil (Prior and Cutler 1992). The knowledge about wood properties can be used to seek likely candidates for fuel wood plantations which are important to protect natural ecosystems from overexploitation for wood. Our chemists are looking at the properties of medicinal plants to find which ones that are used in local folk medicine are likely to be effective cures and should be grown by local people who cannot afford to buy pills from the drug store.

Education and Local Example

Although my allocated subject is science in botanic gardens I cannot finish without saying a few words on other aspects, because they are so intimately linked to the new research opportunities of gardens. The education programmes must now have a content that clearly reflects the new mission that we have in today's world. The youngest pupils in school groups to the oldest pupils in our continuing education programmes offer us a unique opportunity to carry the message of our science and of the global crisis to a wide audience. I hope that we will all take this opportunity and make sure that educationalists interpret our message to the world and that our scientists share their data with those whose responsibility it is to educate through classes, museums and interpretive labelling throughout our gardens.

In our gardens we have an opportunity to set an example of contemporary environmentally-caring lifestyle. We need to build buildings that conserve energy and give an environmental message; to recycle our waste products whether they be computer printouts from our offices or organic products from the garden. Two of our most important successes in this area at Kew have been the introduction of biological control of pests in our main greenhouses and the substitution of peat with coir as a growing medium for our potted plants. Both these changes involved considerable research by our horticultural staff, but as a result we no longer subject our gardeners or our public to toxic chemicals and we are no longer destroying the peat bogs of Europe by using vast quantities of peat.

Botanical garden science will continue to play a vital role in the world if we both adapt to the new challenges open to us by global change and maintain the stable resource environment whereby we can embark on long-term taxonomic research and long-term plantings for future generations. In this paper I have outlined many aspects of botanic garden research that can help to fulfil our role in addressing the environmental crisis which we face. I am fully aware that not all gardens can have the luxury of as extensive a research programme as Kew. When resources are limited it is important for gardens to chose one or two of these areas and do them well rather than try to do everything poorly. Many aspects can be done on very limited funds, such as basic taxonomic work, vegetation inventory, the preparation of florulas, work in floral biology or ethnobotany; other fields require greater resources. This meeting and indeed the whole work of Botanic Gardens Conservation International is encouraging networking. We need to make sure that our scientific research efforts are also well coordinated through the network that we form. There is so much scientific work to do to save the plant species of the world and the habitats in which they grow that we must all work closely together. Some gardens will make large contributions to science and others smaller ones, but if these efforts are coordinated even the smallest contributions will be a most vital part of the total effort.

References

Preface  |  Contents List  |  Congress Report  |  Workshop Conclusions  |  List of Authors