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De-Accessions Policy for Plant Collections: Responsibility Versus Practicality

Volume 2 Number 2 - July 1993
David Rae

Many collections of live plants in botanic gardens are amassed to support the research work of taxonomists. Good examples at the Royal Botanic Garden, Edinburgh include the extensive Zingiberaceae collection made by Miss R. Smith and the south-west Asian plants gathered by Mr A.G. Miller. These types of collection may incidentally include rare or endangered species but, more recently, there have been initiatives to amass entire ex situ conservation collections, such as the Edinburgh-based Rare Conifer Conservation Programme. From a conservational point of view there are important differences between the two types of collection. In one, the plants have been gathered to support taxonomic work and there will usually be only a few individuals of several species. In the other, there will typically be many individuals of fewer species. This paper is restricted to the disposal of plants from the first type: taxonomic collections, but assumes that the colection will include plants of conservation status.

Botanic gardens in which collections of living plants are used to support in-house research tend to be unlike other gardens because, when a particular line of research ceases, a large number of plants may suddenly become redundant and could be disposed of. The accumulation of these plants will have taken considerable time and skill, to say nothing of the costs involved. Such collections may be considered unique, even priceless, biological research tools and serious thought should be given to any other uses to which they could be put before breaking them up; once dispersed they almost certainly could never be reassembled. The disposal of any such unwanted plant material poses problems for curators but when the collection contains species of conservation importance additional problems arise. On the one hand, space is required for new collections, so curators will want to dispose of as many plants as possible as quickly as possible, but on the other hand, most will appreciate that there is some moral obligation not to dispose of rare, threatened or endangered plants. The dilemma is one of responsibility versus practicality.

When the collection has no conservation value there are few problems and the plants can be gifted, sold or composted. However, what should be done when the collection does contain plants of conservation value? What should be kept, what can be destroyed and is there such a thing as responsible disposal? At the Royal Botanic Garden, Edinburgh, the Conservation Advisory Committee has been attempting to formulate a series of steps that can be followed by curators when breaking-up long established collections that are no longer required for research. The discussions are at an early stage but before going any further it would be useful to receive comments from others who face similar problems. Once a deaccessions policy has been formulated it will be added to the accessions policy of the Garden and the two together will create a fundamental plant management tool so that managers, staff and other interested parties can have a clear idea about how and why plants enter and leave the Garden. This paper now lists the series of steps that have been suggested so far for dealing with "redundant" collections.

For the whole collection:

  1. Check that all the plants have been named and that the names have been verified recently.
  2. Ensure that the cultivation and propagation requirements for the group in general are well understood and recorded.
  3. Preserve and photograph specimens of the most important species, unless this has already been done in the course of taxonomic research. At present traditional herbarium sheets and spirit collections offer the only practical way of preserving plant material and from these at least the morphological structure of plants can be studied. In the future it should be possible to preserve samples of intact DNA.
  4. Decide which are the "conservation" plants. These are species that are rare, threatened or endangered in the wild. This should have been determined when the collection was being cultivated but it must be checked again before disposal as the status might have changed. If in doubt about status the following groups or sources should be consulted: Botanic Gardens Conservation International; IUCN Species Survival Commission Specialist Groups; World Conservation Monitoring Centre; the taxonomist who has been working on the group; a botanic garden, government agency or natural history society in the country concerned.
  5. Dispose of the non-conservation plants; try to disperse as a collection rather than as individuals.

For the conservation plants:

  1. Ascertain the cultural and propagation requirements of each species. Record the results. It is obviously better to start doing this while the plant collection is being amassed and worked on rather than at the end.
  2. Preserve and photograph all the plants. Most of this work will have already been done at step 3.
  3. Offer the collection to another botanic garden that has an interest in the group. This option is likely to offer the best long-term survival as plants will be tended more carefully in an institution that has a special interest in the plants (be it for research, display or cultural purposes) rather than in a garden that has only a general interest. However, there can be no guarantee that this botanic garden will want to keep the plants indefinitely.
  4. Offer the remainder to a botanic garden in the plant's country of origin.
  5. Consider reintroduction. Arguably this should be at the top of the list but the many problems, such as the availability of suitable sites for reintroduction and their future management, coupled with the very few successful reintroduction trials that have been carried out as models, mean this is not yet a practical option. At present, botanic garden collections that have been accumulated to support taxonomic, rather than conservation aims, typically have very few accessions of each species and a policy of reintroduction based on asexually propagated plants from the same individual would be seriously flawed. The reintroduction debate is currently very vigorous but the scientific principles and field practicalities are slowly emerging. In future, this may be a serious option for the "leftovers" of taxonomic research but at present they are probably best left out of such programmes. However, if it is considered, then it should be done in conjunction with the appropriate authorities in the country concerned and as part of a planned species recovery programme.
  6. Offer the plants to a nature reserve nearest to their original collection point.
  7. Keep the accessions as seed if possible, after taking appropriate precautions to avoid hybridization; alternatively, investigate the possibility of keeping them as micropropagules, or as deep-frozen in vitro tissue.
  8. Offer them to a gifted amateur if realistic assurances can be given about their futures.
  9. If the plants are of the same accession as other individuals grown in at least 5 other botanic gardens then they can be disposed of, but ensure that the other gardens are informed.
  10. If they are of different accessions or if they are grown in less than 5 other botanic gardens and cannot be responsibly gifted, then there is an obligation to keep them until any of the above criteria can be met.

These steps are intended to be responsible yet practical and realistic. There can be no guarantee that a plant gifted to another institution will be held for ever but the procedure outlined above has been designed to bestow a reasonable degree of security on conservation plants held in botanic gardens.

I would emphasise that these are still proposals rather than policy at Edinburgh and any comments will be welcomed. Once the ideas have been refined they will be applied to a group to test practicality.



Ex Situ Conservation

Ex situ conservation is the conservation and maintenance of samples of living organisms outside their natural habitat, in the form of whole plants, seed, pollen, vegetative propagules, tissue or cell cultures.

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