Establishment and implementation of ex situ conservation

Ex situ conservation is the conservation of biological diversity outside its natural habitat. It involves locating, sampling, transferring and storing samples of the target taxa for conservation away from their native habitat (Maxted et al. 1997). Since the Convention on Biological Diversity (CBD) (CBD 1992), ex situ conservation as been seen—at least for the broader biodiversity conservation community—as a safety back-up strategy to provide security for the favoured in situ approach. While recognizing that it would be foolish to implement a National Strategic Action Plan (NSAP) for the conservation and sustainable use of CWR and to establish key national conservation areas without a safety back-up to help guarantee long-term conservation of the populations, it is recognized that CWR diversity has historically been almost exclusively conserved ex situ. It can be argued that ex situ collections provide the most practical means of access to germplasm by the user community. At least in the short-term, how many plant breeders or researchers are likely to approach PA managers for germplasm to use in their breeding programmes? As ex situ conservation provides the practical route for germplasm access for the user community, even if populations are adequately conserved in situ, there is still an imperative to duplicate diversity ex situ for the benefit of the user community. Conversely, in situ conservation has a unique role in maintaining the process of adaptation to changing environments, which is not possible with ex situ conservation; each ex situ accession is a snapshot of that population’s diversity at the time of sampling. Both ex situ and in situ techniques have their advantages and disadvantages and should not be seen as alternatives to one another, but as complementary strategies.

There are a range of ex situ conservation techniques available (see Ex situ conservation techniques), but, for CWR, seed storage in genebanks predominates as it is usually the most practical ex situ conservation technique. This is because the vast majority of CWR have orthodox seeds, which means they can be dried and stored at -18⁰C without loss of viability.