GENMEDOC an inter-regional network of mediterranean seed banks

"ex situ" conservation

The ex situ conservation consists of a series of actions in the framework of which the endangered plant and animal species that have to be protected are removed from their natural habitats and secured under the protective surveillance of man. This constitutes a fundamental strategy of conservation that is particularly applied to rare and threatened species, when the “in situ” strategy is not feasible or is insufficient.

The usual places where ex situ conservation takes place are: Zoos, Aquariums, Vivariums, Botanical Gardens, Arboreta and Banks (of seeds, pollen, cell cultures, etc.). The role of these structures is not only to conserve the species and their genetic heritage in adapted conditions, but also to sensitize the public to the importance of protecting biodiversity and to make the material accessible for research (basic or applied) in order to develop our knowledge regarding the life cycle of various species and to elaborate ex situ all the strategies that have to be gradually experienced in situ, with the intention of reconstituting or restoring degraded natural ecosystems.

The Botanical Gardens and the Conservation Centres play a key role in averting the impoverishment of the vegetal world, on account of the studies they perform and the information they provide. Speaking of numbers, at present there are more than 2.000 Botanical Gardens & Arboreta in 153 different countries around the world, which attract in total around 150 to 200 millions visitors per year; their herbaria preserve approximately 142 million specimens; about 80.000 different species are cultivated and conserved on their premises. And if, besides the number of species, the total number of subspecies, cultivars, varieties, forms, hybrids and other taxonomic entities is calculated, the numbers double and reach a total of 160.000 cultivated taxa. Photo of the Botanical Garden of Catania (from left to right): with night lights, a visit of schoolchildren and the Sicilian Garden (© 2005 Pietro Pavone).

Concerning the plant kingdom, ex situ conservation anticipates a long term commitment, the use of rather complex procedures and a good knowledge of the reproductive biology of the species to be protected, the latter being essential for collecting material and for obtaining good specimens without damaging the natural populations.

Some aspects of ex situ conservation, such as seed and pollen conservation and living collectionses, are well known as from long ago; other aspects, such as in vitro conservation and DNA conservation are more recent and sometimes controversial. These are techniques adapted to the conservation of both wild and cultivated species.


Photo : (left) The French Mediterranean Botanical Conservatory of Porquerolles and (right) the Institute of Arid Regions at Medenine (Tunisia). (© 2005 Pietro Pavone).