The first institution in the world created with the sole purpose of conserving threatened plant species celebrated its 40th anniversary in Brest, Brittany, last year.
The Conservatoire Botanique National (CBN) was founded in 1975 by Jean-Yves Lesouëf and the Bretagne Vivante association in collaboration with the mairie of Brest and the Ministry of the Environment.
“Our priority is the conservation of species in nature,” said Dominique Dhervé, the present-day head of the CBN. It is responsible for the conservation of plants in the Massif Armoricain (comprising Lower Normandy, Brittany and the Pays de la Loire, excluding Sarthe), but also conducts its work in areas with globally significant biodiversity, such as Madagascar.
At the heart of the CBN’s work is a vast bank containing seeds from about 2,000 plants that are rare, threatened, or have disappeared from nature.
It is also home to 2,500 more common plant species, which can be seen in its botanic garden and tropical greenhouses, open to the public.
The size of the CBN’s seed stock makes it one of the largest collections of endangered plant seeds in the world: it is rivalled only by the stocks housed in the Royal Botanic Gardens at Kew and Edinburgh.
In order to be classified as a threatened species, a plant must exist in only very small numbers in nature and have experienced an ongoing strong decline. It is the interaction of these two criteria that determine the level of threat faced by a species.
A third criteria that is sometimes applied is the presence of the species in cultivated – as opposed to natural – habitats. In other words, unless it thrives in the wild, a species can be deemed to be threatened even if it has been cultivated in significant quantities.
In collaboration with Bretagne Vivante, the CBN had an early conservation success with the Narcisse des Glénan (also known as the Narcissus triandrus), native to the Glénan archipelago in the Finistère. This had all but disappeared by 1985, when only 6,500 individual plants were counted; as a result of conservation work by last year 271,000 were counted.
More recently, the CBN has successfully begun to reintroduce wild tulips to vineyards in the Pays de la Loire, where modern agricultural practices caused them to decline.
Conserving a threatened plant species that can still be found in nature, albeit in tiny numbers, is extremely difficult. Reinvigorating a species that has already disappeared is an even greater challenge. As Mr Dhervé explains, this is where new technologies come in.
The CBN has had one of its biggest successes with Cylindrocline lorencei, a plant species native to Mauritius.
The species had disappeared entirely from its natural habitat and, even in Brest, the only remaining specimen was a single seed. Parts of that seed had already died off, leaving just a few living cells.
Mr Dhervé said: “Of course it was impossible for us to sow the seed, which was mostly dead, so we were left with no other option than to try in-vitro fertilisation.”
This technique was used to multiply the number of living cells, which in turn generated around half a dozen plants – an intervention that brought the species back from the brink of extinction. Since 2012, the CBN has had a programme of reintroducing plant species including the Cylindrocline lorencei to Mauritius in the hope that they will once again flourish in the wild. Mr Dhervé said: “The government in Mauritius has a strong policy to support this conservation work and this gives the programme a good chance of success.”
The CBN’s work is carried out by its 40 full-time employees. Mr Dhervé explains that it also calls upon the services of a network of more than 600 volunteer amateur botanists, who conduct surveys and submit their observations. A significant proportion of the CBN’s data derives from this information, without which progress would be slower.
Even with a seed bank and research base as extensive as that found at Brest, the task of conserving threatened plant species in a rapidly changing environment requires the CBN to engage in politics at every level – from the international to the local.
It also has to engage with the public and businesses to sensitise ordinary people to the need to preserve what exists naturally all around them.
Its public engagement activities fall into four categories.
The first category consists of getting involved in development projects in the west of France that could disrupt nature: “If a new railway is proposed, we get involved from the outset. If there are species at risk that lie in the path of the railway, we see how the project can be adapted to limit its impact.”
The second category involves helping nature reserve and park managers, to ensure that they are able to safeguard the species in their care properly.
The third category deals with regulation: the CBN helps to amend and update the lists of plant species that are protected and banned under legislation.
Finally, it has an extensive education programme that involves working with schools and students and providing professional training, as well as public information via its website, garden and exhibitions.
A significant area of growth for the CBN is its work with the farming community. Mr Dhervé said: “This is a very important development since farming is absolutely key to conservation work.”
His organisation is increasingly called upon to provide assistance and training to farmers – who do not necessarily have a good understanding of biodiversity, or the impact of various modern farming practices on the land they farm.
One project under way is the reintroduction of les plantes messicoles – the hardy annual blooms such as poppies and cornflowers that have traditionally grown alongside grain crops – to agricultural land in Normandy.
Other areas the CBN plans to focus on are the raising of awareness among other conservationists and the public, and the development of aerial survey technology to help in the counting of plants.
One of its principal means of disseminating information to the public is through visits to its botanical garden and tropical greenhouses, where many of the 4,500 plant species, including some close to extinction, can be viewed by the public.