One of the most important roles of botanical gardens for conservation is certainly environmental education . Each year, more than 150 million people visit the gardens of the world and thus have the opportunity to get in touch with nature. Botanical gardens are a unique environment to raise awareness and the importance of biodiversity to the general public, to help them become aware of current threats and to realize that nature conservation is deal with each of us. Hence the importance for gardens of maintaining interpretive programs, hosting school groups, exhibiting, etc.
The second obvious role of botanic gardens for the conservation of biodiversity is ex situ conservation . Ex situ conservation , that is, the cultivation of wild plants out of their environment, has several advantages, but it should not be seen as an objective in itself. It is rather one of the elements of a global strategy for the conservation of species in their environment. Ex situ conservation achieves this goal by providing material for the reintroduction of a plant in a degraded environment or to reinforce an existing population.
It also helps to remove wild populations from the pressures of scientists, horticulturists or collectors. Indeed, the presence of a rare species in a botanical garden makes it available for scientific research, education and possible horticultural or commercial exploitation without affecting wild populations. Ex situ conservation can also serve as an “insurance policy” for endangered species by creating a protected reserve of seedlings of particularly vulnerable species or populations. It may even be the only solution if the natural habitat has been destroyed or if a species disappears. Botanical gardens are the ideal place to practice ex situ conservationbecause of their proper facilities and competent staff in botany and horticulture. Ex situ conservation includes, of course, greenhouse or garden plant cultivation, but it also includes the maintenance of seed, pollen or propagule samples and cell and tissue cultures in vitro.
One of the main objectives of a botanical garden for conservation may be to work on the conservation of its local flora . Actions in this direction range from scientific research to collaboration with municipalities and local organizations for the conservation or restoration of habitats. This collaboration of gardens with other organizations plays an important role in the implementation of national or regional conservation plans. Gardens can provide expert advice, practical assistance, and the databases and information needed for good plant management for its conservation and sustainable use