The global network of botanic gardens is our best hope for saving some of the world's most endangered plants.
- Samuel Brockington
The world's botanic gardens contain at least 30% of all known plant species, including 41% of all those classed as 'threatened', according to the most comprehensive analysis to date of diversity in 'ex-situ' collections: those plants conserved outside natural habitats.
The study, published in the journal Nature Plants, found that the global network of botanic gardens conserves living plants representing almost two-thirds of plant 'genera' (the classification above species) and over 90% of plant families.
However, researchers from the University of Cambridge discovered a significant imbalance between temperate and tropical regions. The vast majority of all plants species grown ex-situ are held in the northern hemisphere.
Consequently, some 60% of temperate plant species were represented in botanic gardens but only 25% of tropical species, despite the fact that the majority of plant species are tropical.
For the study, researchers analysed datasets compiled by Botanic Gardens Conservation International (BGCI). They cross-referenced the working list of known plant species – currently sitting at 350,699 – with the species records of a third of botanic gardens on the planet, some 1,116 institutions. They say this provides a "minimum estimate" for the plant diversity held in botanic gardens.
Image: Cambridge University Botanic Garden (CUBG)
Credit: CUBG
Reproduced courtesy of the University of Cambridge