When it comes to conserving species nearing extinction, Kew has a long track record
from libraries around the world, drawing on Kew’s global network of contacts to locate material even from countries generally regarded as inaccessible.
Analysis of those data provide useful lessons about which plants are most vulnerable. Shrubs and trees were more likely to be reported extinct than other types of plants but, surprisingly, it didn’t make much difference which family a plant belonged to. ‘A member of the rose family, say, is no more likely to be declared extinct than a member of, say, the birch or palm family,’ explains Aelys. Where plants grow matters much more. A map of extinctions revealed the highest rates on islands, in the tropics and in places with a Mediterranean climate. These are all biodiversity hotspots, home to many unique species, but also places where rapid development poses a growing threat.
Kew is a world leader in plant conservation, drawing on its great breadth of accumulated knowledge and expertise and working closely with its global network of partners to protect plants both in their natural habitats and at Kew. Recent initiatives include a big push to speed up assessments of the risks to tropical species and identifying areas of the tropics most in need of protection (known as Tropical Important Plant Areas). By 2020, Kew is aiming to safeguard seeds from a quarter of the world’s flora in the Millennium Seed Bank (MSB) – one of Kew’s biggest contributions to global conservation.
When it comes to conserving species nearing extinction, Kew’s scientists and horticulturists have a long track record. ‘When plants are on the edge of extinction we need to rapidly intervene using the full conservation toolkit at our disposal,’ says Colin Clubbe, head of conservation science. That includes collecting seeds for the MSB if the plants are producing enough, and growing plants in the conservation collection, usually in an appropriate glasshouse at Kew or Wakehurst and, if there are suitable facilities, in the country of origin too. ‘We have many critically endangered plants thriving in our collections, especially plants from islands such as St Helena and Madagascar,’ says Colin.
On the ground, Kew staff work with local botanists and conservation teams to protect rarities, restore habitats and sometimes reintroduce plants raised from banked seeds, in an attempt to restore declining populations. ‘We use all our horticultural skills, applying them in the wild,’ says Colin.
The challenge, he says, is to understand and reverse the threats that put a species at risk of extinction – and not just the direct threats. ‘Understanding indirect drivers of extinction, such as human poverty, is critical.’
For some plants, extinction turns out to be temporary or not quite as close as feared. The Kew study reported 431 ‘extinct’ plants that had been later rediscovered, and botanical expeditions occasionally find unexpected populations of critically endangered species, greatly improving their prospects.
‘I always remain optimistic that a threatened plant will turn up in an under-explored area,’ says Colin. That optimism
KEW AUTUMN 2019