Here's what botanic gardens can do to keep up with the biodiversity crisis

We need to focus on three key actions that make a real difference to save endangered plants.

- Samuel Brockington

As I wander around Cambridge University Botanic Garden, a tree called the Wollemi pine often catches my eye. It's one of our rarest trees, and a distinctive-looking pine, with broad needles and bark that reminds you of Coco Pops.

It was first discovered in 1994 in a ravine in the Wollemi National Park in Western Australia, and only a few hundred of it survive in the wild. Although it has been on planet Earth for hundreds of thousands of years, it is close to extinction. This tree species, like many others, represents a paradox: a rare and threatened species thriving in cultivation while its wild counterparts are just about hanging on to existence.

As a curator of one of the world's largest university botanic gardens, I often talk about the power of living collections. I also recognise their limits. The world's botanic gardens hold an extraordinary diversity of plants. But, they are struggling to keep up with the accelerating biodiversity extinction crisis.

Botanic gardens are often seen simply as peaceful retreats from the daily rat race or living museums where species are catalogued and displayed. But they are far more than that. Collectively, the world's gardens form an extensive network of living plant collections, acting as refuges for biodiversity, sources of genetic material for research, and hubs for ecological restoration.

Our recent study, published in the journal Nature Ecology & Evolution, analysed 50 of the world's largest living plant collections, currently growing 41 per cent of all species in cultivation, and 500,000 individual plants. Our research spanned a century of digitised data and the findings are striking.