In a sobering development for global biodiversity, the world’s botanic gardens are sounding the alarm that they are running out of space to protect endangered plant species. The risk of plant extinction is accelerating at a pace that conservation efforts are struggling to match, according to a new study from the University of Cambridge.
Botanic Gardens Pushed to Capacity Limits
The research, published in Nature Ecology & Evolution, analyzed records spanning a century from 50 botanic gardens collectively housing half a million plants. The findings paint a dire picture – these living collections have reached peak capacity.
As Cambridge University Botanic Garden curator Prof Sam Brockington explains:
Botanic gardens are full. We’re running out of space and resources. The rate at which plants are being listed as threatened is increasing much more rapidly than the rate at which we’re managing to respond.
The risk of extinction is accelerating and our response is too slow.
Prof Sam Brockington
40% of Plant Species at Risk
The urgency is underscored by 2020 research from Royal Botanic Gardens at Kew which estimated that 40% of the world’s plant species are at risk of extinction due to the destruction of natural habitats. Yet as threats to biodiversity mount, botanic gardens are struggling to expand their conservation capacity to keep pace.
Cambridge University Botanic Garden itself houses over 8,000 species – more than some tropical countries – in a limited space. Despite constraints, it added 500,000 seeds from rare wild plants and numerous critically endangered species from other gardens to its collection last year.
Space for Science and Conservation Competes
However, threatened plants must vie for garden space not only with each other but with the need to attract visitors, support scientific research, and provide educational value. Prof Brockington estimates only 5-10% of botanic garden capacity is devoted specifically to conservation, despite the escalating risks.
Cultivating Conservation Through Global Collaboration
The study suggests that one path forward is establishing more botanic gardens in the global south, as current gardens are concentrated in western countries while critical biodiversity hotspots are underrepresented. However, international regulations on collecting and exchanging endangered plant material present hurdles to globally coordinated conservation.
Prof Brockington advocates for botanic gardens to unite their individual specimens of endangered species into a collaborative “meta collection” to safeguard genetic diversity. As he warns:
The ramifications of not acting are that we will lose far more species to extinction than we would otherwise. Maintaining plant diversity could lead to groundbreaking discoveries about food, medicine or materials in the future.
My fear is that we could lose that diversity before we understand its value to human society.
Prof Sam Brockington
With time as a dwindling resource for rare plants, the clarion call from botanic gardens is clear – protect biodiversity now, or risk losing species forever. The question is whether conservation efforts can blossom fast enough to outpace extinction.
