More than 20% of Earth’s plant species are found only on islands – and time is running out to save them

Islands have long intrigued explorers and scientists. These isolated environments serve as natural laboratories for understanding how species evolve and adapt.

Islands are also centres of species diversity. It has long been speculated that islands support exceptionally high amounts of global biodiversity, but the true extent was unknown until now.

In world-first research published in Nature today, my colleagues and I counted and mapped the diversity of plant life on Earth’s islands. We found 21% of the world’s total plant species are endemic to islands, meaning they occur nowhere else on the planet.

These findings are important. Island plants are at higher risk of extinction than those on mainlands. Detailed knowledge of plants species, and where they grow, is essential for monitoring and conserving them.