State of the World’s Plants and Fungi 2023: What we know, what we don’t, and how we find out

Kew’s State of the World’s Plants and Fungi 2023 has arrived, shedding light on our current understanding of plants and fungi, and what we need to find out in order to protect them.

Kew’s fifth State of the World’s report draws on the expertise of 200 scientists in over 100 institutions from 30 different countries to gain a global understanding of biodiversity and tackle the nature emergency we find ourselves in.

Finding fungi

But plants are only half the picture. We can’t forget about our fungal friends. Even though they are just as crucial to our ecosystems as plants, we understand far less about them, and only 155,000 have been formally named to science.

Until now, estimates on the total number of fungal species have varied widely. But now scientists have come up with the most accurate estimate to date, by looking at information such as the ratio of plants to fungi in different areas of the world, as well as exploring DNA data taken from soil samples. 

The new estimate says the world is home to 2.5 million species of fungi, meaning we have barely scratched the surface. We currently name around 2,500 species a year, meaning it would take nearly a millennium to describe them all! The researchers have suggested using DNA databases to transform the way we identify new species.

Calculating the risk

In one of the report’s most shocking stats, it is revealed that 45% of flowering plant species are estimated to be at risk of extinction.

But perhaps even more alarming, it’s believed that three out of every four unknown plant species are predicted to be under threat, based on a model that used data for plants with known conservation status to predict extinction risk for unassessed species. 

The findings indicated that epiphytes – plants that grow on other plants, like bromeliads and orchids – were the most threatened plant life forms. They also found that plants only found in one country and nowhere else in the world, known as country endemics, are more likely to be at risk of extinction.

In light of this knowledge, scientists at Kew are calling for all newly described plant species to be presumed threatened with extinction until proven otherwise.

Not to forget about fungi, only 0.4% of known fungi species have been assessed for their IUCN Red List conservation status, which makes only 0.02% of all predicted 2.5 million species. 

Of what we do know, fungi are currently threated by both land use and climate change. In the report, scientists indicate we must preserve fungi both in their natural habitat, as well as in collections, to give them the best chance at survival.

What’s next?

The State of the World’s Plants and Fungi 2023 report has some stark messages. 

Plant and fungal species that scientists don’t even know exist are at risk of disappearing. There are regions of our planet that are complete botanical mysteries. And the rate at which we are uncovering these mysteries is perhaps too slow to make a difference.

But it’s also a message of hope. By highlighting what we don’t know, it gives us better targets to work towards. By collaborating more effectively with scientists across the globe, we can aim for shared targets, and learn what, where and how we need to take action to protect our planet’s fragile biodiversity.