40% of the world's wild plants are threatened with extinction
NEW YORK (Reuters Health) – Nearly 40% of the world’s wild flora is classified as very rare and more at risk of extinction than other species due to human activity and climate change, a new scientific study has found.
The findings were published in a special issue of Science Advances ahead of the 2019 UN Climate Change Conference, also known as COP 25, in Madrid on December 2-3.
Nearly half a million species The work of 35 researchers from research institutions worldwide under the auspices of the University of Arizona took ten years to compile 20 million records of wild plants in the world. They counted approximately 435,000 different species of terrestrial plants on Earth, the largest data set on plant biodiversity to date.
“When we talk about global biodiversity, we had an approximation of the total number of wild plant species, but we didn’t have a real number of these species,” said Brian Enquist, professor of ecology and evolutionary biology at the University of Arizona.
“What we really want to understand is the nature of this diversity and what will happen in the future. Some species have been found everywhere and others are very rare.”
Enquist and his team revealed that more than 158,000 plant species – 36.5% of all wild plant species – are “extremely rare” – less than five times observed in all regions of the world.
This number is higher than the researchers expected. “According to ecological and evolutionary theory, we expected many species to be rare, but the actual number we found was really amazing,” they say.
Hot spots Moreover, scientists have found that rare species tend to congregate at a limited number of hotspots, such as the North Andes of South America, Costa Rica, South Africa, Madagascar, and Southeast Asia.
They found that these areas have been climatically stable since the end of the last ice age about 10,000 years ago, allowing these rare species to persist.
But the fact that these species have enjoyed a relatively stable climate in the past does not mean they will have a stable future, the researchers say. The study also revealed that areas with rare plant species are expected to experience high rates of future climate change and human disturbances.
Many of these areas are experiencing increased human activity such as urbanization, agriculture, land use, and reclamation, which threaten these stable ecosystems. If nothing is done, there will be a significant reduction in diversity – especially in rare species for which little science is known – because their low numbers make them more vulnerable to extinction.
By focusing on the identification of rare species, the study highlighted the dual threats to climate change and human impact on areas harboring many of the world’s rare plant species and underscores the need for a strategic plan of action to protect plant biodiversity globally.