Nearly 600 Plant Species Have Gone Extinct in Last 250 Years—More Than Twice the Number of Birds, Mammals and Amphibians Combined

The Earth is entering what scientists have described as the "sixth mass extinction crisis," with some estimates indicating that current extinction rates are hundreds of times above what is considered "normal."

While threatened animal species, such as gorillas and the white rhino, tend to receive the most attention, plants are also dying out at an alarming rate. This is significant because plant extinctions endanger other organisms, ecosystems and the ability of humans to survive on our planet.

Now a team of scientists from the Royal Botanic Gardens, Kew, in the U.K., and Stockholm University have put together the first global analysis of plant extinction data, covering around 90,000 species—and the results are sobering.

According to the study, published in the journal Nature Ecology and Evolution, 571 plant species have completely disappeared from the wild in the past 250 years—more than twice the number of bird, mammal and amphibian species combined to have gone extinct in the same period combined.

Furthermore, the researchers say that plants are going extinct at rates up to 500 times higher than the rate of loss before human intervention. In fact, around a third of the 90,000 species the team analyzed could be considered threatened in some way.

"Most people can name a mammal or bird that has become extinct in recent centuries, but few can name an extinct plant," Aelys Humphreys, an author of the study from Stockholm University, said in a statement.

"This study is the first time we have an overview of what plants have already become extinct, where they have disappeared from and how quickly this is happening," she said. "We hear a lot about the number of species facing extinction, but these figures are for plants that we've already lost, so provide an unprecedented window into plant extinction in modern times."

According to the team, plant extinctions are occurring at the highest rates in islands, tropical regions and areas with a Mediterranean climate. In addition, the situation looks to be worse woody plants (such as shrubs and trees) or plant species with narrow geographical ranges.

"The study reveals that plant extinctions are happening, that they are happening all over the world and that they are happening fast," Humphreys told Newsweek.

Furthermore, she suggests that the situation could be worse in reality than what is presented in the study.

"Although we have learned a lot with this study, we have also revealed important knowledge gaps," Humphreys said. "We are certain that the figure we present (571 species) is an underestimate. This is partly because our knowledge of botanical diversity in some parts of the world, such as tropical Africa and South America, is poor. This means that we have not yet discovered and named all the plants that occur there. If we don't know what occurs there, how can we know if they are becoming extinct?"

"The other reason why our figure is an underestimate is because plants can live for a very long time without reproducing," she said. "This means that they are not flowering and not setting seed, and therefore not building new generations. If a single tree is still living, its species is not extinct, but it does not mean that the species is 'alive and well.' We refer to this as being 'functionally extinct' but we do not know how many species are in this state."

Despite the gloomy outlook for planet Earth, the study does provide some glimmers of hope. The team found that 430 plant species which were thought to have gone extinct were rediscovered in the period they investigated. However, it should be noted that 90 percent of these rediscovered plants have a high extinction risk.

The scientists say that understanding more about which plants have gone extinct and from where will play a key role in aiding future conservation efforts.

"Plants underpin all life on earth, they provide the oxygen we breathe and the food we eat, as well as making up the backbone of the world's ecosystems—so plant extinction is bad news for all species," Eimear Nic Lughadha, a co-author of the study from the Royal Botanic Gardens, said in a statement.

"This new understanding of plant extinction will help us predict—and try to prevent—future extinctions of plants, as well as other organisms," Lughadha said. "Millions of other species depend on plants for their survival, humans included, so knowing which plants we are losing and from where, will feed back into conservation programmes targeting other organisms as well."

Thankfully, the researchers offer some potential avenues for ameliorating the crisis that we find ourselves when it comes to plant extinction.

"We need to continue to protect any remaining natural habitat on islands, because they are known to be very vulnerable to human activities," Humphreys said. "We all need to be conscious about how we use our resources—for example, not use products or food that encourage increased deforestation."

We need to get people interested in plants and provide funding for more professional botanists around the world. This will help us to improve our knowledge of plant diversity and our ability to detect extinctions," she said. "We need to support botanical gardens in cultivating plants that are extinct in the wild, or on the brink of extinction, so that their secrets will not be lost forever, and with the ultimate aim of reintroducing them into the wild so that all the other organisms that depend on them may also be conserved."

This article was updated to include additional comments from Aelys Humphreys.

endangered Brodiaea plant
The endangered Brodiaea plant blooms in the hills above Glendora, California on May 12, 2017 in the midst of its largest bloom in modern times. The Brodiaea is one of the most endangered plants in Southern California and still exists in only a few locations, described as a shy and tiny flower. AFP/Getty Images/FREDERIC J. BROWN