Some 600 plant species have gone extinct since the mid-18th century: it’s an extinction rate 500 times above normal.
Animals, large and small, are going extinct at shocking rates, but plants at least are doing fairly well.
Or so we tend to think. A general image is that the increased levels of CO2 in the air are actually beneficial to plants and, while they are losing plenty of habitat, they are not being targeted for poaching as relentlessly as many endangered animal species like pangolins, rhinos, elephants and tigers are.
Yet this image is wrong, stresses a team of scientists from the Royal Botanic Gardens in Kew, in the United Kingdom. The scientists have published an alarming new study on the extinction rate of plants, which, they say, is far more serious than commonly assumed.
Based on a comprehensive global analysis, the researchers say that at least 571 plant species have gone extinct since the mid-18th century. That extinction rate is 500 times higher than the natural rate and twice all the extinctions combined in amphibians, mammals and birds.
“[O]ur estimated extinction rate, while elevated, is still likely to prove an underestimate of ongoing extinction of plant diversity,” they stress. “It is way more than we knew and way more than should have gone extinct,” adds Dr Maria Vorontsova, an author of the study. “It is frightening not just because of the 571 number but because I think that is a gross underestimate.”
Yet many experts and laypeople alike remain unware of the actual rate because databases like the International Union for Conservation of Nature’s Red List of Threatened Species are not fully up to date. The IUCN’s list does not include 491 species of plant that have likely gone extinct, the authors argue.
On a more positive note, however, they point out that several rare plants formerly declared extinct have since been rediscovered. Yet many of these plants, too, remain highly vulnerable because their range is often limited to small stretches of isolated spaces such as mountain ranges and small islands. A relatively small-scale environmental calamity could wipe them all out.
Worse: there are numerous plant species that have yet to be discovered or rediscovered by science. As many as 2,000 new species of plant are found by botanists worldwide each year. As biodiversity hotspots like the Amazon’s rainforests and Borneo’s tropical jungles continue to be decimated, however, many of these rare plants in remote area might well go extinct before we even realize they have even existed or before scientists get the chance to rediscover them.
“How are you going to check the entirety of the Amazon for your lost plant?” Vorontsova observes.
She cites a rare grass species called Sartidia perrieri, which was last seen by a French botanist on the island of Madagascar in 1914. On a recent trip to the island, Vorontsova was looking high and low for it, but to no avail. “We scoured the hills and mountains,” she explains, “but it was not there.”
The plant may well have been driven extinct by now. “In the places where it would be growing, there are cattle grazing, regular fires and people growing rice,” she says.