Modern mass extinction in Ecuadorian cloud forest turns out to be a mirage

One of the most notorious mass extinction events of modern times occurred on a hilltop on the coast of Ecuador in the 1980s. Ninety species of plants known nowhere else on Earth – including many are new to science and not yet given a name – disappeared when the last cloud forests of the Centinela Range were cleared for agriculture. Centinela’s uplifting story has long been a driving force in the fight to save the world’s rainforests. But did it really happen?

In a new study published in Natural plantsan international team of botanists reveals that, indeed, this did not happen. The researchers, who spent years scouring natural history museums, biodiversity databases and the slopes of Centinela, found no evidence of extinction, but plenty of evidence that Centinela’s flora lives still in the scattered fragments of the coastal forests of Ecuador.

“It’s a miracle,” said lead author Dawson White, a postdoctoral researcher in Harvard’s Department of Organic and Evolutionary Biology. “Many Centinela plants are still on the brink of extinction, but fortunately, reports of their demise have been exaggerated. There is still time to save them and turn this story around.”

The study found that one reason previous researchers overestimated the probability of extinction in Centinela was because these researchers were collecting a multitude of new and undescribed species, with limited information on plant species. which grow in the most diverse forests of the world. Over the decades that followed, these early collections yielded more than 50 new species.

Additionally, as botanists began collecting more widely and natural history museums digitized their specimens, plants thought to be extinct at Centinela reappeared at other sites in South America, while others were moved in situ by the team. Of the 90 species initially presumed extinct, only one has yet to be rediscovered or confirmed to grow elsewhere.

“Understanding what plants grow in a given Andean cloud forest is a monumental task because you will undoubtedly discover new species,” White said.

“What our investigation highlights is that it takes decades of work by taxonomic experts to describe new species in such forests. And only once will we have the names of these species which will then be noted in our scientific networks so that we can begin to understand where these plants grow and their risk of extinction.

Ecuador, although small, is incredibly diverse, illustrating how difficult it is for scientists to monitor and protect tropical biodiversity. It contains more than 20,000 species of plants, 4,000 of which occur nowhere else on Earth, hundreds of them have no names, and none of them have been fully mapped. Faced with these challenges, the study highlights the vital role of herbarium collections.

“Herbaria give us the fundamental information about the what and where of plant biodiversity,” said co-author Juan Guevara, of the University of Las Américas in Quito. “They are the ones who helped solve this mystery. They are the basis of everything we know about endangered plants.”

The authors also found that Centinela’s forests are more resilient than initially thought. Recent fieldwork has identified a number of original forest fragments that were previously overlooked due to their small size and remoteness. The team found that these mail-sized remains, often less than an acre, were home to many species thought to be extinct, including Gasteranthus extinctus, a wildflower named after its own extinction that was rediscovered by the team in 2021.

“Over the past two years, we have studied about a dozen fragments in the region,” said co-author Andrea Fernández of Northwestern University and the Chicago Botanic Garden. “They are small islands lost in an ocean of plantations, but they are nonetheless full of amazing plants.”

Not only were the researchers surprised to find much of Centinela’s ancient flora intact, but they were also doubly surprised to discover a multitude of new and previously undescribed plants. Over the past five years, researchers have described or discovered eight new species ranging from tiny wildflowers to towering canopy trees.

“One of our most amazing discoveries is a completely new species of canopy tree in the Cotton family,” Fernández said.

“It is one of the tallest trees we have encountered, but it is extremely rare; there may only be 15 individuals alive at Centinela. It is now actively targeted by local loggers, so we are rushing to describe this new tree species and grow its seeds in botanical gardens.

Once isolated due to its dark past, Centinela is now teeming with scientists who see abundant opportunities for research and conservation in its decimated forests. In Ecuador, botanical gardens are building collections of the region’s rarest and most endangered plants, while conservationists collect seeds for future reforestation efforts and seek long-term solutions to maintain the fragments remaining.

Globally, Centinela’s resurrection has inspired the launch of a new conservation initiative by Earth imaging company Planet Labs, which promises to boost conservation projects through high-quality satellite imagery.

Even though the new study corrects the assessment of a mass extinction event, it does not cast doubt on the world’s ongoing biodiversity crisis. According to the IUCN Red List, more than 45,000 species on Earth are currently threatened with extinction, including nearly half of all amphibians, a third of all corals, and a quarter of all mammals. Scientists at Kew Botanic Gardens have compiled a list of more than 800 plant species thought to be extinct to date.

“Plants in coastal Ecuador and many other hard-hit places in the tropics are finding a way to hang on in the last nooks and crannies,” said co-author Nigel Pitman, of the Field Museum of Natural History. “They won’t survive long in these conditions, but we still have time to act before they disappear forever.”