Scientists have known for some time that tropical tree species were in danger. But a new study reveals that it might be worse than they thought.
The new study suggests that deforestation threatens more than half of all tree species in the Amazon. Specifically, the study, which was published in the journal Science Advances Friday, suggests that at least 36 percent and up to 57 percent of all Amazon tree species are likely at risk of extinction depending on deforestation rates in the future.
Researchers examined the status of more than 15,000 Amazonian tree species, which included the plants that produce cacao and acai palm along with the Brazil nut. About two-thirds of those were considered rare species.
The researchers utilized a listing criteria from the International Union for Conservation of Nature (IUCN), which holds a “red list” of threatened species on Earth, to determine which species should be considered at risk of extinction, The Washington Post reported.
Nigel Pitman, a tropical ecologist at the Field Museum in Chicago and one of the paper’s co-authors, explained that one of the paper’s strengths is the IUCN framework it uses. “The problem is there are lots of definitions of the word ‘threatened,'” Pitman said. “Each country–oftentimes agencies with a country, NGOs, researchers–have different definitions. One thing that’s special about this paper is that we’ve made a real point of reporting our results using the most common currency of conservation status, the IUCN red list framework.”
Despite differing definitions of threatened, their findings suggest that the number of threatened plant species globally could increase by roughly 22 percent and globally threatened tree species by 36 percent, according to The New York Times.
“We’ve never had a good idea of how many Amazonian species were vulnerable,” said Pitman. “And now, with this study, we’ve got an estimate.”
Pitman is one of more than 150 researchers from almost 100 institutions listed as the paper’s authors. And almost every author went into the Amazon to collect branches, flowers, fruits and leaves and measure tree diameters. They recorded data from 1,485 plots, about two acres each, NY Times reported.
After the information was gathered, researchers created a computer model that analyzed the data in two scenarios. The first, or the “business as usual” model, predicted that by 2050, 40 percent of Amazon’s original forest would be gone. And the second, which contained heavier government preservation regulations, estimated that 21 percent would be gone by 2050.
The research team said that 8,690 of tree species out there today would be “threatened” under the first model whereas 5,515 would be under the second.
On a lighter note, a botanist at Agteca-Amazonica in Santa Cruz, Bolivia, Timothy J. Killeen, said in a news conference that “fortunately, deforestation rates in the Brazilian Amazon, which represents about 60 percent of the total Amazon area, have decreased by about 75 percent since 2005.”
Killeen added that the current estimates had the Amazon doing better than predicted. Despite the Amazon’s current condition, researchers said that their threatened species estimates were valid since government policies can change fast and put species at risk.
“If we can keep these reserves from suffering degradation, then we can actually protect a substantial part of the diversity in the Amazon,” tropical ecologist at Naturalis Biodiversity Center in the Netherlands and lead author Hans ter Steege said.