The authors termed these species "hyperdominants." While the study suggests that hyperdominants just 1.4 percent of all Amazonian tree species account for roughly half of all carbon and ecosystem services in the Amazon, it also notes that almost none of the 227 hyperdominant species are consistently common across the Amazon. Instead, most dominate a region or forest type, such as swamps or upland forests.
The study also offers insights into the rarest tree species in the Amazon. According to the mathematical model used in the study, roughly 6,000 tree species in the Amazon have populations of fewer than 1,000 individuals, which automatically qualifies them for inclusion in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. The problem, say the authors, is that these species are so rare that scientists may never find them.
Ecologist Miles Silman of Wake Forest University, another co-author of the paper, calls the phenomenon "dark biodiversity".
"Just like physicists' models tell them that dark matter accounts for much of the universe, our models tell us that species too rare to find account for much of the planet's biodiversity. That's a real problem for conservation, because the species at the greatest risk of extinction may disappear before we ever find them," says Silman.
While the authors are confident that these hyperdominants also dominate the vast expanses of Amazonia where scientists have never set foot, they do not know why some species are hyperdominant and others are rare.
The authors note that a large number of hyperdominants including Brazil nut, chocolate, rubber, and aai berry have been used and cultivated for millennia by human populations in Amazonia.
"There's a really interesting debate shaping up," says
|Contact: Nancy O'Shea|