There are an estimated 16,000 different tree species in the Amazon rainforest—far more than in Europe and the US combined—but it's just a small fraction of them that do most of the carbon-capturing that's vital to the planet's health, according to new research. Just 182 species lock up more than half of the carbon stored in the vast forest, a study published in the journal Nature Communications finds. An earlier study found that 227 "hyperdominant" species make up more than half the Amazon's 390 billion or so trees, the BBC notes, but the top carbon-storers include some especially big and long-lived species, as well as the most common ones, Scientific American reports.
The Brazil nut tree, which can grow to be more than 100 feet tall, played a major role in carbon uptake despite its rank as only the 243rd most common species, Scientific American notes. So could the world deal with its greenhouse gas problem by simply planting huge numbers of the most carbon-hungry trees? Not a great idea, a study co-author says. "Given the amount of changes that are occurring in tropical regions, such as with the climate and with land-use changes, in the future there might be different species that become more important," she tells the BBC, explaining that only a very diverse forest is properly equipped to deal with a changing environment. Still, says an ecology professor not connected with the research, "if you were managing these forests, you would leave these trees." (A major Amazon nutrient source: long-dead African fish.)