Data from "Hyperdominance in Amazonian forest carbon cycling Amazon".

The extraordinary diversity of Amazonian forests conceals that tree abundance is 121 strongly skewed towards relatively few ‘hyperdominant’ species. In addition to their 122 diversity, Amazonian trees are a key component of the global carbon cycle, 123 assimilating and storing more carbon than any other ecosystem on Earth. Here, we 124 ask, using a unique dataset of 530 forest plots, if the functions of storing and 125 producing woody carbon are concentrated in a small number of tree species, whether 126 the most abundant species also dominate carbon cycling, and whether dominant 127 species are characterized by specific functional traits. We find that dominance of 128 forest function is even more concentrated in a few species than is dominance of tree 129 abundance, with only ≈1% of all Amazon tree species responsible for 50% of carbon 130 storage and productivity. Whilst those species that contribute most to biomass and 131 productivity are often abundant, species maximum size also has a critical role.