The Species That Actually Holds The Most Mass On Earth

The ant fact everyone repeats is wrong. You have heard that all the ants on Earth weigh roughly what all the humans weigh. They do not. We outweigh them five to one. Termites might beat us, but even that comparison falls apart, because there are thousands of ant species and exactly one of us.

So Signore Galilei went looking for the real answer in a post dated 27 September 2026. If you score each single species by its total mass, the biomass, who actually wins? The result is a list that quietly rearranges how you picture the planet.

Start with the animals, our own division. Humans land near the top at about 350 million tonnes. The top wild animal is Antarctic krill, at 379 million tonnes. Each krill weighs about two grams. Their population in the Southern Ocean puts them in a statistical dead heat with us, and they keep the blue whales fed. But the animal winner is cattle, at roughly 650 million tonnes. Pigs come second at 140 million tonnes, behind both us and the krill.

Then the frame shifts. Animals are among the lightest kingdoms of life. A 2018 study by Bar-On and colleagues measured every kingdom by carbon mass instead. Cattle's 650 million tonnes of body weight is only 61 million tonnes of carbon. Animals as a whole hold 2 billion tonnes of carbon. Viruses hold 0.2 billion. Protists hold 4 billion, archaea 7 billion, fungi 12 billion, bacteria 70 billion. Plants hold 450 billion.

That last number is where the story turns. Trees seem to hold every superlative. The most massive single organism is Pando, a clonal colony of aspen with interconnected roots, weighing 6,000 tonnes by itself. Aspens are rare, though. For total mass across a whole species, you go to the boreal forest ringing the Arctic. Three or four tree species can hold more than half the mass of that entire forest, where a tropical forest needs a hundred species to reach the same share.

Two candidates met in the literature. The black spruce, Picea mariana, is the most common tree in arctic Canada, with more than 11 billion tonnes growing there and some in the United States. The Dahurian larch is the most common tree in Russia. Russia's forest inventory is thinner on species detail, but larches as a group cover 35.6 percent of its forest land, and the country holds 82.2 billion cubic metres of forest. Sorting that out gives at least 8.4 billion tonnes of Dahurian larch, and possibly more.

Living black spruce wood is about 51 percent carbon. That means one tree species holds nearly three times as much carbon as all animals combined. Humans still shape the biosphere in a hundred visible ways. On this one honest metric, the larches and spruces have not been close for a very long time. The full piece, with the numbers and the sources for each estimate, is at https://signoregalilei.com/2026/09/27/whats-earths-dominant-species-by-mass/

■ Filed from Canopy: the Plants, Light wing of the city.