What's Earth's dominant species by mass?
This piece unearths the surprising contenders for Earth's dominant species by mass, from krill to cattle to colossal boreal trees. HN readers gravitated to its well-researched, counterintuitive findings, prompting spirited discussions on overlooked ecological players and humanity's outsized biomass influence.
The Lowdown
The common belief about ants and humans having comparable biomass is a myth; humans actually outweigh ants five to one. This article instead asks which single species truly dominates by total mass (biomass), revealing some unexpected champions across different biological kingdoms.
- Among animals, humans (350 million tons) are significant, but wild Antarctic krill (379 million tons) slightly surpass them. However, the true animal heavyweight is domesticated cattle, weighing in at a staggering 650 million tons.
- Animals are dwarfed by other life kingdoms, with bacteria (70 billion tons carbon) and especially plants (450 billion tons carbon) holding vastly more biomass.
- In domesticated plants, while maize harvests are massive, sugar cane takes the lead with over 2 billion metric tons harvested annually, likely having an even higher standing biomass due to its perennial nature.
- The ultimate biomass champions are wild plants. Specific boreal tree species like the Black Spruce (over 11 billion tons in Canada alone) and the Dahurian Larch (at least 8.4 billion tons in Russia) represent colossal amounts of living matter, with single species containing nearly three times the carbon of all animals combined.
The article effectively shatters anthropocentric views of ecological dominance, highlighting how domesticated species and, most overwhelmingly, specific wild tree species represent the vast majority of Earth's living biomass.
The Gossip
Anthropocentric Anxieties & Ecological Footprints
Many commenters reflected on humanity's disproportionate impact on the planet, both through our own biomass and the vast quantities of domesticated animals and plants we cultivate. This led to discussions about humanity's ecological footprint and our unique, often disruptive, place in the global ecosystem, with some even pondering an alien observer's perspective on our species.
Biomass Brawls and Overlooked Organisms
Several users challenged or expanded upon the article's conclusions, suggesting other species or biological categories that might contend for the top spot, such as Bristlemouth fish or various grasses. There was also a notable debate on the methodology of counting biomass, particularly whether the 'dead cells' of wood in trees should be included, drawing parallels to human bone structure and questioning the definition of 'living' biomass.
Facts, Figures, and Fun Diversions
The discussion thread was peppered with related scientific trivia, historical anecdotes, and humorous analogies that explored similar 'what if' scenarios. Commenters brought up J.B.S. Haldane's fondness for beetles, the classic 'all humans in a cube' thought experiment (often linking to XKCD or Wait But Why), and other surprising statistics about population density and collective mass.