The Biomass Distribution in Earth’s Ecosystems

Biomass, the total mass of living organisms in an area, is a key metric for understanding ecosystem dynamics, ranging from microscopic bacteria to towering trees. This measure, often expressed in gigatons of carbon (Gt C), highlights the varying contributions of different organisms to carbon cycling and energy flow. Terrestrial ecosystems typically feature a pyramid-shaped biomass distribution, with plants at the base and progressively smaller biomasses at higher trophic levels. Conversely, marine ecosystems often exhibit inverted pyramids, driven by the rapid turnover of microscopic phytoplankton supporting larger biomasses of consumers, underscoring the complexity and diversity of Earth’s ecosystems.