Biomass (or biomass weight) is the total mass of plants, animals and other organisms present in an ecosystem (biogeocoenosis) of a given size or level. A distinction is made between phytomass, zoomass, microbomass and others.

Biomass on planet Earth is 2,420 billion tonnes. Biomass is the total mass of hydrobionts, including fish (ichthyomass), of a species, group of species or whole biocoenosis per unit area or volume of water. It is expressed in units of mass of raw material, dry matter, organic carbon, energy or other units.

Insects, arthropods and the like make up most of the terrestrial organisms that support plant life.

Biomass: The total mass of hydrobionts, including fish (ichthyomass), of a species, group of species or entire biocoenosis per unit area or volume of water. It is expressed in units of mass of raw material, dry matter, organic carbon, energy or other units.