Biomass (ecology)
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In ecology, biomass refers to the accumulation of life that is possibly living matter.[2] That is, it is the total living biologica (usually measured per square metre or square kilometre). This means that only 30% of the weight of any creature is counted, the rest being water.
The most successful animal, in terms of biomass, is the Antarctic krill, Euphausia superba, with a biomass of probably over 500 million tons, roughly five times the total biomass of humans. The entire earth contains about 75 billion tons of biomass[dubious ], or 0.00000000126% of the total mass of the Earth. Humans comprise about 100 million tons (0.13%) of the Earth's biomass[3], domesticated animals about 700 million (1.0%), and crops about 2 billion tons or 2.7% of the Earth's biomass.[citation needed] The total biomass of bacteria is estimated to equal that of plants [4].
Biomass may also be a measure of the dried organic mass of an ecosystem. As the trophic level increases, the biomass of each trophic level decreases. That is, producers (grass, trees, scrubs, etc.) have a much higher biomass than animals that consume them (deer, zebras, insects, etc.). The level with the least biomass is the highest predators in the food chain (foxes, eagles, etc.) Biomass is also influenced by net primary productivity (NPP).
[edit] See also
[edit] References
- ^ Nicol, S., Endo, Y. (1997). Fisheries Technical Paper 367: Krill Fisheries of the World. FAO.
- ^ International Union of Pure and Applied Chemistry. "biomass". Compendium of Chemical Terminology Internet edition.
- ^ The world human population was 6.6 billion in January 2008. At an average weight of 100 pounds (30 lbs of biomass), that equals 100 million tons.
- ^ Whitman, Coleman, and Wiebe, Prokaryotes: The unseen majority, Proc. Natl. Acad. Sci. USA, Vol. 95, pp. 6578–6583, June 1998
