Biomass (ecology)

Biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals.[3] The mass can be expressed as the average mass per unit area, or as the total mass in the community.

This article is about the ecological measure. For the renewable energy source, see biomass (energy).

The total global live biomass has been estimated at about 550 billion tonnes carbon,[1] most of which is found in forests.
Shallow aquatic environments, such as wetlands, estuaries and coral reefs, can be as productive as forests, generating similar amounts of new biomass each year on a given area.[2]

How biomass is measured depends on why it is being measured. Sometimes, the biomass is regarded as the natural mass of organisms in situ, just as they are. For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. For other purposes, only biological tissues count, and teeth, bones and shells are excluded. In some applications, biomass is measured as the mass of organically bound carbon (C) that is present.

In 2018, Bar-On et al. estimated the total live biomass on Earth at about 550 billion (5.5×1011) tonnes C,[1] most of it in plants. In 1998 Field et.al. estimated the total annual net primary production of biomass at just over 100 billion tonnes C/yr.[4] The total live biomass of bacteria was once thought to be about the same as plants,[5] but recent studies suggest it is significantly less.[1][6][7][8][9] The total number of DNA base pairs on Earth, as a possible approximation of global biodiversity, is estimated at (5.3±3.6)×1037, and weighs 50 billion tonnes.[10][11] Anthropogenic mass (human-made material) is expected to exceed all living biomass on earth at around the year 2020.[12]

Ecological pyramids
An energy pyramid illustrates how much energy is needed as it flows upward to support the next trophic level. Only about 10% of the energy transferred between each trophic level is converted to biomass.
Main article: Ecological pyramid

An ecological pyramid is a graphical representation that shows, for a given ecosystem, the relationship between biomass or biological productivity and trophic levels.

  • A biomass pyramid shows the amount of biomass at each trophic level.
  • A productivity pyramid shows the production or turn-over in biomass at each trophic level.

An ecological pyramid provides a snapshot in time of an ecological community.

The bottom of the pyramid represents the primary producers (autotrophs). The primary producers take energy from the environment in the form of sunlight or inorganic chemicals and use it to create energy-rich molecules such as carbohydrates. This mechanism is called primary production. The pyramid then proceeds through the various trophic levels to the apex predators at the top.

When energy is transferred from one trophic level to the next, typically only ten percent is used to build new biomass. The remaining ninety percent goes to metabolic processes or is dissipated as heat. This energy loss means that productivity pyramids are never inverted, and generally limits food chains to about six levels. However, in oceans, biomass pyramids can be wholly or partially inverted, with more biomass at higher levels.

Terrestrial biomass
     Relative terrestrial biomasses
of vertebrates versus arthropods

Terrestrial biomass generally decreases markedly at each higher trophic level (plants, herbivores, carnivores). Examples of terrestrial producers are grasses, trees and shrubs. These have a much higher biomass than the animals that consume them, such as deer, zebras and insects. The level with the least biomass are the highest predators in the food chain, such as foxes and eagles.

In a temperate grassland, grasses and other plants are the primary producers at the bottom of the pyramid. Then come the primary consumers, such as grasshoppers, voles and bison, followed by the secondary consumers, shrews, hawks and small cats. Finally the tertiary consumers, large cats and wolves. The biomass pyramid decreases markedly at each higher level.

Changes in plant species in the terrestrial ecosystem can result in changes in the biomass of soil decomposer communities.[13] Biomass in C3 and C4 plant species can change in response to altered concentrations of CO2.[14] C3 plant species have been observed to increase in biomass in response to increasing concentrations of CO2 of up to 900 ppm.[15]

Ocean biomass
marine food chain
(typical)
  Sun
↓
phytoplankton
↓
herbivorous zooplankton
↓
carnivorous zooplankton
↓
  filter feeder
↓
  predatory vertebrate
See also: Marine life

Ocean or marine biomass, in a reversal of terrestrial biomass, can increase at higher trophic levels. In the ocean, the food chain typically starts with phytoplankton, and follows the course:

Phytoplankton → zooplankton → predatory zooplankton → filter feeders → predatory fish

Ocean food web showing a network of food chains
Biomass pyramids
Compared to terrestrial biomass pyramids, aquatic pyramids are inverted at the base
Prochlorococcus, an influential bacterium

Phytoplankton are the main primary producers at the bottom of the marine food chain. Phytoplankton use photosynthesis to convert inorganic carbon into protoplasm. They are then consumed by zooplankton that range in size from a few micrometers in diameter in the case of protistan microzooplankton to macroscopic gelatinous and crustacean zooplankton.

Zooplankton comprise the second level in the food chain, and includes small crustaceans, such as copepods and krill, and the larva of fish, squid, lobsters and crabs.

In turn, small zooplankton are consumed by both larger predatory zooplankters, such as krill, and by forage fish, which are small, schooling, filter-feeding fish. This makes up the third level in the food chain.

A fourth trophic level can consist of predatory fish, marine mammals and seabirds that consume forage fish. Examples are swordfish, seals and gannets.

Apex predators, such as orcas, which can consume seals, and shortfin mako sharks, which can consume swordfish, make up a fifth trophic level. Baleen whales can consume zooplankton and krill directly, leading to a food chain with only three or four trophic levels.

Marine environments can have inverted biomass pyramids. In particular, the biomass of consumers (copepods, krill, shrimp, forage fish) is larger than the biomass of primary producers. This happens because the ocean's primary producers are tiny phytoplankton which are r-strategists that grow and reproduce rapidly, so a small mass can have a fast rate of primary production. In contrast, terrestrial primary producers, such as forests, are K-strategists that grow and reproduce slowly, so a much larger mass is needed to achieve the same rate of primary production.

Among the phytoplankton at the base of the marine food web are members from a phylum of bacteria called cyanobacteria. Marine cyanobacteria include the smallest known photosynthetic organisms. The smallest of all, Prochlorococcus, is just 0.5 to 0.8 micrometres across.[16] In terms of individual numbers, Prochlorococcus is possibly the most plentiful species on Earth: a single millilitre of surface seawater can contain 100,000 cells or more. Worldwide, there are estimated to be several octillion (1027) individuals.[17] Prochlorococcus is ubiquitous between 40°N and 40°S and dominates in the oligotrophic (nutrient poor) regions of the oceans.[18] The bacterium accounts for an estimated 20% of the oxygen in the Earth's atmosphere, and forms part of the base of the ocean food chain.[19]

Bacterial biomass

Bacteria and archaea are both classified as prokaryotes, and their biomass is commonly estimated together. The global biomass of prokaryotes is estimated at about 30 billion tonnes C,[20] dominated by bacteria.[1]

Geographic location Number of cells (× 1029) Billion tonnes of carbon
Open ocean
1.2[1][5]
1.6[1] to 2.2[5]
Ocean subsurface
5[20]
10[20]
Terrestrial soil
3[1]
8[1]
Terrestrial subsurface
2 to 6[20]
4 to 12[20]
Total
11 to 15[20]
23 to 31[20]

The estimates for the global biomass of prokaryotes had changed significantly over recent decades, as more data became available. A much-cited study from 1998[5] collected data on abundances (number of cells) of bacteria and archaea in different natural environments, and estimated their total biomass at 350 to 550 billion tonnes C. This vast amount is similar to the biomass of carbon in all plants.[1][5] The vast majority of bacteria and archaea were estimated to be in sediments deep below the seafloor or in the deep terrestrial biosphere (in deep continental aquifers). However, updated measurements reported in a 2012 study[6] reduced the calculated prokaryotic biomass in deep subseafloor sediments from the original ≈300 billion tonnes C to ≈4 billion tonnes C (range 1.5-22 billion tonnes). This update originates from much lower estimates of both the prokaryotic abundance and their average weight.

A census published in PNAS in May 2018 estimated global bacterial biomass at ≈70 billion tonnes C, of which ≈60 billion tonnes are in the terrestrial deep subsurface.[1] It also estimated the global biomass of archaea at ≈7 billion tonnes C. A later study by the Deep Carbon Observatory published in 2018 reported a much larger dataset of measurements, and updated the total biomass estimate in the deep terrestrial biosphere. It used this new knowledge and previous estimates to update the global biomass of bacteria and archaea to 23 - 31 billion tonnes C.[20] Roughly 70% of the global biomass was estimated to be found in the deep subsurface.[7][21] The estimated number of prokaryotic cells globally was estimated to be 11-15 × 1029.[20] With this information, the authors of the May 2018 PNAS article[1] revised their estimate for the global biomass of prokaryotes to ≈30 billion tonnes C,[22] similar to the Deep Carbon Observatory estimate.[20]

These estimates convert global abundance of prokaryotes into global biomass using average cellular biomass figures that are based on limited data. Recent estimates used an average cellular biomass of about 20-30 femtogram carbon (fgC) per cell in the subsurface and terrestrial habitats.[1][20][23]

Global biomass
External image
image icon Visualizing the biomass of life

The total global biomass has been estimated at about 550 billion tonnes C. [24][1] A breakdown of the global biomass is given by kingdom in the table below, based on a 2018 study by Bar-On et. al.[1]

Kingdom Global biomass in billion tonnes of carbon Global dry biomass in billion tonnes Global wet biomass in billion tonnes Image
Plantae
450[1]
900
2700
Bacteria + Archaea
30[20][22]
60
200
Fungi
12[1]
24
80
Protista
4[1]
8
25
Animalia
2[1]
4
13
Total
500
1000
3000
Humans and their livestock represent 96% of all mammals on earth in terms of biomass, whereas all wild mammals represent only 4%.[1]

Animals represent less than 0.5% of the total biomass on Earth, with about 2 billion tonnes C in total. Most animal biomass is found in the oceans, where arthropods, such as copepods, account for about 1 billion tonnes C and fish for another 0.7 billion tonnes C.[1] Roughly half of the biomass of fish in the world are mesopelagic, such as lanternfish,[25] spending most of the day in the deep, dark waters.[26] Marine mammals such as whales and dolphins account for about 0.006 billion tonnes C.[27]


Land animals account for about 500 million tonnes C, or about 20% of the biomass of animals on Earth.[1] Terrestrial arthropods account for about 150 million tonnes C, most of which is found in the topsoil.[28] Land mammals account for about 180 million tonnes C, most of which are humans (about 80 million tonnes C) and domesticated mammals (about 90 million tonnes C). Wild terrestrial mammals account for only about 3 million tonnes C, less than 2% of the total mammalian biomass on land.[27]

The global biomass broken down by kingdom and into taxonomic groups for animals.[1] The estimates for bacteria and archaea have been updated to 30 billion tonnes C combined since this figure was made.[20]

Most of the global biomass is found on land, with only 5 to 10 billion tonnes C found in the oceans.[24] On land, there is about 1,000 times more plant biomass (phytomass) than animal biomass (zoomass).[29] About 18% of this plant biomass is eaten by the land animals.[30] However, marine animals eat most of the marine autotrophs, and the biomass of marine animals is greater than that of marine autotrophs. [1][30]

According to a 2020 study published in Nature, human-made materials, or anthropogenic mass, outweigh all living biomass on earth, with plastic alone exceeding the mass of all land and marine animals combined.[31][12][32]

name number of species date of estimate individual count mean living mass of individual percent biomass (dried) global dry biomass in million tonnes global wet (fresh) biomass in million tonnes
Terrestrial
Humans
1
November 2022
8 billion[33]
50 kg
(incl children)[34]
40%[35]
160
400[27]
2005
4.63 billion adults
62 kg
(excl. children)[36]
287[36]
Cattle
1
2021
1.5 billion[37]
300 kg
30%
125
416[27]
Sheep
1
2021
1.3 billion[37]
30 kg
30%
12
39[27]
Goats
1
2021
1.1 billion[37]
30 kg
30%
10
32[27]
Chickens
1
2021
26 billion
0.9 kg for broilers, 1.8 kg for layers[38]
30%
8[1]
25
Ants
15,700[39]
2022
20-90×1015[39]
3.7 mg[28]-5.5 mg[39]
22.8%[40]
10–100[39]
40-450
Earthworms
7,000-30,000[41]
2016
10 mg (dry weight)[42]
10-25%[43]
400[1]
1,600
Termites
2,972
2022
2 mg[40]
27%[40]
100[28][44]
440[45]
Marine
Blue whales[46]
1
Pre-whaling
340,000
40%[47]
36
2023
50,000[27]
60,000 kg
40%[47]
1.2
3[27]
Fish
>20,000[48]
2022
30%[49]
3,000
9,000[26]
Antarctic krill
1
2008
7.8×1014[50]
0.486 g[50]
379 (in peak season)[50]
Copepods
(a zooplankton)
13,000
10−6–10−9 kg
Cyanobacteria
(a picoplankton)
?
2003
1,000[51]

Global rate of production
Globally, terrestrial and oceanic habitats produce a similar amount of new biomass each year (56.4 billion tonnes C terrestrial and 48.5 billion tonnes C oceanic).

Net primary production is the rate at which new biomass is generated, mainly due to photosynthesis. Global primary production can be estimated from satellite observations. Satellites scan the normalised difference vegetation index (NDVI) over terrestrial habitats, and scan sea-surface chlorophyll levels over oceans. This results in 56.4 billion tonnes C/yr (53.8%), for terrestrial primary production, and 48.5 billion tonnes C/yr for oceanic primary production.[4] Thus, the total photoautotrophic primary production for the Earth is about 104.9 billion tonnes C/yr. This translates to about 426 gC/m2/yr for land production (excluding areas with permanent ice cover), and 140 gC/m2/yr for the oceans.

However, there is a much more significant difference in standing stocks—while accounting for almost half of total annual production, oceanic autotrophs account for only about 0.2% of the total biomass.

Terrestrial freshwater ecosystems generate about 1.5% of the global net primary production.[52]

Some global producers of biomass in order of productivity rates are

Producer Biomass productivity
(gC/m2/yr)		 Ref Total area
(million km2)		 Ref Total production
(billion tonnes C/yr)
Swamps and marshes 2,500 [2] 5.7 [53]
Tropical rainforests 2,000 [54] 8 16
Coral reefs 2,000 [2] 0.28 [55] 0.56
Algal beds 2,000 [2]
River estuaries 1,800 [2]
Temperate forests 1,250 [2] 19 24
Cultivated lands 650 [2][56] 17 11
Tundras 140 [2][56] 11.5-29.8 [57][58]
Open ocean 125 [2][56] 311 39
Deserts 3 [56] 50 0.15

See also

References
  1. Bar-On YM, Phillips R, Milo R (June 2018). "The biomass distribution on Earth". Proceedings of the National Academy of Sciences of the United States of America. 115 (25): 6506–6511. Bibcode:2018PNAS..115.6506B. doi:10.1073/pnas.1711842115. PMC 6016768. PMID 29784790.
  2. Ricklefs RE, Miller GL (2000). Ecology (4th ed.). Macmillan. p. 192. ISBN 978-0-7167-2829-0.
  3. IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "biomass". doi:10.1351/goldbook.B00660
  4. Field CB, Behrenfeld MJ, Randerson JT, Falkowski P (July 1998). "Primary production of the biosphere: integrating terrestrial and oceanic components". Science. 281 (5374): 237–40. Bibcode:1998Sci...281..237F. doi:10.1126/science.281.5374.237. PMID 9657713.
  5. Whitman WB, Coleman DC, Wiebe WJ (June 1998). "Prokaryotes: the unseen majority" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 95 (12): 6578–83. Bibcode:1998PNAS...95.6578W. doi:10.1073/pnas.95.12.6578. PMC 33863. PMID 9618454.
  6. Kallmeyer J, Pockalny R, Adhikari RR, Smith DC, D'Hondt S (October 2012). "Global distribution of microbial abundance and biomass in subseafloor sediment". Proceedings of the National Academy of Sciences of the United States of America. 109 (40): 16213–6. Bibcode:2012PNAS..10916213K. doi:10.1073/pnas.1203849109. PMC 3479597. PMID 22927371.
  7. Deep Carbon Observatory (10 December 2018). "Life in deep Earth totals 15 to 23 billion tons of carbon -- hundreds of times more than humans - Deep Carbon Observatory collaborators, exploring the 'Galapagos of the deep,' add to what's known, unknown, and unknowable about Earth's most pristine ecosystem". EurekAlert!. Retrieved 11 December 2018.
  8. Dockrill, Peter (11 December 2018). "Scientists Reveal a Massive Biosphere of Life Hidden Under Earth's Surface". Science Alert. Retrieved 11 December 2018.
  9. Gabbatiss, Josh (11 December 2018). "Massive 'deep life' study reveals billions of tonnes of microbes living far beneath Earth's surface". The Independent. Retrieved 11 December 2018.
  10. Landenmark HK, Forgan DH, Cockell CS (June 2015). "An Estimate of the Total DNA in the Biosphere". PLOS Biology. 13 (6): e1002168. doi:10.1371/journal.pbio.1002168. PMC 4466264. PMID 26066900.
  11. Nuwer R (18 July 2015). "Counting All the DNA on Earth". The New York Times. New York. ISSN 0362-4331. Retrieved 18 July 2015.
  12. Elhacham, Emily; Ben-Uri, Liad; et al. (2020). "Global human-made mass exceeds all living biomass". Nature. 588 (7838): 442–444. Bibcode:2020Natur.588..442E. doi:10.1038/s41586-020-3010-5. PMID 33299177. S2CID 228077506.
  13. Spehn, Eva M.; Joshi, Jasmin; Schmid, Bernhard; Alphei, Jörn; Körner, Christian (2000). "Plant diversity effects on soil heterotrophic activity in experimental grassland ecosystems". Plant and Soil. 224 (2): 217–230. doi:10.1023/A:1004891807664. S2CID 25639544.
  14. He, Jin-Sheng; Bazzaz, Fakhri A.; Schmid, Bernhard (2002). "Interactive Effects of Diversity, Nutrients and Elevated CO2 on Experimental Plant Communities". Oikos. 97 (3): 337–348. doi:10.1034/j.1600-0706.2002.970304.x. ISSN 0030-1299. JSTOR 3547655.
  15. Drag, David W; Slattery, Rebecca; Siebers, Matthew; DeLucia, Evan H; Ort, Donald R; Bernacchi, Carl J (12 March 2020). "Soybean photosynthetic and biomass responses to carbon dioxide concentrations ranging from pre-industrial to the distant future". Journal of Experimental Botany. Oxford University Press (OUP). 71 (12): 3690–3700. doi:10.1093/jxb/eraa133. ISSN 0022-0957. PMC 7475242. PMID 32170296.
  16. Kettler GC, Martiny AC, Huang K, Zucker J, Coleman ML, Rodrigue S, Chen F, Lapidus A, Ferriera S, Johnson J, Steglich C, Church GM, Richardson P, Chisholm SW (December 2007). "Patterns and implications of gene gain and loss in the evolution of Prochlorococcus". PLOS Genetics. 3 (12): e231. doi:10.1371/journal.pgen.0030231. PMC 2151091. PMID 18159947.
  17. Nemiroff, R.; Bonnell, J., eds. (27 September 2006). "Earth from Saturn". Astronomy Picture of the Day. NASA.
  18. Partensky F, Hess WR, Vaulot D (March 1999). "Prochlorococcus, a marine photosynthetic prokaryote of global significance". Microbiology and Molecular Biology Reviews. 63 (1): 106–27. doi:10.1128/MMBR.63.1.106-127.1999. PMC 98958. PMID 10066832.
  19. "The Most Important Microbe You've Never Heard Of". npr.org.
  20. Magnabosco, C.; Lin, L.-H.; Dong, H.; Bomberg, M.; Ghiorse, W.; Stan-Lotter, H.; Pedersen, K.; Kieft, T. L.; van Heerden, E.; Onstott, T. C. (24 September 2018). "The biomass and biodiversity of the continental subsurface". Nature Geoscience. 11 (10): 707–717. Bibcode:2018NatGe..11..707M. doi:10.1038/s41561-018-0221-6. ISSN 1752-0908. S2CID 133768246.
  21. Observatory, Deep Carbon. "Life in deep Earth totals 15 to 23 billion tons of carbon—hundreds of times more than humans". phys.org. Retrieved 24 July 2023.
  22. Bar-On, Yinon M.; Milo, Ron (21 February 2019). "Towards a quantitative view of the global ubiquity of biofilms". Nature Reviews Microbiology. 17 (4): 199–200. doi:10.1038/s41579-019-0162-0. ISSN 1740-1534. PMID 30792541. S2CID 67789580.
  23. Griebler, Christian; Mindl, Birgit; Slezak, Doris; Geiger-Kaiser, Margot (26 June 2002). "Distribution patterns of attached and suspended bacteria in pristine and contaminated shallow aquifers studied with an in situ sediment exposure microcosm". Aquatic Microbial Ecology. 28 (2): 117–129. doi:10.3354/ame028117. ISSN 0948-3055.
  24. Groombridge B, Jenkins MD (2000) Global biodiversity: Earth’s living resources in the 21st century Page 11. World Conservation Monitoring Centre, World Conservation Press, Cambridge
  25. Schwarzhans, Werner; Carnevale, Giorgio (19 March 2021). "The rise to dominance of lanternfishes (Teleostei: Myctophidae) in the oceanic ecosystems: a paleontological perspective". Paleobiology. 47 (3): 446–463. Bibcode:2021Pbio...47..446S. doi:10.1017/pab.2021.2. ISSN 0094-8373. S2CID 233678539.
  26. Hatton, Ian A.; Heneghan, Ryan F.; Bar-On, Yinon M.; Galbraith, Eric D. (12 November 2021). "The global ocean size spectrum from bacteria to whales". Science Advances. 7 (46): eabh3732. Bibcode:2021SciA....7.3732H. doi:10.1126/sciadv.abh3732. ISSN 2375-2548. PMC 8580314. PMID 34757796.
  27. Greenspoon, Lior; Krieger, Eyal; Sender, Ron; Rosenberg, Yuval; Bar-On, Yinon M.; Moran, Uri; Antman, Tomer; Meiri, Shai; Roll, Uri; Noor, Elad; Milo, Ron (7 March 2023). "The global biomass of wild mammals". Proceedings of the National Academy of Sciences. 120 (10): e2204892120. Bibcode:2023PNAS..12004892G. doi:10.1073/pnas.2204892120. ISSN 0027-8424. PMC 10013851. PMID 36848563.
  28. Rosenberg, Yuval; Bar-On, Yinon M.; Fromm, Amir; Ostikar, Meital; Shoshany, Aviv; Giz, Omer; Milo, Ron (3 February 2023). "The global biomass and number of terrestrial arthropods". Science Advances. 9 (5): eabq4049. Bibcode:2023SciA....9.4049R. doi:10.1126/sciadv.abq4049. ISSN 2375-2548. PMC 9897674. PMID 36735788.
  29. Gosh, Iman (20 August 2021). "Misc All the Biomass of Earth, in One Graphic". Visual Capitalist. Retrieved 16 December 2021.
  30. Hartley, Sue (2010) The 300 Million Years War: Plant Biomass v Herbivores Royal Institution Christmas Lecture.
  31. Laville, Sandra (9 December 2020). "Human-made materials now outweigh Earth's entire biomass – study". The Guardian. Retrieved 9 December 2020.
  32. "Anthropogenic mass: Comparing human-made mass to the living Biomass on earth". Anthropogenic mass: Comparing human-made mass to the living Biomass on earth. Retrieved 31 July 2023.
  33. Nations, United. "Day of 8 Billion". United Nations. Retrieved 9 July 2023.
  34. Hern, Warren M. (September 1999). "How Many Times Has the Human Population Doubled? Comparisons with Cancer". Population and Environment. 21 (1): 59–80. doi:10.1007/BF02436121. JSTOR 27503685. S2CID 86671730 – via JSTOR.
  35. Jéquier, E.; Constant, F. (February 2010). "Water as an essential nutrient: the physiological basis of hydration". European Journal of Clinical Nutrition. 64 (2): 115–123. doi:10.1038/ejcn.2009.111. ISSN 1476-5640. PMID 19724292. S2CID 205129670.
  36. Walpole SC, Prieto-Merino D, Edwards P, Cleland J, Stevens G, Roberts I (June 2012). "The weight of nations: an estimation of adult human biomass". BMC Public Health. 12 (1): 439. doi:10.1186/1471-2458-12-439. PMC 3408371. PMID 22709383.
  37. "FAOSTAT". www.fao.org. Retrieved 26 July 2023.
  38. IPCC 2006, 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). Published: IGES, Japan.
  39. Schultheiss, Patrick; Nooten, Sabine; Wang, Runxi; Wong, Mark; Brassard, François; Benoit, Guénard (19 September 2022). "The abundance, biomass, and distribution of ants on Earth". Proceedings of the National Academy of Sciences. 119 (40): e2201550119. Bibcode:2022PNAS..11901550S. doi:10.1073/pnas.2201550119. ISSN 0027-8424. PMC 9546634. PMID 36122199.
  40. Petersen, Henning; Luxton, Malcolm (December 1982). "A Comparative Analysis of Soil Fauna Populations and Their Role in Decomposition Processes". Oikos. 39 (3): 288–388. doi:10.2307/3544689. JSTOR 3544689. Retrieved 26 July 2023.
  41. Joint Research Centre (European Commission); Johnson, Nancy C.; Scheu, Stefan; Ramirez, Kelly S.; Lemanceau, Philippe; Eggleton, Paul; Jones, Arwyn; Moreira, Fatima M. S.; Barrios, Edmundo (2016). Global soil biodiversity atlas. LU: Publications Office of the European Union. doi:10.2788/2613. ISBN 978-92-79-48168-0.
  42. Fierer, Noah; Strickland, Michael S.; Liptzin, Daniel; Bradford, Mark A.; Cleveland, Cory C. (13 October 2009). "Global patterns in belowground communities". Ecology Letters. 12 (11): 1238–1249. doi:10.1111/j.1461-0248.2009.01360.x. PMID 19674041.
  43. Edwards, Clive A.; Normal, Arancon Q. (27 April 2022). "Earthworm Physiology". Biology and Ecology of Earthworms (4 ed.). New York, NY: Springer. pp. 33–54. ISBN 978-0-387-74943-3.
  44. Tuma, Jiri; Eggleton, Paul; Fayle, Tom M. (25 December 2019). "Ant‐termite interactions: an important but under‐explored ecological linkage". Biological Reviews. 95 (3): 555–572. doi:10.1111/brv.12577. ISSN 1464-7931. PMID 31876057. S2CID 209482348.
  45. Sum of [(biomass m−22)*(area m2)] from table 3 in Sanderson, M.G. 1996 Biomass of termites and their emissions of methane and carbon dioxide: A global database Global Biochemical Cycles, Vol 10:4 543-557
  46. Pershing AJ, Christensen LB, Record NR, Sherwood GD, Stetson PB (August 2010). Humphries S (ed.). "The impact of whaling on the ocean carbon cycle: why bigger was better". PLOS ONE. 5 (8): e12444. Bibcode:2010PLoSO...512444P. doi:10.1371/journal.pone.0012444. PMC 2928761. PMID 20865156. (Table 1)
  47. Jelmert A, Oppen-Berntsen DO (1996). "Whaling and Deep-Sea Biodiversity". Conservation Biology. 10 (2): 653–654. doi:10.1046/j.1523-1739.1996.10020653.x.
  48. Fisheries, NOAA (3 May 2022). "Fun Facts About Fascinating Fish | NOAA Fisheries". NOAA. Retrieved 30 July 2023.
  49. Johnson, Brett M.; Pate, William M.; Hansen, Adam G. (2017). "Energy Density and Dry Matter Content in Fish: New Observations and an Evaluation of Some Empirical Models". Transactions of the American Fisheries Society. 146 (6): 1262–1278. doi:10.1080/00028487.2017.1360392.
  50. Atkinson A, Siegel V, Pakhomov EA, Jessopp MJ, Loeb V (2009). "A re-appraisal of the total biomass and annual production of Antarctic krill" (PDF). Deep-Sea Research Part I. 56 (5): 727–740. Bibcode:2009DSRI...56..727A. doi:10.1016/j.dsr.2008.12.007.
  51. Garcia-Pichel F, Belnap J, Neuer S, Schanz F (2003). "Estimates of global cyanobacterial biomass and its distribution" (PDF). Algological Studies. 109: 213–217. doi:10.1127/1864-1318/2003/0109-0213.
  52. Alexander DE (1 May 1999). Encyclopedia of Environmental Science. Springer. ISBN 978-0-412-74050-3.
  53. "What are wetlands?" (PDF). ramsar.org. Retrieved 28 August 2023.
  54. Ricklefs RE, Miller GL (2000). Ecology (4th ed.). Macmillan. p. 197. ISBN 978-0-7167-2829-0.
  55. Mark Spalding, Corinna Ravilious, and Edmund Green. 2001. World Atlas of Coral Reefs. Berkeley, California: University of California Press and UNEP/WCMC.
  56. Park CC (2001). The environment: principles and applications (2nd ed.). Routledge. p. 564. ISBN 978-0-415-21770-5.
  57. "Tundra - Biomes - WWF". World Wildlife Fund. Retrieved 5 October 2021.
  58. "Tundra". ArcGIS StoryMaps. 17 January 2020. Retrieved 5 October 2021. the tundra is a vast and treeless land which covers about 20% of the Earth's surface, circumnavigating the North pole.

Further reading
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