Energy transfer between trophic levels is generally considered as equal to 10% of the net production at the preceding trophic level (the Ten percent law) => this law is used in numerous models, and I thought its origin was from Lindeman 1942, but is it not the case. Do you know what is the origin of this law ?
Not sure about the origin, but there was a nice review in TREE that revolved around transfer efficiencies and may point you in the right direction: "Ecosystem ecology: size-based constraints on the pyramids of life" by Trebilco et al.
It seems that Lindenmann was the first one to consider the issue of trophic transfer efficiency. See: http://books.google.com/books?id=PoRP0g2Jh9YC&pg=PA142&lpg=PA142&dq=who+first+proposed+the+10%25+trophic+transfer+efficiency&source=bl&ots=ull6ejniZ5&sig=UkJIC_KL4uBii8T8a8ODfqkP8UU&hl=en&sa=X&ei=wmwnUq7JJvK9sQS3uYHwDQ&ved=0CFQQ6AEwBw#v=onepage&q=who%20first%20proposed%20the%2010%25%20trophic%20transfer%20efficiency&f=false. Slobodkin, later on suggested an average value of 10-30% efficiency.
Dont know its origin. And I dont think anyone should consider it a "law". It is a reasonable average for free=living consumers. Christensen and Pauly 1992 summarize many studies with a fairly wide range of valuesfrom a few % to the 20s %. BTW, the few studies on parasites/parasitoids indicate much higher values, up to 70%.
Indeed, it is not a law, but rather an average observation. The main point is that efficiency is
"Elton's Law" - I think it's the principle used to estimate the average amount of energy available to the next level on the pyramid.
You can search for Ecossystem produtivity it's related to the 2nd law of thermodynamic and the entropy on systems.
I used to teach this on Environmental Sciences for Eletric Engineering ... but there are 2 years passed
If I am not wrong... I think you can search for Odum or Shapiro references...
None of the above but Hans comes the closest. Larry Slobodkin wrote a mea culpa in his paper on the 'reification' of this and some other incorrect-but-popular 'beliefs'.
http://www.eeb.uconn.edu/courses/EEB302/EverthingInHereAsOfJan2006/SlobodkinGoodBadReified.pdf
The mea culpa occurs on page 3.
To me it is incredible that this kind of nonsense actually is still considered to be 'true' by anyone, much less by people who think they are ecologists.
It was the 10th conclusion on ecological efficiencies reported in 'A Critical Evaluation of the Trophic Level Concept. I. Ecological Efficiencies'.by Daniel G. Kozlovsky. Ecology, Vol. 49, No. 1 (Jan., 1968), pp. 48-60
Salvador, as I noted above, Slobodkin admitted making the claim that "10% is a universal value" in his earlier paper in 1962:
Slobodkin, L. 1962. Energy in animal ecology. Adv. Ecol.1: 69–101.
Ecological efficiency is the ratio of net production trophic level n over n-1 (ie the one preceding it). The term can be somewhat misleading, suggesting great physiological inefficiency.
Consider a fox eating a mouse. Some consumed mouse biomass will be excreted (~15%), the rest assimilated into biomass production, maintenance, and activity. Thus, only a small amount of assimilated energy (which does important work) actually leads to new biomass (growth + reproduction). An adult male, for instance, contributes no new biomass to level n. If the population were composed of only adult male foxes, the ecol efficiency would be zero. Of course, some foxes are growing and having babies, so the eco efficiency is never zero. For endotherms it might be on the order of 1-5% (I believe), reflecting the high costs of thermoregulation and locomotion. So although the assimilation efficiency is fairly high for carnivores, the ecological efficiency must always be low. However, even if foxes didn't move, didn't thermoregulate, and only grew and made babies, thermodynamics constraints dictate some transfer efficiency loss in converting consumed biomass into new biomass (I'm not sure what the maximum value is for that though). I believe this is reflected as heat, which occurs at all steps in which metabolic work is done.
Thus, the ecological efficiency value reflects the inability to completely assimilate a prey, allocation to homeostasis and activity, and the thermodynamic costs of doing biological work (reflected as heat loss). To understand the origin of the ~10% rule, one must consider the fraction of energy expended and lost at each step. This will vary depending on the type of prey being eaten (plants are tough) and the lifestyle of the consumer.
As far as I know, Lindeman was the first to actually measure energy lost at each upward trophic step. See Chapter 2 in: http://link.springer.com/chapter/10.1007/978-3-540-68058-1_2#page-1
The 10% value has since been discussed and precised considering different ecosystem types. You can look at an article by Michael Baumann (1995) "A comment on transfer efficiencies" (Fisheries Oceanography 4:3, 264-266,1995), and also Libralato et al. (2008) "Novel index for quantification of ecosystem effects of fishing as removal of secondary production" (MEPS 355, 107-129) that distinguished different values for temperate shelves and seas (14%), the tropical ones (10%), coastal areas and coral reefs (13%), upwellings (5%) and lagoons (11%).
Lindeman wasnot the first to actually measure energy lost at each upward trophic step. Much early a several scientists wrote about this at least from 1914. Russian scientists (V.V. Stanchinsky, I.V. Ivlev, G.G. Winberg) measured that and published results in 1930-1937. Lindeman knew these results from his teacher Raymond Laurel Lindeman who knew about this from Vernadsky.
But of cause it's not law, it's only near average value which may fluctuate in wide range as shown in several papers including in my (Shadrin, 2011: ИСЧЕРПАЛ ЛИ СЕБЯ БАЛАНСОВО-ЭНЕРГЕТИЧЕСКИЙ ПОДХОД В ГИДРОБИОЛОГИИ: ВОЗМОЖНОСТИ И ОГРАНИЧЕНИЯ /Did energy budget approach exhaust itself in hydrobiology: Possibilities and limitations)
The point made by Nickolai Shadrin is correct but that leaves the question of whether there is an underlying theory that can determine this variability. For that i favour element stochiometry theory. The theory deals with the mismatch in stochiometry between carbon and nitrogen or phosphorus between the prey and predator, especially the transfer from plants to herbivores. For example, the plasticity of the autotrophs stochiometry constrains the production of the herbivore and the amount of excess energy as carbon going to the detrital pool and heat. For the plant the stochiometry will value from either excess energy, light, and thus carbon or excess from nutrient poor conditions and vice versa. In this way it can explain the paradox of herbivores eating themselves to extinction in high energy highly productive meadows i.e the green desert farmers refer to. In general there is a re examination of the stochiometric approach to many problems in ecology, it appears to be have the potential to vertically integrate across many scales and approaches towards explanations and predictions
There is a special feature on this from the major protagonists in Ecology, Vol. 85, No. 5 (May, 2004), pp. 1177-1178 by Hessen which introduces the subsequent papers.
At least for marine sytems, to call it a law is clearly wrong. Besides, 10% trophic efficiency is kind of a rule-of-thumb. Check these two papers; one mentions the trophic efficiency but provides no reference, and the other offers different values, at least for microbial communities (bacterioplankton):
http://www.sciencedirect.com/science/article/pii/S1385110100000186
http://www.sciencedirect.com/science/article/pii/S0924796313000274
10% is more estimated contractual value, than real one, for popularization of science and for first time of introduction of quantitative approach....
I would be interested in hearing which models use this 10% law for most trophic levels. In the population dynamics modelling literature that I am familiar with, one typically uses different efficiencies for different trophic levels e.g. 15% for herbivores but 55% for carnivores. Theoretical ecologist Peter Yodzis had a nice paper on using energetic reasoning and allometric scaling laws in population dynamics models (attached). He referred to a 1983 book by Robbins for the efficiency estimates.
Article Body Size and Consumer-Resource Dynamics
This value is very variable and is function of body size, temperature, concentration of food, part of N in food, etc. It's big mistake to use some constant
Very interesting discussion. Just wondering ... but the question was not if there is a law or not or even if there is correct or not...
She just wish to have the information about the origin of this"magical number = 10%".
Perhaps we tend to complicate a very simple question sometimes.
But I am very happy to follow the answers. I may change a little the way I use to exemplify the concept for engineers... even if for sure, neither me nor my colleagues use to state that 10% = k. And I am sure that anybody does.
still tracking the information you share... thanks
magical number = 10%" was used at first by one scientist in Denmark in 1914... I forgot his name...this magical number is used by engineers as magical but it's not real one
Nickolai, if you can remember him or find a reference to that use in 1914, please share it. I would very much like to add it to my collection of historical articles.
OK, If you need some papers on history of ecology/hydrobiology I can send you some ones, mostly in Russia. Send me your e-mail
My email is [email protected]. I'm interested in a reference for that 1914 source that you mentioned, the Danish scientist. Thanks for helping.
Here is one of the classical papers on energy transfer in trophic levels, written by Raymond L. Lindeman, The Trophic-Dynamic Aspect of Ecology, Ecology Vol. 23, No. 4 (Oct. 1942), 399-417. It has all of his calculations. When I was a student, this was the paper that we read and that was attributed to the "approximate" 10% number. The numbers do vary, based on the organisms and ecosystems being analyzed.
http://lamar.colostate.edu/~aknapp/ey505/Lindeman%201942.pdf
Raymond L. Lindeman, The Trophic-Dynamic Aspect of Ecology, Ecology Vol. 23, No. 4 (Oct. 1942), 399-417 is most known but much earlier there at least Skadovsky, Ivlev, Winberg...
In Lindeman's trophic-dynamic paper, he cites two of Ivlev's papers and describes the calculations Ivlev did on the respiratory efficiencies of tubifex worms and of carp. Lindeman states that Ivlev's contributions were important and Lindeman also discusses other studies that determined respiratory efficiencies. Lindeman uses Ivlev's respiratory efficiencies results, as well as the results of others to conclude that "these differences probably reflect a trophic principal of wide application: the percentage loss of energy due to respiration is progressively greater for higher levels in the food cycle." This certainly illustrates the nature of science in which the contributions of many are needed for the understanding of complex biological systems. So now, I am wondering where the 10% number came from? Could it possibly be that someone writing a textbook used the 10% number as an illustration of energy transfer in an ecosystem and this number has been picked up and passed along?
If I remember correctly Carl Georg Johannes Petersen (1860-1928), a Danish marine biologist, said about 10% about 1914. Russian scientist V.V Stanchinsky wrote about 10% in 1930-1931 (see D. Weiner, 1988?)
When we think about ecology, we usually consider mammals in the terrestrial environment at first. As a speculation, I thought somebody used the result of the experimentation using rat (about 10%?). Therefore scientists who study terrestrial animal and ecology may know the answer. I was sorry, this is just a suggestion.
According to Egerton 2007 Bulletin of the Ecological Society of America 88(1): 50-69, was Karl Semper who in 1881 came up with this 10% 'efficiency.'
the origin is from the experiments of Slobodkin (1959,1962,1964)in his experiments with Chlamydomonas/Daphnia/Homo system and Artemia/Hydra/Homo system found the ecological efficiency to be 10 percent.
Slobodkin, L.B. 1959: Energetics in Daphnia pulex population. Ecology, 40: 232-243.
Slobodkin, L.B. 1962: Energy in animal ecology. In: Advances in Ecological Research (Cragg, J.B. ed.). Vol I, pp. 69-101.
Slobodkin, L.B. 1964: Experimental populations of hydrida. Jub. Supp. Sym. Brit. Ecol. Soc. Pp. 131-148.
about 10 % several researchers talked before Slobodkin in 1914-1935....
Russian scientist V.V. Stanchinsky 1930-1935 ...but I don't remember who from Denmark wrote about 10 % before 1920...V. Ivlev wrote in 1935-1938....But I havenot correct references now here....
Danish scientist //see Petersen C.G.J. Valuation of the Sea. II. The animal communities of the sea bottom and their importance for marine zoogeography // Rept. Dan. Biol. St. 1915. Vol. 21. P. 1–67.
• Petersen C.G.J. The sea bottom and its production of fish-food. A survey of the work done in connection with the valuation of the Danish waters from 1883 to1917 // Rept. Dan. Biol. St. 1918. Vol. 25. P. 1–62.
• Petersen C.G.J., Boysen Jensen P. Valuation of the sea. I. Animal life of the sea bottom, its food and quantity // Rept. Dan. Biol. St. 1911. Vol. 20. P. 1–81.
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