In hmolscience, Peter Mauersberger (1928-2007) was a German geophysicist and hydro-ecologist noted, in limnological thermodynamics, for doing some of the first chemical thermodynamic modelling of aquatic ecosystems, beginning in 1977, resulting in a number of publications outlining a theory of physico-chemical-biological processes in aquatic ecosystems, wherein he treats "biotic species" as but "components" of a Gibbsian system, i.e. physico-chemical species in a system, using Gibbsian thermodynamics methods.
Molecular aquatic ecosystem thermodynamics
In 1977, Mauersberger began working on his theory of physico-chemical-biological processes in aquatic ecosystems (surface water and underground water).
In 1981, in his “Entropy and Free Enthalpy in an Aquatic Ecosystem”, Mauersberger applied chemical thermodynamics to aquatic ecosystems, which he abstracts as follows: [1]
“Modelling aquatic ecosystems, the second law of thermodynamics must be taken into consideration: The local entropy production always is positive definite. Therefore, this paper deals with the definition of thermodynamic functions in the framework of the macroscopic theory of aquatic ecosystems. Taking dissolved and inorganic material, particulate organic matter, solid phases, and aquatic biota at different trophic levels into account, the entropy, the free enthalpy, and the free energy in an aquatic ecosystem are determined on the basis of the theory of dilute solutions.”
In Mauersberger's 1985 publication on the "Local Entropy Production in Aquatic Ecosystems", similar to human molecular theory, albeit in the context of animate matter in liquid environments, ecosystem dynamics are treated as a type of multi-species community, where water, chemical constituents and aquatic organisms are all dealt with in a single formulation. [2] In this work, he states:
"In the thermodynamic theory of aquatic ecosystems our basic postulate is that not only the physical and chemical processes but also some biological phenomena can be studied with reference to the laws of thermodynamics, at least to a good approximation on the macroscopic scale, if the Gibbs relation is generalized by introducing biotic species as "components" of the ecosystem in addition to the chemical constituents (organic and inorganic, particulate and dissolved matter)."
In order to include the animate systems directly into his thermodynamic formulation of aquatic ecosystems, Mauersberger employed two approximations:
- In order to decrease the complexity of considering an individual's biomass, he introduced the concept of the chemical potential
per unit mass for the ith species. The biomass composition of each (animate) species was assumed to be time-independent. - Energy and nutrient storage in aquatic organisms was accounted for by introducing balance equations with mass density terms differentiating photosynthetically produced organic substances, nutrients, chemicals engaged in internal energy storage, and the biomass of each species. [2]
These approximations allow for simplified expressions of the ecosystem's density and mass fractions by summing the water, chemical and biotic constituents directly. The animate components of the system were viewed as interactive entities within the larger aquatic environment, and were separated from the chemical constituents due to their composition and in order to be able to describe their kinetics separately from the purely chemical components. Thus Mauersberger's approach makes no explicit distinction between animate and inanimate components from a thermodynamic point of view.
In 1988, Mauersberger, in his “Generalized Gibbs Equation in the Theory of Aquatic Ecosystems”, outlined what he called the "Gibbs relation" for aquatic systems, namely a formulation of the fundamental Gibbs equation in terms of water, chemical, and biological matter:
where
is the specific entropy density,
is the specific internal energy,
the specific volume,
are the chemical potential and mass fraction of the chemical components, whereas 
are used to denote the species-specific potential and mass fractions. The use of chemical energy by a animate species is accounted for in the terms 
which correspond to the chemical potential and mass fraction of the n-th substance within the k-th animate species. [3]
His work, contrary to people defined as molecules (human molecules or human chemical species) having chemical potentials, has not been the subject of any roaring debates, and indeed have spawned a number of books and papers. Sven Jorgensen, Alexander Zotin and other thermodynamically-inclined biologists and biophysicists have a considerable number of non-human works describing either entire ecosystems or individual organisms as nothing more than molecules or 'chemical species.' [4]
Education
Mauersberger completed his BS in geophysics from Humboldt University, in 1956 he completed his PhD, with a dissertation on the application of the Hamilton-Jacobi theory in hydrodynamics, and in 1964 completed his habilitation, at Humboldt University, with work on the foundations of theoretical magnetohydrodynamics in geophysics. From 1965 until his retirement in 1994, he lectured and researched in hydrology, geophysics, and geoecology, at Humboldt University, eventually becoming department head.
References
1. Mauersberger, Peter. (1981). “Entropy and Free Enthalpy in an Aquatic Ecosystem” (abs), Acta Hydrophysica, 26(1): 67-90.
2. Mauersberger, Peter. (1985). “Local Entropy Production in Aquatic Ecosystems”, Acta Hydrophysica, 24(4): 235-58.
3. Mauersberger, Peter. (1982). Irreversibility in Hydrology (Irreversibilität in der Hydrologie). Akademie-Verlag, Berlin.
4. Banned from Wikipedia and ChemicalForums.com (2010) – Hmolpedia threads.
5. Mauersberger, Peter. (1988). “Generalized Gibbs Equation in the Theory of Aquatic Ecosystems”, Acta Hydrophysica, 32:27-36; in: Complex Ecology (editors: Bernard Patten and Sven Jorgensen) (Gibbs relation, pgs. 31-46). Prentice Hall, 1994.
Further reading
● Mauersberger, Peter. (1982). “Rates of Primary Production, Respiration, and Grazing in Accordance with the Balances of Energy and Entropy” (abs), Ecological Modelling, 17: 1-10.
● Mauersberger, Peter. (1987). “Deterministic and Stochastic Phases in the Time Evolution of Water Resources”, Acta Hydrophysica, 31(3/4): 165-72.
● Mauersberger, Peter. (1991). “The Role of Fundamental Laws of Physics, Chemistry, and Biology in Limnological Research”, Acta Hydrophysica, 35(1): 21-31.
● Mauersberger, Peter. (1996). “From a Theory of Local Processes in Aquatic Ecosystems to a Theory at the Ecosystem Scale”, The Science of the Total Environment, 183: 99-106.
External links
● Peter Mauersberger (German → English) – Wikipedia.
