Thermodynamic Orientors: How to Use Thermodynamic Concepts in Ecology

Abstract

In this chapter I will try to answer the following questions: How should we apply thermodynamic methods and concepts to ecology; how can we describe the ecosystem’s behavior in the terms of physics (and particularly, thermodynamics); and what kind of physical criteria can be used for the estimation of anthropogenic impacts on ecosystems? From the viewpoint of thermodynamics, any ecosystem is an open system far from thermodynamic equilibrium, in which the entropy production is balanced by the outflow of entropy to the environment. I suggest the “entropy pump” hypothesis: that climatic, hydrological, soil and other environmental conditions are organized in such a way that only a natural ecosystem which is specific for these conditions can be in the dynamic equilibrium (steady state). In the framework of this hypothesis I can calculate the entropy production for an ecosystem under anthropogenic stress.

By considering systems far from thermodynamic equilibrium, we can prove that the so-called exergy is a functional of a dissipative function, which is undertaken along the trajectory going from a thermodynamic equilibrium to a dynamic one. It was shown there is a close connection between the measure of an additional information (Kullback measure) and the exergy.

And finally I try to show the deep internal connection between Lyapunov functions which are the main instruments of the stability theory and basic thermodynamic concepts, especially in applications to ecology.

“…nobody knows what entropy is in reality, that is why in the debate you will always have an advantage”

J. von Neumann

“Teleology is a lady no biologist can live without, but whose company seems shameful in society”

G. von Brükke

“Thermodynamics is full of highly scientific and charming terms and concepts, giving an impression of philosophical and scientific profundity. Entropy, thermal death of the Universe, ergodicity, statistical ensemble—all these words sound very impressive posed in any order. But, placed in the appropriate order, they can help us to find the solution of urgent practical problems. The problem is how to find this order…”

(from table-talks in Moscow)