C0 SQlnl 1 DCi

where SQ are the change Of cOncentratiOns at the end Of anthrOpOgenic impact in cOmparisOn with sOme successiOnally clOse natural ecOsystem.

Let us cOnsider the follOwing thermOdynamic mOdels.

Model 1. We cOnsider an "average" equilibrium. In Other wOrds, we assume that the equilibrium cOnditiOn dS/dt = 0 hOlds in sOme average sense, i.e. oT = 0 . We alsO assume that the unique way tO prOvide the last equality is tO change the prOductivity sO that

Thus, we Obtained the thermOdynamic mOdel fOr the reductiOn Of the ecOsystem prOductivity under anthrOpOgenic pressure.

Model 2. SOmetimes we have an experimental (Observed) dependence Of productivity GPP On Wf and C. By calculating the average (GPP) we can check the equality (9.7). If (GPP) < CPP0 — (1/ T)(Wf + Wch) then we assume that there is anOther, in addition tO the reductiOn in prOductivity, mechanism which sucks the entrOpy excess. Such mechanism wOuld be, in general, the envirOnmental degradatiOn. The entrOpy measure Of the degradatiOn is equal tO

Model 3. Let the dynamics Of the anthrOpOgenic system (in particular with respect tO the chemical lOad) be "impulsive", i.e. at the end Of each year the system is spOntaneOusly returned tO the initial ("natural") state sO that at the beginning Of every next year the system is starting frOm the initial state. This situatiOn is typical fOr agrO-ecOsystems, which are nOt tOO far from the natural Ones. This spOntaneOus transition is accOmpanied by the entropy production described by Eq. (9.5) for t = 1 year. Since the averaging interval is equal tO 1 year we can cOnsider the average values as the annual Ones. If we alsO assume that frOm year tO year the system is, On average, in the equilibrium state, then we can intrOduce the fOllOwing entrOpy measure fOr an envirOnmental degradatiOn:

where

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