ENTROPY AND EXERGY IN THE DEVELOPMENT OF LIVING SYSTEMS - A CASE-STUDY OF LAKE-ECOSYSTEMS

The entropy production in lake-ecosystem consists of the entropy produ ction dependent on solar radiation and that independent of solar radia tion. These entropy productions are calculated and compared for oligot rophic (not so polluted) Lake Biwa and eutrophic (polluted) Lake Mendo ta. Based on the results, an entropy law for eutrophication is propose d: Entropy production in lake-ecosystems increases with time in the co urse of eutrophication. On the contrary, in the senescent stage of lak e-ecosystems, the trend will be reversed. By extending and generalizin g the arguments, an entropy principle is proposed for the life span of living systems from organisms to ecosystems, that is, entropy product ion in living systems consists of an early increasing stage, an interm ediate/transitional stage and a later decreasing stage. By virtue of t he Gouy-Stodola theorem, these tendencies are also applied to exergy d estruction, which is a thermodynamical quantity closely related to irr eversibility of process like entropy production but in the opposite wa y.