Abstract. The experimental data used for testing the
applicability of the thermodynamic equations presented in the
theoretical section were obtained from an ecological restoration project
implemented at a manganese tailing site. Restoration of the plant
community was shown to be an irreversible process characterized by
spontaneous increases in its total biomass C T and
total number of plant species N associated with increases in its
enthalpy H , Gibbs free energy G and entropy S .
Species enrichment was the cause for the decease in mass ratiox i (biomass of a speciesC i divided by C T) and
biomass growth potential μ i (the partial
derivative of G i with respect toC i). The increase ins /C T (s denoting the ratio ofS to gas constant R ) associated with decrease inf /C T (f denoting the ratio ofG to RT ) with increasing N confirmed that the
restored plant community possessed natural trends towards increase in
its species richness and evenness. The observed trends gave support to
use of the thermodynamic functions for describing the
productivity-biodiversity relationship. The present analysis did not
fully prove the use of the Shannon form of information entropy as a
biodiversity index for the investigated plant communities. Because of
the presence of significant differences in individuals among species,
the biodiversity of the plant community could not be uniquely determined
by its individual numbers. In comparison, the entropy factor swas shown to be a suitable biodiversity index. The fact that N is
the key factor that determines the changes ins /C T andf /C T makes △N > 0 a
useful index for determining the direction of spontaneous changes for
all open systems with continuous input of matter and energy. As a
measure of disorder, s can be generally applied as a diversity
index for all systems involving transformations of matter and energy.
Key words: ecological restoration; metal contamination;
thermodynamic functions; spontaneous changes; biodiversity.