The evolution of terrestrial ecosystems (F. di Castri). Ecological succession and evolution of freshwater ecosystems (I. Ferrari, V.U. Ceccherelli). Concept of ecosystem stress and its assessment (R.D. Gulati). Concept of stress and recovery in aquatic ecosystem (R.D. Gulati). Concept of stress, natural and anthropogenic, in terrestrial ecosystems (G.H. Kohlmaier). Dynamic equilibria in material systems and their response to perturbations (G.H. Kohlmaier et al.). Ecological assessment of the degradation and recovery of rivers from pollution (R.W. Edwards). Biomanipulation of aquatic food chains to improve water quality in eutrophic lakes (R. de Bernardi). Lake ecosystem degradation and recovery studied by the enclosure method (O. Ravera). The impact of heavy metals on terrestrial ecosystems: Biological adaptation through behavioural and physiological avoidance (H. Eijsackers). Persistent chemicals in soil ecosystems and optimization of biological degradation processes (H. Eijsackers, P. Doelman). Air pollution effects in terrestrial ecosystems and their restoration (B. Ulrich). Air pollution effects on aquatic ecosystems and their restoration (A. Henriksen). Mining effects of ecosystems and their recovery (B.E. Davis). Heavy metal pollution and ecosystem recovery (R. Baudo). Index.