The state of freshwater ecology

Abstract

1. The case is advanced that freshwater ecologists need to champion the relevance of their work to the development of ecological theory and to the understanding of ecosystem function and behaviour, not least for its importance in addressing pressing applications to the stewardship of the biosphere. An essential step is to review, and update where necessary, the paradigms of aquatic ecology. 2. It is proposed that the major constraint on the organisms, their attributes and adaptations are related first to the physical properties of the medium in which they live. The drives to grow and reproduce relate to the trophic transfer of reduced carbon with important microbial interventions. General principles of 'emergy' apply. The supportive capacities of given environments may be set by chemical constraints, but it is suggested that, with the exception of chronically resource-deficient waters, population dynamics relate to opportunities incumbent upon system variability and the consequent pulsation of resources. 3. Variability affects diversity, through frequent revision of the thermodynamic base. Frequent structural change promotes species diversity and, because function is maintained, it appears that efficient function is dependent upon high diversity. Caution is necessary because high productivity and high diversity are both products of the disturbances consequent upon external forcing and manifestly non-equilibrium conditions. 4. Reactions to these statements are canvassed.