Ecological Continuum: Fundamental Concepts and Use in Applied Hydrobiology

The article deals with discussion of the continuity and discreteness concepts, which are basic not only in fundamental ecology and hydrobiology, but also in the applied issues, particularly in environmental protection. At present, the scope of the continuity-discreteness concept in ecology and hydrobiology has been extended. The continuum is interpreted not only as continuity, but also as the absence of differences (indistinguishability), the similarity of any two points in ecological space/time. The continuum of the second type is a vectorized continuity from one state/structure of a system to another. This type is a basis of the river continuum concept (RCC) − one of the widely used concepts in hydrobiology. The river continuum model can be considered as an example of a "generalized image" of the types of ecosystems, biogeomes. In applied hydrobiology, particularly in the EU Water Framework Directive, the ecological continuum is understood as the possibility for the hydrobionts to have free access to the necessary life resources (both in space and time). Some specific variants of the ecological continuum interruption, associated with both natural and anthropogenic factors have been discussed.