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As with conceptual models of physical process and form, conceptual models of
ecological process and form emphasize particular aspects of a river ecosystem, such
as longitudinal patterns, lateral connectivity, or alternations through time. These
conceptual models can facilitate identification of particular processes and forms that
are vital to river health, such as the flow pulses that temporarily enhance connectivity and nutrient processing in a braided river.
2.4.3 Commonalities of Physical and Ecological Conceptual
Models
Areas of substantial overlap between physical and ecological conceptual models of
river corridors include an emphasis on downstream trends and changes through
time. Downstream trends can be conceptualized as primarily progressive downstream changes (downstream hydraulic geometry, river continuum concept) or
abrupt downstream changes (process domains, river styles, serial discontinuity concept). Physical and ecological conceptualizations of change through time focus on
Fig. 2.9 Schematic illustration of the flood-pulse cycle and the importance of lateral connectivity
within river corridors. (After Junk et al. 1989, Fig. 2)
2 Rivers as Ecosystems