The riparian landscape is heterogeneous, i.e. it contains an assortment of tesserae whose configuration is itself important. The arrangement of tesserae and the assemblages of species comprise the internal structure of riparian landscape elements. In reference to vegetation, Rejmanek (1977) defined structure in three steps: the identity of species (presence–absence), the relative abundances of the species, and their spatial pattern. If we consider step 3 to be the arrangement of communities, not simply individuals, then this definition can serve as a starting point for considering internal structure in riparian landscapes. The relative abundance and configuration of tesserae determine the internal heterogeneity of the riparian landscape element, and heterogeneity varies among regions and is related to regional and local controls (Baker 1989).

Basic descriptions of riparian environments are a starting point for consideration of internal structure. Early ecological reports provide an array of concepts, ranging from visual to structural classifications, which differentiate among tesserae.