Research in Soviet landscape science, the discipline devoted to the study of integral physical-geographic landscapes, has focused largely on the homogeneity of mapped landscape entities. There is also a place in landscape research for paradynamic landscape systems, based on the principle of contrastivity. In the study of contrasting, contiguous landscapes making up such paradynamic systems, the focus would be on external landscape interaction through mass and energy exchange rather than on internal structure. A particular case of paradynamic complexes would be paragenetic complexes, which in addition to interacting also have a common origin. Paradynamic complexes may be simple (consisting of two contiguous members) or intricate (multimember systems). An example of a simple system would be the combination of slope and floodplain complex on a valley side. A multimember complex might consist of a slope a bedrock outcrop above, and a debris cone below. An interesting aspect of landscape contrastivity is the unusual biological activity that tends to develop along zones of contact.