which is not a structural aspect of ecosystem\tproductivity\tspecies composition\tdiversity\tlife cycle

An ecosystem is a term first used by a Tansley, an ecologist from Britain, to mean all of the organisms in a particular environment and how they interact. Examples of ecosystems are forests, lakes, or deserts. But an ecosystem is not truly complete without considering the non-biological, or abiotic, components as well. The structure and function of an ecosystem depends on all of these factors incorporated together.
Productivity is not a structural aspect of ecosystem.