Which one of the following statements is incorrect?
A. Interaction of biotic and abiotic components results in a physical structure that is characteristic for each type of ecosystem.
B. Horizontal distribution of different species occupying different levels is called stratification.
C. The decomposers of a pond ecosystem are the fungi, bacteria and flagellates.
D. The consumers of a pond ecosystem are represented by the zooplankton, the free swimming and bottom dwelling animals.