Answer
Energy flows through an ecosystem in a one-way direction. Matter, on the other hand, flows between ecosystems in closed loops.
Work Step by Step
The energy available in an ecosystem flows from the primary producer to the consumers, with only 10 percent of the energy from one trophic level passing on to the next trophic level. The other 90 percent of the energy is released into the environment as heat.
Matter, however, does not flow linearly like energy does. Matter moves between ecosystems and, although it changes from one form to another, the same amount of matter still remains.