Matter cycles through ecosystem as elements like water , carbon, and move between living things like animals, plants, decomposers and then non-living parts as soil, air like a food web. Energy flows in one direction, from the sun to the plants, through photosynthesis then to animals, and finally through decomposers where they break down the dead things, return them back to soil. It matters because it helps the animals and living things be able to get nutrients to grow, to live and reproduce. Without these cycles the life cannot continues.