How does the food chain affect the ecosystem?

1. A food chain symbolizes the path of energy within an ecosystem.
2. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem.
3. Each tier represents a different trophic level. 
4. For example – Primary producers such as green plants translate solar energy into carbohydrates. This energy is then tapped by primary and secondary consumers and ultimately recycled by decomposers. 
5. A food-chain model shows a simplified linear sequence. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

Further Readings – 

1. Energy Flow in Ecosystem
2. Biodiversity – Species, Genetics & Ecosystem