FOOD CHAINS AND FOOD WEBS
- A food chain is a diagram depicting a step by step sequence of who eats whom in an ecosystem
- A food web is a diagram that shows the interconnectedness of organisms in an ecosystem.
- Orgnismsm in an ecosystem are organized in trophic levels; i.e. hirearchical orders.
- Plants form the foundation of the food web.
- Plants are in the 1st trophic level and are called producers.
- This includes also microscopic plants that live in fresh or salt water.
- The bases of some food chains include detritus, e.g., the sludgy matter at the bottom of ponds.
- Detritus contains wastes (from living animals and plants) and the remains of dead plants and animals.
- Food webs containing detritus also contain decomposers that feed on it. In doing so, they create nutrients that feed plants and algae.
- Moving up through the chain or web we encounter the 2nd trophic level containing the primary consumers that feed on the plants.
- Above them are secondary consumers, in the 3rd trophic level.
- The 4th trophic level contains the tertiary consumers and finally, the 5th trophic level contains a single top predator.
