Food Chains & Webs

A Little More Detail...

So, we have levels of organisation in a habitat. Through each one, there are predators and prey, until you reach the top level. This top level is called the Apex Predator. This level system is called trophic levels.

Interesting fact: a food chain can have multiple prey and predators in it, but will then be classed as a food web, with interlinking animals and species.

Levels of Organisation

So, as humans, we like to organise things. The way a habitat or ecosystem works, we really need to do this, just so we can gain a better understanding of how things work. To do this, we have come up with the trophic level system. This system shows us who preys on the lower levels, and who the predators are to the lower levels.

Sounds difficult, doesn't it? I'm sure I have a picture on the right that will show you a trophic level system. They are also known as energy pyramids.

Back to the Food Chain

So, to explain it further, I've found a YouTube video which explains it well.

If you watched the video, you'll have seen that all components in a food chain begin with the sun. Let's take a look at the other components.

Producers

Producers are the most abundant component of a food chain. They are the plants and trees that grow using the sunlight in the process for photosynthesis. Without these in the world, there would be no trophic levels, because there would be no life on Earth as we know it.

Consumers

A consumer is an animal that will consume the lower level, whether that be a producer, or another animal in the food chain. A primary consumer is the first component in the line to eat something. This is usually a herbivore. There can be many different levels of consumer - primary, secondary, tertiary, and so on.

Decomposers

A decomposer is an organism that eats away at the matter that is left when another organism dies. They usually reside close to the ground (or under it), and break down the dead matter. Any nutrients they find along the way, they return to the Earth for plants to use, and this is part of the Carbon cycle.

Time for another YouTube video to explain is visually.

Apex Predator

An apex predator is a predator that has no other predator above them. They are animals like a Golden Eagle, or a lion. There is no natural predator of these animals in the animal kingdom (humans have been known to be their predator, usually for profit of some sort). This can be three, four or five items up in the food chain, but they are the top of the food chain.

Food Webs

When one or more food chains overlap, they then become a food web. This is simply to show that there are multiple predators for each prey. They all link up and interlink as well.

Interdependence

So, you have a selection of food chains that link together to form a food web. Great. But it all becomes a bit messy. Let's look a little closer. Your simple food chains are great, but linked together and formed into the food web, means that there are constant crossovers of food chains.

This is called interdependence. It means that one prey may have several predators - a mouse may have a fox, or a badger, or a cat as their predators. They each rely on these different prey in order to survive and procreate as a species. It works in similar fashion to us as humans. We rely on different foods in order to maintain our body as a healthy temple. Yes, you do... Admit it!