Food Webs
The food chain above is rather simplistic. It implies that cows only eat grass and humans only eat cows. This is obviously incorrect as both cows and humans can eat a variety of things. What is needed is a diagram which shows how food chains can be interlinked. Below is an example of such a diagram.
As you can see the diagram is much more realistic but also more complex. Even this diagram is a simplification. With a food web we can begin to see how organisms inter-relate. We can also begin to look at how changes in populations can have a knock-on effect for other organisms. For example, if the population of toads suddenly fell then it would mean that the population of centipedes would rise as there would be fewer predators. As the foxes have less to eat their population may go down. The foxes though would propbably eat more rabbits and so their population would go down. This shows how the population of one organism could have a dramatic knock-on effect for the populations of other organisms which may be in a completely different food chain.
