In my last post I spoke about how the ecosystem was all connected in relation to how energy is passed on from organism to another. There are two main ways to visually see how each organism is connected to the others. Food chains are essentially a line-up of organisms that pass energy on to each other. See example below…
By following the example above, we can see that the energy from the grass moves to the grasshopper, to the mouse, and finally reaches the owl. It’s a simple chain and shows what is eaten by each animal.
Now, a food web works in the same way as a food chain. It is still a representation of what animal eats what, but imagine if you combine a whole bunch of food chains together. A food web would look like this…
Looks kind of messy huh? A food web is a bunch of food chains connected together to represent the interactions in an ecosystem. So in the example above we see a bunny at the bottom of the picture. The arrow that leads from the grass to the bunny means that the bunny eats the grass. The arrows leading away from the bunny show that it can be eaten by either a fox or an owl. What is not shown on these pictures are the decomposers. Decomposers are normally a group of bacteria, fungi, or a wide variety of invertebrates.
Now you know how to read food chains and food webs. Try creating one of each to ensure that you understand how they work. It’s easy! Just follow these steps:
- Pick a producer and 2-3 consumers
- Starting with the producer on the left then place the animals in order of who eats who
- Draw in your arrows and double check your work!
To make a food web:
- Choose lots of animals (make sure you have producers, consumers, and decomposers)
- Place the producers at the bottom of your web and the consumers above them
- Draw arrows from the producers to the animals that eat them
- Draw arrows from consumers to the animals that might eat them
- Draw arrows from the producers and composers to the decomposers
- Double check your work!