biodiversity

Brief description

Biodiversity is the variety of life on Earth.

More information

A variety of plants and animals (biodiversity) can be found within an ecosystem. An ecosystem is a system of living things; plants, animals, fungi, algae, bacteria and viruses and the non-living environment (for example soil, rocks or water) in which they live, interact and depend on one another for survival.

An ecosystem can be as small as a puddle or a tree branch that has fallen into a river or as large as the river itself. Our whole planet Earth could even be considered as an ecosystem!

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Where can we see biodiversity?

Picture a river with a variety of habitat types - that is, a range of places that animals can live, feed, breed and shelter from predators. OK, that's a big ask if you have only just started to learn about ecosystems. Let's help get you started.

Imagine a river bank that has varied levels of vegetation :

• tall trees that cast dappled shade over the water and provide a home for nesting birds,
• medium-sized shrubs that drop their leaves into the water, providing a rich source of food for small animals,
• and thick, healthy plants (known as sedges and rushes) that line the river, supporting the banks and filtering pollutants from the water and providing a hiding spot for young fish.

Imagine a range of different water features: shallow rocky areas or riffles, flat areas of water (called runs), and pools, where fish, turtles and crustaceans can find a safe place to hide.

See a few fallen tree branches in the water, providing a perfect perch for birds above the surface and shelter for small fish below.

We could go on and describe more about this beautiful ecosystem that is forming in your imagination, but you get the idea for now, don't you? In the rich and varied setting like the one we just described, you will find a range of habitats and a perfect location for biodiversity in plant and animal species.

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What's so important about habitat?

Habitats are necessary for living, feeding, breeding and seeking safety from predators. Some habitats can be large and exist in a number of settings, others can be smaller and more limited and some are very specific, where even a slight change in conditions might affect the plants and animals that live there.

Many areas of rivers in Western Australia do not flow continually and have dry periods throughout the year. This affects different animals in different ways.

• Some have different needs at different stages of development, so benefit from the variations of the flow of the river
• Some adapt to the seasonal changes
• Some migrate to follow higher water levels or even other countries
• Some, sadly, cannot survive unless they reach another suitable habitat

Animals are affected the most when areas of the river remain dry for longer than they normally do, or if excessive flooding occurs and damages the habitats that the animals depend on to survive.

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Is biodiversity in danger?

Yes. In many of our river systems the diversity of native plants and animals is declining due to damage that has been done to the environment, both in the past and today.

Find out more about this damage by checking out the Threats to River Systems section of this website.

Threats can be very serious, but there are things that can be done to protect our rivers and to make sure that they provide a range of habitats for plants and animals for years to come. There are many things that you can do at home, at school or out in the community to protect our beautiful rivers, while enjoying them at the same time.