A habitat is the place where a plant or animal usually lives. Just like your home. 

An ecosystem is a community of plants and animals that live together. Plants and animals that live in a community are usually dependent on each other for survival.  

A healthy ecosystem has the right balance of both plants and animals, predators and prey.

National parks protect important habitats and ecosystems which help the survival of native plants and animals. This is one of the main reasons why national parks have been created.

In a healthy ecosystem, there is always balance between the animals and plants that live there; also with who eats who and what.

To keep this balance, some predators consume a prey animal that only lives in a certain part of an ecosystem. For example, the powerful owl preys on the ringtail possum for food to survive. The ringtail possum in turn relies on the fruit and flowers growing in one part of the ecosystem to survive.

To help us understand the importance of a healthy ecosystem for plant and animal survival, let's explore:

• living things

• animal and plant features, and some animal profiles

• life cycles

• food chains and food webs.

Scientists who study living things place them into categories, or 'classes', based on their features. This is called classification.

During plant research, they look at external features such as flower, seed, leaf size and shape, the size and shape of the whole plant and where it grows.

Scientist research animals by looking at:

• physical features, e.g. body coverings, beaks

• how they move, e.g. legs, tails, wings, feet or fins

• how they reproduce, e.g. lay eggs or give birth to live young

• how they collect their food and what they eat (their diet) 

• where they live, e.g. in water or on dry land.

We'll study the external features of some Australian animals living in NSW national parks in the activities at the end of this lesson.

Everything in nature is interdependent. That means all plants and animals are dependent on, and affected by, other plants and animals for survival.

• Some animals eat plants – they are called herbivores.

• Some animals eat other animals – they are called carnivores.

• Some animals eat both plants and animals – they are called omnivores.

Some animals eat seeds, insects, fungus and already-dead things that are rotting. These are called decomposers. Nothing is wasted in nature, and every living thing relies on each other in some way.

Food chains and food webs show us who eats who and what, and how the energy transfers from one living thing to another. Food chains always start with a plant; plants make their own food using sunlight.

Review the 'Food chains and webs' presentation below to find out more.