2. Ecosystems
The term species is used to describe
different types of organisms.
Sustainable ecosystems provide a habitat
for species to live. Natural ecosystems are
sustainable.
3. Ecosystems (cont’d)
Human activities can change the
environment, leading to unsustainable
ecosystems.
When this happens,
species will leave their habitat.
If they cannot find another,
they are in danger of
becoming extinct.
4. Extinction
A species is said to be extinct when it hasn’t
been seen in the wild for over 50 years, and
the last known individual has died.
5. Australia
In the past 200 years more than 125 species
of Australian native plants and animals have
become extinct due to hunting and
changes to the environment.
6. Around the World
Humans are impacting species all over the
world. In Sumatra, Indonesia, the elephant,
tiger, rhino and orang-utan are critically
endangered. This is because 50% of the
rainforests there have been logged and
burned in the last 35 years.
7. Questions
1.
2.
3.
4.
Why are natural ecosystems sustainable?
Name three ways humans can affect
ecosystems
Define the term extinct
Why do you think so many plants and
animals in Australia have become
extinct in the last 200 years?
