Changes to Ecosystems

Invasive Species

An invasive species can be any kind of living organism—animal, plant, insect, fish, fungus, bacteria, seeds or eggs—that is not native to an ecosystem and causes harm. 

The invasive species can outcompete the native species for food and habitats and sometimes even cause their extinction.

Multiple Choice

problem that occurs when grazing animals like cattle and sheep eat too much vegetation (grass)

• habitat

• overgraze

• thrive

• global warming

Multiple Choice

Which of the following would have a negative impact on an ecosystem

• constructing highways
• planting trees
• recycling paper

Multiple Choice

A park is home to a large number of robins, squirrels and rabbits. The robins and squirrels live in the park’s trees. The robins feed on earthworms and insects that live on the ground. The squirrels eat the acorns produced by the park’s oak trees. The rabbits hide in the bushes and feed on the grass. Which factor would negatively impact the number of rabbits living in the park?

• Collecting acorns off the ground.
• Planting more trees.
• Removing park bushes.
• Removing the squirrels.

Multiple Choice

What would happen if the mouse population went extinct?

• The Kestrel (Hawk) population would increase

• The Blackberry plants would increase

• The Rabbit population would decrease

• The grass would increase

Multiple Choice

What would cause a decrease in the rabbit population?

• An increase in grass growing

• A decrease in caterpillars

• An increase in owls

• An increase in fox