The living world: Ecosystems - Changes Affecting Ecosystems

Question 1

Changes affecting ecosystems:

Answer 1

Ecosystems take hundreds of years to develop. Ecosystems need to be in balance, if there is a change to one of the components, it may well affect the rest of the ecosystem.

Question 2

Causes of change:

Answer 2

• global scale changes, such as climate change.

- local scale change, such as changes to a habitat – e.g. when a hedge is removed.

Question 3

Natural changes:

Answer 3

Extreme weather events like droughts can be devastating to ponds and lakes.
Plants will dry out and die.
Fish starved of oxygen might not survive.

Question 4

Human changes:

Answer 4

Changing one component has been changed it can have serious knock-on effects on the ecosystem:

• agricultural fertilisers can lead to eutrophication.
• ponds may be drained to use for farming.