Measuring Change Flashcards
What can environmental changes be caused by?
- Living factors, such as change in a predator, food source or competitor.
- Non-living factors, such as a change in temperature or rainfall.
What do changes in the environment affect?
The distribution and behaviour of living organisms.
What are some local effects of deforestation?
Reduction in food and shelter for animals.
What are some widespread effects of deforestation?
Changes in rainfall and temperature.
What happens if the prey population grows?
Predator numbers will respond to the increased food supply by increasing as well. Growing predator numbers will eventually reduce the food supply to the point where it can no longer sustain the predator population and the number of predators will go down.
What is the most common source of air pollution?
The combustion of fossil fuels. This usually happens in vehicle engines and power stations.
What can lichens be used as?
Air pollution indicators, especially of the concentration of sulphur dioxide in the atmosphere.
When is sulphur dioxide released?
Sulphur dioxide is released if the fuel contains sulphur compounds. This gas contributes to acid rain.
What are lichens?
Lichens are plants that grow in exposed places such as rocks or tree bark.
What do lichens need to be very good at?
Absorbing water and nutrients to grow in exposed places.
What contains just enough nutrients to keep lichens alive?
Rainwater
What can damage lichens and prevent them from growing?
Air pollutants dissolved in rainwater, especially sulphur dioxide.
If there are no lichens growing anywhere, what is this usually a sign of?
It is often a sign that the air is heavily polluted.
How can you tell if the water is polluted?
Many aquatic invertebrate animals cannot survive in polluted water, so their presence or absence indicates the extent to which a body of water is polluted.
How can oxygen levels in water be measured?
Using oxygen probes. These are often connected to a data logger.
