First 278 words of the document:
Competition and Environmental Change
Organisms compete in their environment for resources to survive and reproduce. Plants and animals
compete for different resources.
Plants compete for water, space, light and minerals.
Animals compete for mates, territory, water and food.
Environmental changes are caused by different factors which we class as either living factors or non-
A change in the number of predators
A change in the number of prey or food available
A change in the amount of infectious diseases
A change in the number or types of competitors
Factors A change in the amount of rainfall
A change in the amount of air/water pollution
A change in the temperature
These changes could either cause the population to increase, decrease, or cause the population
distribution to change.
An increase in population could be caused by an increase in the amount of prey/food available. It
could also be increased by a decrease in predators in the area.
A decrease in population could be caused by an increase in infectious diseases, a decrease in the
availability of food and an increase in the number of predators.
The distribution can change if the temperature decreases in the area, and the organisms living there
are adapted to high temperatures. They would move to areas with higher temperatures meaning a
change in the distribution.
Measuring Environmental Change
Scientists can use indicator species to measure the amount of air pollution or water pollution.
They are known as indicator species.
Other pages in this set
Here's a taster:
If the amount of raw sewage increases in a lake/river, the bacterial population will increase and use
up the oxygen. Certain indicator species are very sensitive to the amount of oxygen dissolved in the
water. If you find species such as mayfly larvae it means the water is very clean, but other species
such as rat-tailed maggots suggest the water is dirty.…read more