Organisms need things from their environment and from other organisms in order to survive and reproduce.
- Plants need light, space, water and minerals from the soil.
- Animals need territory, food, water and mates.
Organisms compete with other species and members of their own species for the same resources.
Red and Grey Squirrels
Red and Grey Squirrels live in the same habitat and eat the same food but competition with the Grey Squirrels for these resources means there's not enough food for the reds so the population of Red squirrels is decreasing.
What causes environmental changes?
The environment which plants and animals live in changes all the time. These changes are caused by living and non-living factors such as:
- Living factors:
- a chnage in the occurence of infectious diseases