All of the above
Growing quickly
Having deep roots
Developing fire-resistant cover
Tundra
Temperate forest
Grassland
Desert
Their territories don't overlap
They all migrate in different directions
They eat different foods
They avoid each other as much as possible
They have thorns
They have toxic chemicals
A combination of the above defenses
Ants protect them
Australia
Asia
Antarctica
North America
The savanna gets a fair amount of rain, at least 20 inches a year.
Different temperatures
Rain shadows
Midlatitudes
Bajadas
Spring and summer
Winter and summer
Dry and wet
Winter and fall