Fireweed on Mt. St. Helens adapted by growing through the crust. Some organisms perish. Organisms that perish do not survive. A turtle may survive a fire. If it cannot meet its needs after the fire, it may not survive.
Some organisms relocate.
An organism that relocates finds a new home. Birds that lived in trees on Mt. St. Helens could fly to other trees. Habitat destruction and overcrowding are not the only threats to organisms. Other threats include hunting and pollution. In some cases organisms become endangered.