Bare rock, no organisms – Glacier leaves behind bare rock; Volcano produces
bare rock with no organisms.
bare rock with no organisms.
Step One
Pioneer species begins breaking down rock. Pioneer species: 1st organism to live in an area. Pioneer species, usually lichens, grows on rock. Lichens secrete acids that begin breaking rock into small particles, which mix with lichen remains to begin making soil.
Step Two
More complex plants, usually mosses, begin growing when soil is deep enough, after many years; eventually replace (succeed) lichens.
Tiny organisms such as insects move in, add their remains to soil.
Tiny organisms such as insects move in, add their remains to soil.
Step Three
Larger, more complex plants: As soil gets thicker ferns succeed mosses.
Grasses and wildflowers may succeed ferns.
When enough soil has developed, shrubs and small trees move into the area.
Grasses and wildflowers may succeed ferns.
When enough soil has developed, shrubs and small trees move into the area.
Step Four
Forests: Soil may be deep enough after hundreds or thousands of years for
pine or hardwood forests.
pine or hardwood forests.
Step Five
