Feb 22, 2016
Bare rock is expos
ed
Lichens form Their acids break down rock into
particles These particles mix
with other dead lichens to form soil.
klk
After many years,
there is enough soil
Lichens are
replaced by
mosses Insects & other tiny organisms begin to live here.
Soil deepens Mosses are replaced by
ferns Ferns are replaced
by grasses & wildflowers
Small trees may grow if there is enough soil &
shrubs
Hundreds to thousands of years pass Soil can be deep and
stable enough to support a
forest.
Weeds such as crabgrass begins to
grow first.
New weeds such as horseweed appears due to seeds being spread by
wind or small insects.
Disturbance or natural disaster occurs causing severe damage to the
area. In this case, it is a fire.
In approximately 5 to 15 years, small conifer
trees may start growing among the weeds. The trees continue to grow. In about 100 years, a
forest may form
As older conifers die, they may be replaced by hardwoods, such as
oak or maple trees if the environment can
support them.
Crabgrass
Horseweed
Conifer Trees
Hardwoods(Oak or Maple)