 Lichens are a ______of fungi and bacteria.  ______

Pioneer Species  These pioneer species are the ______to inhabit an area.  Examples: ______, ______ These organisms will modify or ______the environment (by forming soil, etc.) and eventually the habitat becomes ______to other species.  Start recovery following a ______in BOTH ______and ______succession. In primary, pioneer species create ______. New Soil  Soil begins to form as lichens weather and break down rocks into ______.  When the lichens die, they add ______matter to the rock.  Plants such as ______and ferns grow in this ______.  The soil layer ______, and grasses, wildflowers, and other plants take over.  When these plants die, they add more ______to the soil.  The soil can now support the growth of shrubs and trees and eventually ______.

Secondary Succession  After a forest fire, not much seems to be left except dead trees and ash-covered ______.  All that remains is ______.  But, the soil already contains the seeds of ______, ______, and ______.  Causes: ______, floods, changes in ______, etc.

Climax Community  A community of plants that has reached an ______of succession.  There are fewer changes of species ______unless there is fire, etc.  This community is a relatively ______environment that can last for ______of years.

Ecological Succession  Succession refers to the normal, slow ______that occur in the ______that live in an area.  The ______way in which an ecosystem develops ______.  Succession ______differently in different places. Ecological succession can be classified in two ways:  ______ ______

Primary Succession  Primary succession ______in an area that was previously ______.  Involves the ______of soil, micro- organisms, plants and animals to establish or restore populations in areas that are ______of living things.  It starts with ______.