1
Ecological Succession is…
• The observed process of change in the species structure of an ecological community over time.
• The community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community.
• Succession occurs in all natural environments. Each environment has a particular name that expresses the nature of their ecological succession: Primary and
Secondary
2
Ecological Succession
1st year
Horseweed
dominant; crabgrass, pigweed
2nd year
Asters
dominant; crabgrass 3rd to 18th year Grass scrub community; broomsedg e grass, pines coming in during this stage 19th to 30th year Young pine forest 30th to 70th year Mature pine forest; Understory of young hardwoods 70th to
100th year
Pine to hardwood transition
100th year plus Climax oakhickory forest 3
There are two main types of
Ecological Succession
• Primary Succession: The process of creating life in an area where no life previously existed.
• Secondary Succession: The process of re-stabilization that follows a disturbance in an area where life has formed an ecosystem.
4
Examples of Succession
Primary
Secondary
5
Primary Succession
• The development of an ecosystem in an area that has never had a community living within it occurs by a process called PRIMARY
SUCCESSION.
• An example of an area in which a community has never lived before, would be a new lava or rock from a volcano that makes a new island.
6
Primary Succession
6/5/03
M-DCC / PCB 2340C
7
Secondary Succession
• SECONDARY SUCCESSION begins in habitats where communities were entirely or partially destroyed by some kind of damaging event.
• When an existing community has been cleared by a disturbance such as a fire, tornado, etc...and the soil remains intact, the area begins to return to its natural community. Because these habitats previously supported life, secondary succession, unlike primary