Succession...
Mount St. Helen’s Video
Part 1
What is Succession?
Succession
An orderly change in communities of organisms that occurs over time
Primary Succession- begins with bare rock after geologic activity (ex: volcano)
Secondary Succession- begins on soil from which previous community has been removed (fire, agriculture...)
Primary Succession
Secondary Succession
Think about here...An area of the
field outside is left to grow, how would it change over time?
Field Succession
Grass Shrubs Trees Forest
Primary or Secondary?
Primary or Secondary?
Primary or Secondary?
Primary or Secondary?
Pioneer Species- the first to arrive
Climax Community- the final goal
How Does an Ecosystem “Start Over”?
Clear Cutting- People can speed up succession after by planting trees
Lava Flow- New rock over top.
Fire- cleans out an area
Palmetto vs Scrub Oak
Some Disturbance is Devastating
How about a water system?
Take the picture and try and place them in order from beginning of succession to climax community in order.
Good Luck!
Pioneer Stage• Bare muddy or
sandy bottom
• Algae is primary producer
•Caddisfly Larva and fish that nest or burrow in bottom
Submergent Plant Stage
•Organisms decay forming soil on bottom
• Small aquatic plants grow but do not reach surface
•Dragonfly and Mayfly larva as well as weedy bottom fish
Emergent Plant Stage•Continues to fill with
decaying matter
• Larger plants grow through surface
•Cattails, bullrushes, water lilies
• Frogs, turtles, salamanders, a few fish
• Bacteria consume O2, less available to fish
Marsh
•No large open areas of water
• Vegetation covers most of the land
•No truly aquatic fish can survive
Swamp
•Marsh has become more dry, filled with more soil
• Trees start to grow like swamp maple and swamp willow
Forest
• Swamp has filled in with soil and dried up
• Trees like maple and beech dominate
•Mount St. Helen’s Regrowth Video Part 5
•Mount St. Helen’s Regrowth Video Part 6