Succession.... Mount St. Helen’s Video Mount St. Helen’s Video Part 1.

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

Forest Fires (and Wildfires)

Video

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