Succession: Ecosystem Development

What is Succession?

• Succession is the orderly process of an ecosystem changing over time. These changes occur in a given way and are therefore predictable. The changes usually occur from simple to complex as the ecosystem develops.

What causes succession?

• Succession results from the changes of both the physical environment and biodiversity and population structure within the community. Example: As conditions for life become more stable and nutrients increase more organisms are able to migrate into the ecosystem and thrive. More producers bring in more consumers and the biodiversity increases over time.

The two types of Succession :

Primary

&

Secondary

Primary succession occurs on essentially new substrata: water or land that has

never been colonized before.

SUCCESSION THAT BEGINS ON A STERILE AREA WHERE CONDITIONS OF EXISTENCE ARE NOT AT FIRST FAVORABLE IS TERMED:

Can you think of any examples where conditions for living organisms would be unfavorable at first?

VOLCANO ISLAND- when it starts nothing is living on it until stuff gets washed up on shore and life begins

•

MORE EXAMPLES:

GLACIERS

AND SAND DUNES!!!!

So given the definition of Primary Succession, can you

predict what secondary succession would be?

The term SECONDARY SUCCESSION refers to community development on

sites previously occupied by well-developed communities, or succession

where nutrients and conditions of existence are already favorable.

Can you think of where some examples of this type of succession

would take place?

FIRE-

FLOODS-

ABANDONED FARMLAND

Succession starts with a pioneer community: The first biotic factors that can survive and tolerate the abiotic

conditions.

PIONEER ORGANISMS: Bold enough to go where no organisms have gone before.

Pioneers: First organisms in ecosystemExamples:

LICHEN (combo of algae and fungus), GRASSES

After a pioneer community is established nutrients increase along with other favorable abiotic and biotic factors that allow the ecosystem to continue to change into other developmental stages.

The various stages are called…

Eventually the ecosystem will reach a steady state which is

called a

Examples of seral stages of succession:

Try the review questions.

• The different succession stages are called?• The final steady state of an ecosystem is called?• The first plants and animals into an ecosystem are

called?• Succession begins with the arrival of the ____ and

leads eventually to establishment of a ___________________

Index Species

Index species point out the development of a specific seral stage

• Good index species are specific to only one seral stage. The have specific needs that only allow them to thrive in that stage of development.

• Good index species are also abundant enough to help identify the specific stage. Mostly they are plants or animals common to that stage.

Keeping track of Succession

• As succession takes place we see the following:

• The ecosystem goes from a simple to complex community.

• Biodiversity, biomass, and nutrients all increase over time.

Biodiversity Index

• Scientists love to measure things (collect data)

• Biodiversity can be quantified.

• Using a transect line the biodiversity of an ecosystem can be measured by looking at the change in species of organisms as you move along the line. RUNS/# of organisms.

Try the B.I. Problems in your packet.

Rivers undergo Succession

• Do you remember how young rivers compare to old rivers?

• Speed?

• Depth?

• Load (amount of sediments/nutrients?)

• Course, straight vs. meandering

In this unit we are going to spend some time considering the primary succession of Sand

dunes of Lake Michigan.

Illinois Beach State Park, a field trip through time!

Located at Illinois Beach State Park is the “Dead River”

• It is a lot like what the Chicago river Looked like some 300 years ago prior to European settlement.

• It was a shallow meandering river that ran parallel to the Lake Michigan shoreline.

• It follows the ridges of land created by glaciers and old sand dunes.

• It eventually turns toward the lake and flows into it during large rain event.

Pictures of the Dead River

Looking west from the mouth of the river

Mr. Piskel jumps the mouth of the Dead River.

On this field trip we will collect data on the plant species found to determine if succession has taken place over the last

12000 years.

• Lake Michigan and the Great lakes system was originally a river system that was scooped out by large Glaciers some 12000 years ago.

• During that time the lake changed depth several times revealing more lake shore as it became shallower.

• This means the land closer to the lake is younger than the land further inland!

If succession of the ecosystem is taking place it should be reflected by the type of plants, the

biodiversity and the biomass of the plants as we move away form the lakeshore (back in time)

You will be put into groups to collect data on the types and amounts of plants found as you

move away from the lake.

• You will collect data on the different species found.

• Their relative number and biodiversity.

• The slope of the land. (topography of the landscape.)

• The soil and moisture conditions.

• Any signs of animal life including insects, feces, feathers, actual animals found.

Pictures of some of the different plants and animals we find.

Sand sunflower

Prickly Pear Cactus? Say what?

Beach Worm Wood

Kill Deer: Nest on ground, can you see the egg?

Rare Lake Michigan Monster washed up on beach

At first we were scared but it was very friendly

Creeping Juniper

Plantain

Bear berry

Sand Cress

Wild Rose

Cottonwood tree

Deer Feces, not raisins!

On the day of the field trip we will:

• Take a walk along the Dead River and learn to identify the plants for the data.

• Collect the data regarding succession.

• Eat lunch at the beach.

• Relax, explore, and enjoy the great outdoors at the Lake Michigan Shoreline.