Change and Succession

Theme: Sustainable Development

PRIMARY SUCCESSION

FROM BARE ROCK TO FOREST

Change and SuccessionAfter thousands of years many parts of Canada at best have a few cm of soil or are yet bare rock. Where forests, prairies and other ecosystems exist the process called “succession” has shaped them from a barren landscape. (Notice how the process succession is closely related to the word success.)

Forests, prairies and other ecosystems exist today where there was once barrenness. The process of ecological succession has built on barrenness with pioneer plants. Then the remains of one ecosystem was gradually replaced by another over time. This process of succession can be clearly seen in time capsule form in community zoning.

Bare Rock Succession(soil formation)Pioneer plants are organisms that can live in places without soil or shelter.

Pioneer Plants:These lichens are pioneer plants.

The community zones seen as bands of vegetation on this rock mark a time capsule of succession from bare rock to forest.

ecotone

lichens(pioneer plants)

FOREST(climax community)

bare rock

Pause and Reflect:• The process called ecological “succession” gradually replaces one

community with another that has better adapted plants and animals until a balanced climax community is reached.

• A climax community will remain balanced,successful with its limiting factors.

• Is this climax community balance permanent? • A climax community will remain balanced with its limiting factors

until a natural or manmade event, like fire changes the limiting factors.• Then a secondary succession will take place on the remains of the old

ecosystem. Ecological “succession” will again gradually replace one community with another community until a similar climax community is reached.

Secondary Succession

after 17years

Climax Community

Conclusion:

• The process called ecological “succession” gradually replaces one community with another community that has better adapted plants and animals until a balanced climax community is reached.

• A climax community will remain balanced with its limiting factors until a natural or manmade event, like fire changes the limiting factors.

• Then a secondary succession will take place on the remains of the old ecosystem. Ecological “succession” will again gradually replace one community with another until a similar climax community is reached.

OPEN Research Opportunity

• There are satellites in earth orbit dedicated to watching changes in the earth’s surface particularly vegetation of forested areas deserts . . .

• First choose the satellite RADARSAT @ http://www.fourmilab.to/earthview/satellite.html

• This along with the others is a live satellite eye. Use it to explore rainforest areas to find evidence of deforestation.

• Can the historic archive of observations also be viewed and compared with the present?

• What did you find? Can you see evidence of deforestation? • Take screenshots to support your conclusions.

Change and SuccessionPresentation 2001

Terry Knock Picture Files 2000