1. Topic 6
Succession and Changes in Ecosystems

2. Succession Changes are constantly occurring in an ecosystem.
A landslide can quickly destroy an ecosystem
Other changes are slow: wind moves seeds, which cause grass to grow in a parking lot
If strong enough certain plants can establish themselves and replace old plants that were already growing.
Succession- is the gradual process by which some species replace other species in an ecosystem.

3. Succession
Primary Succession- is the gradual growth of organisms in an area that was previously bare, such as on bare rocks.
As they become established and grow they change the landscape of the area they are in.

5. Succession
Secondary Succession- Is like primary succession but it is the change of an already existing ecosystem where life had existed.

7. Adapting to Change – by people
Humans have a drastic effect on the environment around them
Forestry technologies
Industrial Processes
Transportation
Farming technologies
Urban sprawl (cities)
Construction
When humans change an environment the ecosystem responds – some organisms succeed while others cannot

8. Adapting to Change
The clearing of land for farming has led to the decline of songbirds, the warbler and vireos.
The brown-headed cowbird spread and took over song bird nests
The cowbird babies quickly take over the smaller birds

9. Adapting to Change
The brown-headed cow bird is very well adapted to the prairies and competes with song birds
The coyote can survive in cities, but the wolf cannot (scavenger)
The wolf is being forced into smaller and smaller habitats.

10. What do you think?
Where do you think these foxes are adapted to survive

11. Pest Control – Pesticides
A side effect of using pesticides like DDT is it can kill beneficial organisms for farmers.
The right shows the Lygus bug. It kills alfalfa and canola crops.
The spraying for Lygus bugs kills bees.
Why do you think this is a problem farmers?

12. Pest Control – Biological Controls
Biological Controls are a natural way to kill of pests by using natural predators.
The leafy spurge is a weed that infests land and cattle will not eat it
The black dot spurge beetle will feed on it returning the land back to its normal state.

13. Pest Control – Biological Controls
Biological control can be risky especially if a species that is not native to an area is introduced.
If it has no natural predators then it can be become a pest itself.

14. Introduced Species
Species introduced to an area can be a huge risk if they are not normally found there.
Without predators, some species populations can get so large they cannot be controlled.
They can take over an entire ecosystem
Purple Loosestrife
Black margined loosestrife beetle

15. Invasive Species Great Lake Asain Carp Mussels in the Great Lakes
Snakehead Fish

16. Species In Danger
Many species in Alberta and worldwide are endangered.
The loss of habitat is the number one reason why species are at risk of going extinct.
Other reasons include:
Competition with non native species
Over use and overhunting
Pollution and Climate Change
The Polar Bear

17. Species in Danger – Extinct Cdns
Great Auk
Sea Mink
Dawson’s Caribou
Blue Walleye

18. Species in Danger Many species are at risk of going extinct.
They are called Endangered Species
Canadian Species at Risk

19. Eastern Cougar

20. Piping Plover

21. Grizzly Bear

22. Whooping Crane

23. Sea Otter

24. Burrowing Owl
Burrowing Owl