1. 3.0 Changes can be Observed and Monitored in Ecosystems

2. Changes in Ecosystems Ecosystems are always changing
Sometimes these changes are natural (eg. Droughts and floods), while other changes come as a result of human activity (eg. Forest clear-cutting and dams).

3. Natural Changes
For example, after the glaciers retreated from Alberta there was very little fertile soil.
The first plants to grow were very hardy ones called pioneer species, such as lichens and grasses. These plants became established in the sand, silt and clay that covered the landscape.
Their roots grew into cracks and helped to break down these mostly unfertile materials. When these plants died, the organic material in them combined with the sand and clay to form a simple soil. 

6. Human Caused Changes Wabamun Lake
Intensive exploitation of lake resources and habitat destruction resulted in marked decrease in fish population so that commercial operations were halted and recreational fishing is limited to catch and release.
Years of construction activity on the lake's limited watershed has resulted in lowered water levels.
Heavy metals (aluminum, chromium, arsenic, and copper) dissolved in the water as a result of coal burning

7. Changing water level

8. Pike in Wabamun

10. 3.1 Investigating the Distribution of Living Things in an Environment.
Distribution – of living things refers to the population of any given species of plant and animal in a specific area
Plant and animal populations are not evenly distributed throughout a physical space in the ecosystem

13. 3.2 Interactions and Changes Occur in Ecosystems

14. An imbalance within an ecosystem of either biotic or abiotic factors or both can cause problems.
Example: Drained wetlands used as farmland destroyed many organisms in the ecosystem).

15. All Things Change
Factors that can cause ecosystems to change:

16. Bioinvasion – is when a non-native species is introduced, either intentionally or accidentally, into an ecosystem.
A lack of predators, or a naturally stronger species, can result in the successful introduction of that species.
Example: 100 starlings intentionally introduced to Central Park in New York in 1890 now number more than 200 million species.
25% of all plant species in Canada are NOT native (eg. Zebra mussels).

17. Poster
Map of Invasion

18. Competition – involves living things competing with other living things in their community for limited resources such as food, water, and space to live.

19. Predation – occurs when an animal hunts other animals for food.
Large numbers of predators will mean a decrease in the population of prey.
A decrease in the population of prey will then mean a decrease in the population in predators.
Finally, a decrease in the population of predators means an increase in the population of prey.

20. This relationship is cyclical and is typically sustained indefinitely unless human represent the predators, the result could lead to the extinction of the prey. (Fig. 3.6, pg 60)

22. Weather conditions can also affect the ecosystem. Poor conditions (eg
Weather conditions can also affect the ecosystem. Poor conditions (eg. Drought) can slow or stop plant growth. Natural disasters such as floods or fires caused by lightning can also kill plants and animals.

23. 3.3 Succession: How Ecosystems Change over Time

24. What is Succession?
The predictable pattern of change in ecosystems is called succession.
There are two forms of succession: primary & secondary succession

25. Primary Succession
1) Primary Succession – occurs in areas where no life exists due to absence of soil (eg. Volcanic islands). The succession begins with a pioneer species: lichen.
_________ Species – typically the first organism to arrive to an area, helping to break down rocks into soil.
Pioneer

26. What happens next???
Mosses, fungi, grasses, and herbs are next to establish themselves in the developing soil, followed by shallow rooted trees, until finally larger trees establish themselves creating a_______ community.
_______ Community – is when diverse species develop into a stable, though still changing, ecosystem. (Fig. 3.9, pg 63).
climax
Climax

27. Primary Succession

28. Secondary Succession
2) Secondary Succession – occurs when a community has been destroyed or disturbed by natural occurrences or human activity (eg. A newly forested area or fire stricken area).

29. - The first species to appear in secondary succession are the wild grasses and weeds. The succession that follows mirrors that of primary succession.

31. Homework
Check and reflect Page 64 #1-6