1. 5.1: Natural Phenomena and Ecosystems Ch: 5 Changing the Balance in Ecosystems

2. Typhoon Haiyan  homeless

4.  Recall from Ch: 2 that natural ecosystems maintain a dynamic equilibrium. Biotic and abiotic factors change over time.  Natural events are part of our biosphere’s dynamic quality  Eg: Volcanic eruptions, earthquakes, tsunamis  have both negative and positive consequences.

5. What happens after a natural phenomena?  Healthy ecosystems will respond by adapting. The time taken to adapt may vary.  Natural succession may create a similar ecosystem as was previous, but not necessarily.

6. Case Study #1: Mount St. Helens  Erupted May 18 th, 1980  Wiped out the surrounding ecosystem.  Debris flow filled river valleys killing aquatic organisms.  Hot ash burned hundreds of old-growth forest.

10.  http://www.youtube.com/watch?v=-H_HZVY1tT4

11. A. Weather related phenomena  Eg: Floods, droughts, tornados, hurricanes, blizzards, infestations.  The warming of atmospheric air and ocean temperature are contributing to the severity of weather related phenomenon.

12. Case Study #2: Pine Beetle  Pine Beetle has infected acres of trees across British Columbia.  Live inside the bark and digest sapwood.  Beetle cuts off trees nutrients and obstructs water movement.

14. How does weather play a role?  In previous years the pine beetle population has been kept in check as many larvae were killed off during cold, winter months.  Now BC climate has become milder.

15.  http://www.youtube.com/watch?v=yo69NtUMXBY

16. B. Geological events  Some natural phenomena are the result of geological activity in Earth’s crust. Examples: Volcanic eruptions, tsunami

17. Volcanic Eruption Negative  Habitat destruction  Vegetation covered by ash  Landslide  Ash in atmosphere Positive  New lakes  New soils