1. Chapter 4: Principles of Ecology
How Ecosystems Work
Assignment: Finish reading chapter 4.
Point/Counterpoint, pg 58
Do Study Quiz for Chap. 2

2. 4.2 Ecology: The Study of Natural Systems
Ecology is a field of science that seeks to describe relationships between organisms and their chemical and physical environment.
Courtesy of the National Park Service

3. The Biosphere
The biosphere is an enormous biological system, spanning the entire planet.
The materials within this closed system are recycled over and over in order for life to be sustained.
The only outside contribution to the biosphere is sunlight, which provides energy for all living things.

4. Biomes and Aquatic Life Zones
The biosphere consists of distinct regions called biomes and aquatic life zones.
Each has its own chemical and physical conditions and unique assemblage of organisms.
Humans inhabit all biomes but are most prevalent in those with the mildest climates.

5. Five Major Types of Biomes
Tundra
Taiga
Temperature deciduous forest
Grassland
Desert
Also 4 types of Aquatic life zones, these are discussed in Chapter 5:
Coral reefs
Estuaries (mouths of rivers where fresh and salt waters mix)
Deep Ocean
Continental Shelf

6. © Photos.com

7. Courtesy of U.S. Fish & Wildlife Services

8. © Photos.com

9. Courtesy of Tim McCabe/NRCS USDA

10. © Anthony Ricci/ShutterStock, Inc.

11. What Is An Ecosystem?
Ecosystems: biological systems consisting of organisms and their environment.
Biotic components
Abiotic components

12. FIGURE 2: The world’s biomes

13. Range of Tolerance

14. Algal Bloom
© Josh Meyer/ShutterStock, Inc.

15. FIGURE 05: The cool water flowing out of the bottom of the reservoir created by Glen Canyon Dam has endangered the razorback sucker and several other native fish species
© gary718/ShutterStock, Inc.
Inset © Ken Lucas/Visuals Unlimited

16. Food Chains and Food Webs
Food and energy flow through food chains that are part of much larger food webs in ecosystems.
FIGURE 8: A grazer food chain and a decomposer food chain, showing the connection between the two

17. FIGURE 7: Simplified grazer food chains

18. FIGURE 9: A food web

19. Trophic Levels: 1. 2. 3.

20. FIGURE 10: Flow of energy and biomass through a food chain

21. FIGURE 11: Biomass pyramid

22. FIGURE 12: Comparison of biomass pyramids

23. FIGURE 13: Nutrient cycle

24. FIGURE 14: A simplified view of the carbon cycle

25. FIGURE 15: A simplified view of the nitrogen cycle

26. The Nitrogen Cycle
Humans alter the nitrogen cycle in at least four ways:
In the soil or water 1. 2. 3.
In the atmosphere 4.

27. FIGURE S01_1: A solar-aquatic plant
Solar aquatic plant by John Todd “EcoMachine” at Sugarbush, VT was first one.
A miniartificial ecosystem is set up to process the waste.
1. Raw sewage contains ammonia, pollutant
2. Bacteria in cylinders convert ammonia to ammonium nitrate. Which is a plant nutrient
Algae consumes the nitrates, shrimp eat eat the algae. Fish eat the shrimp (also snails eat sludge that settles to bottom, and fish eat snails)
FIGURE S01_1: A solar-aquatic plant
Courtesy of John Todd, University of Vermont

28. FIGURE S01_2: Cross-section of Watson Wick Filter