1. LIVING IN THE ENVIRONMENT 17 TH MILLER/SPOOLMAN CHAPTER 3 Ecosystems: What Are They and How Do They Work?

2. Core Case Study: Tropical Rain Forests Are Disappearing Cover about 2% of the earth’s land surface Contain about 50% of the world’s known plant and animal species Disruption will have three major harmful effects Reduce biodiversity (accelerating extinction) Accelerate global warming (deforestation) Change regional weather patterns (preventing re- growth)

3. Natural Capital Degradation: Satellite Image of the Loss of Tropical Rain Forest Fig. 3-1a, p. 54

4. 3-1 What Keeps Us and Other Organisms Alive? Concept 3-1A The four major components of the earth’s life-support system are the atmosphere (air), the hydrosphere (water), the geosphere (rock, soil, and sediment), and the biosphere (living things). Concept 3-1B Life is sustained by the flow of energy from the sun through the biosphere, the cycling of nutrients within the biosphere, and gravity.

5. The Earth’s Life-Support System Has Four Major Components Atmosphere Troposphere: where weather happens (inner layer) 78% = N 2, 21% = O 2 Remaining 1% = Greenhouse Gases = H 2 O, CO 2, CH 4 Absorbs and Releases energy warming the earth Necessary to prevent frigid temperatures Supports life as we know it Stratosphere: contains ozone layer in the lower portion O 3 Filters 95% of UV radiation Supports life

6. Hydrosphere = all water on or near the surface of the earth Ocean water covers 71% of the earth holding 97% of earth’s water Geosphere = earth’s hot core, the rocky mantle, and thin outer crust Biosphere = the layer that supports life = parts of the atmosphere, hydrosphere, and geosphere.

7. Natural Capital: General Structure of the Earth Fig. 3-2, p. 56

8. The Diversity of Life Fig. 3-3a, p. 56

9. Three Factors Sustain Life on Earth One-way flow of high-quality energy: Sun → plants → living things → environment as heat → radiation to space As the energy moves through the ecosystem, it becomes low quality energy. Second Law of Thermodynamics = As energy is converted from one form to another…we end up with lower quality/less usable energy...often dispersed as heat losing temperature with each step Cycling of nutrients through parts of the biosphere Fixed quantity of matter on earth….nutrients are forever recycled = The Law of Conservation of Matter Gravity holds earths atmosphere Keeps the atmosphere in place Aides in the cycling of nutrients

10. Sun, Earth, Life, and Climate Sun: UV, visible, and IR energy Energy from the sun is a result of nuclear fusion Travels to the sun via electromagnetic waves as high quality energy Radiation Absorbed by ozone and other atmosphere gases Absorbed by the earth Reflected by the earth (back into space as low quality energy) Radiated by the atmosphere as heat Natural greenhouse effect Sun energy vibrates the atmosphere molecules including ozone KE increases warming the atmosphere Supports life on earth

11. Flow of Energy to and from the Earth Fig. 3-4, p. 57

12. Greenhouse Gases…. Human activities increase greenhouse gases Burning carbon compounds (fuels: coal, gasoline, natural gas) releases huge amounts of CO 2 Growing crops and raising livestock increases methane gas CH 4 and nitrous oxide N 2 O These added inputs are intensifying the greenhouse effect …warming the earth’s atmosphere and surface Expected to alter the climate in this century

13. 3-2 What Are the Major Components of an Ecosystem? Concept 3-2 Some organisms produce the nutrients they need, others get their nutrients by consuming other organisms, and some recycle nutrients back to producers by decomposing the wastes and remains of organisms.

14. Ecologists Study Interactions in Nature Ecology: how organisms interact with each other and their nonliving environment Organisms Populations Communities Ecosystems Biosphere

15. Smallest unit of a chemical element that exhibits its chemical properties Atom Molecule Chemical combination of two or more atoms of the same or different elements Cell The fundamental structural and functional unit of life Organism An individual living being Population A group of individuals of the same species living in a particular place Community Populations of different species living in a particular place, and potentially interacting with each other Stepped Art Ecosystem A community of different species interacting with one another and with their nonliving environment of matter and energy Biosphere Parts of the earth's air,water, and soil where life is found OxygenHydrogen Water Fig. 3-5, p. 58

16. Ecosystems Have Living and Nonliving Components Abiotic Water Air Nutrients Rocks Heat Solar energy Biotic Living and once living

17. Fig. 3-6, p. 59 Precipitaton Oxygen (O 2 ) Carbon dioxide (CO 2 ) Producer Secondary consumer (fox) Primary consumer (rabbit) Producers Water Decomposers Soluble mineral nutrients

18. Producers and Consumers Are the Living Components of Ecosystems (1) Producers, autotrophs Photosynthesis: CO 2 + H 2 O + sunlight → glucose + oxygen Chemosynthesis Consumers, heterotrophs Primary consumers = herbivores Secondary consumers Tertiary consumers Carnivores, Omnivores

19. Producers Fig. 3-7a, p. 59

20. Consumers Fig. 3-8a, p. 60

21. Producers and Consumers Are the Living Components of Ecosystems (2) Decomposers Consumers that in the process of obtaining their own nutrients (taken from the wastes or remains of plants and animals), release nutrients back into the soil/water/air Most are Bacteria or Fungi Detritivores Feed on dead bodies/wastes of other organisms Earthworms Vultures

22. Decomposer Fig. 3-9a, p. 61

23. Fig. 3-10, p. 61 Detritus feeders Decomposers Carpenter ant galleries Bark beetle engraving Termite and Dry rot fungus Long-horned beetle holes Wood reduced to powder Fungi Time progression Powder broken down by decomposers into plant nutrients in soil carpenter ant work

24. Producers and Consumers Are the Living Components of Ecosystems (3) Aerobic respiration Using oxygen to turn glucose back to carbon dioxide and water Anaerobic respiration = fermentation End products are carbon compounds such as methane or acetic acid

25. Energy Flow and Nutrient Cycling One-way energy flow from sun Nutrient cycling of key materials

26. Fig. 3-11, p. 62 Solar energy Chemical nutrients (carbon dioxide, oxygen, nitrogen, minerals) Heat Decomposers (bacteria, fungi) Producers (plants) Consumers (plant eaters, meat eaters) Heat

27. Science Focus: Many of the World’s Most Important Species Are Invisible to Us Microorganisms…MOST are beneficial! Bacteria—ex. Bacteria in the gut aide in food breakdown Protozoa Fungi—used in food production, organic decomposition, Phytoplankton—produce oxygen, regulate earth’s temperature by removing carbon dioxide

28. 3-3 What Happens to Energy in an Ecosystem? Concept 3-3 As energy flows through ecosystems in food chains and webs, the amount of chemical energy available to organisms at each succeeding feeding level decreases.

29. Energy Flows Through Ecosystems in Food Chains and Food Webs Food chain Movement of energy and nutrients from one trophic level to the next Photosynthesis → feeding → decomposition Food web Network of interconnected food chains

30. Fig. 3-12, p. 63 First Trophic Level Second Trophic Level Third Trophic Level Fourth Trophic Level Producers (plants)Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Heat Solar energy Heat Decomposers and detritus feeders

31. Fig. 3-13, p. 64

32. Usable Energy Decreases with Each Link in a Food Chain or Web Biomass Dry weight of all organic matter of a given trophic level in a food chain or food web Decreases at each higher trophic level due to heat loss Pyramid of energy flow 90% of energy lost with each transfer Less chemical energy for higher trophic levels

33. Fig. 3-14, p. 65 Usable energy available at each trophic level (in kilocalories) Heat Tertiary consumers (human) 10 Heat Secondary consumers (perch) Heat Decomposers Heat 100 Primary consumers (zooplankton) Heat 1,000 10,000 Producers (phytoplankton)

34. Some Ecosystems Produce Plant Matter Faster Than Others Do Gross primary productivity (GPP) Rate at which an ecosystem’s producers convert solar energy to chemical energy and biomass Kcal/m 2 /year (kilocalories per square meter per year) Net primary productivity (NPP) Producers must use of the energy within their biomass for their own respiration. Rate at which an ecosystem’s producers convert solar energy to chemical energy, minus the rate at which producers use energy for aerobic respiration Ecosystems and life zones differ in their NPP

35. Fig. 3-15, p. 66 Terrestrial Ecosystems Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest (taiga) Savanna Agricultural land Woodland and shrubland Temperate grassland Tundra (arctic and alpine) Desert scrub Extreme desert Aquatic Ecosystems Estuaries Lakes and streams Continental shelf Open ocean