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AP Bio: Monday, 12.20.10 Unit 7: Ecology

AP Bio: Monday, 12.20.10 Unit 7: Ecology. Homework: Decide which biome you will do for your project Finish reading and taking notes on Chapter 54 Do Now: How do you define ecology ? Goals for Today: Describe the differences between the way that energy and nutrients move through ecosystems

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AP Bio: Monday, 12.20.10 Unit 7: Ecology

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  1. AP Bio: Monday, 12.20.10Unit 7: Ecology • Homework: • Decide which biome you will do for your project • Finish reading and taking notes on Chapter 54 • Do Now: • How do you define ecology? • Goals for Today: • Describe the differences between the way that energy and nutrients move through ecosystems • Define and explain primary productivity and explain what factors influence it • Agenda: • Introduce Biome Project • Lecture: Intro to Ecology

  2. Ecology - • The study of interactions between organisms and their environment • other organisms – abiotic factors Big Themes of this Unit: • Energy flow – in one direction, and inefficient transfer • Nutrient cycling (my waste = your food) • Interdependence (within populations, and between species [food webs]) • Human impacts on ecosystems

  3. Ecosystems Ecology Ecosystem – all the organisms and abiotic factors in a given area Ex: • a hardwood forest ecosystem in central MA • a freshwater pond Ecosystem components interact through transfers of energy and nutrients.

  4. What do the following images show concerningenergy flow vs. nutrient cycles?

  5. Energy Flow: Nutrient Cycling: Cyclic transfer of nutrients between biotic and abiotic components Soil/waterProducers DecomposersConsumers All atoms are continually recycled – no net inputs or outputs in the biosphere • One-way series of energy transfers: Solar energy Chemical energy stored in organisms Heat energy • Inefficient transfer at each step (1% - 20% transferred; the rest is used for metabolism & ultimately lost as heat) • Energy can’t be recaptured or used again once it’s lost as heat

  6. Energy Transfer is Inefficient…

  7. Energy Pyramid: ~ 10% of energy transfer between each trophic level 1% of solar energy captured by primary producers

  8. Foundation of the Food Web: Primary Productivity PP = the amount of light energy converted to chemical energy (organic compounds i.e. sugars) by producers (autotrophs) in a given time period Can be thought of as… • The amount of photosynthesis done • The amount of carbon fixed Gross PP = total amount Net PP = total amount minus the energy used for cell respiration by the producers themselves NPP = GPP – Resp.

  9. Global NPP: What influences it?

  10. Primary Productivity inAquatic Ecosystems • Limited by availability of… • Light • Nutrients • How do we measure aquatic PP? (this week’s lab) 6C02 + 6H20  C6H12O6 + 602 • Oxygen produced during photosynthesis dissolves in water – DO2 • Measuring DO gives a measure of PP

  11. AP Bio: Tuesday, 12.21.10Nutrient Cycles • Homework: • Work on your biome project • Do Now: • What powers the water cycle? • Goals for Today: • Explain how water, carbon, and nitrogen cycle through ecosystems • Agenda: • Hand back tests • Lecture/Discussion of Notes: Nutrient Cycles • Practice MCQs

  12. Nutrient Cycles Water Cycle: Carbon Cycle:

  13. Nutrient Cycles Nitrogen Cycle:

  14. How Does Nutrient Availability Affect Aquatic Ecosystems?

  15. How Does Nutrient Availability Affect Aquatic Ecosystems? • Eutrophication • process in which aquatic ecosystems become (overly) full of nutrients like N, K, and P • Allows algae to grow (too) prolifically  algae bloom • Algae blocks sunlight for other plants • Algae die and decomposer bacteria eat them and flourish • Bacteria use up all the DO2 • None left for fish and other organisms  they die  ocean dead zones

  16. Interactions between Organisms and Nutrients: The Hubbard Brook Experiment • Cut down all trees, measure nutrients in run-off water

  17. Interactions between Organisms and Nutrients: The Hubbard Brook Experiment Conclusions? • Trees help hold nutrients in the ecosystem!

  18. AP Bio: Wednesday, 12.22.10Population & Community Ecology • Homework: • Work on your biome project • Do Now: • Get a laptop • Goals for Today: • Identify the key characteristics and major species of your biome or ecosystem • Apply ecological concepts to a particular biome or ecosystem • Describe the factors that influence population growth in a species • Identify types of interactions between species in a community • Agenda: • Period 1: Work on Biome Project • Period 2: Lecture – Population & Community Ecology

  19. Population Ecology “Life history strategies” - based on reproductive strategies Two extremes: The Fast and the Furious/ Slow and Steady The Young and the Restless

  20. Survivorship Curves Fraction of Survivors Max. Life Span

  21. Population Growth: • Determined by birth rate and death rate • Density-dependent factors limit population growth • Resources (food, nutrients, light, habitat/territory) • Disease • Aggressive behavior • Density-independent populations– birth and death rates don’t change with increasing population size

  22. Two Models for Population Growth • Exponential Growth dN/dt = rN • r-selected populations (r = growth rate; this determines pop. growth)

  23. (2) Logistic Growth dN/dt = rN([K-N]/K K = Carrying Capacity - The maximum population size that an ecosystem can sustainably support over time K-selected populations – carrying capacity determines population size

  24. Human Population Growth • Exponential or logistic? • What is Earth’s carrying capacity for humans?

  25. Community Ecology(interactions between species) • Niche – • The particular role that a species plays in its community • Food, predators, micro-habitat, active time of day • Interactions between species can be positive, neutral, or negative +/+ +/n +/- -/-

  26. Competition - • Species compete for food, water, light, habitat • Occurs when niches overlap • Introduced / “Exotic Invasive” Species – often outcompete native species

  27. AP Bio: Thursday, 12.23.10Ecological Succession • Homework: • Work on your biome project • Have a great vacation! • Do Now: • If the clear-cut area shown above were left alone (no more trees cut) for 20 years, how do you think the community of species would change over time? • Why? • What do you think the phrase “ecological succession” means?

  28. AP Bio: Thursday, 12.23.10Ecological Succession • Goal for Today: • Predict how and why ecological communities change after a disturbance • Agenda: • Partner Practice-Quiz: Free Response Question • Grade question and discuss succession • Finish up lecture from yesterday • (Sorry, we couldn’t get computers for today… )

  29. AP Bio: Monday, 1.3.11Welcome Back & Happy New Year! • Homework: Lab 12 Pre-Lab (#1-5) • Do Now: (please write this in your notebook) • Describe one cool thing you did or learned over the break. • Do you want to present your biome project to the whole class? • What is primary productivity? (check your notes for a reminder) • Goals for Today: • Define and explain primary productivity • Identify key characteristics of major biomes

  30. Foundation of the Food Web: Primary Productivity PP = the amount of light energy converted to chemical energy (organic compounds i.e. sugars) by producers (autotrophs) in a given time period Can be thought of as… • The amount of photosynthesis done • The amount of carbon fixed Gross PP = total amount Net PP = total amount minus the energy used for cell respiration by the producers themselves NPP = GPP – Resp.

  31. Global NPP: What influences it?

  32. Primary Productivity inAquatic Ecosystems • Limited by availability of… • Light • Nutrients • How do we measure aquatic PP? (this week’s lab) 6C02 + 6H20  C6H12O6 + 602 • Oxygen produced during photosynthesis dissolves in water – DO2 • Measuring DO gives a measure of PP

  33. AP Bio: Monday, 1.3.11Biome Projects • Homework: Lab 12 Pre-Lab (#1-5) • Goals for Today: • Define and explain primary productivity • Identify key characteristics of major biomes

  34. AP Bio: Tuesday, 1.4.11Dissolved Oxygen Lab • Homework: Lab 12 Part A – Graph and analysis • Do Now: • Take out Lab 12 • Goals for Today: • Experimentally determine how temperature affects the dissolved oxygen content of water • Agenda: Lab!

  35. AP Bio: Tuesday, 1.4.11Lab 12 Part B: Primary Productivity • Homework: None • Do Now: • Take out Lab 12 and turn to page 8 • Goals for Today: • Set up an experiment to determine how water depth (aka % light) affects primary productivity of aquatic algae • Agenda: • Review Lab 12 Part A • Biome Presentation • Pre-Lab for Part B • Set up Part B • Biome browsing

  36. Predation • One species eats another • Predator adaptations • Prey adaptations • Cryptic coloration • Toxins and warning coloration • Mimicry

  37. Predator-prey population cycles

  38. Keystone Species

  39. Biologicalmagnification

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