AP Bio: Friday, 12/16/11 Intro to ECOLOGY

1. AP Bio: Friday, 12/16/11Intro to ECOLOGY • Homework: • PLANTS Test on Tuesday (review Monday after school) • Chapter 50 & 54 Notes due Wednesday – and BIOME CHOICE for project • Do Now: • What is the difference between biotic and abiotic? • Define a… community population ecosystem • Goals for Today: • Identify the realms of population, community, and ecosystems ecology • Describe the difference between r- and K-selected species and their modes of population growth

2. Themes of Ecology • Interdependence – Food webs and population interactions • Energy flowsin one direction and is transferred inefficiently • Nutrients cycle: your waste = my food • Human impacts

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

4. Survivorship Curves Fraction of Survivors Max. Life Span

6. Population Growth • Determined by… • Birth rate • Death rate • Immigration • Emigration

7. Factors Influencing Population Growth: • Density-dependent – • Depends on population density (has a greater effect on higher-density populations) • Ex: • Density-independent – • Does not depend on population density (kills same proportion regardless) • Ex: weather conditions, toxic pollutants, amount of sunlight

8. Two Models for Population Growth:(1) – Exponential Growth Occurs when… • Unlimited food • Low levels of predation • Not a lot of disease Lack of density-dependent factors r-selected populations dN/dt = rmaxN N = population size rmax = natural rate of increase

9. African Elephants in Kruger National Park, South Africa

10. (2) Logistic Growth Carrying Capacity (K) – the maximum population size that an environment can sustainably support over time Logistic growth occurs when… Density-dependent factors (food, habitat, etc.) are in effect K-selection dN/dt = rmaxN[(K-N)/K]

13. Make a prediction… • What kind of growth is the human population experiencing?

14. Human Population Growth • What is Earth’s carrying capacity for humans?

15. AP Bio: Wednesday, 12/21/11Community Ecology • Homework: • Revisions on Free Response section of plant test – required for anyone who has written comments even if you scored a 10! • Completed Ecology notes and top 3 Biome choices • Do Now: Get back your test and look it over… • Goals for Today: • Define and explain niche and succession • Describe relationships in community ecology

16. Community Interactions • Niche – • The particular way that a species uses biotic and abiotic resources in its environment • “Job description” – includes habitat, food & water sources, etc. • Species interactions can be positive, negative, or neutral • Examples…

17. Competition • Occurs when two species have overlapping niches! • Examples • Niche partitioning via natural selection • Introduced/Exotic Invasive Species • Often out-compete native species • Why? • Result?

18. AP Bio: Thursday, 12/22/11Community Ecology • Homework: • Work on your Biome Project over break. Nothing due right when we get back so have a well-deserved vacation! • Do Now: What are some adaptations of prey? • Goals for Today: • Explain how natural selection drives adaptations in predators and prey • Interpret a food web • Define and explain succession • Start your Biome project!

19. Predation • One organism eats another • Can drive natural selection in both predator and prey • Predator adaptations • Prey adaptations • Cryptic coloration • Toxins and warning coloration • Mimicry

20. Predation • Predator-prey population cycles

21. Food Webs – Arrows follow energy flow!

22. Keystone Species

23. Ecological Succession This picture shows a mountainside in NH that was clear-cut (all trees removed). How do you think this area would look in a year? In 5 years? In 50 years?

24. Ecological Succession • The changes in community composition (number and type of species) over time, after an ecological disturbance • Primary Succession – when a new community is established in a lifeless area (no soil, etc.) • After a glacier, volcanic eruption, new volcanic island • Secondary Succession - when an existing community is wiped out, but soil and some life remains • After forest fire, or land cleared for farmland

25. Ecological Succession • Colonization of the disturbed area often shows a predictable sequence of steps, with predictable species • Pioneer species – first ones to colonize • Climax species – those that are dominant in the stable, end-stage, fully “recovered” community

28. AP Bio:Tuesday, 1/3/12Review of POPULATION & COMMUNITY ECOLOGY Homework: • Work on Biome Project Do Now: On an index card… • What is one thing you learned in our ecology unit before break? • How is your biome project going? What have you accomplished so far? Where are you getting stuck? What are your next steps? Do you need my help or advice on anything? • Goal for Today: • Apply knowledge of population and community ecology to AP Biology exam questions.

29. AP Bio:Wednesday, 1/4/12Energy Flow in Ecosystems Homework: • Work on Biome Project Do Now: • Sit with your partner from yesterday • We’ll correct your practice quizzes together… Goal for Today: • Define and explain trophic levels and primary productivity • Explain energy transfer through ecosystems, and relate this to biological magnification

30. Food Webs (Review) and Trophic LevelsDo Now: Complete the worksheet…

31. AP Bio:Thursday, 1/5/12Energy Flow and Nutrient Cycles Homework: • Lab 12 Pre-Lab for Part A (read all background info, answer questions on pages 1-2) Do Now: • Take out your notebooks • Get ready to answer the question on the next slide Goal for Today: • Define and explain trophic levels and primary productivity • Explain energy transfer through ecosystems, and relate this to biological magnification • Explain how water, carbon, and nitrogen cycle through ecosystems • Explain the effects of clear-cutting and run-off on forest and aquatic ecosystems • Apply all of this to your biome project!

32. Chemical cycling vs. Energy flow What’s the difference? What do you notice?

33. ENERGY FLOW Energy flow: Open system! Input: Solar energy Output: Heat Energy flows in one direction (producer  consumer …) Energy is lost as heat during every energy transfer!

36. The 10% rule – only about 10% of the energy from one level gets transferred to the next trophic level. The rest is used for cell respiration and/or lost as heat.

37. If the seawater is contaminated with a chemical toxin, which organism will show the highest levels of the toxin in its tissues?

38. Biological Magnification The increase in the concentration of a toxin within organisms’ tissues as you move up a food chain Why does this happen?

39. What determines how much energy is captured and flows through an ecosystem?

40. Primary Productivity Total PP (also known as gross primary productivity) = the total amount of light energy that is converted into chemical energy by photosynthesis in a given amt. of time. Net PP = Gross PP minus the energy used by producers for cell respiration • This is the amount available to the rest of the food web NPP = GPP – Respiration

41. Factors determining primary productivity: • Amount of sunlight • Amount of water • Temperature • Amount of nutrients

44. NUTRIENT CYCLING Closed system – no inputs or outputs! Chemical nutrients cycle between abiotic sources (air, water, soil) and biotic sources (producers, consumers, decomposers)

45. Water Cycle What powers it?

46. Carbon Cycle Water is both a reactant and a product in the carbon cycle. Explain! In what form is the carbon at this point in the cycle?

48. Important Macro-Nutrients for Plants: • Nitrogen (N) • Phosphorus (P) • Potassium (K)

50. N P