1. Ecology

2. Scientific study of the interactions between organisms and their environment

3. Levels of Study Organism –Individual –1 turtle

4. Levels of Study Population Individuals of the same species living in the same area All the turtles of the same species

5. Levels of Study Community All the organisms living in an area All the turtles, plants, insects, algae, bacteria

6. Levels of Study Ecosystem All the organisms and all the abiotic factors All the organisms & the soil, water, gases, minerals

7. Levels of Study Biosphere All the organisms & all the abiotic factors on Earth Earth

8. Abiotic Factors Nonliving Temperature Climate Soil type Rainfall Gases Minerals

9. Biotic Factors Living Predators Parasites Herbivores Carnivores Decomposers

10. Biomes Tropical rainforest Tall trees High temperature Heavy rainfall

11. Biomes Savannas Tropical Grasslands Scattered trees High temperature Less rainfall than tropical rain forest

12. Biomes Temperate grasslands Grasses Seasonal droughts Occasional fires Lower temperature & less rainfall than savannas

13. Biomes Deciduous forests Deciduous trees Oak, maple Warm summers Cold winters Moderate rainfall

14. Biomes Taiga Coniferous forests Pines & firs Cold winters Heavy snowfall

15. Biomes Tundra Grasses & sedges Very cold winters Permafrost High winds Little rain

16. Population Characteristics Density Number of individuals per unit area or volume

17. Population Characteristics Dispersal Patterns Spacing between individuals Clumped Uniform Random

18. Population Characteristics Dispersal Patterns Clumped

19. Population Characteristics Dispersal Patterns Uniform

20. Population Characteristics Dispersal Patterns Random (ferns)

21. Population Characteristics Demographics Study of vital statistics Age structure –Groupings by age –Graphed Sex ratio –% of females compared to males

22. Population Characteristics

23. Survivorship Curves Graph of # of survivors vs. relative age

24. Survivorship Curves Type I Most survive to middle age Humans

25. Survivorship Curves Type II Likelihood of death same at any age Squirrel

26. Survivorship Curves Type III Most die young Oyster

27. Limiting Factors Prevent population from reaching biotic potential Types –Density dependent –Density independent

28. Limiting Factors Density dependent Effect becomes more intense with increased density Examples –Parasites & diseases –Competition for resources –Toxic effect of waste products –Predation

29. Limiting Factors Density independent Occur independently of density Examples: –Natural disasters –Climate extremes

30. Population Growth Models Exponential Growth Change in # of individuals (  N) over time (  t) is equal to the growth rate (r) times the number of individuals (N)

31. Population Growth Models Exponential Growth J-shaped curve

32. Population Growth Models Logistic Growth When limiting factors restrict size of population to carrying capacity Carrying capacity (K) = max. # of individuals of a population that can be sustained by the habitat

33. Population Growth Models Logistic Growth Sigmoid (S) shaped curve

34. Life-History Strategies r-selected species Exhibit rapid growth (J-curve) Examples – grasses, insects Characterized by opportunistic species –Quickly invade habitat –Quickly reproduce –Then die Produce many offspring that are small, mature quickly, require little parental care

35. Life-History Strategies k-selected species Population size remains relatively constant Example - humans Produce small number of relatively large offspring that require extensive parental care Reproduction occurs repeatedly during lifetime

36. Community Interactions Interspecific Competition Competition between different species When 2 species compete for same resources one will be more successful To survive, the less successful species –Must use slightly different resources –Must use resources during different time of day

37. Community Interactions Predation Any animal that totally or partly consumes a plant or animal True predator kills and eats another animal Parasite lives in and off a host Herbivore is an animal that eats plants

38. Community Interactions Symbiosis Two species that live together in close contact Types –Mutualism –Commensalism –Parasitism

39. Community Interactions Mutualism Both species benefit from relationship Examples –Bacteria in root nodules –Lichens – algae & fungus living together

40. Community Interactions Commensalism One species benefits while the other is neither harmed nor helped Examples –Birds building nests in trees –Egrets that eat insects around cattle

41. Community Interactions Parasitism One species benefits while the other is harmed Examples –Tapeworm inside animal –Ticks on dog

42. Ecosystems – Trophic Levels Primary producers Plants Photosynthetic bacteria Algae

43. Ecosystems – Trophic Levels Primary consumers Herbivores Eat producers

44. Ecosystems – Trophic Levels Secondary consumers Carnivores Eat primary consumers (herbivores)

45. Ecosystems – Trophic Levels Tertiary consumers Secondary carnivores Eat secondary consumers

46. Ecosystems – Pyramids Pyramid of numbers Most = producers Least = top level consumers

47. Ecosystems – Pyramids Pyramid of energy Most = producers Least = top level consumers

48. Ecosystems – Pyramids 10% rule Only 10% of energy available at each trophic level is converted into new biomass at the next level

49. Ecosystems – Food Chain

50. Ecosystems – Food Web

51. Nitrogen Cycle

52. Water Cycle

53. Carbon Cycle

54. Human Impact Greenhouse effect Ozone depletion Acid rain Deforestation Pollution Species extinction