2.1 - Structure

1. Topic 2 – The Ecosystem 2.1 - Structure IB Topics 2.1.1-2.1.7

2. Biotic and Abiotic Components Biotic Abiotic All non-living components of the ecosystem Ex: • All living components of the ecosystem • Ex:

3. Food Chains • The position an organism occupies in a food chain is called the trophiclevel.

4. Local Food Chain Example:

7. Food Webs • Ecosystems contain many interconnected food chains

9. Pyramid of Numbers • A graphical model of the number of organisms in a food chain

11. Pyramid of Biomass • A graphical model of the amount of biomass present in a food chain at a certain point in time

12. Pyramid of Productivity • A graphical model of the rate of energy production over time

13. Key Words (define and provide a local example of each) • Species • Population • Habitat • Niche • Community • Ecosystem • Parasitism • Mutualism • Predation • Herbivory

14. Topic 2 – The Ecosystem 2.2 – Measuring Abiotic Components IB Topics 2.2.1-2.2.2

15. Significant Abiotic Factors • Terrestrial Ecosystem • Marine Ecosystem • Freshwater Ecosystem

16. Topic 2 – The Ecosystem 2.3 – Measuring Biotic Components IB Topics 2.3.1-2.3.5

17. Estimating abundance of organisms • Counting the number of organisms is almost always done using an estimate

18. Lincoln Index • A mathematical model to estimate population size • Capture-mark-release-recapture

19. Example 1 Example 2 75 Ladybugs were caught and marked 80 Ladybugs were caught the second time and 3 were marked • 13 deer were caught and marked • 14 deer were caught the second time and 5 were marked

20. Quadrats • A square of area used to measure the population of non-mobile organisms • Can help to calculate population density and percentage cover

21. Diversity • The number of different species • The number of individuals of each species

22. Simpson’s Diversity Index • Used to compare diversity between areas • High value of D implies stable ecosystem • Low value of D implies unstable ecosystem

23. Topic 2 – The Ecosystem 2.4 – Biomes IB Topics 2.4.1-2.4.2

24. Biomes • A collection of ecosystems that share similar climactic conditions

27. Topic 2 – The Ecosystem 2.5 – Function IB Topics 2.5.1-2.5.7

28. Photosynthesis

29. Respiration

35. Gross Primary Productivity (GPP) • The amount of energy produced by producers

36. Net Primary Productivity (NPP) • The amount of energy stored by producers and available to consumers

37. Gross Secondary Productivity (GSP) • The amount of energy consumed by consumers

38. Net Secondary Productivity (NSP) • The amount of energy stored by consumers and available to the next trophic level

39. Topic 2 – The Ecosystem 2.6 – Changes IB Topics 2.6.1-2.6.7

40. Carrying Capacity • The maximum number of organisms an ecosystem can support sustainably over a long period of time

41. Limiting Factors • Factors that limit the amount of individuals in an ecosystem

42. Tolerance • Species will be most abundant within a certain range of a limiting factor

43. Population Curves • S Curve • Reaches carrying capacity and stabilizes • J Curve • Unchecked population growth

44. Limiting Factors • Density-dependent factors • Limit population size more as population increases

45. Limiting Factors • Density-independent factors • Limit population size regardless of population size

46. Limiting Factors • External vs Internal Factors • Human Caused:

47. K-strategists r-strategists • Opportunistic species • Inhabit unstable/changing environments • Reproduce early/often, mature quickly • Slow growing/maturing species • Few offspring • Long lifespans C-strategists • In between r & K

49. Survivorship Curve

50. Succession • A natural increase in the complexity of the structure and species composition over time