Chapter 55: Ecosystems and Restoration Ecology

1. Chapter 55: Ecosystems and Restoration Ecology

2. Essential Knowledge • 2.a.1 – All living systems require constant input of free energy (55.2 & 55.3). • 2.d.1 – All biological systems from cells and organisms to populations, communities, and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy (55.1 – 55.4) • 4.a.6 – Interactions among living systems and with their environment result in the movement of matter and energy (55.1, 55.3, 55.4, 55.5).

3. Ecosystem • All the organisms and abiotic factors in a community.

4. Ecosystem Studies 1. Energy Flow – the movement of energy through trophic levels. 2. Chemical Cycling – the movement of matter from one part of the ecosystem to another.

5. Trophic Levels • Division of an ecosystem based on the source of nutrition (energy).

6. Trophic Levels 1. Primary Producers 2. Primary Consumers 3. Secondary Consumers 4. Detritivores

7. Primary Producers • Usually plants, capture energy and store it in chemical bonds. • Are the source of the energy available to an ecosystem.

8. Primary Consumers • Organisms that feed on the producers. • Ex: Herbivores

9. Secondary Consumers • Organisms that feed on the Primary Consumers. • Ex: Carnivores

10. Detritivores • Get their energy from the organic waste produced by all levels. • Ex: bacteria and fungi

11. Food Chain • Linear pathway of who eats who in an ecosystem.

12. Food Webs • Network showing all the feeding relationships in an ecosystem.

13. Primary Productivity • The rate at which light energy is captured by autotrophs or primary producers.

14. Primary Productivity • NPP = GPP - Rs • NPP = Net Primary Productivity • GPP = Gross Primary Productivity • Rs = Respiration

15. Available Energy • Daily - 1022 joules of solar radiation. • 1% - captured by Ps. • About 170 billion tons of organic matter is created each year.

16. Primary Producers • 50 - 90% of GPP is lost to Rs by the primary producers. • NPP = 10 - 50% • Animals - use only NPP, which limits the food webs.

17. Limiting Factors • Material or nutrient that is not present in sufficient quantity for the primary producers. • Ex: N, P, K, Mg Light, CO2

18. Energy Transfers • Not 100% efficient. • Averages 10% with each tropic level change • Why? • Second law of thermodynamics. • Waste. • Materials that can’t be digested etc.

19. Question ? • Why do most ecosystems have only 3 - 4 trophic levels? • There isn’t enough energy passed up through the food web to support more levels.

20. Implications • There has to be fewer high level consumers in a food web. • The higher level consumers usually need a large geographical area.

21. Pyramids • Graphical representation of relationships in ecosystems. • Ex: 1. Productivity 2. Biomass 3. Numbers

23. Question • What would a numbers pyramid look like in an Indiana forest? • Inverted pyramid. Few producers (trees) and many primary consumers. • What would a Biomass pyramid look like in an Indiana forest? • Pyramidal in shape.

24. Chemical Cycling • Matter is recycled through ecosystems. • Ex: Biogeochemical Cycles

25. Matter Reservoirs 1. Organic Materials 2. Inorganic Materials • Available  Unavailable

26. Representative Biogechemical Cycles • Water • Carbon • Nitrogen • Know one or more of these cycles for various multiple choice questions and possibly a short answer question

27. Water cycle

28. Carbon cycle

29. Nitrogen cycle

30. Energy vs Matter • Energy - flows through ecosystems and is mostly lost as heat. • Matter - cycles in ecosystems.

31. Question ? • What is Man's influence on Ecosystems ? • Humans have had many negative impacts.

32. Biological Magnification • The concentration of toxins in successive levels of a food web. • Ex: DDTHeavy metals -Hg, Cd, Pb

33. Causes • Not broken down by digestion/decomposition. • Lipophilic. • Concentrates and effects the upper levels of the food web.

34. DDT Example

35. Greenhouse Effects • The trapping of heat by the Earth's atmosphere. (CO2, H2O etc.). • Causes: • Warms Earth’s temperatures • Global warming

37. Carbon Dioxide Levels • Prior 1850 - 274 ppm 1958 - 316 ppm 1992 - 351 ppm • Point: the levels of CO2 are rising. • Cause? Probably due to humans.

38. Human CO2 Increase Causes • Industrialization. • Burning of fossil fuels. • Loss of forests.

39. Result • Earth will heat up. • Ice caps melt and sea levels will rise. • Climate shifts. • Increased Ps (?)

40. Exotic Species • When transplanted species are too successful and upset the ecosystem in new areas. • Ex: Starlings Fire Ants Carp Invasive species website

41. Australia • Has had many problems with transplanted species • Ex: RabbitsCactiFoxes Cane toads

42. Succession • Changes in species composition over time.

43. Succession Stages • Sere: unstable stage usually replaced by another community. • Climax: stable stage, self-reproducing.

44. Succession Types 1. Primary 2. Secondary

45. Primary Succession • Building a community from a lifeless area. • Ex: volcanic islands glaciated areas road cuts

46. Comment • The first example of primary succession was worked out on the Indiana Dunes. • Stages: • Open Beach • Beach Grasses • Conifers (Junipers and Pines) • Oaks • Beech-Maple forest (Climax)

48. Secondary Succession • Where a community has been disturbed and the soil is mostly intact. • Ex: • Cutting down a forest • Blow-outs on the Dunes

49. Summary • Identify the trophic levels of ecosystems. • Recognize the flow of energy through food chains and food webs. • Recognize the calculations used in measuring productivity. • Recognize how productivity and energy transfers can be diagramed in pyramid form. • Recognize that matter cycles in ecosystems. • Identify the concept of Biological Magnification. • Recognize several current environmental concerns.