2. MODULE: EARTH & SPACE

3. ECOSYSTEM Observatory Chapter 10 PAGES 317 - 347

4. Ecosystems and Trophic Relationships

5. Ecosystems It is a community of living organisms and nonliving factors interacting together in a given environment. They can vary in size and composition.

6. Ecosystems Nonliving components are: ▫1) temperature ▫2) sunlight ▫3) soil constituents ▫4) etc.

7. Trophic Relationships All organisms need energy for survival. Food chains show trophic relationships and trophic levels. ▫Producers ▫Consumers ▫Decomposers

8. In a food chain, the arrow points in the direction that the organism will go after it is eaten. grass  rabbit  wolf

9. Producers AKA: ‘autotroph’ because they are self-feeding ▫at bottom of food chain ▫introduces energy into ecosystem ▫self-feed with sunlight and soil nutrients ▫transforms inorganic into organic matter ▫Examples: plants, algae, certain bacteria

10. Photosynthesis is a process that producers use to feed themselves. carbon + water + light → glucose+ oxygen dioxide energy 6CO 2 + 6H 2 O + light → C 6 H 12 O 6 + 6O 2

11. Primary Productivity in Ecosystems Biomass is the total mass of all organic matter (plant and animal). Primary productivity is the amount of new biomass made by producers.

12. ▫The amount depends on the number of living organisms. ▫It allows for greater capacity of ecosystem to supply energy to organisms (to consumers).

13. ▫3. access to nutrients for producers  C, N, K, P, etc. ▫4. temperature – certain weather conditions promote growth

14. Primary productivity depends on 4 factors: ▫1. amount of light (for radiation for photosynthesis) ▫2. amount of available water (for photosynthesis)

15. BILL NYE THE SCIENCE GUY: PLANTS

16. Consumers AKA: ‘heterotroph’ because they eat other organisms ▫Cannot make their own food

17. Consumers  Consumer Types:  Primary (1 st order) herbivores ▫eat producers, granivorous (seed-eating), frugivorous (fruit-eating)  Secondary(2 nd ), tertiary (3 rd ), quatiery (4 th order) ▫Eat consumers of preceding order ▫2 nd or higher = carnivore

18.  Omnivores  Can be several different orders at once (bears)  Their order depends on what they have eaten or what eats them.  The same animal can be a different ‘order’ depending on their position in a food chain.

19. Decomposers AKA: ‘detrivores’ Connected to all levels of food chain They feed on detritus (dead organic matter) ▫fallen leaves ▫excrement ▫animal remains Examples: worms, fungi, some bacteria, certain insects (sow bugs)

20. Detrivores/De composers

21. Food Web It shows all the trophic relationships in an ecosystem. It can be considered as a ‘trophic network’.

22. QUESTIONS: PAGE 342 #1 TO 5 Observatory Chapter 10

23. Handout: Activity 41 Ecosystem Dynamics and Disturbances

24. BILL NYE THE SCIENCE GUY: FOOD WEB

25. Ecosystem Dynamics This refers to material and energy flow. It is the exchange of material and energy between living organisms and between living organisms with their environment *** In ecosystems and in labs, the following law applies to both ……

26. Law of Conservation of Mass This means: ▫Nothing is lost. ▫Nothing is created. ▫Matter is only transformed. Producers are always changing inorganic matter into organic matter.

27. Law of Conservation of Mass When producers are starved, they will die…the ecosystem will be at risk. Decomposers breakdown organic matter into inorganic matter ▫N, K, P, etc. Ex. Composting is chemical recycling. Matter is always being circulated.

28. Chemical Recycling In Ecosystem Decomposers Environment Producers Detritus Consumers Inorganic Matter Flow Organic Matter Flow

29. Energy Flow Sunlight is the main energy source in an ecosystem. Radiant energy is transformed into chemical energy by plants. (chem energy is also stored in them)

30. Energy Flow Energy gets transferred to animals when producers are consumed. Energy moves up the trophic levels since it stored in tissues.

31. Animals use this energy for moving and heat. Energy of ecosystem is never recycled. Ecosystems need a continuous supply of energy that comes from the sun.

33. QUESTIONS: PAGE 342 #6 TO 10 Observatory Chapter 10

34. Primary productivity is important because: ▫It is the energy available to primary consumers.

35. QUESTIONS: PAGE 342 #10 TO 13 Observatory Chapter 10

36. Disturbances Disturbances are events that damage the ecosystem. ▫Kills organisms ▫Alter the available resources

37. Disturbances Events vary in type, frequency, and seriousness. Disturbances can be either natural or human in origin.

38. Types of Disturbances Depends on location of ecosystem. ▫Snowstorms ▫Hurricanes ▫Volcanoes ▫Sandstorms

39. Frequency of Disturbances Depends on location of ecosystem. ▫Flooding in spring ▫Monsoons in summer

40. Seriousness of Disturbances Depends on location of ecosystem. ▫Ice storm ▫Flooding

41. Natural Disturbances Example: Storms can affect land. There is also a mixing of the surface and subsurface waters that will eventually affect the ocean depths.

42. Natural Disturbances Is normally an environmental phenomena. ▫Volcanoes ▫Forest fires ▫Droughts ▫Floods ▫Frost periods ▫Heat waves

43. Human Disturbances It is where humans are the major source of a disturbance It can be as small as littering to large-scale projects. ▫Logging ▫Oil spills at sea ▫Nuclear power plant meltdown

44. Ecological Succession After a disturbance, the ecosystem will try to recover and gain a balance. Changes made to gain a balance is ecological succession.

45. Ecological Succession Change to plant population will alter animal population and vice versa. The presence or lack of an organism can also bring change to an ecosystem.

46. QUESTIONS: PAGE 342 #14,15, A, C Observatory Chapter 10

47. BILL NYE THE SCIENCE GUY: STORMS

48. BILL NYE THE SCIENCE GUY: VOLCANOES

49. Ecological Footprints Ecological footprints are estimates of the surface area humans or populations require to obtain the resources for satisfying all their “needs” and to ensure the disposal of their waste.

50. Ecological footprint Land used to grow fruits and veggies land used to raise animals Land used to grow trees for lumber Land used to drill for oil, minerals… Factories Waste

51. Ecological carrying capacity The earth ~1.8 hectares per person Canada’s average: 7.6 hectares per person… (1 hectare = 100m x 100m)

52. http://www.footprintnetwork.org/en/index.php/GFN/page/calculators/

53. Ecotoxicology: The study of the ecological consequences of polluting the environment with various substances and radiation, released by human activity.

54. Contaminants Any type of substance or radiation that is likely to cause harm to one or more ecosystems. Inorganic (lead, arsenic, mercury, phosphorus, nitrogen oxides….) Organic (insecticides, pesticides, PCBs, benzene in crude oil) Microbial (viruses and bacteria) Radioactive (uranium, plutonium, radon)

55. PCBs were widely used as coolant fluids in transformers, capacitors and electric motors. It is a Organic Pollutant, banned in 2001. Concerns about the toxicity of PCBs are largely based on compounds within this group that cause endocrine disruption and neurotoxicity. Therefore, the current maximum containment levels as stated by the EPA for PCBs in drinking water systems is 0.5 ppb.

56. Toxicity factors Concentration: ex. drinking water containing more than 0.01 ppm of lead is considered toxic Type of organism it comes in contact with: ex herbicides kill weeds but not the crops Length of exposure: ex. cigarette smoke

58. Toxicity Threshold level of concentration above which a contaminant causes one or more harmful effects in an organism. LETHAL DOSE The amount of contaminant necessary, in a SINGLE DOSE to cause the death of an organism

59. LD 50 The dose that causes death among 50% of individuals.

60. Bioaccumulation Some contaminants cannot be eliminated by an organism. Bioaccumulation is the tendency of contaminants to accumulate over time in the tissues of living organisms.

61. Bioconcentration or bioamplification The concentration of contaminants in tissues increases with each trophic level.

63. Biotechnology How are we trying to solve the problem of contamination? 1) Bioremediation using microorganisms to decompose organic contaminants (biodegradation)

64. 2) Phytoremediation: Using plants or algae to eliminate contaminants from a site. they absorb contaminants and can then be destroyed.

65. 3) Wastewater treatment it can contain ▫sand and other particles ▫pathogens (can cause disease) ▫decomposing organic waste ▫nutrients that would stimulate algae growth ▫chemicals

66. treatment a) Septic tank Solids settle to the bottom Collected as “sludge” and treated Liquids go into drain field Microorganism in the soil treat the liquid

67. b) waste-water treatment plant connected to urban sewer system steps: i) primary/physical treatment ▫removes large debris ▫filter sand ▫sedimentation

68. ii) Secondary/biological treatment microorganisms eliminate contaminants second sedimentation iii) Disinfection chemicals (chlorine, ozone) or radiation (UV) destroys disease-causing microorganisms http://videos.howstuffworks.com/discovery/30 941-dirty-jobs-sewage-treatment-video.htm