Ecology and Human Impact

1. Ecology and Human Impact • Ch. 14: Ecosystems (pg. 253-262) • Ch. 16: The Fragile Earth (pg. 289-307) *GREEN UNIT OVERVIEW SHEET* • http://www.myfoxboston.com/dpp/news/great_white_shark_tagged_off_chatham_090509

2. What is Ecology? Ecology – the study of the interactions of organisms with one another and with their physical environment. Biotic Factors – Organisms (living) ex) animals, plants, bacteria, fungus Abotic Factors – Physical Environment (non-living) ex) water, air, dirt, rocks

3. Ch. 14: Ecosystems What is an Ecosystem? Ecosystem – self-sustaining collection of organisms and their physical environment. ex) forest, river, lake. In your notes: give examples of living (biotic) and non-living (abiotic) factors in a river ecosystem.

4. Why do we study Ecology? • After watching the video, please answer this question in your notes. Be prepared to share with the class. Segment 1 http://player.discoveryeducation.com/index.cfm?guidAssetId=1234A409-B01D-4996-AEA6-935BC9D28D02&blnFromSearch=1&productcode=US Vital for survival of all organisms. The way we use the natural world affects the earth’s ability to provide the resources we need. Ecology tells us that our actions have consequences. Not only for us, but for all organisms that share the earth with us.

5. How do our actions affect other organisms? • Please answer this question in your notes. Be ready to share. Feel free to use your “Unit Overview” to help give you clues for your answer. MERCURY

6. Food Webs and Energy Transfer • Organisms obtain the energy they need to live by eating or taking in other sources of energy. • If the flow of energy is disrupted, it can have disastrous results on the entire ecosystem • What is the first source of energy for the planet?

7. Important Terms • Producer/Autotroph (Auto = self, troph = feeder) • organisms that produce their own food directly from the sun’s energy. • Take in energy from their surroundings and and store it in complex molecules such as carbohydrates. • Use the process of photosynthesis to make complex molecules Ex.

8. Important Terms • Consumers/Heterotrophs (hetero = other) • Organisms that obtain energy by consuming other organisms. Feed on others (hetero-troph) • Feed on producers and other consumers • Can be: • herbivores • carnivores • omnivores • decomposers

9. Important Terms • Primary Consumer – Feeds on plants. All are herbivores. • Secondary Consumer – Feeds on primary consumers. May be omnivore or carnivore • Tertiary Consumer – Feeds on secondary consumer. May be omnivore or carnivore • Quaternary Consumer – Feeds on tertiary consumer. May be omnivore or carnivore.

10. Identify each organism as a producer or the type of consumer they are

11. Food Chain vs. Food Web Food Chain Food Web Food web is the interconnected food chains in an ecosystem • Food chain is one series of energy transfers in an ecosystem

13. Important Terms • Trophic Level – group of organisms whos energy source (the sun) is the same number of steps away from the sun. • Energy flows from producer  consumer. • Producers are always the 1sttrophic level • Heterotrophs (consumers) are always at least the 2ndtrophic level

14. Trophic levels are different than consumer level • Level 5 • Level 4 • Level 3 • Level 2 • Level 1

15. Ecological Pyramids: graphs which illustrate the trophic levels in a community.

16. Less Energy More Energy Most ecological pyramids are large at the base and narrow at the top. This is because every time that an organism is eaten by the next trophic level, some of the energy is lost as heat.

18. 3 TYPES OF PYRAMIDS: • Pyramid of Energy • Pyramid of Biomass • Pyramid of Numbers means you do not have to write this

19. Pyramid of Energy: • Shows the energy available at each trophic level. • The size of the blocks represents the proportion of energy • Measured in Joules or Calories

20. Pyramid of Energy: • Most of the energy available to the community is in the 1st trophic level. • Only 10-20% of the energy is available to the next trophic level (≈ 90% lost)

21. Pyramid of Biomass: • Illustrates the amount of biomass in each trophic level • Biomass weight is determined after dehydration • Shows the amount of matter lost between trophic levels. • Measured in Kg, grams or pounds

22. Pyramid of Biomass Pyramid of Biomass

23. Pyramid of Biomass One problem: They can make a trophic level look like it has more energy than it really does. For example: A bird has a beak, feathers and a skeleton that would count as biomass even though it does not contribute to the overall flow of energy into the next trophic level.

24. Pyramid of Numbers: • Illustration of the number of organisms at each level

25. What kind of Pyramid is this? Energy, the trophic levels are measured in Kilocalories

26. Review Videos • Energy Transfer • http://player.discoveryeducation.com/index.cfm?guidAssetId=7431DF64-E680-49ED-8908-A92ED5CA2725&blnFromSearch=1&productcode=US

27. Biogeochemical Cycles • Water Cycle (hydrological) • How water is transferred from the atmosphere to earth, through organisms and back to the atmosphere • Carbon Cycle • How carbon dioxide and oxygen are cycled from the atmosphere through organisms and back to the atmosphere. • Nitrogen Cycle • How organisms convert (fix) unusable nitrogen in the atmosphere to usable nitrogen to make proteins

28. Water Cycle TERMS • Precipitation • Transpiration • Evaporation • Infiltration(seepage) • Ground Water • Run Off • Condensation http://www.nwlg.org/pages/resources/geog/hydro_cycle/hydro/cycle.htm http://techalive.mtu.edu/meec/module01/HydrologicCycleQuiz.htm

29. CARBON CYCLE

30. Carbon Cycle TERMS • Resipiration • Photosynthesis • Combustion • Decomposition • Fossil Fuels

31. Carbon Cycle

32. CARBON CYCLE TERMS: Cellular Respiration Photosynthesis Combustion Decomposition Fossil Fuels

33. FOSSIL FUELS • Fossil fuels are made from organisms that died millions of years ago and were buried • They are “non-renewable”, meaning there is a limited supply. • Examples: • Coal, oil and gas

34. Renewable Resources • Resources that have unlimited supply. • Often considered “green” • Often do not release harmful pollutants and/or carbon dioxide • Examples: • Wind, solar, nuclear, geothermal, hydroelectric (water)

35. IDENTIFY THE RENEWABLE RESOURCE • GEOTHERMAL • Uses heat generated by the earth

36. IDENTIFY THE RENEWABLE RESOURCE • SOLAR POWER • Harnesses the energy from the sun

37. IDENTIFY THE RENEWABLE RESOURCE • HYDROELECTRIC • is derived from water moving downhill and flowing through a dam where it causes a turbine to rotate, which in turn drives a electric generator

38. IDENTIFY THE RENEWABLE RESOURCE • WIND ENERGY • Harnesses the power of the wind to generate energy

39. IDENTIFY THE RENEWABLE RESOURCE Millstone – Waterford, CT • NUCLEAR ENERGY • produced by the conversion of heat into energy via the process of nuclear fission– the splitting apart of atoms. Uranium atoms are used here.

40. Nitrogen Cycle • Nitrogen is the main component of proteins and genetic materials that build up all organisms. • 78% of the atmosphere is Nitrogen • Organisms cannot use nitrogen in the atmosphere, it needs to be changed (or “fixed”) into a useable form • This is done by bacteria in the soil and plant roots (legumes)

41. Nitrogen in the air and in decaying organisms is fixed by bacteria in the soil • Plants absorb this for themselves • Heterotrophs obtain their nitrogen from plants and animals that eat plants

42. Nitrogen Cycle Terms • Nitrogen Fixation – when bacteria in soil changes nitrogen to a useable form • Decomposition – when dead organisms break down and release nitrogen into the soil • Detritovores – organisms that break down dead material • Ammonia – a useable form of nitrogen • Legumes - seeds that grow inside pods whose roots have nitrogen fixing bacteria

43. Legumes • Legumes are plants whose roots contain nodules that have nitrogen-fixing bacteria. • Used in crop rotation to increase nitrogen in nitrogen-depleted soil Examples: Peanuts, soy, clover

44. Nitrogen Cycle Info • Your body gets the nitrogen it needs to grow from food. • Most plants get the nitrogen they need from soil after bacteria have “fixed” the nitrogen. • Many farmers use fertilizers to add nitrogen to the soil to help plants grow larger and faster. • Both nitrogen fertilizers and forest fires add huge amounts of nitrogen into the soil and nearby lakes and rivers. • Water full of nitrogen causes plants and algae to grow very fast and then die all at once when there are too many for the environment to support.

45. As the human population increases, the toll it takes on the Earth increases • Pollution – anything potentially harmful that humans add to the environment ex) vehicle exhaust, pesticides, CFCs, sulfuric acid, carcinogens

46. Pollution’s Toll • Too much pollution disrupts the relationships in an ecosystem. ex) What would happen if a pesticide killed the shrews living in the ecosystem below?

47. Pollution Endangers Our Water Supply • When substances like mercury and pesticides enter a river, etc. from factory waste, the entire food web can be destroyed. • Negative health effects can also occur

48. Mercury (Hg) • Mercury is a toxic metal that remains in bodies for long periods of time. • Mercury builds up in animals and causes nerve and kidney damage. • The larger the animal, the greater the accumulation of toxic substances. This is biomagnification.

49. Acid Rain • Acid rain is formed when nitric and sulfuric acidis released into the atmosphere from coal-burning power plants. • An increase in the acidity of an ecosystem causes many organisms to die • Ecosystems downwind from factories experience the most acid rain

50. Global Warming • When fossil fuels are burned to make energy, they release CO2 and other harmful substances into the atmosphere. • High levels of CO2 have been linked to increasing temperatures on Earth (Greenhouse Effect) • Increasing temperatures on Earth will lead to climate changes (Global Warming)