Introduction to Environmental Studies

1. Introduction to Environmental Studies • Ecology the study of how plants, animals, and microbes interact with each other and with their physical environment • Environmental Science the study of how humans impact natural ecosystems

2. The First Principle of Ecology: everything is connected to everything else What are the implications of this principle?

3. History of Environmentalism • Thoreau and Emerson • John Muir • Gifford Pinchot • Theodore Roosevelt • Rachel Carson • 1960’s • Earth Day

4. Most famous for his book, Walden, which details simple living in Nature • A. Ralph Waldo Emerson • B. John Muir • C. Aldo Leopold • D. Henry David Thoreau • E. Gifford Pinchot

5. In the late 1800’s, he started the Sierra Club, an environmental organization still going strong today • A. Ralph Waldo Emerson • B. John Muir • C. Aldo Leopold • D. Henry David Thoreau • E. Gifford Pinchot

6. In the book Silent Spring, this author and scientists warned of the dangers of pesticides • A. Aldo Leopold • B. Gifford Pinchot • C. Thoreau • D. Rachel Carson • E. Robert Underwood Johnson

7. Creator of the U.S. Forest Service • A. Theodore Roosevelt • B. Franklin Roosevelt • C. Aldo Leopold • D. Ronald Reagan • E. Henry David Thoreau

8. Changing Worldviews • Expansionist Worldview natural resources are unlimited and for our use • Ecological Worldviews • Conservation wise use and management of natural resources today will insure use for future generations • Preservation minimal use of nature – nature should not be thought of as just here to serve humans – nature deserves to exist for its own sake

9. Deep Ecology

10. Sustainable development – a pattern of resource use that aims to meet human needs while preserving the environment so that these needs will always be met in the future

11. Principles of Ecology To understand environmental issues and foster sustainable development, humans should take lessons form how ecosystems function …

12. Ecosystem – a group of plants, animals, and microbes interacting with each other and the physical environment in a sustainable way

13. ecosystem size … • very small … a small pond … your back yard

14. or very large … the Amazon

15. the Sahara

16. the Serengeti

17. biomes – large terrestrial ecosystemsbiosphere – the earth’s “super-ecosystem” … includes all life forms and the physical environments supporting life

18. Biosphere II

20. the ocean

21. the savanna

23. ecotone – transitional region between adjacent ecosystems

24. Categories of Organisms (common to every ecosystem)

25. autotrophs – (producers) “self-feeding” – typically, green plants

26. heterotrophs – consumers and detritivores and decomposerstypes of consumers …

27. herbivores (primary consumers)

28. carnivores (secondary or tertiary consumers)

29. omnivores (primary, secondary or tertiary, depending on the meal)

30. decomposers (bacteria and fungi)break down organic material recycling nutrients in the process

31. detritivores and scavengers –exploit the available energy in recently dead organisms

32. Feeding Relationships

33. predator - prey

34. grazing (herbivore-producer)

35. parasite - host

36. food chains show the direction of energy flow between organisms in an ecosystem

37. food web a more comprehensive model showing all feeding pathways

38. trophic levels – steps on a food chainbiomass – total mass of biological material (living) – usually refers to specific trophic level

39. Pyramid of Energy Flow Heat Heat Decomposers Tertiary consumers (human) Heat 10 100 1,000 10,000 Usable energy available at each tropic level (in kilocalories) Secondary consumers (perch) Heat Primary consumers (zooplankton) Heat Producers (phytoplankton) Fig. 3-18, p. 49

40. biomass pyramid – shows the relative proportions of biomass at each trophic level • in the most efficient ecosystems, there is only about 10% of food energy available for the next higher trophic level – what happened to the other 90%? • food chains in most terrestrial ecosystems rarely go higher than four trophic levels

41. Biomagnification of DDT DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, or 3 ppt Fig. 9-16, p. 197

42. Toxins in Food Chains • bioaccumulation: the storing of toxins in an organism over time • biomagnification: an increase in the concentration of toxins as you move higher in a food chain

43. Non-feeding Ecological Relationshipssymbiosis – a close physical relationship between two different species

44. commensalism – one organism benefits while the other is unaffected

45. mutualism – beneficial to both organisms

46. competition • intraspecific – competition between members of the same species – a major force in Natural Selection • interspecific – competition for limited resources between different species

47. Abiotic factors – physical and chemical environmental conditions that determine the types of plants and animals in an ecosystem … examples? optimum conditions – for every abiotic factor there exists a certain level at which a species does best limiting factor – an environmental factor that restricts the success of a species

48. range of tolerance – acceptable range of environmental conditions for each species

49. Range of Tolerance Lower limit of tolerance Upper limit of tolerance No organisms Few organisms Few organisms No organisms Abundance of organisms Population Size Zone of intolerance Zone of intolerance Optimum range Zone of physiological stress Zone of physiological stress Low Temperature High Fig. 3-11, p. 43

50. habitat and niche – the place where organism is found and the role it plays