environmental sciences towards a sustainable future chapter 2

1. Environmental Sciences Towards a Sustainable Future Chapter 2 Ecosystems: What They Are Version 1.2 � Term 20051

3. A BCC Professor

4. 30 years of teaching can get to you.

5. It makes one really go ape.

6. The Biosphere

7. Ecosystem Services and Functions

8. Important Definitions Biosphere � the overall ecosystem of the earth.The sum total of all the biomes and smaller ecosystems. Biome � a group of ecosystems that are related by having a similar type of vegetation governed by similar climatic conditions. Ecosystem � a group of plants, animals, and other organisms interacting with each other and their environment. Deserts, grasslands, tundra, and deciduous forests and tropical rain forests

9. What Are Ecosystems? A grouping of plants, animals and microbes occupying an explicit unit of space and interacting with each other and their environment. Environment � a combination of all things and factors external to the individual or population of organisms in question.

10. The Author�s Style of Presentation

11. More about Author�s Style of Presentation

12. Biotic - A really important term. Biotic � living Biotic community � includes all vegetation and animals from the largest to the smallest including microbes. Biotic Communities The plant community The animal community The microbial community

13. More Important Terms Abiotic � non living factors which support or limit a biotic community. Water, temperature, salinity, etc. Species � entirety of a population that can interbred and produce fertile offspring. Population � individuals of a certain species that live within a given area. Ecology � study of ecosystems and the interactions that occur among organisms and between organisms and their environment.

14. Autotrophs and HeterotrophsTwo Categories of the Biosphere The distinction is made on the basis of whether they do or do not produce the organic compounds they need to survive. (Compounds containing carbon.) Autotrophs � do produce organic compounds Green plants and chemosynthetic bacteria Heterotrophs � do not produce organic compounds Must feed on organic materials Cattle, deer, humans, etc. Major Categories Consumers �animals such as cows, sheep, wolves, humans, etc. Detritus feeders (decomposers)

15. How Ecosystems Are Formed?Given a specific set of conditions (moisture and temperature), certain plants and animals will develop. This can predict if there is life on other planets.

16. Transitions of Ecosystems Ecotones on land

17. Land to Aquatic ecosystems ecotone

18. 3 Views of the Biotic Structure of an EcosystemThe text looks at the same material 3 different ways. Don�t get confused. Food chain Who eats who and in what order Nuts are eaten by squirrels and foxes eat squirrels Food Webs Interconnected food chains Trophic (feeding) levels All organisms belong to various feeding levels Producers, herbivores, carnivores

19. Major Trophic Categories Producers � use sunlight to convert C02 and water into glucose and organic matter (via photosynthesis). Consumers � feed on producers and other consumers. Detritus feeders (decomposers) � feed on dead organisms or their products.

20. Trophic Categories and Terminology

21. A categorization depending on whether the organisms produce organic compounds or use them.

22. Predators, Parasites & Pathogens

23. Green Plant Photosynthesis

24. Organic vs Inorganic

25. Inorganic and Organic Characteristics Inorganic Oxygen Carbon dioxide Nitrogen Water pH Organic All living things Products of living things Molecules � proteins, lipids & carbohydrates

26. Inorganic Materials and Organic Organisms

27. Consumers � Based on Trophic Category Primary Consumers (Herbivores) � feed directly on Producers � plant eaters. Secondary Consumers (Carnivores) � feed on primary consumers � animal eaters Omnivores � feed on both plants and animals. Parasites � organisms considered as neither plant or animal. Have an intimate relationship with their prey and feed on it over an extended period of time. Usually without killing it.

28. Symbiotic Relationships: Living Together Mutualism � non-feeding A relationship beneficial to both species. For example flowers and insects. Parasitism - feeding one in which a parasite obtains benefits from a host without killing it. Lichens � composed of a fungus and alga. The fungus protects the alga in dry habitats and the alga produces food for the fungus

29. Trophic relationships Among Producers and Consumers

30. The Detritus Food Web

31. Trophic (feeding) Levels

32. Trophic Categories

33. Terrestrial Food Webs A food web is the transfer of energy through food chains.

34. Marine Food Web

35. Trophic Level Energy Exchanges On the average 10% of the energy is passed to the upper levels.

36. I want meat! I am a secondary consumer, a Carnivore.

37. Biomass and the Pyramid Defined as the total combined mass (weight) of all the organisms at each trophic level. Usually 3 or 4 trophic levels per ecosystem Each trophic level produces much less biomass (energy) than it consumes. In terrestrial systems the biomass is about 90-99% less at each higher trophic level. Grasslands produce approximately 20,000 pounds of biomass per acre. A herbivore ( for example a cow) will be approximately 2,000 pounds of biomass. A human who eats herbivores will be about 200 pounds of biomass. Perhaps we should skip the middle man and just eat grass. It would be much more energy efficient.

38. The Biomass PyramidIt takes a lot of mass from a lower lever to feed and upper lever.

39. Trophic Levels: Pyramid of Biomass

40. Trophic Levels: Pyramid of Energy

41. Nutrient Cycles and Energy Flow

42. MutualismA relationship that provides benefit to both species.

43. A Symbiotic Mutualistic Relationship Lichens � composed of a fungus and an alga

44. Resource PartitioningBirds fly at different heights

45. Factors to which organisms respond Conditions � abiotic factors that vary in space and time Not used up by an organism Temperature, wind, acidity, salinity, fire Resources � abiotic or biotic factors that are consumed by organisms. Objects of competition by organisms Water, chemical nutrients, light, oxygen.

46. Organism Growth Factors Different organisms thrive under different environmental conditions. Optimum level � A condition at which an organism thrives best. Sufficient light, water, etc. Range of Tolerance � The range in which organisms will survive and grow. Zones of Stress � the extremes of a range of tolerance for an organism.

47. Law of Limiting FactorsYes, you can have too much of a good thing.There is an optimal level at which organisms respond best.

48. The Role of Climate in Global Biomes Climate � the average temperature and precipitation. Different temperature and rainfall conditions occur in almost any combination. The amount of rainfall and temperature will effect the particular biome. Examples Temperate deciduous forest biomes are found where the annual rainfall is 30-80 inches. Grassland biomes are found where the rainfall is 10-60 inches. Desert biomes are found where the rainfall is less then 10 inches per year.

49. Major Terrestrial Biomes Deserts Hot and dry Grasslands and Prairies Seasonal rainfall & warm Tropical Rain Forests Daily rainfall & warm Temperate (deciduous) Forests Seasonal rainfall & warm Coniferous Forests Seasonal rainfall & cold Tundra Cold and dry

50. Distribution of Terrestrial Biomes

51. Distribution of Terrestrial Biomes

52. Major Biomes related to Temperature & Rainfall

53. Effects of Latitude and Altitude on GrowthAssume that you are in a rain forest and then go up a nearby mountain.

54. Microclimates � Shade and Sunlight

55. Historical Progression of Systems Natural Systems Developed by Mother Nature. Human Systems Created by Humans A total system including animal husbandry, agriculture and all human developments.

56. Human Ecosystems Differs from Natural Systems in several ways. Produce abundant food Control water flow rate and direction Overcome predation and disease Construct our own sub-ecosystems Overcome competition with other species Destroy natural systems Pollution, agriculture, development, etc.

57. Three Revolutions Human Ancestry -100,000 years ago. Start of present day human evolution Neolithic Revolution � ~12,000 years ago The thinking human. Logic, organization Animal husbandry and agriculture started Industrial Revolution � 17th & 18th Century Scientific and technological beginnings Environmental Revolution � Today?? Stewardship and sustainability

58. Calculate Your Own Ecological Footprint

64. Using the PrtScn Key

65. The EndChapter 2