Environmental Science

1. Environmental Science

2. ECOLOGY The study of living organisms and their interaction with the nonliving environment

3. Historical Background Ecology Eco = “house” ology = “study of” BIOTIC ABIOTIC

4. Realms of Ecology Organisms Populations Communities Ecosystems Biome Biosphere

6. What Ecologists Study Concerned with levels of organization ABOVE population

7. The Biosphere The portion of the earth where living organisms exist If the earth were an apple, the biosphere would be no thicker than the skin

8. Atmosphere The troposphere Surface to 17 km (11 miles) up Contains most of the oxygen and nitrogen The stratosphere 17 to 48 km up Contains most of the O3 Screens out all UV-C Screens out most UV-B Screens out some UV-A

9. Hydrosphere All the water on the earth Liquid water Surface underground Ice Polar ice Icebergs Ice in frozen soil Water vapor in the atmosphere

10. Lithosphere Crust and upper mantle Contains all fossil fuels Contains all usable minerals Contains all nutrients for plant life

11. What Sustains Life on Earth? Life on Earth depends on three interconnecting factors One way flow of energy From the sun Through plants and animals Cycling of matter All nutrients must be recycled repeatedly Gravity Allows the planet to hold its atmosphere Causes downward movement of chemicals in cycles

12. How the Sun Helps Sustain Life Lights and warms the planet Supports photosynthesis Powers matter cycling Drives climate and weather systems

13. How the Sun Helps Sustain Life Lights and warms the planet Earth receives about 1/1,000,000,000 of the suns energy output 34% reflected back into space The remaining 66% Warms the troposphere and land Evaporates water Generates winds

14. How the Sun Helps Sustain Life Supports photosynthesis Creates carbohydrates Creates oxygen Speeds decomposition

15. How the Sun Helps Sustain Life Powers matter cycling Carbon cycle Nitrogen cycle Water cycle Oxygen cycle Phosphorous cycle

16. How the Sun Helps Sustain Life Drives climate and weather systems Distributes heat Distributes fresh water

17. Natural Greenhouse Effect Most solar radiation is degraded into heat Greenhouse gasses keep the heat around the planet Water vapor Carbon dioxide Methane Nitrous oxide ozone Without the greenhouse effect, Earth would be as cold as Mars

18. Ecosystem Concepts Biomes – large regions of land characterized by a distinct climate and specific animal and especially plant species Forests Desserts Grasslands Jungles

22. Ecosystem Concepts Biomes - consist of two components abiotic Water Air Solar energy nutrients Biotic (biota) Animals Plants microorganisms

23. Ecosystem Concepts Ecotones – biomes do not have clear-cut edges. They blend into one another Ecotones contain a mixture of organisms from each biome and frequently species found nowhere else Ecotones are more biologically diverse than either of the bordering biomes

24. Ecosystem Concepts Ecotones – biomes do not have clear-cut edges. They blend into one another Ecotones contain a mixture of organisms from each biome and frequently species found nowhere else Ecotones are more biologically diverse than either of the bordering biomes

25. Deciduous Forest/River Ecotone

26. Aquatic/Marine life Zones Fresh water life zones Lakes & ponds Streams & rivers Marine life zones Estuaries Coastlines Coral reefs Deep oceans

27. Abiotic Limitations Abiotic Water – how much or how little Solar energy – shade or sun Nutrients – rich or poor

28. Range of Tolerance There is an optimum range of each abiotic component of a biome for each species Individuals in a population may have slightly different tolerances

30. Law of Tolerance The levels, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the ranger tolerated by that species. Translation: Don’t expect to find polar bears in Tahiti

31. Limiting Factor Principle Too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance. Translation: If the restaurant serves really spicy food, don’t look for Anglos

32. Limiting Factor Principle Too much of a particular abiotic factor can also be a limiting factor Limiting factors can change

33. Limiting Factor Principle Aquatic or marine life zones also have limiting factors Sunlight Dissolved oxygen Nutrient availability Salinity

34. Living Components of the Biome Metabolism – all living creatures capture and transform matter and energy from their environment to supply their needs for survival, growth and reproduction

35. Living Components of the Biome All living things are divided into two groups Producers – make their own food from components obtained from the environment Consumers – obtain nutrients and energy by consuming other organisms or their remains

36. ProducersAutotrophs Most producers capture sunlight and abiotic nutrients to produce carbohydrates (such as glucose (C6H12O6) in a process called Photosynthesis

38. Photosynthesis Carbon dioxide + water + solar energy ? glucose + oxygen CO2 + 6 H2O + solar energy ? C6H12O6+ 6 O2

39. Chemosynthesis Hydrogen sulfide + carbon dioxide + geothermal heat ? nutrients H2S + CO2 + geothermal heat ? nutrients

41. ConsumersHeterotrophs Obtain their energy and nutrients by consuming other organisms or their remains

42. ConsumersHeterotrophs All these organisms consume living prey Herbivores – (primary consumers) feed directly on producers Carnivores – (meat eaters) feed on other consumers Secondary consumers – feed only on primary consumers Tertiary consumers – (higher level consumers) feed on other carnivores Omnivores – feed on both plants and animals

43. HerbivoresPrimary Consumers

44. CarnivoresSecondary Consumers

45. Heterotrophssome feed on the dead or dying Scavengers – feed on dead animal carcasses Detritivores – feed on waste, parts of carcasses or cast off parts Detritus feeders – feed on partially decomposed organic matter Decomposers – (mostly bacteria and fungi) break down dead organic materials to simpler inorganic compounds

46. Aerobic Respiration and Photosynthesis Photosynthesis Energy + Carbon Dioxide + water ? glucose + oxygen sunlight + CO2 + H2O ? C6H12O6 + O2 Aerobic Respiration glucose + oxygen ? carbon dioxide + water + Energy C6H12O6 + O2 ? CO2 + H2O + Energy

47. Energy Cycling Solar energy is collected by plants (producers) Most of the energy from the sun is lost as heat Primary consumers (herbivores) eat the plants Most of the energy is lost as heat Secondary consumers (carnivores) eat the primary consumers Most of the energy is lost as heat

48. Energy Cycling Tertiary consumers eat the secondary consumers Most of the energy is lost as heat Detritivores consume the dead and dying Most of the energy is lost as heat

49. Energy Cycling As you pass up the energy pyramid, the number of organisms decreases. At each step in the pyramid, ~90% of the energy is lost as heat

50. Food Chains Simplified constructs used to show energy flow in the ecosystem Food chains do not exist in nature

51. Food Webs Food webs are more realistic representations of nature Organisms rarely feed at only one trophic level

52. Available Energy How many trophic levels are present depends on how much energy is available in an ecosystem There are rarely more than four or five trophic levels in an ecosystem The amount of energy an ecosystem produces is called the Net Primary Productivity Measured in kcal/m2/yr or g/m2/yr

53. Net Primary ProductivityEquals Rate at which producers store chemical energy as biomass Minus (produced by photosynthesis) Rate at which producers use chemical energy stored as biomass (through aerobic respiration)

54. Net Primary Productivity

55. Different EcosystemsProduce Different Biomass Most Productive Estuaries Swamps/marshes Tropical rainforests Least Productive Open ocean Tundra Desert

56. Human Biomass Usage Humans have taken over, disturbed or degraded ~73% of the earths’ land surface Humans use, waste or destroy ~27% of the earths’ total potential net primary productivity and ~40% of the total potential net primary productivity of terrestrial ecosystems

57. Matter Cycling Energy is an open system Energy enters the system as sunlight (low entropy) and is degraded and dispersed (high entropy) as organisms use it Matter is a closed system All matter is recycled in one of three ways

58. Matter Cycles There are three major types of nutrient recycling Hydraulic cycle (ex. Water cycle) Atmospheric cycle (ex. Carbon cycle) Sedimentary cycle ( ex. Phosphorous)

59. Hydraulic Cycle Water evaporates and cycles through the biosphere Local Regional global

61. Atmospheric Cycle A large portion of the nutrient exist in the atmosphere and cycle rapidly through soil, organisms and back to the atmosphere Local Regional Global

63. Sedimentary Cycle Earths’ crust is the main storehouse. Elements move from the land to the seabed then back to land through geological uplift and volcanic action global