1. Ecosystems and Human Interferences Chapter 48

2. Outline Biotic Components Biotic Components Autotrophs Autotrophs Heterotrophs Heterotrophs Energy Flow Energy Flow Laws of Thermodynamics Laws of Thermodynamics Ecological Pyramids Ecological Pyramids Biogeochemical Cycles Biogeochemical Cycles Hydrologic Cycle Hydrologic Cycle Carbon Cycle Carbon Cycle Nitrogen Cycle Nitrogen Cycle Phosphorus Cycle Phosphorus Cycle

4. Biotic Components Autotrophs Autotrophs Require only inorganic nutrients (EX?) and an outside energy source (EX?) to produce organic nutrients. Require only inorganic nutrients (EX?) and an outside energy source (EX?) to produce organic nutrients. Examples of autotrophs? Examples of autotrophs?

5. Heterotrophs Heterotrophs need a preformed source of organic nutrients. Heterotrophs need a preformed source of organic nutrients. Consumers Consumers Herbivores EX? Herbivores EX? Carnivores EX? Carnivores EX? Omnivores EX? Omnivores EX? Decomposers EX? Decomposers EX?

6. Biotic Components

7. Abiotic Components: Energy And Matter Energy---Flows through an ecosystem Energy---Flows through an ecosystem WHY? WHY? Matter—Cycles within an ecosystem Matter—Cycles within an ecosystem EXAMPLES? EXAMPLES?

8. Definitions Energy Energy Potential Potential Kinetic Kinetic Chemical Chemical Matter and energy are interconvertible. Matter and energy are interconvertible. Work Work Spontaneous change vs non-spontaneous change Spontaneous change vs non-spontaneous change Do characteristics of life require work? Do characteristics of life require work?

9. Types of Energy in Biological Systems Kinetic energy - energy of motion, work done Potential energy - stored energy, can be released to do work Archer draws bowstring back - used kinetic energy Tension now in bowstring represents potential energy Release of bowstring converts potential energy to kinetic energy

10. Energy (cont’d)

11. Thermodynamics a system: a system: Some portion of the universe that you wish to study The surroundings: The surroundings: The adjacent part of the universe outside the system, i.e. everything but the system NOTE: Changes in a system are associated with the transfer of energy Natural systems tend toward states of minimum energy

13. 1st Law of Thermodynamics   Total Energy in Universe is Constant   energy cannot be created or destroyed   Energy can be converted from one form to another   The pathway of conversion is irrelevant, the energy change between identical initial and final states is equal   When it comes to energy-You can’t get ahead!

14. 2nd Law of Thermodynamics- You can’t break even, either! No conversion is 100% efficient. Total useful energy in a closed system decreases as conversions occur. Closed systems go from complex to simple. Entropy Measure of Disorder  Closed systems tend to their highest state of disorder Entropy of the universe increases with every conversion

15. 2nd Law of Thermodynamics Randomness is spontaneous in a closed system

16. Beaker on left has different colored marbles separated from each other Highly ordered system Low entropy Examples of Entropy low entropy high entropy Beaker on right has different colored marbles scattered amongst each other Highly disordered system High entropy Other examples?

17. SUMMARY-THERMODYNAMICS First Law: Energy cannot be created or destroyed, but it can be changed from one form to another. First Law: Energy cannot be created or destroyed, but it can be changed from one form to another. Second Law: Energy cannot be changed from one form to another without loss of usable energy Second Law: Energy cannot be changed from one form to another without loss of usable energy

18. Thermodynamics The System The System Open Open Closed Closed System+Surroundings=Universe System+Surroundings=Universe First Law—You Can’t Win First Law—You Can’t Win Ways to State? Ways to State? Second Law—You Can’t Break Even Either Second Law—You Can’t Break Even Either Ways to State? Examples? Ways to State? Examples?

19. Energy Balances and Thermoodynamics

20. Energy Flow Food Web - Interconnecting paths of energy flow describing trophic relationships. Food Web - Interconnecting paths of energy flow describing trophic relationships.

21. Ecological Pyramids A trophic level is composed of all the organisms that feed at a particular link in a food chain. A trophic level is composed of all the organisms that feed at a particular link in a food chain. Pyramid of Biomass Pyramid of Biomass Pyramid of Numbers Pyramid of Numbers Pyramid of Energy Pyramid of Energy 10% Rule 10% Rule

22. Ecological Pyramid

23. Chemical Cycling Chemicals cycle as organic nutrients are returned to the producers. Chemicals cycle as organic nutrients are returned to the producers. Excretion Excretion Death Death Cellular Respiration Cellular Respiration

25. Global Biogeochemical Cycles Chemical cycling may involve: Reservoir Exchange Pool Biotic Community When exploring chemical cycles, evaluate the human impact on that cycle

27. Hydrologic Cycle Fresh water evaporates from bodies of water. Fresh water evaporates from bodies of water. Precipitation on land enters the ground, surface waters, or aquifers. Precipitation on land enters the ground, surface waters, or aquifers. Water eventually returns to the oceans. Water eventually returns to the oceans.

28. Hydrologic Cycle

29. Carbon Cycle Exchange pool? Exchange pool? Reservoir? Reservoir? Biotic community: How does carbon enter the biotic community? Biotic community: How does carbon enter the biotic community?

30. Circle of Life Carbon compounds, O 2 CO 2, H 2 O Respiration Photosynthesis Energy

31. Carbon Cycle

32. Greenhouse Effect Greenhouse gases allow solar radiation to pass through atmosphere but trap heat (infrared radiation) from escaping. Greenhouse gases allow solar radiation to pass through atmosphere but trap heat (infrared radiation) from escaping. Carbon dioxide, nitrous oxide, methane, H 2 O Carbon dioxide, nitrous oxide, methane, H 2 O If Earth’s temperature rises, more water will evaporate, forming more clouds and setting up a potential positive feedback loop. If Earth’s temperature rises, more water will evaporate, forming more clouds and setting up a potential positive feedback loop.

33. Earth’s Radiation Balances

34. Nitrogen Cycle Atmospheric nitrogen is fixed by bacteria in order to make it available to plants. Atmospheric nitrogen is fixed by bacteria in order to make it available to plants. Nodules on legume roots (Rhizobium/legume symbiosis). Nodules on legume roots (Rhizobium/legume symbiosis). Nitrification - Production of nitrates. Nitrification - Production of nitrates. Denitrification - Conversion of nitrate to nitrous oxide and nitrogen gas. Denitrification - Conversion of nitrate to nitrous oxide and nitrogen gas. Balances nitrogen fixation. Balances nitrogen fixation.

35. The Nitrogen Cycle

36. Nitrogen and Air Pollution Acid Deposition Acid Deposition Nitrogen oxides and sulfur dioxide are converted to acids when they combine with water vapor. Nitrogen oxides and sulfur dioxide are converted to acids when they combine with water vapor.

37. Thermal Inversion

38. Phosphorus Cycle Phosphorus does not enter the atmosphere. Phosphorus does not enter the atmosphere. Sedimentary cycle. Sedimentary cycle. Phosphate taken up by producers incorporated into a variety of organic molecules. Phosphate taken up by producers incorporated into a variety of organic molecules. Can lead to water eutrophication. Can lead to water eutrophication. Biomagnification Biomagnification

39. Phosphorus Cycle

40. Sources of Water Pollution

41. Review Biotic Components Biotic Components Autotrophs Autotrophs Heterotrophs Heterotrophs Energy Flow Energy Flow Ecological Pyramids Ecological Pyramids Biogeochemical Cycles Biogeochemical Cycles Hydrologic Cycle Hydrologic Cycle Carbon Cycle Carbon Cycle Nitrogen Cycle Nitrogen Cycle Phosphorus Cycle Phosphorus Cycle

42. Energy Balances