Chapter 4

2. Chapter 4 Ecosystems & Energy

3. Ecology • The branch of biology that deals with the interactions between organisms and the relationship between organisms and the environment.

4. Do Now: • Draw a flow chart to represent the organizational relationships between the following terms from the most inclusive to the least inclusive: ecosystem, population, species, community, and biosphere.

5. Levels of Biological Organization

6. Cellular Organization Cells Tissues Organs Organ Systems Organisms SPECIES Ecosystem Organization Species Population Community Ecosystem Landscape Biosphere Levels of Organization

7. Species • A group of organisms capable of producing more members of the same organism.. Homo sapiens with Homo sapiens Not Homo sapiens with Homo habilus

8. Species The Brown Trout Salmo trutta

9. Population • Includes all the members of a species found in a given area. • Ex: sunfish in a pond

10. Community • Includes all the populations in a given area. • Ex: all plants, animals, and microorganisms make up a pond community

11. Ecosystem • Includes all the members of the community plus the physical environment in which they live in. • Interaction of biotic and abiotic factors

12. Abiotic Factors • Nonliving factors. • The abiotic factors of an ecosystem include the physical and chemical factors that affect the capacity of an organism to live and reproduce. These factors are: 1. Intensity and duration of light 2. Temperature range 3. Amount of moisture 4. Type of substrate 5. Availability of inorganic substances and gases 6. pH

13. Biotic Factors • Living factors • These factors directly or indirectly affect the environment. • Thus, the organisms, their presence, parts, interaction, and wastes all act as biotic factors. • These interactions include: 1. Nutritional relationships 2. Symbiotic relationships

14. Requirements for a Stable Ecosystem • The ecosystem involves interactions between living and nonliving things. Certain requirements must be met for a stable ecosystem to exist: • There must be a constant supply of energy (sunlight for photosynthesis). • There must be living organisms that can incorporate the energy into organic compounds (food). • There must be a recycling of materials between organisms and the environment.

15. Limiting Factors • Determines the types of organisms which may exist in that environment. • Examples are: • A low temperature common to northern latitudes determines in part what species of plants can exist in that area. • The amount of oxygen dissolved in a body of water will help determine which species of fish will exist there.

16. Landscape • A spatially heterogeneous region that includes several interacting ecosystems • Connections among ecosystems found in a particular area.

17. Biosphere • The portion of the earth in which life exists. • The biosphere is composed of many complex ecosystems that include water, soil, and air.

18. Ecological Organization Population ( or ) Community ( + + ) Ecosystem ( ) Biosphere ( )

19. Do Now: • Compare and contrast potential energy and kinetic energy using biological or ecological examples and references

20. Types of energy • Energy: the capacity or ability to do work. • Potential Energy: Stored energy. • Kinetic Energy: The energy of motion.

21. Do Now: • Define energy and briefly describe how the different forms contribute to the continual energy needs of organisms

22. Types of energy • Heat Energy: thermal energy that flows from an object with a high temp. (heat source) to an object with a lower temp. (heat sink).

23. Nuclear Energy: energy found within atomic nuclei.

24. Types of Energy • Electrical Energy: energy that flows as charged particles.

25. Thermodynamics: The study of energy & its transformations. 1st Law ofThermodynamics: energy cannot be created nor destroyed, but it can be transformed. 2nd Law ofThermodynamics: when energy is converted some usable energy is degraded into a less usable form. (Entropy)

26. Do Now: • Cellular respiration occurs in both plant and animal cells while photosynthesis only occur in plant cells. How are plant and animals connected via these two processes? Be sure to include balanced chemical equations as part of your answer.

27. Closed and Open Systems Earth is an open system because it receives energy from the sun.

28. Types of Energy Chemical Energy Potential Energy Mechanical (Kinetic) Energy Radiant (Solar) Nuclear Energy Heat Energy Electrical Energy

29. Energy Flow Relationships • For an ecosystem to be self-sustaining, there must be a flow of energy between organisms. • The pathway of energy flow through the living components of an ecosystem are represented by food chains and foodwebs.

30. Nutritional Relationships • Involves the transfer of nutrients from one organism to another within an ecosystem. • In terms of nutrition, organisms are either autotrophs or heterotrophs • SEE OWL LAB

31. Energy Flow through a food Chain

32. Energy Losses • The mouse receives energy from the food it eats. • Cells extract the food's energy for growth, acquiring food, escaping enemies lost as heat. Some lost in the mouse's waste (feces). • The remaining energy is stored in the mouse's body and is available to the organism that preys on it. • About 90% of the energy is used or lost, only 10% is available to predators.

33. Energy Flow

34. Biological Magnification • A nondegradable or slowly degradable substance • That becomes more and more concentrated in the tissues of organisms at higher trophic levels of a food web. • * Dichloro-Diphenyl-Trichloroethane (DDT) • * Polychlorinated biphenyls (PCBs)

35. DDT in Food Webs

36. DDT

37. PCBs in Food Webs • PCB concentrations in animal tissue can be magnified up to 25 million times. • Microscopic organisms pick up chemicals from sediments • Consumed in large numbers by filter feeding zooplankton. • Mysid shrimp then consume zooplankton • fish eat the mysid • and so on up the food web to the herring gull. • (Figure and caption from Our Stolen Future, p. 27)

38. DDT Detection • In 1962, Rachel Carson, a former U.S. Fish and Wildlife Service (USFWS) scientist and writer, published Silent Spring, outlining the dangers of DDT Fig. 41-8, p.736

39. Do Now: • Discuss the contributions of saprotrophs and detritivores to a balanced ecosystem. • Identify two representatives of each group in your discussion

40. (A) Food Chains • Green plants and other photosynthetic organisms are the organisms in an ecosystem that can convert radiant energy from sunlight into food. • A food chain involves the transfer of energy from green plants through a series of organisms with repeated stages of eating and being eaten.

41. Food Chain

42. (B) Food Webs • In a natural community, most organisms eat more than one species and may be eaten, in turn, by more than one species. • Thus, the various food chains in a community are interconnected forming a food web. • SEE OWL LAB

43. Food Web at the Edge of an Eastern Deciduous Forest

44. Do Now: • Define and discuss three applications of the term: ecological pyramid. • What accounts for the shape of the pyramid? • Use sketches of each type of pyramid with associated quantitative units to support your comparison.

45. (C) Pyramid of Energy • The greatest amount of energy in a community is present in the organisms that make up the producer level. • Only a small portion of this energy (10%) is passed on to primary consumers, and only a smaller portion (10% of the original 10%) is passed on to secondary consumers. • A pyramid of energy can be used to illustrate the loss of usable energy at each feeding level.

48. B. ALL living organisms must carry out ALL 8 life functions Nutrition Synthesis Transport Growth Respiration Regulation Reproduction Excretion

49. Autotroph • An organism capable of making their own food • Photosynthetic • Chemosynthetic

50. Chemosynthesis • A type of autotrophic nutrition • Does not require light as an energy source • Energy is obtained by chemical reactions within the cell • Example: Hydrothermal vent bacteria