1. Chapter 3 Ecosystems and Energy

2. Overview of Chapter 3 o Ecology o Energy First Law of Thermodynamics First Law of Thermodynamics Second Law of Thermodynamics Second Law of Thermodynamics o Photosynthesis and Cellular Respiration o Flow of Energy Through Ecosystems Producers, Consumers & Decomposers Producers, Consumers & Decomposers Ecological Pyramid Ecological Pyramid Ecosystem Productivity Ecosystem Productivity

3. Ecology o Ecology “eco” house & “logy” study of “eco” house & “logy” study of The study of interactions among and between organisms in their abiotic environment The study of interactions among and between organisms in their abiotic environment Broadest field in biology Broadest field in biology o Biotic- living environment Includes all organisms Includes all organisms o Abiotic- non living or physical environment Includes living space, sunlight, soil, precipitation, etc. Includes living space, sunlight, soil, precipitation, etc.

4. Ecology o Biology is very organized o Ecologists are interested in the levels of life above that of organism

5. Ecology Definitions o Species A group of similar organisms whose members freely interbreed A group of similar organisms whose members freely interbreed o Population A group of organisms of the same species that occupy that live in the same area at the same time A group of organisms of the same species that occupy that live in the same area at the same time o Community Al the populations of different species that live and interact in the same area at the same time Al the populations of different species that live and interact in the same area at the same time o Ecosystem A community and its physical (abiotic) environment A community and its physical (abiotic) environment o Landscape Several interacting ecosystems Several interacting ecosystems

6. Ecology o Biosphere contains earth’s communities, ecosystems and landscapes, and includes: Atmosphere- gaseous envelope surrounding earth Atmosphere- gaseous envelope surrounding earth Hydrosphere- earth’s supply of water Hydrosphere- earth’s supply of water Lithosphere- soil and rock of the earth’s crust Lithosphere- soil and rock of the earth’s crust

7. Energy o The ability or capacity to do work Chemical, radiant, thermal, mechanical, nuclear, electrical Chemical, radiant, thermal, mechanical, nuclear, electrical o Energy exists as: Stored energy (potential energy) Stored energy (potential energy) Kinetic energy (energy of motion) Kinetic energy (energy of motion)

8. Thermodynamics o Study of energy and its transformations o System- the object being studied Closed System- Does not exchange energy with surroundings (rare in nature) Closed System- Does not exchange energy with surroundings (rare in nature) Open System- exchanges energy with surroundings Open System- exchanges energy with surroundings

9. Laws of Thermodynamics o First Law of Thermodynamics Energy cannot be created or destroyed; it can change from one form to another Energy cannot be created or destroyed; it can change from one form to another Ex: organisms cannot create energy they need to survive- they must capture it from another source Ex: organisms cannot create energy they need to survive- they must capture it from another source Focus is on quantity Focus is on quantity o Second Law of Thermodynamics When energy is converted form one form to another, some of it is degraded to heat When energy is converted form one form to another, some of it is degraded to heat Heat is highly entropic (disorganized) Heat is highly entropic (disorganized) Focus is on quality Focus is on quality

10. Photosynthesis o Biological process by which energy from the sun (radiant energy) is transformed into chemical energy of sugar molecules o Energy captured by plants via photosynthesis is transferred to the organisms that eat the plants 6 CO 2 + 12 H 2 O + radiant energy C 6 H 12 O 6 + 6 H 2 O + 6 O 2

11. Cellular Respiration o The process where the chemical energy captured in photosynthesis is released within cells of plants and animals o This energy is then used for biological work Creating new cells, reproduction, movement, etc. Creating new cells, reproduction, movement, etc. C 6 H 12 O 6 + 6 O 2 + 6 H 2 O 6 CO 2 + 12 H 2 O + energy

12. Energy Flow o Passage of energy in a one-way direction through an ecosystem Producers Producers Primary consumers Primary consumers Secondary consumers Secondary consumers Decomposers Decomposers

13. Food Chains- The Path of Energy Flow o Energy from food passes from one organisms to another Each “link” is called a trophic level Each “link” is called a trophic level

14. Food webs represent interlocking food chains that connect all organisms in an ecosystem

15. Ecological Pyramids o Graphically represent the relative energy value of each trophic level Important feature is that large amount of energy are lost between trophic levels to heat Important feature is that large amount of energy are lost between trophic levels to heat o Three main types Pyramid of numbers Pyramid of numbers Pyramid of biomass Pyramid of biomass Pyramid of energy Pyramid of energy

16. Web activity

17. Pyramid of Numbers o Illustrates the number of organisms at each trophic level Usually, organisms at the base of the pyramid are more numerous Usually, organisms at the base of the pyramid are more numerous Fewer organisms occupy each successive level Fewer organisms occupy each successive level o Do not indicate the biomass of the organisms at each level or the amount of energy transferred between levels

18. Pyramid of Biomass o Illustrates the total biomass at each successive trophic level Biomass: measure of the total amt of living material Biomass: measure of the total amt of living material Biomass indicates the amount of fixed energy at a given time Biomass indicates the amount of fixed energy at a given time o Illustrates a progressive reduction in biomass through trophic levels

19. Pyramid of Energy o Illustrates how much energy is present at each trophic level and how much is transferred to the next level Most energy dissipates between trophic levels Most energy dissipates between trophic levels o Explains why there are so few trophic levels Energy levels get too low to support life Energy levels get too low to support life

20. Ecosystem Productivity o Gross Primary Productivity (GPP) Total amount of energy that plants capture and assimilate in a given period of time Total amount of energy that plants capture and assimilate in a given period of time o Net Primary Productivity (NPP) Plant growth per unit area per time Plant growth per unit area per time Represents the rate at which organic material is actually incorporated into the plant tissue for growth Represents the rate at which organic material is actually incorporated into the plant tissue for growth o GPP – cellular respiration = NPP Only NPP is available as food to organisms Only NPP is available as food to organisms

21. Variation in NPP by Ecosystem

22. Human Impact on NPP o Humans consume more of earth’s resources that any other animal Humans represent 0.5% of land-based biomass Humans represent 0.5% of land-based biomass Humans use 32% of land-based NPP! Humans use 32% of land-based NPP! o This may contribute to loss of species (extinction) o Humans’ high consumption represents a threat to planet’s ability to support both human and non-human inhabitants

24. Our Net Primary Productivity Lab o Results

25. My Hero Dr. Wangari Maathai o http://www.nytimes.com/2011/09/27/worl d/africa/wangari-maathai-nobel-peace- prize-laureate-dies-at-71.html http://www.nytimes.com/2011/09/27/worl d/africa/wangari-maathai-nobel-peace- prize-laureate-dies-at-71.html http://www.nytimes.com/2011/09/27/worl d/africa/wangari-maathai-nobel-peace- prize-laureate-dies-at-71.html o http://www.cnn.com/2011/09/26/world/af rica/wangari-maathai-tribute/ http://www.cnn.com/2011/09/26/world/af rica/wangari-maathai-tribute/ http://www.cnn.com/2011/09/26/world/af rica/wangari-maathai-tribute/