Please take out your Chapter 3 Reading Assignment

Check your work! Module 6: 1. A2. D3. A4. C5. B6. E Module 7: 1. D2. B3. C4. A5. E6. D7. C Module 8: 1. B2. C3. D4. E5. C

End of Chapter MC 1. D10. E 2. D11. E 3. B12. B 4. C13. C 5. D14. A 6. A15. A 7. E16. B 8. A17. E 9. B18. B

Section 3.1

Levels of Organization Living things can be studied at many levels: In Ecology, we will study everything above individuals Biosphere Biomes Ecosystems Communities Populations Individuals Cells/ Tissues

Levels of Organization Biosphere: Our earth! Biome: areas of biosphere that have similar climate, plants, and animals Ecosystem: collection of living and non-living things that make up an environment Biosphere Desert Biome Old Growth Forest Ecosystem

Levels of Organization Community: populations of different species living together (ex: humans and bacteria living together) Population: group of one species living together Species: a group of organisms that can only breed with each other Community of macaws, grasses, insects… Population of prairie dogs (a species)

What do Ecosystems Need? For ecosystems to thrive, its members need energy and matter Matter = liquid, solid, and gas ‘stuff’ Energy moves in a one-way flow, while matter recycles. Today’s focus = energy

Energy for Ecosystems The sun provides the initial energy for ecosystems Plants harvest sunlight and turn light energy into chemical energy (glucose) This is called photosynthesis CO2 + H2O + light glucose + O2 In an ecosystem, we call plants producers

Energy for Ecosystems Chemical energy (glucose) stored in plants is passed on to herbivores, which eat the plants Chemical energy in herbivores (protein, fat, sugar) is passed on to carnivores, which eat the herbivores This forms a food chain/web.

Quick Vocabulary Carnivores eat animals Herbivores eat plants Omnivores eat both

ENERGY ALWAYS FLOWS THE SAME WAY THROUGH AN ECOSYSTEM: Sun Producers Consumers Energy does not recycle. It is lost as heat when organisms burn it off!

How is the chemical energy used? Plants AND consumers use the energy in sugar for cellular respiration. Glucose + O2 CO2 + H2O + ATP It’s converted to a smaller, more useable molecule called ATP, which is converted to kinetic energy.

Players in the Food Web Plants are called producers, and also autotrophs Autotroph = makes own food using sunlight First level consumers eat producers Second level consumers eat first level consumers, and so on Consumers are also called heterotrophs (get food/energy from outside source)

Other Players Detritivores (mites, snails, and worms) feed on dead matter Decomposers (bacteria and fungi) break down dead matter

Practice Time Watch the Planet Earth video clip Make a food web on your whiteboard Label producers (P), 1 st, 2 nd, 3 rd level consumers, detritivores, decomposers (inferred) Put a star next to heterotrophs

Trophic Levels Each step along a food chain or web is called a trophic level Producers are the first trophic level Consumers make up the second, third, and higher trophic levels Trophic levels are the order in which energy is eaten Label your whiteboard organisms with trophic levels!

Energy Pyramids The energy that producers and consumers can possibly make and pass on can be represented in an energy pyramid Because producers photosynthesize and are numerous, they are on the bottom of the pyramid

Pyramid of Energy Example

Measures of Energy in Ecosystems Gross Primary Productivity (GPP) = total solar energy captured by plants (ONLY ABOUT 1%) Net Primary Productivity (NPP) = total energy captured minus the energy used by producers for their own respiration (what’s left over for consumers!) NPP = GPP – Respiration by Producers

Practice Problem A forest has an NPP of 1.4 kg C/m 2 /year and the rate of cellular respiration is 2.4 kg C/m 2 /year. What is the GPP? NPP = GPP – Respiration 1.4 = GPP – 2.4 GPP = = 3.8 kilograms of Carbon per square meter per year

Biomes Differ in NPP

Ecological Efficiency Proportion of energy that is passed between trophic levels, after cellular respiration 10% on average!

10% rule... 10% 90% lost as heat

How much energy is at each level? 1000 Cal ? Cal

How much energy is at each level? 1000 Cal 100 Cal 10 Cal 1 Cal 900 Cal as heat 9 Cal as heat 90 Cal as heat

Energy Bucks Activity Let’s try it out the 10% rule for ourselves!

Data from Energy Bucks Amount of Energy taken in: Final Amount of Energy Available: 1275Grasses242 Crickets159 Frogs63 Hawks18 TOTAL482 Which number is NPP? GPP? How could we find total respiration?

At which level is the most biomass located? Biomass= total mass of living matter in an area Pyramid of Biomass

Same as pyramid of energy More mass in bottom trophic levels 1000 grams 600 grams 200 grams 100 grams

EcoColumns  Time to add consumers to your ecosystem!  Do steps  We already collected baseline readings, so we will take our next set of data next week  Record what you add/subtract in your data table

Due Dates Energy Flow in an Ecosystem Worksheet and 1 st current event due next time. Take retakes by Friday at 2pm.