Please take out your Chapter 3 Reading Assignment

Check your work!Module 6:1. A 2. D 3. A 4. C 5. B 6. E

Module 7:1. D 2. B 3. C 4. A 5. E 6. D 7. C

Module 8:1. B 2. C 3. D 4. E 5. C

End of Chapter MC1. D 10. E2. D 11. E3. B 12. B4. C 13. C5. D 14. A6. A 15. A7. E 16. B8. A 17. E9. B 18. B

Section 3.1

Levels of OrganizationLiving things can be studied at many levels:In Ecology,we will study everythingaboveindividuals

Levels of OrganizationBiosphere: Our earth! Biome: areas of biosphere that have similar

climate, plants, and animalsEcosystem: collection of living and non-living

things that make up an environment

BiosphereDesertBiome

Old Growth Forest Ecosystem

Levels of OrganizationCommunity: 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 matterMatter = liquid, solid, and gas ‘stuff’Energy moves in a one-way flow,

while matter recycles. Today’s focus = energy

Energy for EcosystemsThe sun provides the initial energy

for ecosystemsPlants harvest sunlight and turn light

energy into chemical energy (glucose)This is called photosynthesisCO2 + H2O + light glucose + O2

In an ecosystem, we call plants producers

Energy for EcosystemsChemical energy (glucose) stored in plants is

passed on to herbivores, which eat the plantsChemical energy in herbivores (protein, fat,

sugar) is passed on to carnivores, which eat the herbivores

This forms a food chain/web.

Quick VocabularyCarnivores eat animalsHerbivores eat plantsOmnivores 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 WebPlants are called producers, and also

autotrophsAutotroph = makes own food using sunlight

First level consumers eat producersSecond level consumers eat first level

consumers, and so onConsumers are also called heterotrophs (get food/energy from outside source)

Other PlayersDetritivores (mites, snails, and worms) feed on

dead matterDecomposers (bacteria and fungi) break down dead matter

Practice TimeWatch the Planet Earth video clipMake a food web on your whiteboardLabel producers (P), 1st, 2nd, 3rd level

consumers, detritivores, decomposers (inferred)

Put a star next to heterotrophs

Trophic LevelsEach step along a food chain or web is called

a trophic levelProducers are the first trophic levelConsumers make up the second, third, and

higher trophic levelsTrophic levels are the order in which energy

is eaten

Label your whiteboard organisms with trophic levels!

Energy PyramidsThe 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 EcosystemsGross 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/m2/year

and the rate of cellular respiration is 2.4 kg C/m2/year. What is the GPP?

NPP = GPP – Respiration1.4 = GPP – 2.4GPP = 1.4 + 2.4 = 3.8 kilograms of

Carbon per square meter per year

Biomes Differ in NPP

Ecological EfficiencyProportion 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

? 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 ActivityLet’s try it out the 10% rule for ourselves!

Data from Energy BucksAmount of Energy taken in:

Final Amount of Energy Available:

12751275 Grasses 242

Crickets 159

Frogs 63

Hawks 18

TOTAL 482

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

Pyramid of Biomass

Same as pyramid of energy

More mass in bottom trophic levels

1000 grams

600 grams

200 grams

100 grams

EcoColumnsTime to add consumers to your ecosystem! Do steps 15-17 We already collected baseline readings, so we

will take our next set of data next weekRecord what you add/subtract in your data

table

Due DatesEnergy Flow in an Ecosystem Worksheet and

1st current event due next time.Take retakes by Friday at 2pm.