Chapter 4Chapter 4

Ecosystems & EnergyEcosystems & Energy

Your Responsibilities for Ch.4Your Responsibilities for Ch.4 Ecosystems & Energy Introduction p. 63-64

Photosynthesis & Respiration p.69 Life Without the Sun, p.69-70

How Humans Have Affected the Antarctic Food Web, p.74-75

Envirobriefs p74, 75

hint..hint..

BioticBiotic

AbioticAbiotic

EcologyEcology

Species Species

PopulationPopulation

CommunityCommunity

EcosystemEcosystem

LandscapeLandscape

BiosphereBiosphere

BIOLOGY REVIEW…..

Energy of LifeEnergy of Life

Pages 67-69Pages 67-69

EnergyEnergyEnergyEnergy = capacity or ability to do work. = capacity or ability to do work.

Forms:Forms: ChemicalChemical = stored in chemical bonds of = stored in chemical bonds of

molecules (food)molecules (food)

Radiant / SolarRadiant / Solar = transported from the sun = transported from the sun (electromagnetic waves)(electromagnetic waves)

HeatHeat = thermal energy that flows from an object with a = thermal energy that flows from an object with a higher temp to one with a lower temp higher temp to one with a lower temp (source to sink!)(source to sink!)

MechanicalMechanical = movement of matter = movement of matter

NuclearNuclear = inside atomic nuclei = inside atomic nuclei

ElectricalElectrical = flows as charged particles= flows as charged particles

EnergyEnergy

Usually expressed as units Usually expressed as units of work (kJ) or units of of work (kJ) or units of heat energy (kcal)heat energy (kcal) 1kcal = 4.184 kJ1kcal = 4.184 kJ

Can exist as Can exist as potentialpotential energy or energy or kinetickinetic energy energy Energy can change forms! Energy can change forms!

Study of energy & its Study of energy & its transformations = transformations = THERMODYNAMICSTHERMODYNAMICS!!

ThermodynamicsThermodynamics Some lingo…Some lingo…

““System” refers to the object being studied.System” refers to the object being studied. ““Surroundings” are… Surroundings” are…

You guessed it… the surroundings! You guessed it… the surroundings! Three types of systems:Three types of systems:

Closed System Closed System Open SystemOpen System IsolatedIsolated

……. Does that exist???. Does that exist???

NOTENOTE: systems are relative : systems are relative to what you’re studyingto what you’re studying… …

11stst Law of Thermodynamics Law of Thermodynamics Energy Energy cannotcannot be created or destroyed, but it be created or destroyed, but it

cancan be transformed. be transformed.

The energy of a system and its surroundings is The energy of a system and its surroundings is always constant… always constant… Energy can flow in/out of the system, but overall, Energy can flow in/out of the system, but overall,

the entire system’s energy remains the same.the entire system’s energy remains the same.

How is it transformed?How is it transformed? Ex: Ex: Chemical energyChemical energy (stored in food) (stored in food)

is transformed into is transformed into mechanical energymechanical energy (for us to move). (for us to move).

22ndnd LAW of THERMODYNAMICS LAW of THERMODYNAMICS When energy is transformed, some usable energy is lost When energy is transformed, some usable energy is lost

to the environment as heat. to the environment as heat. Less-usable energy is more diffuse/disorganized.Less-usable energy is more diffuse/disorganized. EntropyEntropy = measure of disorder or randomness. = measure of disorder or randomness.

Organized, usable energy = _____ entropyOrganized, usable energy = _____ entropy Disorganized, unusable energy = _____ entropy (heat)Disorganized, unusable energy = _____ entropy (heat)

Entropy is always increasing over time Entropy is always increasing over time NO process NO process requiring energy transformation is ever 100% efficient.requiring energy transformation is ever 100% efficient. Much of it is dispersed as heat.Much of it is dispersed as heat. Ex: automobile engine is 20-30% efficientEx: automobile engine is 20-30% efficient

Organisms are highly organized and as they grow they Organisms are highly organized and as they grow they remain organized. remain organized. Why doesn’t this refute the 2Why doesn’t this refute the 2ndnd law? law?

A cup of hot coffee left on a A cup of hot coffee left on a table eventually cools, but a cup table eventually cools, but a cup of cool coffee in the same room of cool coffee in the same room

never gets hot by itself….never gets hot by itself….

The high-temperature energy of The high-temperature energy of the coffee is degraded the coffee is degraded

(transformed into a less useful (transformed into a less useful form at a lower temperature) form at a lower temperature) once it is transferred to the once it is transferred to the

surrounding air. surrounding air.

How does cartoon exhibit entropy?How does cartoon exhibit entropy?

Photosynthesis & Cellular Photosynthesis & Cellular Respiration… Respiration…

PHOTOSYNTHESISPHOTOSYNTHESIS

6CO6CO22 + 12 H + 12 H22O + Radiant Energy O + Radiant Energy C C66HH1212OO66 + 6H + 6H22O + 6OO + 6O22

CC66HH1212OO66 + 6H + 6H22O + 6OO + 6O22 Energy + 6CO Energy + 6CO22 + 12 H + 12 H22O O

CELLULAR RESPIRATIONCELLULAR RESPIRATION

They are one big cycle!!!They are one big cycle!!!

Photosynthesis v.s. ChemosynthesisPhotosynthesis v.s. Chemosynthesis

??????QUESTIO

NS

QUESTIONS

The Flow of Energy The Flow of Energy Through EcosystemsThrough Ecosystems

Pages 70-73Pages 70-73

Who’s Smarter than Me???Who’s Smarter than Me??? You have received a chart of vocabulary terms.You have received a chart of vocabulary terms. You have 5 minutes to write a short definition of You have 5 minutes to write a short definition of

each term that you already know. each term that you already know.

Leave all others blank!Leave all others blank! Go!Go!

Now, spend the next 5 minutes finding people who Now, spend the next 5 minutes finding people who are are “smarter than you”“smarter than you”… … Find someone who knows one definition you don’t.Find someone who knows one definition you don’t.

Here’s your little Here’s your little vocabulary lesson…vocabulary lesson…

Be ready… Be ready…

I’m going to fly through this!!!I’m going to fly through this!!!

Flow of Energy through EcosystemsFlow of Energy through Ecosystems ENERGY FLOWENERGY FLOW = movement of energy in a = movement of energy in a

one-way direction through an ecosystem.one-way direction through an ecosystem.

PRODUCERPRODUCER = manufacture complex organic = manufacture complex organic molecules from simple inorganic substances molecules from simple inorganic substances (CO(CO22 and H and H22O), usually using radiant energy.O), usually using radiant energy.

AUTOTROPHAUTOTROPH = same as a producer. = same as a producer. AutoAuto = “self” = “self” TrophTroph = “nourishment” = “nourishment” Use either photosynthesis or chemosynthesisUse either photosynthesis or chemosynthesis

CONSUMERCONSUMER = use bodies of other = use bodies of other organisms as a source of food energy and organisms as a source of food energy and bodybuilding materials. (ex: animals)bodybuilding materials. (ex: animals)

HETEROTROPHHETEROTROPH = same as a consumer. = same as a consumer. HeteroHetero = “different” = “different” TrophTroph = “nourishment” = “nourishment”

3 3 types:types: PRIMARY CONSUMER / HERBIVOREPRIMARY CONSUMER / HERBIVORE SECONDARY CONSUMERSECONDARY CONSUMER TERTIARY CONSUMERTERTIARY CONSUMER

CARNIVORE = 2CARNIVORE = 2°° and 3 and 3°° consumers consumers OMNIVORE = eats plants & animalsOMNIVORE = eats plants & animals

Flow of Energy through EcosystemsFlow of Energy through Ecosystems

Flow of Energy through EcosystemsFlow of Energy through Ecosystems DETRITUSDETRITUS = organic matter that includes animal = organic matter that includes animal

carcasses, leaf litter, and feces.carcasses, leaf litter, and feces. DETRITUS FEEDER / DETRITIVOREDETRITUS FEEDER / DETRITIVORE

Ex: snails, crabs, clams, worms, termites, beetles, millipedesEx: snails, crabs, clams, worms, termites, beetles, millipedes

DECOMPOSER / SAPROTROPHDECOMPOSER / SAPROTROPH = microbial = microbial heterotrophs that break down dead organic material heterotrophs that break down dead organic material and use the decomposition products for energy. and use the decomposition products for energy.

Release simple inorganic molecules (CORelease simple inorganic molecules (CO22 + mineral salts) that + mineral salts) that producers reuse.producers reuse.

SaproSapro = “rotten” = “rotten” TrophTroph = “nourishment” = “nourishment” Ex: bacteria and fungiEx: bacteria and fungi

Difference between Detritivore and DecomposerDifference between Detritivore and Decomposer:: Detritivores actually EAT dead/decaying matter. Detritivores actually EAT dead/decaying matter.

Decomposers secrete enzymes that digest the organic matter, Decomposers secrete enzymes that digest the organic matter, and then absorb the remaining molecules for nutrition.and then absorb the remaining molecules for nutrition.

3 Ecological Categories3 Ecological Categories

ProducersProducers

ConsumersConsumers

DecomposersDecomposers

Flow of Energy through EcosystemsFlow of Energy through Ecosystems FOOD CHAINFOOD CHAIN = energy from food passes = energy from food passes

from one organism to the next in a from one organism to the next in a sequence.sequence.

TROPHIC LEVELTROPHIC LEVEL = each level in the = each level in the chain.chain.

Flow of Energy through EcosystemsFlow of Energy through Ecosystems Simple foodchains are Simple foodchains are

rare in nature! rare in nature! Why??Why?? FOOD WEBFOOD WEB = complex of = complex of

interconnected food interconnected food chains in an ecosystem.chains in an ecosystem.

Food webs are much Food webs are much more realistic than food more realistic than food chains.chains.

Note: Note: Energy flow is always Energy flow is always

linear.linear. Energy lost as heat is Energy lost as heat is

unavailable to other unavailable to other organisms.organisms.

Don’t Forget….Don’t Forget….You should be You should be READINGREADING through the through the CHAPTERCHAPTER!!!!!!

BR

AIN

B

RA

IN

BR

EA

K!!

!B

RE

AK

!!!

Ecological PyramidsEcological PyramidsPages 75-76Pages 75-76

Ecological PyramidsEcological PyramidsA diagram that shows the relative amount A diagram that shows the relative amount

of energy in different trophic levelsof energy in different trophic levels3 types:3 types:

Energy PyramidEnergy Pyramid Total Energy at each trophic levelTotal Energy at each trophic level Energy is lost as: heat, life functions, waste, not Energy is lost as: heat, life functions, waste, not

all parts of each animal/plant are consumedall parts of each animal/plant are consumed Ecological EfficiencyEcological Efficiency: the percentage of : the percentage of

energy transferred from one trophic level to energy transferred from one trophic level to anotheranother

LAW of 10%LAW of 10% : when all the energy loss is added : when all the energy loss is added up, only 10% of the energy entering one trophic up, only 10% of the energy entering one trophic level forms new biomass level forms new biomass

Reason for 5 or less trophic levels in a webReason for 5 or less trophic levels in a web

Total energy at Total energy at each trophic each trophic

level.level.

Energy lost as:Energy lost as:-HeatHeat

-Life FunctionsLife Functions-WasteWaste

-Not all parts Not all parts

consumedconsumed

Biomass PyramidBiomass Pyramid Shows the Shows the DRYDRY weight of organic matter in weight of organic matter in

each trophic level each trophic level Represents the Represents the chemical energychemical energy stored in the stored in the

organic matter of a trophic level.organic matter of a trophic level. UsuallyUsually follows the 10% law follows the 10% law

1000 Lbs

100 Lbs

1 Lb

10 Lbs

1/10 Lbs

Algae- producer

Copepods- Primary consumers

Minnows- Secondary consumers

Bass- Secondary consumers

Pike- Tertiary consumers

Pyramid of NumbersPyramid of Numbers

Total number of organisms at each levelTotal number of organisms at each level Decreases as you go up trophic levelsDecreases as you go up trophic levels

175 blades of grass

40 Grasshoppers

5 Woodpeckers

1 Hawk

1000 metric tons of grass supports: 1000 metric tons of grass supports:

27,000,000 27,000,000 grasshoppersgrasshoppers

90,000 Frogs90,000 Frogs

300 Trout300 Trout

1 person for 30 days1 person for 30 days

If… If… - You eliminate trout from the flow, 30 people You eliminate trout from the flow, 30 people

could survive for 30 days by consuming 100 could survive for 30 days by consuming 100 frogs a dayfrogs a day

- You eliminate frogs from the flow, 900 people You eliminate frogs from the flow, 900 people could survive for 30 days by eating 1,000 could survive for 30 days by eating 1,000 grasshoppers a day.grasshoppers a day.

Exceptions?Exceptions?

Are there exceptions to:Are there exceptions to:

Pyramid of Energy?Pyramid of Energy?

Pyramid of Biomass?Pyramid of Biomass?

Pyramid of Numbers?Pyramid of Numbers?

YESYES

NO

ARE THERE ANY EXCEPTIONS ARE THERE ANY EXCEPTIONS

TO THIS PYRAMID???TO THIS PYRAMID???

Productivity of ProducersProductivity of Producers

Pages 76-78Pages 76-78

Productivity of ProducersProductivity of Producers Gross Primary Productivity (GPP)Gross Primary Productivity (GPP)

The The raterate at which energy is captured during at which energy is captured during photosynthesis.photosynthesis.

But… plants must respire to use that energy for metabolic But… plants must respire to use that energy for metabolic processes…processes…

So, the plant’s respiration acts as a drain on its photosynthesis.So, the plant’s respiration acts as a drain on its photosynthesis.

Net Primary Productivity (NPP)Net Primary Productivity (NPP) The The raterate at which organic matter is actually incorporated at which organic matter is actually incorporated

into plant tissues for growth.into plant tissues for growth. NPP = GPP – RNPP = GPP – RPP

Net Primary Net Primary Gross PrimaryGross Primary Plant PlantProductivity Productivity = = Productivity Productivity - Respiration - Respiration(plant growth per unit (plant growth per unit (total photosynthesis per(total photosynthesis per (per unit area(per unit area

area per unit time)area per unit time) unit area per unit time)unit area per unit time) per unit time)per unit time)

P

IMP

OR

TA

NT

!

GPP & NPPGPP & NPP Only the energy represented by NPP is available Only the energy represented by NPP is available

for consumers, and remember: they only use a for consumers, and remember: they only use a portion of it!portion of it!

The Earth’s total NPP is the upper limit The Earth’s total NPP is the upper limit determining the planet’s carrying capacity determining the planet’s carrying capacity for all species.for all species.

GPP & NPP are expressed as:GPP & NPP are expressed as: Energy per unit area per unit time (kcal/mEnergy per unit area per unit time (kcal/m22/yr)/yr) Dry weight (g carbon/mDry weight (g carbon/m22/yr)/yr)

Humans & Ecosystem ProductivityHumans & Ecosystem Productivity Tropical RainforestsTropical Rainforests

Most nutrients are in the vegetation, not in the soil.Most nutrients are in the vegetation, not in the soil. The land will therefore lose nutrients quickly when they’re The land will therefore lose nutrients quickly when they’re

cleared for growing crops.cleared for growing crops. Then, it’s $$$$$$ to add lots of fertilizers!Then, it’s $$$$$$ to add lots of fertilizers!

Agricultural LandAgricultural Land Highly modified and managedHighly modified and managed Goal: increase the NPP and biomass by adding water and Goal: increase the NPP and biomass by adding water and

nutrients like nitrates and phosphates.nutrients like nitrates and phosphates. Does it work??Does it work??

Humans use, waste, or destroy ~27% of Earth’s total Humans use, waste, or destroy ~27% of Earth’s total potential NPP, and 40% of Earth’s land NPP.potential NPP, and 40% of Earth’s land NPP.

NPP for selected ecosystemsNPP for selected ecosystems Not all ecosystems have the same NPP. Some are Not all ecosystems have the same NPP. Some are

much more productive than others!much more productive than others!

WHAT MONTH IS THIS?WHAT MONTH IS THIS?

SECONDARY PRODUCTIVITYSECONDARY PRODUCTIVITY

c

Calculating Ecosystem ProductivityCalculating Ecosystem Productivity First, read the paragraphs and understand the First, read the paragraphs and understand the pyramid and food web at the bottom of the page.pyramid and food web at the bottom of the page.

Then, spend 10 minutes working on the Then, spend 10 minutes working on the calculations BY YOURSELF. The formulas are calculations BY YOURSELF. The formulas are

included to help you. Plug and Chug!included to help you. Plug and Chug!

Then, you’ll get time to work with a neighbor to Then, you’ll get time to work with a neighbor to understand the calculations.understand the calculations.

Finish ALL of these calculations for homework.Finish ALL of these calculations for homework.

ECOSYSTEM ECOSYSTEM PRODUCTIVITYPRODUCTIVITY

Step by StepStep by Step

For Class ReviewFor Class Review

Productivity and Respiration in Productivity and Respiration in Three Theoretical EcosystemsThree Theoretical Ecosystems

Useful formulas:Useful formulas: Net Primary Productivity (NPP) = Gross Primary Productivity (GPP) - Plant Respiration (Rp)Net Primary Productivity (NPP) = Gross Primary Productivity (GPP) - Plant Respiration (Rp) Net Ecosystem Productivity (NEP) = NPP - Consumer Respiration (Rc)Net Ecosystem Productivity (NEP) = NPP - Consumer Respiration (Rc) Net Ecosystem Respiration (R) = Rp + RcNet Ecosystem Respiration (R) = Rp + Rc

1.1. Which ecosystem has the greatest gross primary Which ecosystem has the greatest gross primary productivity? productivity?

....the greatest net primary productivity? ....the greatest net primary productivity? ……..the greatest net ecosystem productivity? ..the greatest net ecosystem productivity?

2. Which ecosystem has the highest ratio of productivity to 2. Which ecosystem has the highest ratio of productivity to respiration? respiration? …….has the lowest? .has the lowest?

3. What does a ratio of 1.0 mean? 3. What does a ratio of 1.0 mean? This means that 100% of the ecosystem’s production This means that 100% of the ecosystem’s production is being used in respiration… basically, the ecosystem is being used in respiration… basically, the ecosystem is maintaining the status quo, neither growing nor is maintaining the status quo, neither growing nor shrinking.shrinking.

Alfalfa Field

Alfalfa FieldAlfalfa Field

Deciduous Forest

Deciduous Forest

3. 3. The forest and prairie ecosystems are unmanaged, and the The forest and prairie ecosystems are unmanaged, and the alfalfa field is managed for agricultural purposes. What are alfalfa field is managed for agricultural purposes. What are some of the differences between agricultural and unmanaged some of the differences between agricultural and unmanaged ecosystems?ecosystems?

Agricultural lands are managed to drastically increase production Agricultural lands are managed to drastically increase production so that they can be harvested for a profit. Lands that are so that they can be harvested for a profit. Lands that are unmanaged will naturally have a lower productivity, because unmanaged will naturally have a lower productivity, because nobody is there to help increase the production. Managed lands nobody is there to help increase the production. Managed lands will have lower consumption rates so that the net production is will have lower consumption rates so that the net production is higher.higher.

4. 4. What source(s) of respiration has been omitted from the table?What source(s) of respiration has been omitted from the table?DecomposersDecomposers

5. 5. If this (these) factor(s) were taken into account, how would the If this (these) factor(s) were taken into account, how would the GPP/R be affected?GPP/R be affected?

Considering decomposers’ respiration, the R would be higher, Considering decomposers’ respiration, the R would be higher, causing the Growth Efficiency (GPP/R) to be lower.causing the Growth Efficiency (GPP/R) to be lower.

1. Calculate the net primary productivity if the 1. Calculate the net primary productivity if the gross productivity of the grasses is 500,000 gross productivity of the grasses is 500,000 kJ/m2/yr and their annual respiration is kJ/m2/yr and their annual respiration is 340,000 kJ/m2/yr. 340,000 kJ/m2/yr.

NPP = ?

GPP = 500,000 kJ/m2/yr

RP = 340,000 kJ/m2/yr

NPP = GPP – RP

NPP = 500,000 kJ/m2/yr – 340,000 kJ/m2/yr

NPP = 160,000 kJ/m2/yr

2. 2. Calculate the net ecosystem productivity if the gross Calculate the net ecosystem productivity if the gross productivity of the grasses is 500,000 kJ/m2/yr and productivity of the grasses is 500,000 kJ/m2/yr and the ecosystem organisms’ respiration rates are as the ecosystem organisms’ respiration rates are as follows: follows:

Grasses: 340,000 kJ/m2/yrGrasses: 340,000 kJ/m2/yrMice: 80,000 kJ/m2/yrMice: 80,000 kJ/m2/yr Cats: 60,000 kJ/m2/yrCats: 60,000 kJ/m2/yr Wolves: 40,000 kJ/m2/yrWolves: 40,000 kJ/m2/yr

Total R =Total R =

RRPP = 340,000 kJ/m2/yr = 340,000 kJ/m2/yr RRCC = 180,000 kJ/m2/yr = 180,000 kJ/m2/yr NEP = ?NEP = ? GPP = 500,000 kJ/m2/yrGPP = 500,000 kJ/m2/yr

NEP = GPP – R

NEP = 500,000 kJ/m2/yr – 520,000 kJ/m2/yr

NEP = -20,000 kJ/m2/yr

NEP = NPP – RC

NEP = (GPP – RP) - RC

NEP = 500,000 - 340,000 - 180,000

NEP = -20,000 kJ/m2/yr

RC = 180,000 kJ/m2/yr

OR…

520,000 kJ/m2/yr

3. What does your answer to the previous 3. What does your answer to the previous question say about the ecosystem? What’s question say about the ecosystem? What’s happening to it?happening to it?

NPP is GPP – RP. So, since the NEP is NPP is GPP – RP. So, since the NEP is negative, the ecosystem is using more than it negative, the ecosystem is using more than it is producing. is producing. An ecosystem in such a state is losing An ecosystem in such a state is losing biomass.biomass.

2. Explain how there can be two equations for 2. Explain how there can be two equations for NEP in the box above.NEP in the box above.

The first equation includes the RP in the NPPThe first equation includes the RP in the NPPThe second equation is putting it in a different The second equation is putting it in a different place: in the total Respiration, which is R = place: in the total Respiration, which is R = RP + RCRP + RC

3.3. Calculate the % trophic level efficiency of the Calculate the % trophic level efficiency of the wolves if the productivity of the cats eaten by wolves if the productivity of the cats eaten by the wolves is 96,000 kJ/m2/yr and the the wolves is 96,000 kJ/m2/yr and the productivity of the wolves is 9,000 kJ/m2/yr.productivity of the wolves is 9,000 kJ/m2/yr.

% TLE = ?% TLE = ? Production(cats) = 96,000 kJ/m2/yrProduction(cats) = 96,000 kJ/m2/yr Production(wolves) = 9,000 kJ/m2/yrProduction(wolves) = 9,000 kJ/m2/yr Consumption(wolves) = Production(cats)Consumption(wolves) = Production(cats)

% TLE = ( Prod(wolves) / Cons(wolves) ) * 100% TLE = ( Prod(wolves) / Cons(wolves) ) * 100% TLE = ( 9,000 kJ/m2/yr / 96,000 kJ/m2/yr ) * 100% TLE = ( 9,000 kJ/m2/yr / 96,000 kJ/m2/yr ) * 100% TLE = 9.38%% TLE = 9.38%

4. 4. What is the % growth efficiency of the What is the % growth efficiency of the mouse population in this ecosystem if they mouse population in this ecosystem if they consume 50,800 kJ/m2/yr of grass and grow consume 50,800 kJ/m2/yr of grass and grow (produce) 1500 kJ/m2/yr?(produce) 1500 kJ/m2/yr?

% GE = ?% GE = ? Consumption(mouse) = 50,800 kJ/m2/yr of grassConsumption(mouse) = 50,800 kJ/m2/yr of grass Production(mouse) = 1,500 kJ/m2/yr Production(mouse) = 1,500 kJ/m2/yr

% GE = ( Prod(wolves) / Cons(wolves) ) * 100% GE = ( Prod(wolves) / Cons(wolves) ) * 100% GE = (1,500 kJ/m2/yr /50,800 kJ/m2/yr)*100% GE = (1,500 kJ/m2/yr /50,800 kJ/m2/yr)*100% GE = 2.95%% GE = 2.95%

1. 1. What is the energy content of a tree that What is the energy content of a tree that weighs 250 kg and is composed of 30% roots weighs 250 kg and is composed of 30% roots and 70% wood?and 70% wood?

Steps1. Convert 250 kg g

2. Find 30% & 70% of that3. Convert roots g & wood g

to kJ/g using the chart4. Add kJ together

STEP 1STEP 1

250 Kg 1000g = 250,000g tree250 Kg 1000g = 250,000g tree 1Kg 1Kg

STEP 2STEP 2

250,000 (.70) = 175,000 g wood250,000 (.70) = 175,000 g wood

250,000 (.30) = 75,000 g Roots250,000 (.30) = 75,000 g Roots

STEP 3STEP 3

75,000 g 19 kJ = 1,425,000 kJ75,000 g 19 kJ = 1,425,000 kJ X g X g

175,000g 17kJ = 2,975,000 kJ175,000g 17kJ = 2,975,000 kJ

XX g g

STEP 4STEP 4

1,425,000 kJ + 2,975,000 kJ= 1,425,000 kJ + 2,975,000 kJ=

4,400,000 kJ4,400,000 kJ

2.Give an example of an everyday scenario 2.Give an example of an everyday scenario which demonstrates the First Law of which demonstrates the First Law of Thermodynamics. EXPLAIN your answer.Thermodynamics. EXPLAIN your answer.

Any activity where energy is Any activity where energy is

transformed from one form to another.transformed from one form to another.

3.Give an example of an everyday scenario 3.Give an example of an everyday scenario which demonstrates the Second Law of which demonstrates the Second Law of Thermodynamics. EXPLAIN your answer.Thermodynamics. EXPLAIN your answer.

Anything you do that gives off heatAnything you do that gives off heat

4.If the production of herbivorous rabbits is 4.If the production of herbivorous rabbits is 1100kJ/m2/year, and the production of the 1100kJ/m2/year, and the production of the grasses they feed upon annually is 12,000 grasses they feed upon annually is 12,000 kJ/m2, then what is the % trophic level kJ/m2, then what is the % trophic level efficiency?efficiency?

1100 kJ/m2/yr (100) = 9.16% 1100 kJ/m2/yr (100) = 9.16% (about 10 % energy)(about 10 % energy)

12,000 kJ/m2/yr12,000 kJ/m2/yr

5. The biological production and biomass at each 5. The biological production and biomass at each higher tropic level decreases. What factors higher tropic level decreases. What factors account for this?account for this?

Loss of energy due to biological Loss of energy due to biological functions/workfunctions/work

Old slides from this point on….Old slides from this point on….

PhotosynthesisPhotosynthesis

Light energy from the sun is transformed into Light energy from the sun is transformed into chemical energy in carbohydrates.chemical energy in carbohydrates.

Chlorophyll Chlorophyll Green pigment Green pigment

that absorbs radiant energy.that absorbs radiant energy. Most of the Chlorophyll is green, so what does it do Most of the Chlorophyll is green, so what does it do

with the light?with the light? Reflects green back to you, absorbs all other colors.Reflects green back to you, absorbs all other colors.

6CO6CO22 + 12 H + 12 H22O + Radiant Energy O + Radiant Energy C C66HH1212OO66 + 6H + 6H22O + 6OO + 6O22

Why Photosynthesis???Why Photosynthesis???

Who photosynthesizes?Who photosynthesizes? PlantsPlants Some bacteriaSome bacteria AlgaeAlgae A A FEWFEW Animals Animals

Why do these organisms photosynthesize?Why do these organisms photosynthesize? To make chemical energy for themselvesTo make chemical energy for themselves

Recall from BioRecall from Bio: Carbohydrates (sugars) = quick energy!: Carbohydrates (sugars) = quick energy! To make chemical energy for other To make chemical energy for other

organisms who eat them as foodorganisms who eat them as food

Cellular RespirationCellular Respiration Chemical energy in glucose & food is Chemical energy in glucose & food is

transformed into energy to be used for transformed into energy to be used for biological work biological work

(growing, reproduction, (growing, reproduction,

movement, etc)movement, etc)

ALL ORGANISMS RESPIRE!ALL ORGANISMS RESPIRE! But some organisms don’t use OBut some organisms don’t use O22

CC66HH1212OO66 + 6H + 6H22O + 6OO + 6O22 6CO 6CO22 + 12 H + 12 H22O + EnergyO + Energy