Core Case Study: Tropical Rain Forests Core Case Study: Tropical Rain Forests Are DisappearingAre Disappearing

• Cover about 2% of the earth’s land surfaceCover about 2% of the earth’s land surface• Contain about 50% of the world’s known plant and Contain about 50% of the world’s known plant and

animal speciesanimal species• Disruption will have three major harmful effectsDisruption will have three major harmful effects

• Reduce biodiversityReduce biodiversity• Accelerate global warmingAccelerate global warming• Change regional weather patternsChange regional weather patterns

Natural Capital Degradation: Satellite Natural Capital Degradation: Satellite Image of the Loss of Tropical Rain ForestImage of the Loss of Tropical Rain Forest

3-1 What Is Ecology?3-1 What Is Ecology?

• Concept 3-1 Ecology is the study of how organisms interact with one another and with their physical environment of matter and energy.

Cells Are the Basic Units of LifeCells Are the Basic Units of Life

• Cell TheoryCell Theory• Eukaryotic cellEukaryotic cell• Prokaryotic cellProkaryotic cell

Fig. 3-2, p. 52

Stepped Art

Cell membrane

(a) Eukaryotic Cell(a) Eukaryotic Cell

Nucleus(DNA)

Proteinconstruction

Energyconversion

Protein construction and energyconversion occur without specializedinternal structures

(b) Prokaryotic Cell

DNA (no nucleus)

Cell membrane

Structure of a Eukaryotic Call and a Structure of a Eukaryotic Call and a Prokaryotic CellProkaryotic Cell

Species Make Up the Encyclopedia of Species Make Up the Encyclopedia of LifeLife

• SpeciesSpecies• 1.75 Million species identified1.75 Million species identified• Insects and other arthropods make up most of the Insects and other arthropods make up most of the

known speciesknown species• Perhaps 10–14 million species not yet identifiedPerhaps 10–14 million species not yet identified

Ecologists Study Connections in Ecologists Study Connections in NatureNature• Ecology Ecology • Levels of organizationLevels of organization

• PopulationPopulation• Genetic diversityGenetic diversity

• CommunityCommunity• EcosystemEcosystem• Biosphere Biosphere

Fig. 3-3, p. 52

Stepped Art

Smallest unit of a chemical element that exhibits its chemical propertiesAtom

Molecule Chemical combination of two or more atoms of the same or different elements

CellThe fundamental structural and functional unit of life

Organism An individual living being

Population A group of individuals of the same species living in a particular place

Community Populations of different species living in a particular place, and potentially interacting with each other

Ecosystem A community of different species interacting with one another and with theirnonliving environment of matter and energy

Parts of the earth's air, water, and soil where life is found

Biosphere

Ecology

Genetic Diversity in a Caribbean Genetic Diversity in a Caribbean Snail PopulationSnail Population

Science Focus: Have You Thanked Science Focus: Have You Thanked the Insects Today?the Insects Today?

• PollinatorsPollinators• Eat other insectsEat other insects• Loosen and renew soilLoosen and renew soil• Reproduce rapidly Reproduce rapidly • Very resistant to extinctionVery resistant to extinction

Importance of InsectsImportance of Insects

3-2 What Keeps Us and Other 3-2 What Keeps Us and Other Organisms Alive?Organisms Alive?• Concept 3-2 Life is sustained by the flow of energy

from the sun through the biosphere, the cycling of nutrients within the biosphere, and gravity.

The Earth’s Life-Support System Has The Earth’s Life-Support System Has Four Major ComponentsFour Major Components

• AtmosphereAtmosphere• TroposphereTroposphere• StratosphereStratosphere

• HydrosphereHydrosphere• GeosphereGeosphere• BiosphereBiosphere

Fig. 3-6, p. 55

Rock

AtmosphereVegetationand animals

Lithosphere

Biosphere

Mantle

Crust

Soil

Biosphere(living organisms)

Geosphere(crust, mantle, core)

Mantle

Core

Hydrosphere(water)

Crust(soil and rock)

Atmosphere(air)

Natural Natural Capital: Capital: General General

Structure Structure of the of the EarthEarth

Life Exists on Land and in WaterLife Exists on Land and in Water

• BiomesBiomes• Aquatic life zonesAquatic life zones

• Freshwater life zonesFreshwater life zones• Lakes and streamsLakes and streams

• Marine life zonesMarine life zones• Coral reefsCoral reefs• EstuariesEstuaries• Deep oceanDeep ocean

Fig. 3-7, p. 55

Average annual precipitation

100–125 cm (40–50 in.)75–100 cm (30–40 in.)50–75 cm (20–30 in.)25–50 cm (10–20 in.)below 25 cm (0–10 in.)

AppalachianMountains

Coastal mountainranges

Sierra Nevada

Great American

Desert

RockyMountains

GreatPlains

MississippiRiver Valley

Deciduous forestCoastal chaparraland scrub

Coniferous forest Desert Coniferous forest Prairie grassland

San Francisco

BaltimoreDenver

St. Louis

Major Biomes along the 39th Parallel in the U.S.

Three Factors Sustain Life on EarthThree Factors Sustain Life on Earth

• One-way flow of high-quality energy beginning with One-way flow of high-quality energy beginning with the sunthe sun

• Cycling of matter or nutrientsCycling of matter or nutrients

• GravityGravity

What Happens to Solar Energy What Happens to Solar Energy Reaching the Earth?Reaching the Earth?

• UV, visible, and IR energyUV, visible, and IR energy• Radiation Radiation

• Absorbed by ozoneAbsorbed by ozone• Absorbed by the earthAbsorbed by the earth• Reflected by the earthReflected by the earth• Radiated by the atmosphere as heatRadiated by the atmosphere as heat

• Natural greenhouse effectNatural greenhouse effect

Fig. 3-8, p. 56

Lower Stratosphere(ozone layer)

Solarradiation

UV radiation

Visiblelight Heat radiated

by the earth

Mostabsorbedby ozone

Absorbedby the earth

Greenhouseeffect

Reflected byatmosphere Radiated by

atmosphereas heat

Heat

Troposphere

Flow of Energy to and from the Earth

3-3 What Are the Major Components 3-3 What Are the Major Components of an Ecosystem?of an Ecosystem?

• Concept 3-3A Ecosystems contain living (biotic) and nonliving (abiotic) components.

• Concept 3-3B Some organisms produce the nutrients they need, others get their nutrients by consuming other organisms, and some recycle nutrients back to producers by decomposing the wastes and remains of organisms.

Ecosystems Have Living and Ecosystems Have Living and Nonliving ComponentsNonliving Components

• AbioticAbiotic• WaterWater• AirAir• NutrientsNutrients• RocksRocks• HeatHeat• Solar energy Solar energy

• BioticBiotic• Living and once livingLiving and once living

Fig. 3-9, p. 57

Decomposers

PrecipitationOxygen (O2)

Carbon dioxide (CO2)

Producer

Primaryconsumer(rabbit)

Secondaryconsumer(fox)

Producers

Water

Soluble mineralnutrients

Major Biotic and

Abiotic Parts of an

Ecosystem

Fig. 3-10, p. 58

Feworganisms

Feworganisms

Noorganisms

Noorganisms

Lower limitof tolerance

Higher limitof tolerance

Abundance of organisms

Zone ofintolerance

Zone ofphysiological

stress

Optimum range

Temperature

Zone ofintolerance

Zone ofphysiological

stress

Low High

Po

pu

lati

on

siz

eRange of Tolerance for a Population of Organisms

Several Abiotic Factors Can Limit Several Abiotic Factors Can Limit Population GrowthPopulation Growth

• Limiting factor principleLimiting factor principle• Too much or too little of any abiotic factor can Too much or too little of any abiotic factor can

limit or prevent growth of a population, even if all limit or prevent growth of a population, even if all other factors are at or near the optimal range of other factors are at or near the optimal range of tolerancetolerance

Producers and Consumers Are the Producers and Consumers Are the Living Components of Ecosystems Living Components of Ecosystems

• Producers, autotrophsProducers, autotrophs• PhotosynthesisPhotosynthesis• ChemosynthesisChemosynthesis

• Consumers, heterotrophsConsumers, heterotrophs• PrimaryPrimary• SecondarySecondary• Third and higher levelThird and higher level

• DecomposersDecomposers

Producers and Consumers Are the Producers and Consumers Are the Living Components of Ecosystems Living Components of Ecosystems

• DetritivoresDetritivores• Aerobic respirationAerobic respiration• Anaerobic respiration, fermentationAnaerobic respiration, fermentation

Fig. 3-11, p. 60

Mushroom

Detritus feeders Decomposers

Long-hornedbeetle holes

Time progression Powder broken down bydecomposers into plantnutrients in soil

Bark beetleengraving

Carpenterant galleries Termite and

carpenterant work Dry rot

fungus

Woodreducedto powder

Energy Flow and Nutrient Cycling Energy Flow and Nutrient Cycling Sustain Ecosystems and the BiosphereSustain Ecosystems and the Biosphere

• One-way energy flowOne-way energy flow• Nutrient cycling of key materialsNutrient cycling of key materials

The Main Structural

Components

of an Ecosystem

Many of the World’s Most Important Many of the World’s Most Important Species Are Invisible to UsSpecies Are Invisible to Us

• MicroorganismsMicroorganisms• BacteriaBacteria• ProtozoaProtozoa• FungiFungi

3-4 What Happens to Energy in 3-4 What Happens to Energy in an Ecosystem?an Ecosystem?

• Concept 3-4A Energy flows through ecosystems in food chains and webs.

• Concept 3-4B As energy flows through ecosystems in food chains and webs, the amount of chemical energy available to organisms at each succeeding feeding level decreases.

Energy Flows Through Ecosystems in Energy Flows Through Ecosystems in Food Chains and Food WebsFood Chains and Food Webs

• Food chainFood chain• Food webFood web

Fig. 3-13, p. 62

Heat Heat

Heat

Heat Heat

Heat

Heat

Solarenergy

Tertiaryconsumers

(top carnivores)

First TrophicLevel

Second TrophicLevel

Third TrophicLevel

Fourth TrophicLevel

Producers(plants)

Primaryconsumers(herbivores)

Secondaryconsumers(carnivores)

Decomposers and detritus feeders

Fig. 3-14, p. 63

Squid

Fish

Herbivorouszooplankton

Krill

Sperm whale

Petrel

Adeliepenguin

Emperorpenguin

Leopardseal

Crabeaterseal

Blue whale

Elephantseal

Killerwhale

Phytoplankton

Carnivorousplankton

Humans

Usable Energy Decreases with Each Usable Energy Decreases with Each Link in a Food Chain or WebLink in a Food Chain or Web

• BiomassBiomass• Ecological efficiencyEcological efficiency• Pyramid of energy flowPyramid of energy flow• Food chain/pyramid song

Pyramid of Energy Flow

Some Ecosystems Produce Plant Some Ecosystems Produce Plant Matter Faster Than Others DoMatter Faster Than Others Do

• Gross primary productivity (GPP)Gross primary productivity (GPP)• Net primary productivity (NPP)Net primary productivity (NPP)

• Ecosystems and life zones differ in their NPPEcosystems and life zones differ in their NPP

Estimated Annual Average NPP in Major Life Zones and Ecosystems

3-5 What Happens to Matter in 3-5 What Happens to Matter in an Ecosystem?an Ecosystem?

• Concept 3-5 Matter, in the form of nutrients, cycles within and among ecosystems and the biosphere, and human activities are altering these chemical cycles.

Nutrients Cycle in the BiosphereNutrients Cycle in the Biosphere

• Biogeochemical cycles, nutrient cyclesBiogeochemical cycles, nutrient cycles• HydrologicHydrologic• CarbonCarbon• NitrogenNitrogen• PhosphorusPhosphorus• Sulfur Sulfur

• Connect past, present , and future forms of lifeConnect past, present , and future forms of life

Water Cycles through the BiosphereWater Cycles through the Biosphere

• Natural renewal of water quality: three major processesNatural renewal of water quality: three major processes• EvaporationEvaporation• PrecipitationPrecipitation• TranspirationTranspiration

• Alteration of the hydrologic cycle by humansAlteration of the hydrologic cycle by humans• Withdrawal of large amounts of freshwater at rates faster Withdrawal of large amounts of freshwater at rates faster

than nature can replace itthan nature can replace it• Clearing vegetationClearing vegetation• Increased flooding when wetlands are drainedIncreased flooding when wetlands are drained

Hydrologic Cycle Including Harmful Impacts of Human Activities

Science Focus: Water’s Unique Science Focus: Water’s Unique PropertiesProperties• Properties of water due to Properties of water due to hydrogen bondshydrogen bonds between water between water

molecules:molecules:• Exists as a liquid over a large range of temperatureExists as a liquid over a large range of temperature• Changes temperature slowlyChanges temperature slowly• High boiling point: 100High boiling point: 100˚C˚C• Adhesion and cohesionAdhesion and cohesion• Expands as it freezes Expands as it freezes • SolventSolvent• Filters out harmful UVFilters out harmful UV

Carbon Cycle Depends on Carbon Cycle Depends on Photosynthesis and RespirationPhotosynthesis and Respiration

• Link between photosynthesis in producers and respiration in Link between photosynthesis in producers and respiration in producers, consumers, and decomposersproducers, consumers, and decomposers

• Additional COAdditional CO2 2 added to the atmosphereadded to the atmosphere• Tree clearingTree clearing• Burning of fossil fuelsBurning of fossil fuels

Carb

on C

ycle

Nitrogen Cycles through the Nitrogen Cycles through the Biosphere: Bacteria in ActionBiosphere: Bacteria in Action

• Nitrogen fixedNitrogen fixed• LightningLightning• Nitrogen-fixing bacteriaNitrogen-fixing bacteria

• Nitrification Nitrification • DenitrificationDenitrification

Nitrogen Cycles through the Nitrogen Cycles through the Biosphere: Bacteria in ActionBiosphere: Bacteria in Action• Human intervention in the nitrogen cycleHuman intervention in the nitrogen cycle

• Additional NO and NAdditional NO and N22O O • Destruction of forest, grasslands, and wetlandsDestruction of forest, grasslands, and wetlands• Add excess nitrates to bodies of waterAdd excess nitrates to bodies of water• Remove nitrogen from topsoilRemove nitrogen from topsoil

Nitr

ogen

Cyc

le

Annual Increase in

Atmospheric N2 Due to

Human Activities

Phosphorus Cycles through the Biosphere• Cycles through water, the earth’s crust, and living organisms

• May be limiting factor for plant growth

• Impact of human activities• Clearing forests• Removing large amounts of phosphate from the earth to

make fertilizers

Phos

phor

us C

ycle

Sulfur Cycles through the BiosphereSulfur Cycles through the Biosphere

• Sulfur found in organisms, ocean sediments, soil, rocks, and Sulfur found in organisms, ocean sediments, soil, rocks, and fossil fuelsfossil fuels

• SOSO22 in the atmosphere in the atmosphere

• HH22SOSO44 and SO and SO44- -

• Human activities affect the sulfur cycleHuman activities affect the sulfur cycle• Burn sulfur-containing coal and oilBurn sulfur-containing coal and oil• Refine sulfur-containing petroleumRefine sulfur-containing petroleum• Convert sulfur-containing metallic mineral oresConvert sulfur-containing metallic mineral ores

Sulfu

r Cyc

le

3-6 How Do Scientists Study 3-6 How Do Scientists Study Ecosystems?Ecosystems?• Concept 3-6 Scientists use field research, laboratory

research, and mathematical and other models to learn about ecosystems.

Some Scientists Study Nature DirectlySome Scientists Study Nature Directly

• Field research: “muddy-boots biology”Field research: “muddy-boots biology”• New technologies availableNew technologies available

• Remote sensorsRemote sensors• Geographic information system (GIS) softwareGeographic information system (GIS) software• Digital satellite imagingDigital satellite imaging

• 2005, Global Earth Observation System of Systems (GEOSS)2005, Global Earth Observation System of Systems (GEOSS)

Some Scientists Study Ecosystems Some Scientists Study Ecosystems in the Laboratoryin the Laboratory

• Simplified systems carried out inSimplified systems carried out in• Culture tubes and bottlesCulture tubes and bottles• Aquaria tanksAquaria tanks• GreenhousesGreenhouses• Indoor and outdoor chambersIndoor and outdoor chambers

• Supported by field researchSupported by field research