G. Tyler Miller’sLiving in the Environment13th Edition

G. Tyler Miller’sLiving in the Environment13th Edition

Ecosystems: Components, Energy Flow, and Matter Cycling

Chapter 4

Ecosystems: Components, Energy Flow, and Matter Cycling

Chapter 4

Key ConceptsKey Concepts

• What is ecology?What is ecology?• What basic processes keep us and What basic processes keep us and

other organisms alive?other organisms alive?• What are the major components of What are the major components of

the ecosystem?the ecosystem?• What happens to energy in the What happens to energy in the

ecosystem?ecosystem?• How do scientists study the How do scientists study the

ecosystem?ecosystem?• What are ecosystem services?What are ecosystem services?

What is ecology?What is ecology?

The study of how organisms interact The study of how organisms interact with one another and with their non-with one another and with their non-living environment.living environment.

((oikos oikos “place to live”“place to live” logoslogos “study “study of”)of”)

How nature is connected.How nature is connected.

Communities

Subatomic Particles

Atoms

Molecules

Protoplasm

Cells

Tissues

Organs

Organ systems

Organisms

Populations

Populations

Communities

Ecosystems

Biosphere

Earth

Planets

Solar systems

Galaxies

Universe

Organisms

Realm of ecology

Ecosystems

Biosphere

DNA(informationstorage, nonucleus)

Cell membrane(transport ofraw materials)

Protein constructionand energy conversionoccur without specializedinternal structures

Prokaryotic Cell

Proteinconstruction

Nucleus(information storage)

Energyconversion

Cell membrane(transport of raw

materials andfinished products)Packaging

Eukaryotic Cell

Figure 4-3 (1)Page 67Figure 4-3 (1)Page 67

The Nature of EcologyThe Nature of Ecology

OrganismOrganismAny form of lifeAny form of life

Ecosystem OrganizationEcosystem Organization

The Nature of EcologyThe Nature of Ecology

• OrganismOrganism– Any form of lifeAny form of life– SpeciesSpecies

• Group of organisms Group of organisms that resemble one that resemble one anotheranother

• Actually or potentially Actually or potentially breed with one breed with one anotheranother

• Produce live, fertile Produce live, fertile offspringoffspring

Ecosystem OrganizationEcosystem Organization

The Nature of EcologyThe Nature of Ecology

• CommunitiesCommunities– Populations of the different Populations of the different

species occupying a species occupying a particular placeparticular place

– Biological communityBiological community

• PopulationsPopulations– Group of interacting Group of interacting

individual of the same individual of the same species that occupy a species that occupy a specific area a the same specific area a the same time.time.

• OrganismsOrganisms– Any living organismAny living organism

Ecosystem OrganizationEcosystem Organization

The Nature of EcologyThe Nature of Ecology

•BiosphereBiosphere

All of the earth’s ecosystemsAll of the earth’s ecosystems

•EcosystemEcosystem

A community of different species A community of different species interacting with one another and interacting with one another and their nonliving environmenttheir nonliving environment

Ecosystem OrganizationEcosystem Organization

The Earth’s Life-Support SystemsThe Earth’s Life-Support Systems

Fig. 4-6 p. 68Fig. 4-6 p. 68

•AtmosphereAtmosphere

TroposphereTroposphere

StratosphereStratosphere

•HydrosphereHydrosphere

•LithosphereLithosphere

•BiosphereBiosphere

Sustaining Life of EarthSustaining Life of Earth

One-way flow of One-way flow of energyenergy

SunSun

Living materials and Living materials and living thingsliving things

Into the environmentInto the environment

Cycling of matterCycling of matter

Atoms, ions, Atoms, ions, molecules needed for molecules needed for survivalsurvival

GravityGravity

The Source of EnergyThe Source of Energy

Fig. 4-8 p. 69Fig. 4-8 p. 69

Ecosystem Concepts and ComponentsEcosystem Concepts and Components

• BiomesBiomes– ““By-ohms”By-ohms”– Land Land

ecosystemsecosystems– Distinct climate Distinct climate

and specific and specific life-formslife-forms

• Role of climateRole of climate– Long term Long term

patterns of patterns of weatherweather

– Determines Determines what type of what type of life will thrivelife will thrive

• Aquatic life Aquatic life zoneszones– freshwater freshwater – ocean or ocean or

marine lifemarine life Fig. 4-9 p. 70Fig. 4-9 p. 70

Ecosystem Boundaries: EcotonesEcosystem Boundaries: Ecotones

Fig. 4-10 p. 71

Fig. 4-10 p. 71

Sun

Producers (rooted plants)

Producers (phytoplankton)

Primary consumers (zooplankton)

Secondary consumers (fish)

Dissolvedchemicals Tertiary consumers

(turtles)

Sediment

Decomposers (bacteria and fungi)

Figure 4-11 Page 72Figure 4-11 Page 72

Major components of freshwater ecosystemMajor components of freshwater ecosystem

Sun

Producer

PrecipitationFalling leaves

and twigs

Producers

Primary consumer(rabbit)

Secondary consumer(fox)

Carbon dioxide (CO2)

Oxygen (O2)

Water

Soil decomposers

Soluble mineral nutrients

Figure 4-12 page 72Figure 4-12 page 72

Major components of a terrestrial ecosystemMajor components of a terrestrial ecosystem

Terrestrial Ecosystems Aquatic Life Zones

• Sunlight

• Temperature

• Precipitation

• Wind

• Latitude (distance from equator)

• Altitude (distance above sea level)

• Fire frequency

• Soil

• Light penetration

• Water currents

• Dissolved nutrient concentrations (especially N and P)

• Suspended solids

• Salinity

Principles of Ecological FactorsPrinciples of Ecological Factors

Abiotic factors

Figure 4-13Page 73

Principles of Ecological FactorsPrinciples of Ecological Factors•Law of toleranceLaw of tolerance- - the existence, abundance, and the existence, abundance, and distribution of a species in an ecosystem are distribution of a species in an ecosystem are determined by whether the levels ofdetermined by whether the levels of one or more one or more physical or chemical factors fall within the range of physical or chemical factors fall within the range of tolerance.tolerance.

OptimumRange

Zone ofPhysiological

Stress

Zone ofIntolerance

Principles of Ecological FactorsPrinciples of Ecological Factors

Fig. 4-14 p. 73; Refer to Fig. 4-13 p. 73Fig. 4-14 p. 73; Refer to Fig. 4-13 p. 73

•Limiting factors principleLimiting factors principle – – too much or too little of too much or too little of any abiotic factor can limit or prevent growth of a any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near population, even if all other factors are at or near the optimum range of tolerance.the optimum range of tolerance.

The Biotic Components of EcosystemsThe Biotic Components of Ecosystems

• Producers Producers (autotrophs)(autotrophs)– Transform energy by Transform energy by

PhotosynthesisPhotosynthesis

• Consumers Consumers (heterotrophs)(heterotrophs)– Transform energy by Transform energy by

Aerobic RespirationAerobic Respiration

• DecomposersDecomposers

Fig. 4-16 p. 75Fig. 4-16 p. 75

Ecosystems Use Sunlight As Their Source of EnergyEcosystems Use Sunlight As Their Source of Energy

Conservation of Matter and Energy CaptureConservation of Matter and Energy Capture

PhotosynthesisPhotosynthesis

6 CO6 CO2 2 + 6 H+ 6 H220 0 CC66HH1212OO66 + 6 O + 6 O22

RespirationRespiration

CC66HH1212OO66 + 6 O + 6 O22 6 CO6 CO2 2 + 6 H+ 6 H220 0

Trophic “Feeding” LevelsTrophic “Feeding” Levels

• First Trophic LevelFirst Trophic Level

• Second Trophic LevelSecond Trophic Level

• Third Trophic LevelThird Trophic Level

• Fourth Trophic LevelFourth Trophic Level

ProducersProducers (plants) (plants)

Primary consumersPrimary consumers (herbivores)(herbivores)

– Feed directly on Feed directly on producersproducers

Secondary consumerSecondary consumer (carnivores)(carnivores)

– Feed on Primary Feed on Primary ConsumersConsumers

Tertiary consumerTertiary consumer– Feed on other Feed on other

carnivorescarnivores

Trophic LevelsTrophic Levels

• OmnivoreOmnivore– Eat plants and animalsEat plants and animals

• Detritivores and ScavengersDetritivores and Scavengers– Feed on Feed on detritusdetritus, dead organisms, and waste, dead organisms, and waste

• DecomposersDecomposers– Break down dead organic materialBreak down dead organic material– Release the resulting simpler compounds into the Release the resulting simpler compounds into the

soilsoil– Anaerobic respiration (absence of oxygen)Anaerobic respiration (absence of oxygen)

• Methane, ethyl alcohol, acetic acid, hydrogen sulfideMethane, ethyl alcohol, acetic acid, hydrogen sulfide

MushroomWoodreduced

to powder

Long-hornedbeetle holes

Bark beetleengraving

Carpenterant

galleries

Termite andcarpenter

antwork

Dry rot fungus

Detritus feeders Decomposers

Time progression Powder broken down by decomposersinto plant nutrients in soil

Figure 4-15 page 75Figure 4-15 page 75

Biodiversity:What is it and why is it important?Biodiversity:What is it and why is it important?

The different life-forms and The different life-forms and life-sustaining processes.life-sustaining processes.

Biodiversity:What is it and why is it important?Biodiversity:What is it and why is it important?

Kinds of biodiversity include:Kinds of biodiversity include:• Genetic diversityGenetic diversity

– Variety in the genetic makeup among Variety in the genetic makeup among individuals within a speciesindividuals within a species

• Species diversitySpecies diversity– Variety among species found in different Variety among species found in different

habitats of the planethabitats of the planet

• Ecological diversityEcological diversity– Variety of biological communitiesVariety of biological communities

• Functional diversityFunctional diversity– Biological and chemical processes or Biological and chemical processes or

functions needed for survivalfunctions needed for survival

Connections: Food Webs and Energy Flow in EcosystemsConnections: Food Webs and Energy Flow in Ecosystems

Food chains – sequence of organisms each of which is a food source for the next.

Food chains – sequence of organisms each of which is a food source for the next.

Connections: Food Webs and Energy Flow in EcosystemsConnections: Food Webs and Energy Flow in Ecosystems

Food webs – a network of interconnected food chains

Food webs – a network of interconnected food chains

ECOLOGY

Food Web – chains assembled into one large web.

ECOLOGY

Ecological Pyramid

A food chain that shows the

relationship between the

organisms in each trophic level.

Ecological PyramidsEcological Pyramids

• Pyramid of Pyramid of energy flowenergy flow

• Ecological Ecological efficiencyefficiency– Range 5%-20%Range 5%-20%– Typically 10%Typically 10%

• Pyramid of Pyramid of biomassbiomass

• Pyramid of Pyramid of numbersnumbers

Fig. 4-20 p. 79

The figures represent number of individuals counted at each trophic level.

Ecological Pyramids of Numbers

• The total dry weight of organisms in a particular trophic level is referenced as “biomass”.

Ecological Pyramids of Biomass

BIOMASS=

# of organisms x

the weight of an average individual

Ecological Pyramids of BiomassEcological Pyramids of Biomass

Ecological Pyramids of EnergyEcological Pyramids of Energy

Energy in ecosystems flows from producers to consumers.

Energy is depicted in kilocalories.

Primary producers convert only about 1% of the energy in available sunlight.

The average amount of energy that is available to the next trophic level is about 10%.10%.

Ecological Pyramids of EnergyEcological Pyramids of Energy

Primary Productivity of EcosystemsPrimary Productivity of Ecosystems

• Gross Primary ProductivityGross Primary Productivity (GPP) (GPP)– RateRate at which an ecosystem’s producers convert at which an ecosystem’s producers convert

solar energy into chemical energy as solar energy into chemical energy as biomassbiomass– kg/mkg/m22/year (kcal/m/year (kcal/m22/year)/year)

• Net Primary ProductivityNet Primary Productivity (NPP) (NPP)– Difference between the rate at which producers Difference between the rate at which producers

store energystore energy as biomass and the rate at which as biomass and the rate at which producers producers use chemical energyuse chemical energy stored as biomass stored as biomass

Primary Productivity of EcosystemsPrimary Productivity of Ecosystems

Connections: Matter Cycling in EcosystemsConnections: Matter Cycling in Ecosystems

• Biogeochemical (nutrient) cyclesBiogeochemical (nutrient) cycles– Hydrologic cycle (HHydrologic cycle (H22O)O)

– Atmospheric cycles (C,N)Atmospheric cycles (C,N)

– Sedimentary cycles (S,P)Sedimentary cycles (S,P)

Hydrologic (Water) CycleHydrologic (Water) Cycle

Fig. 4-27 p. 83Fig. 4-27 p. 83

Hydrologic (Water) CycleHydrologic (Water) Cycle

• Absolute humidityAbsolute humidity– The amount of The amount of

water vapor found water vapor found in a mass of air in a mass of air (g water/kg air)(g water/kg air)

• Relative humidityRelative humidity– The amount of The amount of

water vapor in a water vapor in a certain amount of certain amount of air, air, expressed as a expressed as a percentagepercentage the the maximum amount it maximum amount it could hold could hold at that at that temperaturetemperature

• Condensation nucleiCondensation nuclei– tiny particles on which tiny particles on which

droplets of water formdroplets of water form

• Dew pointDew point– Temperature at which Temperature at which

condensation occurscondensation occurs

Affects of Human Activity on the Water CycleAffects of Human Activity on the Water Cycle

• Withdrawing large quantities of water• Clearing vegetation

– Increased runoff– Reduced infiltration– Increased flooding– Soil erosion

• Modifying water quality– Adding nutrients– Other pollutants

The Carbon Cycle (Terrestrial)The Carbon Cycle (Terrestrial)

Fig. 4-28 p. 84-85Fig. 4-28 p. 84-85

The Carbon Cycle (Aquatic)The Carbon Cycle (Aquatic)

Fig. 4-28 p. 84-85Fig. 4-28 p. 84-85 http://www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp29/animations/ch29/1_carbon_cycle.swf

Carbon CycleCarbon CycleCarbon CycleCarbon Cycle

Human Activities Affecting the Carbon CycleHuman Activities Affecting the Carbon Cycle

•Clearing treeClearing tree•Burning fossil fuels and woodBurning fossil fuels and wood

NO3 –

in soil

Nitrogen Fixation

by industry for agriculture

Fertilizers

Food Webs On Land

NH3, NH4+

in soil

1. Nitrification

bacteria convert NH4+ to

nitrite (NO2–)

loss by leaching

uptake by autotrophs

excretion, death,

decomposition

uptake by autotrophs

Nitrogen Fixationbacteria convert to ammonia

(NH3) ; this dissolves to form

ammonium (NH4+)

loss by leaching

Ammonificationbacteria, fungi convert the

residues to NH3 , this

dissolves to form NH4+

2. Nitrification

bacteria convert NO2- to

nitrate (NO3-)

Denitrificationby bacteria

Nitrogenous Wastes, Remains In Soil

Gaseous Nitrogen (N2)

In Atmosphere

NO2 –

in soil

Figure 4-29 Page 86Figure 4-29 Page 86The Nitrogen

Cycle

Nitrogen Cycle Nitrogen Cycle

Human Activities Affecting The Nitrogen CycleHuman Activities Affecting The Nitrogen Cycle

• Burning fossil fuelsBurning fossil fuels– Acid rainAcid rain

• Animal wasteAnimal waste• Removing N from topsoilRemoving N from topsoil• Adding N to aquatic systemsAdding N to aquatic systems

The Phosphorus CycleThe Phosphorus Cycle

Fig. 4-30 p. 88Fig. 4-30 p. 88

Human Activities Affecting the Phosphorus CycleHuman Activities Affecting the Phosphorus Cycle

• MiningMining• Forest removalForest removal• Adding phosphorus to aquatic Adding phosphorus to aquatic

systemssystems– eutrophicationeutrophication

The Sulfur CycleThe Sulfur Cycle

Fig. 4-31 p. 89Fig. 4-31 p. 89

How Do Ecologists Learn About Ecosystems?How Do Ecologists Learn About Ecosystems?

Field researchField research

Remote sensingRemote sensing

Geographic information systems (GIS)Geographic information systems (GIS)

Laboratory researchLaboratory research

Systems analysisSystems analysis

GIS and Systems AnalysisGIS and Systems Analysis

Fig. 4-33 p. 91Fig. 4-33 p. 91Fig. 4-32 p. 91Fig. 4-32 p. 91

Ecosystem Servicesand SustainabilityEcosystem Servicesand Sustainability

Fig. 4-34 p. 92Fig. 4-34 p. 92

•Using renewable Using renewable solar energy as solar energy as an energy sourcean energy source

•Recycling the Recycling the chemical chemical nutrients nutrients organisms need organisms need for survival, for survival, growth, and growth, and reproduction.reproduction.