Ecosystems: What Are Ecosystems: What Are They and How Do They They and How Do They

Work?Work?

Chapter 3Chapter 3

Sections 1-4Sections 1-4

Key ConceptsKey Concepts

What is ecology?What is ecology?

Major components of ecosystemsMajor components of ecosystems

Energy flow and matter cyclesEnergy flow and matter cycles

What are soils and how do they form?What are soils and how do they form?

Ecosystem studiesEcosystem studies

Importance of InsectsImportance of Insects

Ecological ServicesEcological Services

PollinationPollination

Pest controlPest control

Important roles in Important roles in biological communitybiological community

Fig. 3-1, p. 35

Nature of EcologyNature of Ecology What is ecology?What is ecology?

Study of connections in natureStudy of connections in nature

OrganismsOrganisms

CellsCells

SpeciesSpecies

Microbes rule!Microbes rule!Benefits Include:Benefits Include:Decomposition, nutrient cycling, foods, water Decomposition, nutrient cycling, foods, water purification, digestion, antibioticspurification, digestion, antibiotics

Fig. 3-2, p. 37

Nature of EcologyNature of Ecology

Fig. 3-2, p. 37

Insects751,000

Protists57,700

Plants248,400

Prokaryotes4,800

Fungi69,000

Other animals281,000

Known species

1,412,000

Species Total?Estimated 3.6 - 100

million

Levels of organization interaction

AnimationAnimation

Fig. 2-3, p.23

Levels of Levels of Organization Organization

of Matterof Matter

Genetic Diversity in One Snail Genetic Diversity in One Snail SpeciesSpecies

Fig. 3-4, p. 38

What Sustains Life on Earth?What Sustains Life on Earth? Troposphere: Troposphere: Earth’s Earth’s

surface to 17km up-surface to 17km up-78% N, 21% O78% N, 21% O22

StratosphereStratosphere- 17 - 48 km - 17 - 48 km contains ozone layercontains ozone layer

HydrosphereHydrosphere

LithosphereLithosphere= crust & upper = crust & upper mantlemantle

Biosphere = Biosphere = Zone of Earth Zone of Earth where life is found where life is found (skin of the apple)(skin of the apple)* All parts are interconnected!* All parts are interconnected!

Fig. 3-5, p. 38

Fig. 3-5, p. 38

Atmosphere

Biosphere

CrustLower mantle

AsthenosphereUpper mantle

Continentalcrust

Oceaniccrust

LithosphereVegetationand animals

Soil

Rock

Crust (soiland rock)

Atmosphere(air)

Biosphere(living and dead

organisms)

Lithosphere(crust, top of upper mantle)

Hydrosphere(water)

Core

Mantle

What Sustains Life on Earth?What Sustains Life on Earth?

Earth’s Life-Support SystemsEarth’s Life-Support Systems(3 interconnected factors)(3 interconnected factors)

One way flow of high-One way flow of high-quality energyquality energy

Cycling of matterCycling of matter

GravityGravity- holds atmosphere, - holds atmosphere, enables movement of enables movement of chemicals thru various chemicals thru various spheresspheres

Fig. 3-6, p. 39“Energy flows, nutrients cycle.”

Fig. 3-6, p. 39

Biosphere

Carboncycle

Phosphoruscycle

Nitrogencycle

Watercycle

Oxygencycle

Heat in the environment

HeatHeatHeat

Earth’s Life-Support SystemsEarth’s Life-Support Systems“Energy flows, nutrients cycle.”

Flow of Solar Energy to and from Flow of Solar Energy to and from the Earththe Earth

Greenhouse gasesGreenhouse gaseswater vapor, COwater vapor, CO22 NO, CH NO, CH44 , O , O33

Greenhouse effect- Greenhouse effect- Heat trapped in the Heat trapped in the troposphere to warm planettroposphere to warm planet

without natural without natural greenhouse effect life greenhouse effect life would not be possible. would not be possible.

Fig. 3-7, p. 40

Heat radiatedby the earth

Solarradiation

Absorbedby ozone

UV radiation

Visiblelight

Absorbedby theearth

Reflected byatmosphere (34%)

Energy in = Energy out

Radiated byatmosphereas heat (66%)

Lower Stratosphere(ozone layer)

Troposphere Greenhouseeffect

Heat

Flow of Solar Energy to and from Flow of Solar Energy to and from the Earththe Earth

Fig. 3-7, p. 40

Sun to Earth animation

AnimationAnimation

Why is the Earth so Favorable Why is the Earth so Favorable for Life?for Life?

Liquid waterLiquid water

TemperatureTemperature- - Past 3.7 billion yearsPast 3.7 billion years average surface temp. = 50- 68 °F average surface temp. = 50- 68 °F

GravityGravity

AtmosphereAtmosphere

Fig. 3-8, p. 41

Coniferous forest Desert Coniferous forest Prairie grassland Deciduous forest

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.)

Average annual precipitation

4,600 m (15,000 ft.)3,000 m (10,000 ft.)1,500 m (5,000 ft.)

Coastal mountainranges

Sierra NevadaMountains

Great AmericanDesert

RockyMountains

GreatPlains

MississippiRiver Valley

AppalachianMountains

Coastal chaparraland scrub

Major BiomesMajor Biomes

Sun

Producers (rooted plants)

Producers (phytoplankton)

Primary consumers (zooplankton)

Secondary consumers (fish)

Dissolvedchemicals

Tertiary consumers

(turtles)

Sediment

Decomposers (bacteria and fungi)

Fig. 3-9, p. 42

Major Components of Freshwater EcosystemsMajor Components of Freshwater Ecosystems

Sun

Producer

PrecipitationFalling leaves

and twigs

Producers

Primary consumer(rabbit)

Secondary consumer(fox)

Carbon dioxide (CO2)

Oxygen (O2)

Water

Soil decomposers

Soluble mineral nutrients

Fig. 3-10, p. 42

Major Components of a Field Major Components of a Field EcosystemEcosystem

Matter recycling and energy flow animation

AnimationAnimation

ABC’s of EcologyABC’s of Ecology(The study of how organisms interact with one another (The study of how organisms interact with one another

& their non-living environment)& their non-living environment)

•A= Abiotic (Non-living)

•B= Biotic (Living)

•C= Cultural (Human Interactions)

Factors Limiting Population GrowthFactors Limiting Population Growth

Limiting factor principleLimiting factor principle-- Too much or too little of any abiotic factor can limit or prevent growth of Too much or too little of any abiotic factor can limit or prevent growth of population.population.

Limiting factors:Limiting factors:

Excess water or water shortages for terrestrial organismsExcess water or water shortages for terrestrial organisms

Excess or lack of soil nutrientsExcess or lack of soil nutrients

Dissolved oxygen for aquatic organismsDissolved oxygen for aquatic organisms

Salinity for aquatic organismsSalinity for aquatic organisms

Lower limitof tolerance

Upper limitof tolerance

TemperatureLow High

Abundance of organismsFew

organismsFew

organismsNo

organismsNo

organisms

Zone ofintoleranceZone of

physiological stress

Zone ofintolerance Zone of

physiological stress

Optimum range

Po

pu

lati

on

Siz

e

Fig. 3-11, p. 43

Range of ToleranceRange of Tolerance

Factors That Limit Population GrowthFactors That Limit Population Growth

Range of toleranceRange of tolerance::range of abiotic conditions required for population to surviverange of abiotic conditions required for population to survive

Law of tolerance Law of tolerance ““The existence, abundance and distribution of a species in an The existence, abundance and distribution of a species in an ecosystem are determined by whether the levels of one or more ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by physical or chemical factors fall within the range tolerated by that species.”that species.”

Consumers: Feeding and Consumers: Feeding and RespirationRespiration

Decomposers Decomposers (Fungi & Bacteria) - specialized consumers that (Fungi & Bacteria) - specialized consumers that breakdown detritus (dead stuff) into inorganic nutrients that can be reused breakdown detritus (dead stuff) into inorganic nutrients that can be reused by producersby producers

OmnivoresOmnivores

Detritivores- Detritivores- Decomposers & detritus feedersDecomposers & detritus feeders

Aerobic respirationAerobic respirationglucose + oxygen = carbon dioxide + water + ENERGYglucose + oxygen = carbon dioxide + water + ENERGY

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

Fig. 3-12, p. 44

DetritivoresDetritivores

Decomposers convert organic chemicals to inorganic chemicals that can be used by producers

Fig. 3-13, p. 45

Decomposersbacteria, fungi)

Solarenergy

HeatHeat

Heat Heat

Heat

Abiotic chemicals(carbon dioxide,

oxygen, nitrogen,minerals)

Consumers(herbivores,carnivores)

Producers(plants)

Main Structural Components of Main Structural Components of an Ecosysteman Ecosystem

Linked processes animation

AnimationAnimation

The role of organisms in an ecosystem

AnimationAnimation

Fig. 3-14, p. 45

BiodiversityBiodiversity(4 Components)(4 Components)

Fig. 3-15, p. 46

Examples of BiodiversityExamples of Biodiversity

Fig. 3-16, p. 47

First TrophicLevel

Second TrophicLevel

Third TrophicLevel

Fourth TrophicLevel

Producers(plants)

Primaryconsumers(herbivores)

Secondaryconsumers(carnivores)

Tertiaryconsumers

(top carnivores)

Detritivoresdecomposers and detritus feeders)

Solarenergy

Heat

Heat Heat Heat

HeatHeat

Heat

Heat

Model of a Food ChainModel of a Food Chain

Humans

Blue whale Sperm whale

Crabeater seal

Killer whale Elephantseal

Leopardseal

Petrel

Fish Squid

Carnivorous plankton

Krill

Phytoplankton

Herbivorouszooplankton

Emperorpenguin

Fig. 3-17, p. 48

Food Web in the AntarcticFood Web in the Antarctic

Adéliepenguins

Energy Flow in an EcosystemEnergy Flow in an Ecosystem

Ecological efficiencyEcological efficiency= = % of usable energy transferred as biomass from one trophic % of usable energy transferred as biomass from one trophic level to the next (2% - 40%)level to the next (2% - 40%)

10% Rule10% Rule--assumes assumes 10% 10% ecological efficiency ecological efficiency

Ecological PyramidsEcological Pyramids- 3 Types- 3 Types1. Pyramid of Numbers1. Pyramid of Numbers2. Pyramid of Biomass2. Pyramid of Biomass3. Pyramid of Energy Flow3. Pyramid of Energy Flow

Fig. 3-18, p. 49

Secondaryconsumers

(perch)

10

100

1,000

10,000Usable energy

available ateach tropic level(in kilocalories)

Heat

Heat

Heat

Heat

Heat

Producers(phytoplankton)

Tertiaryconsumers

(human)

Primaryconsumers

(zooplankton)

Ecological Pyramids (3 Types)Ecological Pyramids (3 Types)

Decomposers

Biomass ProductivityBiomass Productivity

Gross primary productivity (GPP)Gross primary productivity (GPP)rate at which producers in an ecosystem convert sun into foodrate at which producers in an ecosystem convert sun into food

Net primary productivity (NPP)= Net primary productivity (NPP)= GPP - Respiration GPP - Respiration

NPP and populationsNPP and populationsNPP limits the number of consumers that can live on earthNPP limits the number of consumers that can live on earth

Fig. 3-19, p. 49

Energy lost andunavailable toconsumers

Respiration

Growth and reproduction

Sun

Photosynthesis

Gross primaryproduction

Net primaryproduction(energyavailable toconsumers)

Differences between GPP and NPPDifferences between GPP and NPP

Fig. 3-20, p. 50

Swamps and marshes

Tropical rain forest

Temperate forest

Northern coniferous forest

(taiga)

Savanna

Agricultural land

Woodland and shrubland

Temperate grassland

Tundra (arctic and alpine)

Desert scrub

Extreme desert

Aquatic EcosystemsEstuaries

Lakes and streams

Continental shelf

Open ocean

Terrestrial Ecosystems

800 1,600 2,400 3,200 4,000 4,800 5,600 6,400 7,200 8,000 8,800 9,600

Average net primary productivity (kcal/m2/yr)

Net Primary Productivity in Major Net Primary Productivity in Major Life Zones and EcosystemsLife Zones and Ecosystems