Ecosystems: Components, Energy Flow, and Matter Cycling Chapter 3 The Earth as a System Ecosystems Food Webs and Energy Flow Productivity in Ecosystems.

Ecosystems: Components, Energy Flow, and Matter CyclingEcosystems: Components, Energy Flow, and Matter Cycling

Chapter 3The Earth as a System

EcosystemsFood Webs and Energy FlowProductivity in Ecosystems

Cycling of Matter

Chapter 3The Earth as a System

EcosystemsFood Webs and Energy FlowProductivity in Ecosystems

Cycling of Matter

U ChooseU Choose Describe one specific ecosystem. What are its major Describe one specific ecosystem. What are its major

components; name some biotic and abiotic factors that components; name some biotic and abiotic factors that affect it. Cite one population and how it lives within its affect it. Cite one population and how it lives within its Law of Tolerance. Draw, label and define all terms related Law of Tolerance. Draw, label and define all terms related to the Law of tolerance.to the Law of tolerance.

How is energy used in an ecosystem? What happens to it How is energy used in an ecosystem? What happens to it as it is used (or not used)? What are the tyes of energy and as it is used (or not used)? What are the tyes of energy and how is cellular respiration and photosynthesis related to how is cellular respiration and photosynthesis related to the flow of energy?the flow of energy?

A bumper sticker reads, “Have you thanked a green plant A bumper sticker reads, “Have you thanked a green plant today?” Give two reasons for appreciating a green plant. today?” Give two reasons for appreciating a green plant. Then trace the sources of the materials that make up the Then trace the sources of the materials that make up the bumper sticker, and decide whether the sticker itself is a bumper sticker, and decide whether the sticker itself is a sound application of the slogan.sound application of the slogan.

Key ConceptsKey Concepts

Basic ecological principlesBasic ecological principles

Major components of ecosystemsMajor components of ecosystems

Matter cycles and energy flowMatter cycles and energy flow

Ecosystem studiesEcosystem studies

Ecological servicesEcological services

Natural Capitol: How do humans affect these?Natural Capitol: How do humans affect these?

• Biodiversity • Genetic Diversity of

organisms• Population dispersal• Ecosystem Health• Energy Flow• Nutrient Cycling?

Eukaryotic Cells: have organelles, nucleus, multicellular, derived.

Eukaryotic Cells: have organelles, nucleus, multicellular, derived. Prokaryotic Cells : no nucleus, ancient, single

celledProkaryotic Cells : no nucleus, ancient, single

celled

Organism: any life form Types of CellsOrganism: any life form Types of Cells

Nucleus

The Nature of EcologyThe Nature of Ecology• Ecology- the study of how organisms interact with each

other and their abiotic componants of their environment• Oikos: house logos: study of• Organisms- any life form

– CellsCells- the basic unit of life; come in two flavors• Prokaryote- cells with no defined nucleus; bacteria• Eukaryote- cells with a defined nucleus that contains DNA; most familiar

organisms and multicellular organisms

• Species- groups of organisms that share similar DNA; look similar, have similar behavior, etc.– Asexual Reproduction-cellular division to produce identical

offspring (clones)– Sexual Reproduction- production of offspring by combining sex

cells (gametes) to create progeny that are a combination of each of the parents’ characteristics

Levels of organization within an organismLevels of organization within an organism

• Atom

• Molecule

• Cell

• Tissue

• Organ

• Systems

Levels of organization out oforganismLevels of organization out oforganism

BiosphereBiosphere

BiomesBiomes

EcosystemsEcosystems

CommunitiesCommunities

PopulationsPopulations

OrganismOrganism Chpt4.1Chpt4.1

Chapter 1 What is Life?

What are the Characteristics of Life?

PopulationsPopulations

• Population- all of the organisms within a species that interact in a specific area and at a specific time– Genetic Diversity- similar

but different due to DNA

– Affected by:

• Size

• Age distribution

• Density• Genetic composition

• health

Ecosystems Ecology

An ecosystem is a self-sustaining community of organisms and the non-living environment with which they interact. And range in size.

An ecosystem is the fundamental unit of ecology.

What about biodiversity?What about biodiversity?

BIODIVERSITY BIODIVERSITY The many measures of biodiversity:

The variety or chemicial processes, genetic material, species diversity, and ecosystems found on earth.

Biodiversity Leads to Better productivity…Biodiversity Leads to Better productivity…

Organisms are Genetically adapted to survive more diverse conditions

Have more stable populations because their range of tolerance is wider

Why worry about biodiversity and stability?Why worry about biodiversity and stability?

BIODIVERSITY AND STABILITY BIODIVERSITY AND STABILITY

• Because this understanding is essential for knowing how many species and what types can be lost before a community collapses entirely

How rapid is the current rate of extinction?

The number’s hard to pin down, but generally accepted estimates put it at 10-100 times the rate before extensive human–induced environmental modifications.

For example, in the U.S. ~ 225 vascular plant species have become extinct in the past 50 years and about 650 of the remaining 20,000 species are threatened.

Biodiversity is Being Lost Rapidly Through Extinction

Dire News

Not all agree that we’re seeing a mass extinction, but it’s clear species loss has accelerated sharply above background.

Biodiversity Varies Naturally

There is a trend towards more species in warmer, wetter areas and fewer in colder and drier areas.Warmer Moister areas: RainforestDryer Areas: Deserts - Taigas

Numbers of bird species occupying areas of North America.

There are Biodiversity “Hotspots”

Less than 1% of Earth’s surface supports 20% of known plant species and probably a greater portion of animal species.

Biodiversity hotspots for tropical rain forest and chaparral ecosystems.

Biodiversity hotspots are significant for conservation plans.

Species Distributions Are Now Changing in Response to Global Warming

This map shows projections, but many dramatic shifts in species distribution have already been documented.

• Formula shows health of ecosystem in question

# of specific species found

______________________ = BI

# of species found

What is the biodiversity Index of trees at JCHS?

What contributes to the Index here?

Biodiversity IndexBiodiversity Index

Biodiversity Index ExampleBiodiversity Index Example

# of black spiders

# of all spider species = BI

Lets see…….Lets see…….

Can you match these? Can you match these?

• Functional Diversity

• Genetic Diversity

• Ecological Diversity

• Species Diversity

• Differing DNA material within a single species

• Variety or terrestrial/ aquatic ecosystems in one area

• Number of species present in different habitats

• Biological and Chemical processes needed for survival of species, communities,ecosystems

BiodiversityBiodiversity

• Species Diversity- the variety among the species or distinct types of living organisms found in different habitats of the planet

• Ecological Diversity- the variety of different biomes around the world; all biological communities

• Functional Diversity- biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities

Species Diversity TypesSpecies Diversity TypesSpecies Richness• A large number of species

with only a few members of each species present. This is related to species biodiversity

• How rich are the species in your area?

Species Evenness – • A few species but an

even number of members per species

How even is the diversity?

Rainforest, coral reef , deep sea, large tropical lakes have high species diversity but low species evenness (few members in each)

Rainforest, coral reef , deep sea, large tropical lakes have high species diversity but low species evenness (few members in each)

IF: Species A = 56 members Species B = 55 members

Species C = 52Then: species evenness is good but diversity is low!

IF: Species A = 56 members Species B = 55 members

Species C = 52Then: species evenness is good but diversity is low!

NICHE:NICHE:

• Realized Niche • Fundamental Niche

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

Range of Tolerance- any variation in the physical or chemical environment that an organism can withstand before it is killed/harmed

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

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

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Biosphere:5 miles up and 5 miles downBiosphere:5 miles up and 5 miles down

Productivity of ProducersProductivity of Producers• Ecosystems use solar energy to produce and use biomass at

differing rates

GPP and NPPGPP and NPP• GPP Gross Primary Production: Rate at which

producers convert solar energy to biomass• NPP(Net Primary Productivity): The amount of

biomass left after producers have used what they need for cellular functions such as cellular respiration.

Ecosystem examplesEcosystem examples 

• High NPP Low NPP

• estuaries Open ocean

• Swamps and marshes Tundra

• Tropical rain forests Desert 

Net Primary ProductivityNet Primary ProductivityThe earth’s net primary productivity

is the upper limit determining the planet’s carrying capacity for all consumer species.

Our Share of Earth’s NPP• 1)  We use, waste or destroy about

27% of earth’s NPP• 2)  We use, waste or destroy about

40% of the NPP of terrestrial ecosystems

• Produces are the source of diversity

Carrying CapacityCarrying Capacity

Sustaining Life of EarthSustaining Life of Earth• One-Way Energy Flow: All

energy on earth comes from the sun and eventually escapes earth. It perpetuates the cycles as well.

There are two types of energyThere are two types of energy

High quality energy:

is concentrated and has ability to do useful work. Sun, electricity ,coal, oil , gasoline, nucleii of uranium

– Moves through organisms by feeding interactions

– Becomes low quality energy and radiates as heat

Low quality energy: • is dispersed has little ability to

do useful work. Low temp heat. Can keep each other warm in the cold for short periods of time

- Is typically given off after a reaction of high quality energy

- Escapes into atmosphere and space

The Sun also initiates all biogeochemical cycles with its heat contributing to the abiotic factors of an ecosystem.

The Sun also initiates all biogeochemical cycles with its heat contributing to the abiotic factors of an ecosystem.

Nutrients are cycled through the biosphere for use by food chains, webs, and the biosphere itself in many forms

Carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus are main elementsCarbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus are main elements

The Carbon Cycle

Understanding of the carbon cycle is critical for global climate change, yet it remains incomplete.

The Carbon and oxygen Cycles: Carbon and OxygenThe Carbon and oxygen Cycles: Carbon and Oxygen

• The continuous movement of carbon and oxygen from non-living into living organisms

• CO2 in atmosphere build organic molecules

• Plants use CO2 to produce O2

• This exchange of CO2 for O2 is called Respiration (cellular respiration)

• Combustion or burning releases carbon

Burning trees, fossil fuels: oil and coal

Life On a Changing Planet

Science (2006) 311:1698

Human impacts on the Carbon CycleHuman impacts on the Carbon Cycle• 1.  Clear trees and other plants that absorb carbon

dioxide by photosynthesis destroying the carbon sinks .Sinks are areas of storage for any element.

• 2.   Burning of fossil fuels and wood which add large amounts of carbon dioxide to the atmosphere contributing to global warming.

• 3. Results in loss of biodiversity,collapse of ecosystems, change in species distribution, degradation and collapse of human societies

Example of such activities are the build-up of Greenhouse Gases contributing to Global Warming. Which is when gases absorb heat, the heat is trapped, the earth warms.

Graph shows as human population numbers have increased so have temperatures increased. It also shows a correlation o=to the amount of CO2 that had been available .

Graph shows as human population numbers have increased so have temperatures increased. It also shows a correlation o=to the amount of CO2 that had been available .

A Warming World

The Nitrogen Cycle

Note the key role of mutualism between nitrogen-fixing bacteria and their plant hosts.

Nitrogen fixation is the ‘fixing of unuseable nitrogen into useable nitrogen for plants

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Root nodules on Cassia fasciculata

Fig. 4.32, p. 96

GUANO

FERTILIZER

ROCKS

LAND FOOD WEBS

DISSOLVED IN OCEAN

WATER

MARINE FOOD WEBS

MARINE SEDIMENTS

weathering

agriculture

uptake by autotrophs

death, decomposition

sedimentation settling out leaching, runoff

weathering DISSOLVED IN SOILWATER,

LAKES, RIVERS

uptake by autotrophs

death, decomposition

uplifting over geolgic time

uplifting over geolgic time

miningmining

excretionexcretion

Fig. 4.30, p. 94

NO3-

IN SOIL

NITROGEN FIXATION

by industry for agriculture

FERTILIZERS

FOOD WEBS ON LAND

NH3, NH4+

IN SOIL

1. NITRIFICATION

bacteria convert NH4+ to

nitrate (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-)

DENTRIFICATIONby bacteria

NITROGENOUS WASTES, REMAINS IN SOIL

GASEOUS NITROGEN (N2)

IN ATMOSPHERE

NO2-

IN SOIL

  Nitrogen Cycle (atmospheric cycle)

Human Impact on the Nitrogen CycleHuman Impact on the Nitrogen Cycle

1)      Adding Nitric Oxide gas to the atmosphere when we burn fuel yields Acid Precipitation

 2)      Adding Nitrous Oxide Gas to the atmosphere through anaerobic

bacteria’s action on livestock waste and commercial waste leads to ozone depletion and the greenhouse effect.

 3)      Removing nitrogen from earth’s crust and soil through mining

activities leaves plants devastated. 4)      Removing nitrogen from topsoil by over farming leaves soil

without nitrogen• a.       harvesting nitrogen rich crops• b.      irrigating crops• c.       burning or clearing grasslands and forests before planting crops 5)     

Human Impact continued:Human Impact continued:

5)Adding nitrogen to aquatic through run-off ecosystems - depletes dissolved oxygen killing some aerobic aquatic organisms

• a.       agricultural runoff• b.      municipal sewage 

A real time example of excessive amounts of Nitrogen Fertilizer Harming an Ecosystems

A seasonal “dead zone” where virtually all marine life is killed stretches off the Mississippi Delta.

Why?

About 1.5 million metric tons of nitrogen from fertilizer runoff promotes algal and bacterial blooms that deplete oxygen from the water.

The Water Cycle

Only about 40% of precipitation on land comes from water evaporated over oceans; roughly 60% comes from transpiration of water through plants.

Fig. 4.28, p. 90

Precipitation

Precipitationto ocean

Evaporation

EvaporationFromocean

Surface runoff(rapid)

Ocean storage

Condensation

Transpiration

Rain clouds

Infiltration andPercolation

Transpirationfrom plants

Groundwater movement (slow)

Groundwater movement (slow)

RunoffRunoff

Surface runoff (rapid)Surface runoff (rapid)

Precipitation

The Percentage of Available Global Freshwater is Very Small

Freshwater Is a Precious and Often Scarce Resource

Human Activities and the Hydrologic CycleHuman Activities and the Hydrologic Cycle

• 1.      Over-consumption of surface and groundwater lead to groundwater depletion and saltwater intrusion into groundwater supplies.

• 2.  Clearing vegetation from land leads to increased runoff, decreased infiltration to replenish groundwater, increases risk of floods, and accelerates soil erosion and landslides.

• 3.  Adding nutrients and pollutants to water diminishes the ability of humans and other species to use it and interferes with natural purification. 

The Phosphorus Cycle

Phosphorus Cycle: PhosphorusPhosphorus Cycle: Phosphorus

• An important ingredient in DNA and RNA and all proteins

• Flows in organism in different chemical forms into the surroundings and back into organisms

• Doesn’t enter atmosphere• In soil and rock. Dissolves and is used by plants• Plants are eaten by animals, animals die, cycle

begins again

Phosphorus Cycle (sedimentary cycle)Phosphorus Cycle (sedimentary cycle) 

Human impacts on the Phosphorus Cycle 1. Mining large quantities of phosphate rock depletes resources• a.   inorganic fertilizers• b..  detergents 2. Reducing available phosphate in tropical forests through

slash and burn agriculture depletes it.• a.  phosphate is washed away by heavy rains. 3.  Adding excess phosphate to aquatic ecosystems depletes

dissolved oxygen and disrupts aquatic ecosystems• a.   runoff from animal wastes• b.   runoff of commercial inorganic fertilizers from cropland• c.   discharge of municipal sewage 

Fig. 4.33, p. 97

Hydrogen sulfide(H2S)

+Water (H2O)

Sulfur dioxide (SO2)and

Sulfur trioxide (SO3)

Dimethl(DMS) Industries

Sulfuric acid(H2SO4)

Oceans

+Ammonia (NH2)

+Oxygen (O2)

Ammonium sulfate[(NH4)2SO4]

Animals

Plants

Sulfate salts(SO4

2-)

Hydrogen sulfide(H2S)

Decayingorganisms

Sulfur(S)

Fog and precipitation(rain, snow)

Aerobic conditionsin soil and water

Anaerobicconditions in

soil and water

Volcanoesand

hot springs

Atmosphere

Sulfur CycleSulfur Cycle(atmospheric cycle (atmospheric cycle and land)and land)

Sulfur Cycle (atmospheric cycle) (figure 4-33)Sulfur Cycle (atmospheric cycle) (figure 4-33)

 Human Impacts on the Sulfur Cycle 1. Burning sulfur containing coal and oil to produce electric

power• a.  produces sulfur dioxide>>acid rain 2.  refining petroleum>>sulfur dioxide>>acid rain 3.  smelting to convert sulfur compounds of metallic minerals

into free metals such as copper, lead and zinc.• a.  produces sulfur dioxide and trioxide>>acid rain

We’re in the Driver’s Seat - Human Activities Dominate Many Biogeochemical Cycles

Sustaining Life of EarthSustaining Life of Earth• One-Way Energy Flow: All

energy on earth comes from the sun and eventually escapes earth. Perpetuates the cycles.

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6CO6CO22 + 6H + 6H22O O C6HC6H1212OO66 + 6O + 6O22

PhotosynthesisPhotosynthesisChemical reaction where green Chemical reaction where green

plants use plants use water & carbon dioxidewater & carbon dioxide to store the to store the sun’s energy as sun’s energy as

glucoseglucose

The Sun is the generator of the flow of energy as well. The Sun is the generator of the flow of energy as well.

Cellular Respiration is just the opposite formula Glucose + Oxygen Water and Carbon Dioxide Cellular Respiration is just the opposite formula Glucose + Oxygen Water and Carbon Dioxide

Cellular Respiration6O6O22 + C + C66HH1212OO66 -->  6H -->  6H22O + 6COO + 6CO22

Cellular Respiration6O6O22 + C + C66HH1212OO66 -->  6H -->  6H22O + 6COO + 6CO22

• process of cells breaking down food ,glucose, made by plants, to make ATP. ATP is cell energy cells use to do cellular functions such as

• Metabolism

• Making new cells (Mitosis)

• Growth and development

• Reproduction

• All living organisms respirator

Can you think of any?

Inputs are: Outputs are:Inputs are: Outputs are:

Respiration can be accomplished in two ways by different organismsRespiration can be accomplished in two ways by different organisms

• Aerobic Respiration-the use of oxygen to produce energy– Glucose + Oxygen --> Carbon Dioxide + Water +

Energy– C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O + Energy

• Anaerobic Respiration- (a.k.a. fermentation) a form of cellular respiration in the absence of Oxygen– End products: methane; ethyl alcohol; acetic acid; or

hydrogen sulfide, lactic acidProduction of Energy: different types of energy

productionChemosynthesis (typically bacteria)-The conversion of

simple compounds into more complex nutrient compounds without the aide of sunlight

The Source of EnergyThe Source of Energy Chpt 4.2Chpt 4.2

The Biotic Components of Ecosystems are also supported by the suns energyThe Biotic Components of Ecosystems are also supported by the suns energy

Producers(autotrophs)

Producers(autotrophs)

Consumers(heterotrophs)

Consumers(heterotrophs)

Decomposers Decomposers

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

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Organisms that can make Organisms that can make glucose during glucose during photosynthesis are calledphotosynthesis are called PRODUCERS or AUTOTROPHS.

Organisms that can make Organisms that can make glucose during glucose during photosynthesis are calledphotosynthesis are called PRODUCERS or AUTOTROPHS.

7373

Organisms that cannot Organisms that cannot make their own energy make their own energy are called are called CONSUMERS CONSUMERS oror HETEROTROPHS.HETEROTROPHS.

Organisms that cannot Organisms that cannot make their own energy make their own energy are called are called CONSUMERS CONSUMERS oror HETEROTROPHS.HETEROTROPHS.

Secondary or Secondary or 2nd order 2nd order consumersconsumers

May be a May be a carnivorecarnivore or or omnivoreomnivore

May be a May be a predatorpredator

May be a May be a scavengerscavenger

Consumers that Eat Consumers that Eat other Consumersother Consumers

Consumers that Eat Consumers that Eat other Consumersother Consumers

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Consumers that eat Consumers that eat consumers that consumers that already already ateate a a

consumer:consumer:

Consumers that eat Consumers that eat consumers that consumers that already already ateate a a

consumer:consumer: Tertiary or Tertiary or 3rd order 3rd order consumerconsumer

May be a May be a carnivorecarnivore or or omnivoreomnivore

May be a May be a predatorpredator

May be a May be a scavengerscavenger

Cast of Food Web CharactersCast of Food Web Characters

• Tertiary Consumers – Animals that eat animals that eat animals

• Secondary Consumers – Animals that eat animals that eat plants

• Primary Consumers – Animals that eat plants

• Primary Producers – Plants and Phytoplankton: organisms using the sun for energy

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These levels of These levels of organization are called organization are called

TROPHIC LevelsTROPHIC Levels

Trophic Levels: “steps” in a food chain moving from producers

to different levels of consumers. Trophic Levels: “steps” in a food chain moving from producers

to different levels of consumers.

ProducerPrimary consumer (herbivore)

ProducerPrimary consumer (herbivore)Secondary consumer (carnivore)Secondary consumer (carnivore)

Tertiary consumerTertiary consumer

OmnivoreOmnivoreDetritivores and scavengers Detritivores and scavengers

DecomposersDecomposers

Connections:Food Webs show the transfer of energy in an ecosystemConnections:Food Webs show the transfer of energy in an ecosystem

Connections: Food Chains, a thread of a food web, also show energy Flow in Ecosystems

Connections: Food Chains, a thread of a food web, also show energy Flow in Ecosystems

Fig. 4-18 p. 77; Refer to Fig. 4-19 p. 78Fig. 4-18 p. 77; Refer to Fig. 4-19 p. 78

Food chainsFood chains

Ecological Pyramids have many jobsEcological Pyramids have many jobs

Energy Flow Pyramid

Energy Flow Pyramid Ecological

efficiency

Ecologicalefficiency

Pyramid ofbiomass

Pyramid ofbiomass

Pyramid ofnumbers

Pyramid ofnumbers

Fig. 4-20 p. 79

Pyramid of bioaccumulation

THE ECOLOGICAL PYRAMIDS represent THE ECOLOGICAL PYRAMIDS represent• Energy Flow pyramid: Trophic Levels that depict a

food chain or web delivering chemical energy• Ecological Efficiency: Percentage of useable energy

transferred as BIOMASS limits trophic levels• Pyramid of Numbers: The ten percent rule – only 10

percent of energy is passed on to the next level due to metabolism of organism using it

• Pyramid Biomass: The dry weight of all organic matter at that trophic level

• Pyramid of Bioaccumulation: The increase of the concentration of toxins as it passes through levels of the food web.

How is Energy Moved and Utilized in Ecosystems?

TROPHIC LEVELS AND ENERGY TRANSFER or MOVEMENTTROPHIC LEVELS AND ENERGY TRANSFER or MOVEMENT

90% OF ENERGY IS USED AT EACH Level for cell functions at that level and some is lost as heat. That leaves 10% to be transferred to the next level.

The pyramid of Numbers: Only a Fraction of the Energy Present in Organisms of One Trophic Level Is Captured by Organisms of the

Next

This limits the number of trophic levels.

.10%

1.0%

10%

100%

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Some of the Some of the energyenergy moves into the moves into the atmosphere atmosphere as as heatheat..

Some of the Some of the energyenergy moves into the moves into the atmosphere atmosphere as as heatheat..Some Some energyenergy in the primary in the primary

consumer is consumer is STORED as STORED as GlucoseGlucose or used by the or used by the

consumer itselfconsumer itself

This This energyenergy is is availableavailable for for another another consumerconsumer

87

Energy Pyramids ShowEnergy Pyramids Show Energy Pyramids ShowEnergy Pyramids Show •Amount of available Amount of available energy energy decreasesdecreases for for higher consumershigher consumers•Amount of available Amount of available energy energy decreasesdecreases down down the food chainthe food chain•It takes a It takes a large number large number of producersof producers to support a to support a small number of primary small number of primary consumersconsumers•It takes a It takes a large number large number of primary consumersof primary consumers to to support a small number of support a small number of secondary consumerssecondary consumers

Detritivores and Decomposers Detritivores and Decomposers

All through the food pyramid are Detritivores and decomposers. They are Consumers that break down dead organic materials

They break down and contribute to the biogeochemical cycles.

Celebrating Rot and Decay - Detritivores

Energy isn’t transferred only upwards between trophic levels.

Detritovores use the energy available in dead organisms and allow recycling of essential nutrients in ecosystems.

Do you see the energy flow and cycles connection?Do you see the energy flow and cycles connection?

What is Biomass ?What is Biomass ?The accumulation of dry organic matter that

contributes to a tropic level . It is based on the second law of Thermodynamics: Matter is never destroyed or created, it can be transferred.

1.Which level has the most biomass?

2.Does Biomass change as climates differ?

3.Does more biomass produce more life?

• Since biomass accumulates at a rate in direct response to solar energy then Yes to 2 and 3!

Fig. 4.22, p. 86

Abandoned Field Ocean

Tertiary consumers

Secondary consumers

Primary consumers

Producers

Do different ecosystems have different amounts of available energy or biomass?Do different ecosystems have different amounts of available energy or biomass?

Fig. 4.23, p. 86

Grassland(summer)

Temperate Forest(summer)

Producers

Primary consumers

Secondary consumers

Tertiary consumers

Bioaccumulacation and biomagnificationWhy is food web knowledge important for understanding the impact of DDT on ospreys and eagles?

Bioaccumulacation and biomagnificationWhy is food web knowledge important for understanding the impact of DDT on ospreys and eagles?

Bioaccumulation = the accumulation of a contaminant or toxin in or on an organism from all sources (e.g., food, water, air).

Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted.

Bioaccumulation = the accumulation of a contaminant or toxin in or on an organism from all sources (e.g., food, water, air).

Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted.

Biomagnification = the increase in concentration of toxin as it passes through successive levels of the food web

DDT accumulates at higher levels in organisms that are higher in the food chain

Biomagnification = the increase in concentration of toxin as it passes through successive levels of the food web

DDT accumulates at higher levels in organisms that are higher in the food chain

Biomagnification of a DDT in Aquatic EnvironmentBiomagnification of a DDT in Aquatic Environment

Tertiary Consumer 3-76 µg/g ww

(fish eating birds)

Level Amount of DDT in Tissue

Secondary Consumers 1-2 µg/g ww

(large fish)

Primary Consumers

(small fish)0.2-1.2 µg/g ww

Primary Producers

(algae and aquatic plants)0.04 µg/g ww

Osprey Food Web

Large Mouth Bass

Crayfish

Plant material and algae

3-76 µg/g ww

1-2 µg/g ww

0.2- 1.2 µg/g ww

0.04 µg/g ww

DDT Concentration

Osprey

High levels of DDT cause the female ospreys to lay eggs with thin eggshells.

Thin eggshells have a greater chance of breaking, leading to embryo death.

With high levels of DDT, female ospreys can also lay eggs that contain high enough concentration of DDT to prevent embryo development.

High levels of DDT cause the female ospreys to lay eggs with thin eggshells.

Thin eggshells have a greater chance of breaking, leading to embryo death.

With high levels of DDT, female ospreys can also lay eggs that contain high enough concentration of DDT to prevent embryo development.

Ospreys and eagles are tertiary consumers Making them particularly vulnerable to DDT as

Bioaccumulation and Biomagnification take effect

Ospreys and eagles are tertiary consumers Making them particularly vulnerable to DDT as

Bioaccumulation and Biomagnification take effect

Relationship Between DDE Concentrations and Eggshell Thickness

0.440.450.460.470.480.490.5

0.510.52

0 1 2 3 4 5 6

DDE Concentration

Eg

gsh

ell T

hickn

ess

low concentrations high concentration

normal

thin

• After DDT is applied, some DDT volatizes (vaporizes), some remains on the plant, and some washes off the plant into the soil, eventually making its way to a stream, river, or lake.

• The DDT that remains on the leaves of plants may be ingested by primary consumers such as insects and rodents.

• DDT that has washed into a waterbody, remains in the sediment or is consumed by bottom-feeding organisms or absorbed by fish gills and skin.

• All food makes its way to the tertiary consumer

Make an Energy Pyramid Make an Energy Pyramid• Four sides and four levels!!!• Separate each level with pencil mark• Color each level the same color all the way around!• Make sure all sides line up with the other three sides

meaning! 1st side are the Trophic Levels: Producers,

Herbivores,Carnivores,Top Carnivores 2nd side is type is consumer or producer: do not forget

there are primary,secondary, and tertiary consumers!! 3rd side is type of eater: Autotroph or Heterotroph

4th side is Amount of energy that is transferred to next level 100% 10% 1.0% and .10%

Species Types(6.1): Fill major niches in ecosystemsSpecies Types(6.1): Fill major niches in ecosystems

• Native Species- Normally live and thrive in ecosystem

• Non native, invasive, alien species – have been introduced to a community either accidentally or purposefully. Crowd out, outcompete, have no predators

Indicator SpeciesBiological smoke alarmsIndicator SpeciesBiological smoke alarms

• Fish, birds, amphibians, butterflies

• Indicate ecosystem health: pH, Habitat fragmentation, dissolved oxygen in water communities, pollution, reduction in stratospheric ozone, over hunting…

Keystone SpeciesKeystone Species

• Have a huge effect on the species richness and evenness of an ecosystem.

• A keystone species disappears can lead to population crashes and extinction.

• Ex: Top predators, bees, dung beetles,

Foundation SpeciesFoundation Species

• Species that play major roles in enhancing habitats in ways that benefit other species.

• Elephants push over tress clearing ground for grass to grow,

accelerate cycling

of nutrients

Ecosystem Concepts and ComponentsEcosystem Concepts and Components

• Biomes-areas with a consistent climate and with similar organisms– Climate- long-term

weather patterns in a given area

– Precipitation and Temperature

• Aquatic life zones- marine and freshwater portions of the biosphere

Terrestrial Ecosystems Aquatic Life Zones

• Sunlight•Climate

-Temperature

- Precipitation

• Wind

• Latitude

• Altitude (topography)

• Fire frequency

• Soil

• Light penetration•Depth

• Water currents

• Dissolved nutrient concentrations

(especially Nitrogen and Phosphorus)

• Suspended solids

• Salinity Figure 4-13 Page 73

Figure 4-13 Page 73

Ecosystem Boundaries: EcotonesEcosystem Boundaries: Ecotones

• Ecotone- transitional zones between ecosystems where there are a mixture of species not found together in adjacent ecosystems

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

• Abiotic Factors- all of the nonliving parts in an ecosystem• Biotic Factors-all of the living factors in an ecosystem• Range of Tolerance- any variation in the physical or chemical environment that an

organism can withstand before it is killed/harmed– Law of tolerance-the existence, abundance, and distribution of a species in a n ecosystem are

determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species.

Limiting factors terrestrial and aquaticLimiting factors terrestrial and aquatic

• Terrestrial: Precipitation, temperature, available nutrients(too much or too little)

• Aquatic: temperature, sunlight, nutrient availability, dissolved oxygen, pH, salinity

Regulating Population Growth Regulating Population Growth • Limiting Factors- a distinguishing chemical or

physical factor that regulates the population growth of a species; more specific than any other factor– Limiting Factor Principle- Too much or too little of any

abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance.

• Niche- an organisms functional role within an ecosystem; everything that affects the survival and reproduction of itself and others– Range of tolerance; resources it utilizes (food, space);

interaction with other biota and abiotic factors; its role in the food web/matter cycle

AdaptationsAdaptations

• Plant and animal adaptations respond to limiting factor by adapting in many ways.

• Foods they eat, niches, habitats, physiology, mating timing, how they keep warm, use water….

The Biotic Components of EcosystemsThe Biotic Components of Ecosystems

Producers(autotrophs)

Producers(autotrophs)

Consumers(heterotrophs)

Consumers(heterotrophs)

Decomposers Decomposers

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

LIST NATURAL CAPITOL LIST NATURAL CAPITOL • Major components of

freshwater systems• Major components of

ecosystem• Major Biomes found along

the 39th parallel of the US• Solar capitol – flow of

energy

• Cycling of crucial elements (matter)

• Genetic Diversity among individuals within a species

Ecosystem Servicesand SustainabilityEcosystem Servicesand Sustainability

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

An Uncertain Future?

Of course …

…. but that’s not to say there’s no hope.

Fig. 4.26, p. 88

63%Not used by Humans

8%Lost or Degrades Land

16%Altered by Human Activity

3%Used Directly