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.
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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