G.%20Tyler%20Miller

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G. Tyler MillersLiving in the Environment13th
Edition
AP Environmental Science Unit 3 The Living
World Ecosystems Components, Energy Flow, and
Matter Cycling Chapter 4
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Key Concepts

• Both biotic abiotic factors contribute to the
  characteristics of ecosystems.
• An organisms range is limited by its ability to
  exploit its habitat compete with others for
  resources.
• Trophic levels and food chains describe how
  energy moves through ecosystems.
• Only a fraction of the energy in one trophic
  level is transferred to the next level.

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What is ecology?

• The study of how organisms interact with one
  another and with their non-living environment.
• How nature is connected.

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Prokaryotic Cell
DNA (information storage, no nucleus)
Protein construction and energy conversion occur
without specialized internal structures
Cell membrane (transport of raw materials)
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Figure 4-3 (1)Page 67
Protein construction
Nucleus (information storage)
Energy conversion
Cell membrane (transport of raw materials
and finished products)
Packaging
Eukaryotic Cell
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The Nature of Ecology
Ecosystem Organization

• Organism
• Any form of life
• Species
• Group of organisms that resemble one another
• Populations
• Group of interacting individual of the same
  species that occupy a specific area a the same
  time.
• Communities
• Populations of the different species occupying a
  particular place

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The Nature of Ecology
Ecosystem Organization

• Ecosystem A community of different species
  interacting with one another and their nonliving
  environment
• A particular location influenced by specific mix
  of biotic (living) abiotic (non-living)
  factors.
• Ex Areas with lots of water can support trees
• Biosphere
• All of the earths ecosystems

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Principles of Ecological Factors
Terrestrial Ecosystems
Aquatic Life Zones

• Abiotic factors

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
Figure 4-13Page 73
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Ecosystem Boundaries Ecotones
Fig. 4-10 p. 71
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Boundaries of Ecosystems

• Boundaries form the distinguishing edges of
  ecosystems (i.e. caves)
• Some can be subjective to identify
• Tend to be defined as the range of a particular
  species of interest (i.e. area where wolves roam)
• Can be large (Yellowstone NP) or small
  (water-filled hole in a tree trunk)
• Ecosystems interact with each other? Changes in
  one ecosystem can have far-reaching effects on
  the global environment.

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The Biosphere includes

• Atmosphere
• Troposphere
• Stratosphere
• Hydrosphere
• Lithosphere

Fig. 4-6 p. 68
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Energy Flows, Matter Cycles

• To understand ecosystem function and how to best
  protect and manage them, we must study not only
  components that define ecosystems, but also the
  processes that move energy and matter within them.

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The Sun is the Ultimate Source of Energy

• One-way flow of energy from the Sun
• Plants absorb Suns energy
• Spreads as plants are consumed

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The Source of Energy
Fig. 4-8 p. 69
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The Biotic Components of Ecosystems

• Producers (AUTOTROPHS)
• Transform energy by Photosynthesis
• Consumers (HETEROTROPH)Transform energy by
  Aerobic Respiration
• Decomposers

Fig. 4-16 p. 75
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Ecosystems Use Sunlight As Their Source of Energy
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Conservation of Matter and Energy Capture
Photosynthesis 6 CO2 6 H20
C6H12O6 6 O2
Respiration C6H12O6 6 O2
6 CO2 6 H20
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Photosynthesis

• Plants, algae, and others use the kinetic energy
  of the Sun to produce usable forms of energy.
• Use solar energy (UV) to covert CO2 and Water
  into Glucose (C6H12O6) and O2
• Use the produced glucose to store energy and
  build structures such as leaves, stems, and roots

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Cellular Respiration

• Consumers (Heterotrophs) are incapable of
  photosynthesis must obtain energy by eating the
  tissue of producers to gain energy nutrients
  from the tissue.
• The process that unlocks chemical energy stored
  in organisms and cells
• Cells convert glucose and oxygen into ATP
  (energy), CO2, and Water
• In other words, it is photosynthesis run
  backwards to recover solar energy stored in
  glucose.

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Important to Remember

• Both producers consumers carry out cellular
  respiration to fuel their own growth/metabolism
• Thus, producers both produce and consume O2
• In daytime, generate more O2 than consume
• At night, consume more O2 than make
• Overall, producers photosynthesize more than
  respire, thus an excess of O2 released and extra
  carbon stored

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Trophic Feeding Levels

• First Trophic Level
• Second Trophic Level
• Third Trophic Level
• Fourth Trophic Level

• Producers (plants)
• Primary consumers (herbivores)
• Feed directly on producers
• Secondary consumer (carnivores)
• Feed on Primary Consumers
• Tertiary consumer
• Feed on other carnivores

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Trophic Levels

• Omnivore
• Eat plants and animals
• Detritivores and Scavengers
• Feed on detritus, dead organisms, and waste
• Decomposers
• Break down dead organic material
• Release the resulting simpler compounds into the
  soil
• Anaerobic respiration (absence of oxygen)
• Methane, ethyl alcohol, acetic acid, hydrogen
  sulfide

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Figure 4-15 page 75
Detritus feeders
Decomposers
Bark beetle engraving
Carpenter ant galleries
Termite and carpenter ant work
Long-horned beetle holes
Dry rot fungus
Wood reduced to powder
Mushroom
Powder broken down by decomposers into plant
nutrients in soil
Time progression
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Connections Food Webs and Energy Flow in
Ecosystems
Food chains sequence of organisms each of which
is a food source for the next.
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Connections Food Webs and Energy Flow in
Ecosystems
Food webs a network of interconnected food
chains
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ECOLOGY
Food Web chains assembled into one large web.
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ECOLOGY
Ecological Pyramid A food chain that shows the
relationship between the organisms in each
trophic level.
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Ecological Pyramids

• Pyramid of energy flow
• Ecological efficiency
• Range 5-20
• Typically 10
• Pyramid of biomass
• Pyramid of numbers

Fig. 4-20 p. 79
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Ecological Pyramids of Numbers
The figures represent number of individuals
counted at each trophic level.
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Ecological Pyramids of Biomass

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

BIOMASS of organisms x the weight of an
average individual
biomass
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Ecological Pyramids of Biomass
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Ecological 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.

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Consider

• The Serengeti Plain in East Africa..
• Millions of herbivores far fewer carnivores
• 2nd Law of Thermodynamics shows how one organism
  is consumed, not all energy is transferred some
  is lost as heat.
• All carnivores in an area contain less energy
  than all the herbivores.

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Primary Productivity of Ecosystems

• Gross Primary Productivity (GPP)
• Rate at which an ecosystems producers convert
  solar energy into chemical energy as biomass
• kg/m2/year (kcal/m2/year)
• Net Primary Productivity (NPP)
• Difference between the rate at which producers
  store energy as biomass and the rate at which
  producers use chemical energy stored as biomass

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Primary Productivity of Ecosystems
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Productivity of Producers The Rate Is Crucial

• Gross primary production (GPP)
• Rate at which an ecosystems producers convert
  solar energy into chemical energy as biomass.

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Gross primary productivity (grams of carbon per
square meter)
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Net Primary Production (NPP)

• NPP GPP R
• Rate at which producers use photosynthesis to
  store energy minus the rate at which they use
  some of this energy through respiration (R).

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Sun
Photosynthesis
Energy lost and unavailable to consumers
Respiration
Gross primary production
Net primary production (energy available to
consumers)
Growth and reproduction
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Connections Matter Cycling in Ecosystems

• Biogeochemical (nutrient) cycles
• Hydrologic cycle (H2O)
• Atmospheric cycles (C,N)
• Sedimentary cycles (S,P)

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Hydrologic (Water) Cycle
Fig. 4-27 p. 83
?
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Hydrologic (Water) Cycle

• Absolute humidity
• The amount of water vapor found in a mass of air
  (g water/kg air)
• Relative humidity
• The amount of water vapor in a certain amount of
  air, expressed as a percentage the maximum amount
  it could hold at that temperature

• Condensation nuclei
• tiny particles on which droplets of water form
• Dew point
• Temperature at which condensation occurs

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Affects 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

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The Carbon Cycle (Terrestrial)
Fig. 4-28 p. 84-85
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The Carbon Cycle (Aquatic)
Fig. 4-28 p. 84-85
http//www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp
29/animations/ch29/1_carbon_cycle.swf
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Carbon Cycle
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Human Activities Affecting the Carbon Cycle

• Clearing tree
• Burning fossil fuels and wood

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Figure 4-29 Page 86
Gaseous Nitrogen (N2) In Atmosphere
Nitrogen Fixation by industry for agriculture
Food Webs On Land
uptake by autotrophs
excretion, death, decomposition
uptake by autotrophs
Fertilizers
NO3 in soil
Nitrogen Fixation bacteria convert to ammonia
(NH3) this dissolves to form ammonium (NH4)
Nitrogenous Wastes, Remains In Soil
Denitrification by bacteria
2. Nitrification bacteria convert NO2- to nitrate
(NO3-)
Ammonification bacteria, fungi convert the
residues to NH3 , this dissolves to form NH4
NH3, NH4 in soil
1. Nitrification bacteria convert NH4 to nitrite
(NO2)
NO2 in soil
loss by leaching
loss by leaching
The Nitrogen Cycle
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Nitrogen Cycle
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Human Activities Affecting The Nitrogen Cycle

• Burning fossil fuels
• Acid rain
• Animal waste
• Removing N from topsoil
• Adding N to aquatic systems

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The Phosphorus Cycle
Fig. 4-30 p. 88
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Human Activities Affecting the Phosphorus Cycle

• Mining
• Forest removal
• Adding phosphorus to aquatic systems
• eutrophication

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The Sulfur Cycle
Fig. 4-31 p. 89
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Range of Tolerance

• Ability to survive within variations of a
  physical or chemical environment
• Individuals within a population may have
  differing ranges of tolerance
• Tolerance limits - beyond which no member of a
  species is able to survive

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Range of Tolerance
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Limiting Factors

• Any one factor that is responsible for regulating
  population growth
• Light, water
• In aquatic ecosystems
• D.O.
• Sunlight
• Temperature

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Ecosystem Servicesand Sustainability

• Using renewable solar energy as an energy source
• Recycling the chemical nutrients organisms need
  for survival, growth, and reproduction.

Fig. 4-34 p. 92