Transcript Net Primary Productivity - Sonoma Valley High School

Ecology of
Populations
Day #1:Introduction to Ecology
What is the common
theme for ecology?
Modern Biology
Pages 359-360
• “Interconnectedness”
– Nothing exists by itself.
– Interdependence.
– All living organisms interact with;
• Other organisms
• Physical factors
Key Words:
Interdependence
Niche
Discussion
What are the levels of
organization found in
the environment?
Modern Biology
Pages 361-362
• Biosphere
is broadest
of all.
– All areas
that
support
life.
Key Words:
Biosphere
What are the levels of
organization found in
the environment?
Modern Biology
Pages 361-362
• Biomes are
large areas of
the Earth.
– Common abiotic
conditions in the
area.
Key Words:
Biomes
What are the levels of
organization found in
the environment?
Ecosystems
– All organisms
and non-living
environment in
a given area.
– Can be any
size.
Key Words:
Ecosystems
Modern Biology
Pages 361-362
What are the levels of
organization found in
the environment?
• Communities
– All interacting
organisms in an
area.
– Includes all
species
Key Words:
Communities
Modern Biology
Pages 361-362
What are the levels of
organization found in
the environment?
• Populations
– All members
of a species
living in one
area.
Key Words:
Population
Modern Biology
Pages 361-362
What are the levels of
organization found in
the environment?
• Organism
– Simplest level
of
organization in
ecology.
Key Words:
Population
Modern Biology
Pages 361-362
Ecology of
Populations
Day #2:Ecology of Organisms
How do organisms
interact with their
environment?
Modern Biology
Pages 363-365
• Environmental
factors;
– Abiotic
– Biotic
• Interactions
– Abiotic - abiotic
– Abiotic - biotic
– Biotic - biotic
Key Words:
Abiotic
Biotic
How do organisms
interact with their
environment?
Modern Biology
Pages 363-365
• Abiotic factors
always change,
• Organisms must
tolerate abiotic
changes.
• All organisms
have a range of
tolerance.
Key Words:
Tolerance Curve
How do organisms
interact with their
environment?
• Tolerance
curves shows
how well a
species
tolerates
abiotic changes.
Modern Biology
Pages 363-365
How do organisms
interact with their
environment?
Modern Biology
Pages 363-365
• Acclimation
– Not adaptation
– How organisms
react to
changing
abiotic
conditions.
– Ex: You and
altitude
Key Words:
acclimation
How do organisms
interact with their
environment?
Modern Biology
Pages 363-365
• Conformers
– Change with the
environment.
– Ex: Reptiles and body
temperature.
• Regulators
– Maintain steady
internal conditions.
– Ex: Mammals
Key Words:
Conformer
Regulators
How do organisms
interact with their
environment?
Modern Biology
Pages 363-365
• Escaping
unfavorable
conditions.
– Migration
– Hibernation
– Dormancy
Key Words:
Dormancy
Migration
Ecology of
Populations
Day #3: Energy Transfer in
Ecosystems
Producers Are Essential
To An Ecosystem
Modern Biology
Pages 366
• Energy flows through
ecosystems.
• Producers use energy to
produce organic molecules.
• Autotrophs
– Use energy to produce
carbohydrates.
– Most use
photosynthesis.
– A few use
chemosynthesis.
Key Words:
Producers
Chemosynthesis
Organic molecules
What is
Productivity?
Modern Biology
Pages 366
• Gross Primary
productivity:
– The rate at which
producers capture
energy.
– Equal to all of the
carbohydrates
produced using
photosynthesis.
– Referred to as
biomass.
Key Words:
biomass
Gross Primary Productivity
How is Productivity
Measured?
Modern Biology
Pages 366
• Net Primary Productivity.
– Measured as g/m2/year.
– All organic material in an
ecosystem is referred to as
biomass (dry organic mass).
– All stored energy in the
ecosystem.
– Rate at which biomass
accumulates is NPP.
Key Words:
Net Primary Productivity
Dry Organic Mass
Consumers
Modern Biology
Pages 370
• Consumers are
heterotrophs.
– Obtain energy by
consuming organic
molecules.
•
•
•
•
•
Herbivores
Carnivore
Omnivore
Detritivore
Decomposers
Key Words:
Detritus
Decomposers
Energy Flow
Modern Biology
Pages 368-369
• Energy is transferred from
organism to organism.
• Trophic level is the
feeding position in community.
• Trophic levels:
– 1st level = producers
– 2nd level = herbivores
– 3rd level = carnivore
– 4th level = second carnivore
Key Words:
Trophic Level
How is Energy Lost in
Ecosystems?
Modern Biology
Pages 368-369
Food Chains
• A single pathway of
energy through the
ecosystem.
• 5% of sun’s energy is
preserved in the
producers.
• Approximately 10% of
energy is preserved in
each transfer.
Modern Biology
Pages 368-369
Food Webs
• Several food
chains
interlinked.
• Better shows
energy flow in
an ecosystem.
Modern Biology
Pages 368-369
Why Do We Find Just a
Few Hawks In An
Ecosystem?
Modern Biology
Pages 368-369
What is a
specie’s niche?
Modern Biology
Pages 365
• The niche
– The way of life.
– The role in the
environment
– Includes all
interactions in
ecosystem.
– Generalist Vs
specialist
What factors might be
included in the artic wolf’s
niche?
Key Words:
generalists
specialists
Ecology of
Organisms
• Modern Biology
• Pages 371-372
• Niche Differences
– A species niche can
change over time.
– Generalists have
very broad niches
– Specialists have
very specific
niches.
Why is it an advantage for the adult
to feed on a different food source
than the larva?
Ecology of
Populations
Day #4:Measuring Populations
Properties of
Populations
Modern Biology
Pages 381-384
• Population size
– Determined by:
• actual count
• sampling
How many populations
are shown here?
Properties of
Populations
Modern Biology
Pages 366-369
• Population Density
– Expressed as:
– # of Individuals/area.
Key Words:
Population density
Population dispersion
How would low density effect
the condor population?
Properties of
Populations
Modern Biology
Pages 366-369
• Population dispersion
– Clumped
– Uniform
– Random
• Depends viewing scale in
many cases.
Could redwood trees demonstrate all
three dispersions in different
conditions?
Population
Dynamics
Modern Biology
Pages 383-389
• Dynamics means
changing over time.
• Change is due to:
–
–
–
–
Birth rate.
Death (mortality) rate.
Immigration
Emmigration
What industry (business) pays close
attention to this type of data?
Population
Dynamics
Modern Biology
Pages 383-389
• Survivorship curves
– Type I
– Type II
– Type III
Is survivorship type related to
number of offspring produced?
Population
Dynamics
Modern Biology
Pages 383-389
• Age structure
What information can you get from this chart?
Population
Growth
Modern Biology
Pages 383-389
• Population growth rate is
size change over time.
– Growth can be negative or
positive.
• Depends on any of four
factors
– Birth rate
– death rate
– Emmigration & immigation
What two events might have led to
the rapid increase in human
populations?
Exponential
Growth Curve
Modern Biology
Pages 383-389
• Populations grow more
rapidly as they increase
in size.
• “J” curve.
• Demonstrates species
biotic potential.
• Unlimited resources.
• Only occurs in rare
cases.
Can this growth curve occur for
long periods of time? Why
Logistic
Growth Curve
Modern Biology
Pages 383-389
• Same as exponential for
short time.
• Growth slows and finally
levels out.
• Known as “S” curve.
• Carrying capacity has
been reached.
What resource most likely causes this
curve to flatten out?
Comparison of Expoential and Logistic
Growth Curves
Ecology of
Populations
Day #5:Measuring Populations
Factors that Limit
Population Growth
Modern Biology
Pages 383-389
• Causes growth to be
something less than
biotic potential.
• Referred to as limiting
factors
– Density dependent
• Limits on resources.
• Disease
– Density independent
• Weather
• Fire
Why so
many
rabbits in
Australia?
Factors that Limit
Population Growth
Modern Biology
Pages 383-389
Dangers of Small
Populations
Modern Biology
Pages 383-389
• Leads to:
–
–
–
–
Lack of genetic variation.
Inbreeding.
Lower birth rates.
Susceptible to
extinction.
Do zoos solve the
problems of small
populations?
How is a fundamental
niche different from a
realized niche?
Modern Biology
Pages 363-365
• Fundamental
niche
– Full range of
interactions in
ecosystem.
– All potential
resources
– Theoretical niche
as if no other
organisms present
Why is the realized niche shown above
smaller than the fundamental niche?
Key Words:
Fundamental niche
Realized niche
Ecology of
Organisms
• Modern Biology
• Pages 371-372
• Realized niche
– All resources
actually used.
– Competition with
other organisms
limits fundamental
niche.
– Something less than
the fundamental
niche.
Which species out competes the other
species regarding niche?
Why is there not a mixture of the two species in the overlap
area?
What strategies help the finches to survive?