Transcript or respiration

Environmental Science
Chapter 5:
How Ecosystems Work
How Ecosystems Work Big Ideas
• Energy is transferred from the sun to
producers
• Producers then transfer the energy to
consumers
• Inefficient energy transfer has an effect on
community structure
Section 1: Energy Flow in
Ecosystems
GOALS
• Describe how energy is transferred from the
sun to producers and then to consumers
• Describe how consumers depend on
producers
• Explain how energy transfer in a food web is
more complex than energy transfer in a food
chain
• Explain why an energy pyramid is a
representation of trophic levels
What makes an ecosystem like this “work?”
Life Depends ENERGY, LOTS
OF ENERGY…from the Sun
• Average
Star
• 93 million
miles away
• Nuclear
Fusion
• No Sun,
No Life
Life Depends on the Sun
ALL
organisms
need a
constant
supply of
energy or
they die
Why do
plants grow
upwards?
Life Depends on the Sun
Mmmm,
solar
energy
tastes
good!
• The ultimate source
of almost all energy
for organisms is the
SUN.
• What did you eat?
(Nuclear Powered?)
• Only some deep sea
creatures do not get
energy from sun
What is photosynthesis?
CO2 + H2O + Sunlight  O2 + C6H12O6
The process of
converting carbon
dioxide, water and
sunlight into oxygen
and glucose.
(In plants, algae,
some bacteria)
Occurs in chloroplasts
What is chemosynthesis?
CO2 + 4H2S + O2  CH20 + 4S + 3H2O
The process of converting carbon
dioxide, water and chemical energy
(hydrogen sulfide) into sugar, sulfur
and water.
From Producer to Consumer
• Producer: an
organism that makes
it own food
• Plants
• Autotrophs, selffeeders
• Use sunlight
• Base of all food
chains
What role do Autotrophs
(Producers) Play?
• Gather the energy from the sun and turn it into
food via photosynthesis. Lichens are an example.
Phytoplankton get no credit
From Producer to Consumer
• Consumer: gets it
energy by eating
producers or other
consumers
• Heterotrophs
• Indirectly solar
powered
What role do
Heterotrophs
(Consumers) play?
Heterotrophs eat other
organisms to obtain
their energy.
Stored energy in food
is extracted with or
without oxygen.
Types of Consumers
• Herbivore: eats only producers (vegetarian)
• Cows, sheep, deer, grasshopper, mice, rabbits
Herbivore
Types of Consumers
• Carnivore: eats
other consumers
• Lion, hawks,
snakes, alligator,
toothed whales
Carnivore
Types of Consumers
• Omnivore: eats
both producers and
consumers
• Bears, pigs,
raccoons and most
humans
Omnivore
Types of Consumers
• Decomposer:
breaks down dead
decaying
organisms
• Critical to
ecosystem health
• Returns nutrients
• Fungus, bacteria
Detritivores and decomposers: recycle nutrients
within the ecosystem by breaking down nonliving
organic matter
Decomposer
Essential Question:
If producers/autotrophs are
responsible for supplying the
rest of the world’s organisms
with sugar molecules (glucose),
then how do organisms use the
sugar molecules (glucose)?
How do Organisms Use Energy
Most organisms spend
large amounts of
time/energy in search of
food and a mate.
How do organisms get the energy
from the food (glucose)? Two ways.
Aerobic Respiration –
use oxygen to extract
energy from glucose
Anaerobic Respiration –
oxygen is NOT used to
extract energy from
glucose
Cellular Respiration (Aerobic
Respiration) allows organisms to use
the energy store in glucose.
Aerobic Respiration aka
“Cellular Respiration”
Formula
C6H12O6 + O2
CO2 + H2O + ATP
Photosynthesis & Cellular
Respiration
In photosynthetic
organisms, the processes
of photosynthesis and
cellular respiration work
together.
The products of one can
be used for the other.
Energy Transfer
Each time one
organism eats another,
energy is transferred
Ecosystems are all
about energy flowing
from one organism to
another
Energy Transfer
• Who are the
producers?
• Consumers?
• Herbivores?
• Carnivores?
• Omnivores?
• Decomposers?
• Where does the
energy start?
How does energy flow through an
ecosystem?
• A food chain is a series of
steps in which organisms
transfer energy by eating
or being eaten (arrows?)
• All food chains have a
producer on bottom, which
supplies each level above
with food
• Energy flows in one
direction through a Food
Chain.
• Each step in a food chain is
called a trophic level.
Energy Transfer
• Food Chain: sequence
in which energy is
transferred from one
organism to another
• Starts with producers
• Energy flows in one
direction
Food Web
A food web shows the
various food chains
within an ecosystem.
Can you describe one
food chain within this
food web?
What is missing from
this food web?
Energy Flow
• Food Web:
shows many
feeding
relationships
that are possible
in a ecosystem
• More complex
and realistic
Energy Flow
• Trophic Level:
each step which
energy is
transferred
How is energy monitored in a
food chain?
Energy Pyramid track available energy in a
food chain. Only 10% of the available energy
is passed from one trophic level to the next.
Energy Pyramid
1 unit of energy
10 units of energy
100 units of energy
1,000 units of energy
10,000 units of energy
Energy Pyramid
Energy Flow
• At each trophic
level about 90% of
energy is lost
• Cellular respiration
• Lost to heat body
and carry out living
Energy Flow
• Why are there fewer
organisms at the top?
(Why fewer bears
than the fruit they
feed on)
• Why aren’t there
more than 4-5 trophic
levels in a energy
pyramid?
How energy Loss Affects an
Ecosystem
• So much energy is lost there are fewer
organisms at higher trophic levels
• Loss of energy from level to level limits the
number of trophic levels in an ecosystem
• Not enough energy to support higher
levels
What does this diagram show?
Biological Magnification
Certain toxic substances,
such as mercury or
pesticides, can’t be easily
broken down (will stay in
your system)
This results in biological
magnification, when each
trophic level consumes and
stores higher concentrations
of the substance
Biological Accumulation
Occurs when there
is an increase of a
pollutant from the
environment to the
organisms in a
food chain
Niche (“nitch”)
A species role in its
ecosystem
Ex - Spiders eat many
smaller insects, bees
help to pollinate flowers.
No two species occupy
the same exact niche in
their environment
How do biotic
factors
interact?
1. Competition –
organisms fight for
places to live, food to
eat and organisms to
mate with.
2. Predation – things are eating or being
eaten.
3. Symbiosis – two species living closely
together
Types of Symbiosis:
Mutualism – both species
benefit. (flowers & bees)
Commensalism – one
member benefits the
other is unaffected.
(barnacles & whales)
Parasitism – one member
benefits and the other
may be harmed.
(Tapeworm)
Ecology Review Video
Section 1 Review
• Energy is transferred from the sun to producers
through the process of photosynthesis
• Consumers use the glucose made by producers
for energy
• Food webs show more complex & realistic feeding
relationships in a ecosystem
• Energy pyramids track available energy in a food
chain. Only 10% of the available energy is passed
from one trophic level to the next.
Section 2 – The Cycling of Matter
GOALS
• Describe the short-term and long-term processes
of the carbon cycle
• List the stages of the nitrogen cycle
• Outline the phosphorus cycle
• Describe the hydrologic cycle
• List the steps in the rock cycle
• Identify one way that humans have affected each
cycle
BIOGEOCHEMICAL CYCLES
consumers
animals
eaten
Matter within
ecosystems is
recycled.
die
die
producers
decomposers
green algae
bacteria and fungi
water and salts
soil
minerals and humus
decay
All Cycles Are Related
SO2, NO2
CO2
H2O
Respiration
Decompositio
n
Transpiratio
n
Fossil Fuel
Combustio
n
N2
H2O
Carbon,
Nitrogen, Sulfur,
Phosphorusin
Plants and
Organisms
Urea
Nitrogen
Fixing
Bacteria
Nitrates,
Sulfates,
Phosphates
Phosphate
Runoff
Nitrite, Dead
Organic Mattrer &
Decomposers
Phytoplankton
Zooplankto
n
Nutrient
Recycling
Ocean
Sediment
s
BIOGEOCHEMICAL CYCLES
• Water, carbon, oxygen, nitrogen,
phosphorus & other elements
cycle from the abiotic (“geo”
nonliving environment) to biotic
(“bio” living organisms) & then
back to the environment.
biotic
abiotic
BIOGEOCHEMICAL CYCLES
• Water, carbon, oxygen, nitrogen & other
elements move through a regularly
repeated sequence of events.
• Define a cycle.
A cycle is a repeated
sequence of events.
H2 O C
N
O
BIOGEOCHEMICAL CYCLES
• Most element cycles
have an atmospheric
“bank” where the
element is found in
large amounts.
atmosphere
“bank”
BIOGEOCHEMICAL CYCLES
• Elements move from
the “bank” into
organisms.
atmosphere
“bank”
BIOGEOCHEMICAL CYCLES
• Organisms release
elements in daily
activities or after death.
• Give an example of an
activity that releases
elements.
atmosphere
“bank”
RIP
BIOGEOCHEMICAL CYCLES
• Decomposers (or
combustion or erosion)
break down organic
matter.
• What is a result of their
actions?
atmosphere
“bank”
RIP
BIOGEOCHEMICAL CYCLES
• Four examples of cycles:
–
–
–
–
Hydrologic (Water)
Carbon (carbon-oxygen)
Nitrogen
Phosphorus
H2 O
C
N
P
Link
COMBUSTION –
human and
natural sources
CARBON CYCLE
• Why is the Carbon Cycle often
called the Carbon-Oxygen Cycle?
CO2
respiration
photosynthesis
O2
CARBON CYCLE
• Like other element
cycles, the carbon
cycle links nonliving
& living parts of the
environment.
biotic
abiotic
CARBON CYCLE
• The exchange of gases during
photosynthesis and respiration is a major
example of the living-nonliving cycle of
carbon-oxygen.
CO2
respiration
photosynthesis
O2
CARBON CYCLE
• How does carbon enter the living
part of the cycle?
CO2 CO2
CO2
CO2
CO2CO2 CO2
CO2
Using the process of
PHOTOSYNTHESIS,
plants use CO2 to make
food
CO2 + H2O ----> C6H12O6 + O2
CARBON CYCLE
• Carbon is returned to the atmosphere
environment by:
–
–
–
–
cellular respiration
erosion
combustion
decomposition
CARBON CYCLE
• Use the next diagram to help you
define the relationship of the
following terms to the carbon cycle.
– respiration
– photosynthesis
– decomposition
– combustion
– erosion
CARBON CYCLE
CO2 in Atmosphere
combustion
decomposition
assimilation
by plants
“BANKS” – CO2 in
photosynthesis
plant respiration
by algae
atmosphere and
soil erosion
trapped
respiration
by algae
RESPIRATION
underground
inPHOTOSYNTHES
and aquatic
animals
IS
Plants
use
CO2
is
released
fossil
fuels
litter
dioxide to
into
the
EROSIONback
- CO2
is carbon
make
food
atmosphere
when
released back
into
the
COMBUSTION - CO2 is
fossil fuels is
food
(glucose)
oceans,
limestone
decomposition released
atmosphere
when
back
into
the
coal, gas, petroleum
lakes
broken
down
during
DECOMPOSITION
- COdown
2 is released
erosion breaks
atmosphere
when
animal respiration
• Write a descriptive summary of the events shown.
RED DOTS
WHITE
BLUE
GREEN
DOTS
DOTS
DOTS
- -carbon
-water,
represents
carbon
note
dioxide
how
trapped
respiration
theyin or
released
collide
glucose
combustion
with
from
from
combustion
the
photosynthesi
note
white
the red
dots
(forest
to
s
flash
- represent
note
offire,
green
how
burning
photosynthesi
green
dots
into
dots
fossil
fuels) dots
s
move
white
through
or at
respiration
organisms
soil
(soil and
then
respiration
flashplant
red
& animal
to
and
represent
animal &
carbon cycle animated
Link
Bacteria in soil
and water add
Nitrogen back
into the
atmosphere
NITROGEN CYCLE
• 79% of the atmosphere is nitrogen gas
but it is in a form most living things
cannot use.
N2
free
nitrogen
NITROGEN CYCLE
• If we can’t take in free nitrogen,
how do we acquire it so we can
use it in our bodies?
• Why do we need
nitrogen in our
bodies?
NITROGEN CYCLE
• How do we acquire usable
nitrogen?
• Nitrogen-fixing bacteria convert
nitrogen into nitrates.
• Plants absorb nitrates.
• Animals eat plants.
N2
in air
NITRATES
nitrogen-fixing
bacteria
NITROGEN CYCLE
• How does the nitrogen return to
the atmosphere?
• Denitrifying bacteria convert
the nitrates back into
nitrogen.
denitrifying
bacteria
N2
in air
NITRATES
nitrogen-fixing
bacteria
NITROGEN CYCLE
• Why do we need nitrogen?
protein
?
Nitrogen
NITROGEN CYCLE
• Can plants & animals
use free nitrogen?
N2
free
nitrogen
• In what form must N2 be
to be used by plants?
nitrates
• What organisms can fix
the N2 into a usable
form?
nitrogen-fixing
bacteria
NITROGEN CYCLE
Simplified
• Use the next diagram to help you define the
relationship of the following terms to the
nitrogen cycle.
– free N2 bank
– nitrogen fixation
– nitrates
– organisms
– organic material
– denitrification
NITROGEN CYCLE
Simplified
organisms
Free N2 in
DENITRIFICATION
Atmosphe
Denitrifying
bacteria
re
N2 “BANK” ORGANIC MATERIAL
- FREEfrom
convert nitrates
Pure
nitrogen
Deaddenitrifying
organisms,
decomposition backnitrogen-fixing
“banked”bacteria
in the
bacteria
animal
waste
and
into
free nitrogen.
atmosphere which
organic litter are
NITROGEN
FIXING
ORGANISMS
is
made
up
of 79%
decomposed by
BACTERIA
- nitrogenPlants
take
in
RIP
nitrogen.
NITRATES
bacteria and other
fixing
bacteria
convert
nitrates
and
use
Organic
NITRATES - the
decomposers
material
free
nitrogen
into
them in their
form of
nitrate
compounds
tissues; animals
nitrogen that
NITROGEN CYCLE
gaseous losses
(N2, NOx)
denitrifying
bacteria
lightning
fixes N2 into
nitrates
nitrates
nitrogen-fixing
bacteria
organic
matter
NITROGEN CYCLE
• Nitrogen Cycle Animation
• http://www.bbc.co.uk/schools/gcseb
itesize/biology/ecology/nitrogencycl
erev1.shtml (scroll down to view)
• http://www.bbc.co.uk/schools/gcseb
itesize/flash/bi01013.swf (same graphic
but alone on a page)
Nitrogen Cycle
• Find the brown
dots entering
plants and
animals.
• In what form is
the nitrogen?
• What main
organisms “fix”
the N for use?
(N-fixing
bacteria)
Link
Phosphorus (P) Cycle
• No
phosphorus
in
atmosphere
• Rocks
PP
– Phosphorus
released by
weathering
of rocks
Phosphorus (P) Cycle
• Plants
– Absorb P
into their
roots
P
Phosphorus (P) Cycle
• Animals
P
– Ingest P
when plants
eaten
– P continues
to move up
food chain
Phosphorus (P) Cycle
• Decomposers
– Breakdown
dead matter
and release P
into soil
P
P
Phosphorus (P) Cycle
P
P
P
P
P
P
• Human
Contribution
– Adding
excess P
from
fertilizers
– P washes
into lakes,
etc…
– Excess P
causes
extreme
algae
Link
WATER CYCLE
• Use the next diagram to help
you define the following:
– evaporation
– condensation
– precipitation
– transpiration
– runoff
– accumulation
water cycle diagram
Condensation
Precipitation
PRECIPITATION - water vapor
(gas) changing into a liquid or
solid such as rain, hail, sleet or
snow
Condendation
(clouds form)
Transpiration
CONDENSATION - water vapor
Run-off
(gas) changing to a tiny drops
Evaporation
of water (liquid)
form across
RUN-OFF
- waterthat
moving
clouds
or rain
the
Earth’s
surface (stream,
TRANSPIRATION
ACCUMULATION
- water
- water
loss
fromgathering
plants when
into water
an area
vapor
(pond,
goeslake,
out stream
throughorstomates
ocean)
(little openings) in leaves
river, gully)
Accumulation
EVAPORATION - water changing
from a liquid into a gas (water
vapor)
WATER CYCLE
• Label your diagram of the water cycle.
biotic
abiotic
• Nonliving portions
of the water cycle
include
condensation,
evaporation &
precipitation.
WATER CYCLE
WATER CYCLE
• Living portions of the
water cycle include
plants performing
transpiration and water
intake by all
organisms.
biotic
abiotic
WATER CYCLE
• Water vapor exits
plant leaves during
transpiration
through tiny
openings called
stomata.
WATER CYCLE
• Water loss from plant leaves during
transpiration is caused in part by the sun’s
heat energy in a process similar to the way
we lose water when we perspire.
WATER CYCLE
• Why are water cycles said to be driven by the
sun?
HEAT
Heat energy from the sun causes water to evaporate returning
water vapor to the atmosphere and transpiration to occur from
plants.
WATER CYCLE
• Why are water cycles said to be driven by the
sun?
WATER CYCLE
• If water cycles are driven by the sun’s heat
energy, what effect would global warming
have on the cycle?
Global warming occurs when more of the sun’s heat energy is trapped in the atmosphere
causing it to be warmer. When the atmosphere is warmer, it evaporates more water and
can hold more water vapor. When large water sources are present, this could result in
more clouds and more precipitation. In some areas, especially where water sources are
less available, the increased evaporation/transpiration could dry out soil and vegetation
resulting in loss of plants and more arid conditions. (We will revisit this in Human
Impact.)
Link
Section 2 – Review
• Short-term processes of the carbon cycle occurs
when producers convert CO2 to carbohydrates
• Long-term processes of the carbon cycle occurs
when CO2 is stored in rocks and fossil fuels
• In the nitrogen cycle atmospheric nitrogen is
converted by organisms into a form organisms can
use
Section 2 – Review
• The phosphorus cycle is the cyclic movement of
phosphorus in different chemical forms from the
environment to organisms and then back to the
environment
• The hydrologic cycle traces the path of water
through the atmosphere, biosphere & geosphere
• In the rock cycle rocks are continually formed into
new rocks by the process of lithification, melting,
and recrystallizing
Section 2 – Review
• Humans burn fossil fuels affecting the carbon
cycle, they add nitrogen & phosphorus to soils,
they contaminate our water, and they remove
materials from Earth
Section 3 – How Ecosystems Change
GOALS
• Give examples of ecological succession
• Explain how pioneer species contribute to
ecological succession
• Explain old-field succession
• Describe the role of lichens in primary succession
How do ecosystems change?
Natural Changes: Hurricanes, Tornadoes,
Earthquakes, Forest Fires, Wind & Water
Erosion, Decay, Tsunamis, Flooding.
Unnatural Changes: Pollution, Global Warming,
Ozone Depletion, Littering, Oil Spills, etc.
Succession
Ecological Succession:
Gradual process of change and
replacement of types of species in
a community
Primary Succession:
When succession occurs where no life was
present
Secondary Succession:
Occurs on an area where life had previously
existed, can be where humans have
disturbed, fires, floods, storms,
earthquakes, and volcanoes..
After a Forest Fire
Fire and
secondary
succession
link
Climax Community:
•Final and stable
community of large,
mature trees
•May take hundreds
of years to form
•Signs of climax
community show
mature oak, maple,
and hickory forests
Old-field Succession:
Example of secondary succession, which
occurs when farmland is abandoned. Begins
with weeds and grasses and may end up in
a climax community.
Poster Project: Primary and
Secondary Succession
Using the large sheet of paper provided:
1. Divide the poster into 8 sections like shown below.
2. On the top row, draw and color the process of primary
succession, label your poster with the following terms:
Primary succession, Pioneer Species, Lichens, Mosses,
Shrubs, Trees, Climax Community
3. On the Bottom Row, draw and color the process of
secondary succession, label your poster with the
following terms: Secondary succession, Pioneer
Species, grasses, flowers, trees, Climax Community
4. Complete the chart that compares the two processes,
on the sheet provided.
5. Staple it to your poster, and hand it in.
Section 3 – Review
• Organisms in an environment sometimes follow a
pattern of change over time known as ecological
succession
• Primary succession occurs where no ecosystem
existed before
• Secondary succession occurs where an
ecosystem has previously existed
• Climax communities are made up of organisms
that take over an ecosystem and remain until the
ecosystem is disturbed again