Transcript How Ecosystems Work

How Ecosystems Work
Chapter 5
Energy flow in the Ecosystem
• Life depends on the sun in a process called
photosynthesis
• Plants, algae and some bacteria capture
solar energy and with Carbon Dioxide CO2
and Water H2O make Oxygen O2 and sugar
or glucose C6H12O6
• 6CO2 + 6H2O + sun = C6H12O6 + 6O2
• All organisms ultimately get their energy
from the sun
Energy Flow Through an Ecosystem
•Begins with the
SUN
•Photosynthesis
6CO2 + 6H2O + sunlight & chlorophyll
C6H12O6 + 6O2
http://sps.k12.ar.us/massengale/biology
PRODUCERS
Organisms
that can
make
glucose
during
photosynthe
sis are
called
Producers use
most of the energy
they make for
themselves.
http://sps.k12.ar.us/massengale/biology
The energy that is not
used by producers can
be passed on to
organisms that cannot
make their own energy.
CONSUMERS
Organisms that cannot
make their own energy
Consumers eat
producers to
get energy:
Herbivores- eat
plants
Omnivores – eat
Plants and animals
Carnivores – eat
animals
Most of the energy
is used by the
consumer but
some of the
energy moves into
the atmosphere as
heat.
An Exception to the Rule:
• Deep Ocean Ecosystems
• Hydrothermal Vent
• Bacteria use Hydrogen
Sulfide from the hot
water to make their
own food
• Thus they are producers!
http://www.naturalhistorymag.com
Decomposers
Breaks down dead
organisms in an
ecosystem
and returns
nutrients to
soil, water and air
Bacteria and Fungi
http://soils.usda.gov/sqi/concepts/soi
Cellular
Respiration
Burning the Fuel
CELLULAR
RESPIRATION is the
chemical reaction that
releases the energy in
glucose
6O2 + C6H12O6 -->>
6H2O + 6CO2 + energy
Excess energy is
stored as fat
http://sps.k12.ar.us/massengale/biology
Food Webs:
• Are
interconnected
food chains
• They show the
feeding
relationships in
an ecosystem
FOOD CHAIN – shows the
transfer of energy from the sun
to producer to primary consumer
then to higher order consumers
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Food Chains Show
Available Energy
Trophic
Levels
http://sps.k12.ar.us/massengale/biology
Energy • Amount of available energy
decreases for higher
Pyramid consumers
• Amount of available energy
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decreases down the food
chain
• It takes a large number of
producers to support a
small number of primary
consumers
• It takes a large number
of primary consumers to
support a small number of
secondary consumers
Envi Sci 1/19/11
• Stamp then go over food
chain/web worksheet
• Case Study page 130-131
• Finish up notes…
• Tomorrow Library. Biome
Project!!
The Cycling of Materials
Carbon Cycle
• Cycled between the atmosphere, land,
water and organisms
• Carbon is the basic building block for all
living organisms
• It is moved through the atmosphere by
plants/animals in CO2/O2 exchange through
breathing and photosynthesis
• Large carbon deposits exist in the oceans
and soil from dead organisms in the form
of carbonates or carbon sinks of limestone
How Humans Affect the Carbon Cycle
• When we burn fossil fuels we release carbon
•
•
•
•
•
into the atmosphere
In 2000 1/3 of all carbon dioxide emitted in
the US was from motor vehicles
6 Billion metric tons of carbon a year
released as CO2 into the atmosphere
50% of this remains in the atmosphere which
contributes to global warming
1 Billion metric tons of CO2 are dissolved into
the ocean – carbon sink
Plants absorb the remaining CO2
Carbon Cycle
www.windows.ucar.edu/.../images/carboncycle.jpg
Nitrogen Cycle
• Although the atmosphere is 78%
•
•
organisms cannot utilize
nitrogen in that form
Nitrogen Fixing Bacteria – alter
the Nitrogen to make it usable
for all organisms
This bacteria lives on nodules of
roots
• Nitrogen is essential for plant
growth, obtained through soil
• Nitrogen can be found in all
waste products of animals
Nitrogen Cycle
www.windows.ucar.edu/.../images/nitrogencycle.jpg
Phosphorous Cycle
• Phosphorous is stored in rocks and soil
• Phosphorous is then moved through the
rock and water cycle
• Plants and animals take in phosphorous
Phosphorous Cycle
http://www.ikzm-d.de/abbildungen/59_phosphoruscycle.gif
Acid Precipitation
• When fuel is burned, large amounts of
nitric oxide is release into the atmosphere.
• In the air, nitric oxide can combine with
oxygen and water vapor to form nitric
acid.
• Dissolved in rain or snow, the nitric acid
falls as acid precipitation.
Fertilizers and the Nitrogen and
Phosphorus Cycles
• Excess fertilizer causes excess nitrogen
and phosphorus can cause rapid growth of
algae.
• Excess algae can deplete an aquatic
ecosystem of important nutrients such as
oxygen, on which fish and other aquatic
organisms depend.
• Ecological succession is a gradual
process of change and replacement of the
types of species in a community.
• Primary succession is a type of
succession that occurs on a surface where
no ecosystem existed before
• Secondary succession occurs on a
surface where an ecosystem has
previously existed. can occur in
ecosystems that have been disturbed or
disrupted by humans, animals, or by
natural process such as storms, floods,
earthquakes, or volcanic eruptions.
• A pioneer species is a species that
colonizes an uninhabited area and that
starts an ecological cycle in which many
other species become established
• A climax community is the final, stable
community in equilibrium with the
environment.
Ecological Succession
Succession Collage
• Create a scenario:
–Primary Succession – initial growth
(new volcano, island, receding sea)
–Secondary Succession – calamity,
disaster natural or man made
• Cut out pictures of your area to
represent each stage of succession
• Describe each stage and give a
rationale for it
Ecological Succession
• Primary succession can occur
• on new islands created by volcanic eruptions
• in areas exposed when a glacier retreats
• any other surface that has not previously supported
life
• Primary succession is much slower than
secondary succession. This is because it begins
where there is no soil.
• The first pioneer species to colonize bare rock
will probably be bacteria and lichens, which can
live without soil.
• The growth of lichens breaks down the rock,
which with the action of water, begins to form
soil.