Transcript Energy Flow in ecosystems lisa. l - martin

Roles of producers and consumers
Follow energy flow through an ecosystem
Different types of consumers
Food chains and webs
Energy pyramids and trophic levels
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A food chain is
simply "who eats
what".
A food web weaves
together many food
chains to form a
complicated network
of feeding
relationships.
Many animals eat
more than one thing,
and each link in each
chain is important
and integral to the
entire system.
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As an organism eats another through a food
chain or web there is a transfer of energy
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Energy transfer through an ecosystem is
known as a trophic level
Each time energy is transferred, less of it is
available to the organisms at the next trophic
level.
Think pyramid figure 3-8 pg.61
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Photosynthesis
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6CO2 + 6H2O + light
C6H12O6 + 6O2
Cellular Respiration
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C6H12O6 + 6O2
6CO2 + 6H2O + Energy
Notice that cellular respiration is essentially
photosynthesis in reverse
 Do not confuse cellular respiration (the work cells do)
with breathing (respiration).
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Respiration
In the cells of living things, the process in
which oxygen is used to get energy from food
and is converted into carbon dioxide.
Photosynthesis
The process by which plants make their own
food by using water and carbon dioxide (a gas
that's plentiful in the air) into carbohydrates
(sugars and starches), using the energy of
sunlight.
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Insect type
Job description
Environment
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Electron scanning micrograph of a honeybee leg
Any pollen or extraneous material will attach to it
Humans also pick up stuff through the day
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Pesticides –DDT, pyrethins, diasinon
Chemical –ricin, sarin, nerve gas
Biological – Botulism toxin, Anthrax, Smallpox,
Plague
Define Sentinel
 “One who watches or guards; specifically a solider set
to guard an army, camp or other place, from surprise,
to observe the approach of danger, and give notice of it;
a sentry.”
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Discuss what types of materials/chemicals
insects might pick up. How might this happen?
How could this information be used to help us?
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What are some benefits of understanding insect
behaviour, what they eat, and where they live?
Discuss the role of insects in a food chain or
food web
 You should know what a producer, consumer, levels of
consumers (primary, secondary, tertiary), food web,
herbicide, and insecticide
Transpiration
Evaporation
Transpiration
Condensation
Precipitation
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Carbon Dioxide/Oxygen cycle
The process by which carbon dioxide and oxygen
are cycled and recycled through the
atmosphere
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What can upset the Carbon Cycle?
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By releasing to much Carbon Dioxide into the atmosphere at
one time.
 Burning of Fossil Fuels
 Widespread burning of tropical forests
As long as there is not more carbon than plants can use, the
carbon cycle works well and the system stays in balance.
Bessie the Cow
Landfill or Dumps
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All organisms need nitrogen to build proteins.
Nitrogen gas =78% of the earth’s atmosphere
Only nitrogen fixing bacteria can use the gas directly.
These bacteria fix nitrogen in a form plants can use
Some of these bacteria live in the roots of plants in a
mutualistic relationship. Any extra nitrogen the plant
doesn’t need is released into the soil
Nitrogen is returned to the soil in dead and decaying
matter and decomposers are needed to break this down
and return the nitrogen into the soil again that was locked
in the bodies of plants and animals. Bacteria then
transform it back into gas to return to the atmosphere
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Succession is a regular pattern of changes over
time in the types and species in a community
Can take hundred’s or thousands of years
Primary succession occurs in areas where no
ecosystem existed before
 eg. Island formed by volcanic eruption or glacier melting
to show rock beneath.
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Very slow process
Pioneer species include Lichens (fungus and an
alga) and bacteria, which don’t need soil to grow
Then mosses to small seed plants
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Break down rock
As they die they build up decaying matter and
are added to a building pile of soil
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Ephesus
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Secondary succession occurs where an
ecosystem has previously existed
Mount St. Helens
 Old field abandoned
 Fire
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You should know that:
Organisms can alter the environment in
which they live
Can happen in ANY ecosystem
But … for succession to happen plants
must first become established
You should know that:
When succession happens naturally, it is a slow and
gradual process
It can take 100’s of years
Unnatural events:
Purple Loosestrife
Zebra Mussels
Pulp Mills affect fish growth