Download Ecology of Ecosystems

Ecosystem Ecology
Community interacts with abiotic factors
Abiotic Factors that the community interacts with
• Energy
it is needed by organisms to do the processes to keep alive
Forms: light, chemical, heat
Type of energy used by living things:
• Chemical elements
carbon, nitrogen, phosphorous, oxygen
Organisms are made of these elements
Type of molecules that organisms are made of:
Remember the law of matter and energy!
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Two processes that
transform energy and matter
Photosynthesis
Energy transformation
Matter transformation
Autotrophic organisms (producers)
are the ONLY ones that can do photosynthesis
in plants
Heterotrophic organisms (consumers)
can not do photosynthesis
Cellular Respiration
Energy transformation
Matter transformation
in plants and animals
This occurs in autotrophs AND
in the heterotrophs that eat them
These processes allow for the movement
of energy and chemicals in an ecosystem
Movement of energy and chemicals in an ecosystem
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Movement of energy and chemicals
Movement of energy and chemicals in an ecosystem is different
Energy flows
- not recyclable
- energy as heat can’t be used again
- Ecosystem always needs
an external input of energy
Chemicals cycle
- recyclable
- e.g. carbon dioxide can be used again
- Ecosystem does not need
external input of chemicals
if cycling is complete
Their movement is linked because both depend on transfer of food.
We can represent their movement
Via a food chain: Simplified linear diagram of who eats whom
In an ecosystem,
food chains
interconnect forming
Food Web
Complex network
of who eats whom
We can group organisms
by the level at which they feed
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Trophic structure:
The different feeding relationships in an ecosystem
Detritivores and decomposers eat
nonliving organic matter; they recycle
chemicals.
Animals that eat herbivores are secondary
consumers, at the third trophic level.
Animals that eat plants are primary
consumers, or herbivores, and are at
the second trophic level.
Plants and other photosynthetic organisms
are producers.
What trophic level are you if you eat an apple?
What trophic level are you if you eat a steak?
Amount of energy and Trophic structure
What happens to the energy at each trophic level?
Which energy is available to
the next trophic level?
Energy available to all the consumers and decomposers in an ecosystem
comes from the energy in the producers
What would a diagram showing
the available energy at each trophic level would look like?
Square or a pyramid
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Energy pyramid shows
the available energy to the next trophic level
The higher the trophic level
a species is at,
the less available energy that it has
from the original energy stored
as photosynthesis
Implication:
Animals at higher trophic levels require more vegetation
to provide for their food than animals at lower trophic levels
We can apply this information to the human diet!
Meat eaters vs. Plant eaters
3,000 lbs of corn and soybeans is capable of supporting ONE person if converted
to beef,
however,
the same amount of soybeans and corn utilized directly without converting to beef
will support 22 people!
If the world population ate like in the US,
 ONLY less than ½ of the population could be fed.
If the world population ate strict vegetarian diets
 we could feed 1 billion MORE than present
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BIOMASS PYRAMID shows that amount of
mass is reduced in higher trophic levels
We can use a biomass pyramid
to understand why organisms at higher trophic levels
have higher concentration of toxic chemicals
than lower ones
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What happens to these toxics in the food chain?
As biomass is consumed through food chain
The amount of biomass is reduced
But
The amount of toxic does not (due to persistence)
RESULT:
The concentration of the toxic increases
Having a greater impact on top predators
Biological Magnification or Biomagnification:
accumulation of toxics in tissues of consumers in food chains
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Carbon makes up the skeleton of
all organic molecules
Presence of Carbon Dioxide allows for life on earth
The amount of CO2 in the atmosphere determines
the temperature, by the
GREEN HOUSE EFFECT
Some of the sun energy is absorbed by Earth
some of this absorbed energy is reflected back
some of this reflected energy is reemitted back
by Carbon Dioxide and other GH gases
Without these gases the Earth would be 59oF cooler!!!
What will be the effect of
changing the amount of carbon dioxide in the atmosphere?
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Human impact on the carbon cycle
•
We have increased the amount CO2 in the atmosphere by burning fossil fuels
•
We have decreased the removal of atmospheric CO2 by deforestation
CONSEQUENCE OF TWO
more CO2 than normal enhanced greenhouse effect
 increased global temperature  change in climate
The IPCC reports summarize evidence of
recent changes in global climate
•
Since 1990, the world’s climate scientists have been gathering to produce
the single most comprehensive and authoritative research summary on
climate change:
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Why we need to talk about the scientific
consensus on climate change
Is climate the same as weather?
Weather is for a given day and place
Climate are long term patterns
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Should climate be stable?
Climate changes
naturally and always has
Concerns:
change is happening more quickly
few decades instead of thousands of years
What is causing this current warming?
The relationship between CO2 and temperature is one of cause and effect
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Is the current change natural or human driven ?
Extremely Likely human responsibility
emissions of GH gases from human activities
have caused “most of the observed increase
in globally averaged temperatures since the mid-20th century.”
Adaptation and Mitigation
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What are the observed changes?
If we reduce our emissions,
An estimated $0.14 billion dollars
can be saved from sea level rise by 2050
What are the observed changes?
Scientists
say peak snowpack could be as
much as 30 percent reduced by 2040.
Though the result will be less snow, California is expected to see more intense
storms punctuated by longer periods of drought.
"Then it rains for a very long period of time and we can’t capture it and store it."
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What are
the observed changes?
If we reduce our emissions,
An estimated 1,700 fewer deaths
And savings of $21 billion ,
can be saved from extreme weather by 2050
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Higher ozone concentrations due to rising temperatures could lead to
an average of 3,700 more seniors and 1,400 more infants hospitalized
for respiratory related problems in 2020.
In 2050, that could rise to 24,000 more seniors and 5,700 more infants hospitalized
.
If we reduce our emissions,
An estimated $160-300 million
can be saved from reducing wildfires by 2050
An estimated 13, 000 fewer deaths from poor air quality and savings of $160
billion
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What are the observed changes?
Ocean warming accounts for
more than 90% of the energy accumulated between 1971 and 2010
If we reduce our emissions,
An estimated 53% of coral in Hawaii, 4%
in Florida can be saved by 2050
Losses valued at $1.4 billion
What are the observed changes?
Ocean has absorbed about 30% of the emitted
anthropogenic carbon dioxide, causing ocean acidification
If we reduce our emissions,
An estimated avoided loss of 11% of oyster supply, 12% scallop supply can be
saved by 2050
Consumer benefits
Of $85 million
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What are the observed changes?
Species and Climate Change: More than just the Polar Bear
A large fraction of species face increased extinction risk due to
climate change during and beyond the 21st century.
Geographic ranges of many species have shifted toward the
poles and up in elevation
Most plant species cannot naturally shift their geographical
ranges sufficiently fast to keep up with climate change.
Temperature extremes will cause health problems;
tropical diseases will move north into the U.S.
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We have warmed under 1 oC
Where do we go from here?
We are committed to ½ oC
If we continue business as usual: 1-5 oC
Danger zone is 2 oC!
At the end of the last ice age,
when the Northeast United States was covered by more than 3,000 feet of ice,
The average temperatures were only 5 oC cooler than today.
What can be done?
Texas example
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What can you do?
INFLUENCE U.S. ACTION
5 THINGS YOU CAN DO
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