Download Ecology of Ecosystems

Ecosystem Ecology
Community (biotic factors)
interacts with abiotic factors
Objectives
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Compare the processes of energy flow and chemical cycling as they relate to
ecosystem dynamics.
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Define and list examples of producers, primary consumers, secondary
consumers, and Detritivores in an ecosystem.
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Distinguish between a food chain and a food web.
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Define a energy pyramid and its relationship to human’s diet
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Describe how a biogeochemical cycle works and specifically the cycle of
carbon and nitrogen
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Describe how human activities have disrupted the carbon cycle
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Describe the green house effect and its connection to our current global
warming.
Describe the possible consequences of global warming.
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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
They are what organisms are made of (matter)
Type of matter that organisms are made of:
Remember the law of matter and energy!
Two processes that
transform energy and matter
Photosynthesis
Energy transformation
Matter transformation
Autotrophic organisms (producers)
are the ONLY ones that can do photosynthesis
Heterotrophic organisms (consumers)
can not do photosynthesis
in plants
Cellular Respiration
Energy transformation
Matter transformation
This occurs in autotrophs AND
in the heterotrophs that eat them
These processes allow for the movement
of energy and chemicals in an ecosystem
in plants and animals
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
- 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
Trophic structure:
The different feeding relationships in an ecosystem
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
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
Biogeochemical cycles describe the movement
of elements in the ecosystem
Elements are found in:
Living things  biotic reservoirs
Non-living things  abiotic reservoirs
And they can move:
Between these reservoirs
And within each reservoir
Carbon cycle
Nitrogen cycle
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?
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:
Is climate the same as weather?
Should climate be stable?
Is the current change natural or human driven ?
THE IMPACTS OF CLIMATE CHANGE ON
HUMAN HEALTH
IN THE UNITED STATES:
A SCIENTIFIC ASSESSMENT
Health2016.globalchange.go
v
The impacts of climate change on human
health
• Temperature
• Air quality
• Extremes
• Vector
• Water
• Food
Temperature
Even Small Differences from Seasonal Average Temperatures Result in
Illness and Death
Air quality impacts
• Exacerbated Ozone Health Impacts: these climate-driven increases
in ozone will cause premature deaths, hospital visits, lost school
days, and acute respiratory symptoms
• Increased Health Impacts from Wildfires: Wildfires emit fine
particles and ozone precursors that in turn increase the risk of
premature death and adverse chronic and acute cardiovascular and
respiratory health outcomes
• Worsened Allergy and Asthma Conditions
Increase in extreme events
Vector borne diseases
Mosquito-Borne Disease Dynamics: Rising temperatures, changing
• Changing
precipitation patterns, and a higher frequency of some extreme weather events
associated with climate change will influence the distribution, abundance, and
prevalence of infection in the mosquitoes that transmit West Nile virus and other
pathogens
What can you do?
40 min
Continuation on animals
Phylum Platyhelminthes : flatworms
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Worms flat, unsegmented body
First animals to exhibit bilateral symmetry, three tissue layers
Flatworms are acoelomates
Flatworms can be free living or parasitic
The have a nervous system with cephalization
They have sac like gut
Lack respiratory, how do they exchange gases?
• Lack circulatory systems,
how do they get food and O2
to all the cells?
Planaria is a freeliving flatworm
Tapeworms
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Parasites of vertebrates, in the digestive system
Lack a mouth and digestive tract
Anterior end with hooks and suckers (scolex)
Body has repeating units (proglottids)
Phylum Nematoda: Roundworms
Cylindrical worms with unsegmented body
Body covered by a collagen cuticle (elastic but restricts growth),
molted 4 times during growth
Body wall has only longitudinal muscles
Found in virtually all habitats (poles, deserts, hot springs)
Handful of soil contains thousands of nematodes
Nematode parasites exist in nearly all animal and plant species
Ascaris
Ascaris lumbricoides is one of the largest and most common parasites found in humans.
It is estimated that 25% of the world's population is infected with this nematode.
Host swallows embryonated eggs, juveniles hatch, and burrow through intestinal wall
Carried through the heart to the lungs, coughed up and swallowed, they mature in the
intestine after two months
They feed on intestinal contents and may block or perforate the intestines
Vinegar eel
Vinegar eels
Feed on bacteria and fungi found in
nonpasteurized vinegar.
They are raised by aquarists,
who use them to feed newly hatched fish.
Make your own mount with slowing agent
Ex. 13
• Procedure 3:
Sketch planaria and label
Observe the tape worm specimens
• Procedure 4:
Sketch vinegar eels
Observe Ascaris specimens