Transcript How do Ecosystems work? • • • • • Definition of ecosystem Living and non-living interactions Energy flow What about nutrients? On an index card define nutrients?

How do Ecosystems work?
•
•
•
•
•
Definition of ecosystem
Living and non-living interactions
Energy flow
What about nutrients?
On an index card define nutrients?
Nutrients
• Substance that an organism must obtain
from its surroundings for growth and the
sustainment of life
• These nutrients are necessary for growth
therefore must contain the elements
necessary for building blocks
Questions
• What are the four main elements of life?
– 1. Carbon, hydrogen, nitrogen, oxygen
– 2. Carbon, potassium, nitrogen, oxygen
– 3. Carbon, hydrogen, sulfur, oxygen
– 4. Carbon, water, nitrogen, oxygen.
Energy Flow,
Nutrient
Cycling, &
Feeding
Relationships
•Nutrients (purple)
neither enter nor leave
cycle
•Energy (yellow) is
not recycled
–Captured by
producers
–Transferred
through consumers
(red)
–Each transfer loses
energy (orange)
CARBON
• What are the forms of Carbon on our
planet?
• Carbon dioxide
• Sugars
• How are these forms cycled?
• Photosynthesis
• Cellular respiration
Carbon facts
• Life on Earth is carbon-based.
• Carbon is a lively element that readily combines with
other elements to make organic compounds.
• A lot of your body, and every body, is made of carbon.
• Some carbon parts of your body, right now, were parts
of living plants only a few months ago.
• Plants, through photosynthesis, make carbohydrates
that animals eat for food..
• You eat the plants, salad or bread or pasta, or another
animal (cow), ate the plants then you ate the animal
(meatballs), and pretty soon the carbon that was part of
grass became part of you.
Carbon facts con’t
• Part of the carbon cycle is very fast; the rock-forming
part and coal-petroleum--natural gas part takes millions
of years.
– Enormous amounts of carbon are stored as coal etc
– Human impact
• In the ocean, sediments are the largest reservoirs of
carbon--this carbon is not accessible to life
• On land, forests are the largest reservoirs of carbon--up
to 80% of the aboveground carbon. Most of it is in the
tissues of trees. Russia and the Amazon basin together
hold about 45% of the world's forest carbon.
• Living organisms are crucial to the carbon cycle.
The Carbon Cycle
CO2 in
atmosphere
(reservoir)
CO2 dissolvedBurningFire
of
in oceanRespiration
fossil fuels
(reservoir)
Consumers
Producers
Wastes,
SoilDead
bacteria
&
bodies
detritus feeders
Reservoirs
Processes/
Locations
Trophic
Levels/
Organisms
Nutrient Cycling
• Same pool of nutrients supports all life—
past, present, and future
• Cycle moves nutrients:
– From nonliving to living
– From environmental to organisms
Atmospheric Cycles (C & N)
• Majority of nutrients found in the atmosphere
• Atmospheric nutrients get incorporated into living
organisms
– Carbon—photosynthesis
– Nitrogen—nitrogen fixation
• Nutrients are returned to the environment
– C—respiration (all organisms, detritus feeders,
decomposers)
– N—decomposers and denitrifying bacteria
Nitrogen facts
•
•
•
•
•
Nitrogen is one of the most abundant elements on Earth.
79% of Earth's atmosphere is nitrogen in gas form.
No living cell can exist without nitrogen.
But organisms cannot use nitrogen in gas form.
Multicellular life (plants, animals and fungi) depend
almost entirely on bacteria to obtain (or "fix") nitrogen
from the air and transform it into a chemical form that
plants can use.
Importance of Bacteria in Nitrogen
cycle
• Some of these talented bacteria interlive with
legumes such as beans: these take nitrogen out
of the air in soils.
• Other bacteria live freely in the soil, processing
manures and urine, and also helping to
decompose dead plants and animals.
• A third kind of bacteria lives in the soil and
changes "fixed" nitrogen into nitrates,which
plants can use. Without these nitrifying
bacteria, agricultural fertilizers do not work.
Nitrogen Cycle
• The Nitrogen cycle has two major beginnings
and two major paths.
– Nitrogen from soil air (to) nitrogen-fixing
bacteria (to) nitrifying bacteria (to) plants
(to) animals (to) decomposers
– Nitrogen from dead organisms (to)
decomposers (to) nitrifying bacteria (to)
plants
The Nitrogen Cycle
Nitrogen
Nitrogen in
in
Atmosphere
Atmosphere
Reservoir
Reservoir
Producers
Uptake
Denitrifying
by
bacteria
plants
Electrical storms
produce nitrate
Consumers
Wastes,
Dead bodies
Nitrogen-fixing
Soil bacteria and
detritus feeders bacteria in
legume roots
Ammonia
and soil
& nitrate
Reservoirs
Processes/
Locations
Trophic
Levels/
Organisms
Questions
Which of the following statements best
describes the movements of energy and
nutrients in ecosystems?
–
–
–
–
1.
2.
3.
4.
cycle
Energy and nutrients flow through
Energy cycles and nutrients recycle
Energy increases and nutrients cycle
Energy flows through and nutrients
Energy
• Two forms
– Sunlight
– Stored in chemical bonds
– Demos
Acid Rain
• Sulfuric and nitric acids in rain
• Result from overloading N and S cycles
• Acid rain examples
– Adirondack Mountains—dead lakes
– Mount Mitchell, N.C.—fog pH = 2.9
– Black Triangle in Europe
• Soil pH = 2.2
• Thermal inversions
• Infant mortality
Greenhouse Effect
• Gases which interfere with cooling of Earth
– CO2
• Use of fossil fuels
• Global deforestation by slash & burn
– CFCs (A/C & refrigeration gases)
– Methane
– NO
• Global warming
– What might be the consequences of global warming?
Greenhouse Gases
Contribute to Global Warming
Global Warming Parallels
CO2 Increases
Ozone
• O3 layers protect Earth from damage
– If received the full strength of sun energy destructive
– 19 miles up
• Highest point on Earth Mt. Everest
• Approx 5 miles
• O3 layers can also cause damage when take up all the oxygen
molecules
– SMOG
– Ground level
Satellite Image of
Antarctic Ozone Hole
South America
Antarctica
The “hole”
Questions
• A major ecological concern, the
Greenhouse Effect, is caused by:
–
–
–
–
–
1.
The release of heat energy from
burning fossil fuels
2.
The release of carbon dioxide from
the burning of wood, coal, and oil
3.
The destruction of ozone in the
upper atmosphere
4.
Overuse of fertilizers in farming
5.
Global warming
Questions
What are the results of global
warming?
1. Increase in greenhouse effect
2. Increase in greenhouse gases.
3. Increase in earth’s temperature.
4. All of the above
Questions
• Acid precipitation is the result of
interference with which biogeochemical
cycles?
–
–
–
–
1.
2.
3.
4.
sulfur and nitrogen
sulfur and hydrologic
hydrologic and nitrogen
hydrologic and phosphorus