Transcript File

Three Categories
• Hydrologic cycle
– Water
• Atmospheric cycles
– Nitrogen and carbon
• Sedimentary cycles
– Phosphorus and sulfur
CYCLES IN NATURE
Carbon Cycle
• Carbon moves through the atmosphere
and food webs on its way to and from
the ocean, sediments, and rocks
• Sediments and rocks are the main
reservoir
Part 1: How Does Carbon Move or
Change?
The questions following are about
four processes that take in or give
off carbon dioxide.
Draw the picture and answer the
question
Trees Growing
1. Look at the arrows going
into and out of the plant. You
may have heard that plants
take in carbon dioxide and
give off oxygen. What do you
think happens to the carbon
atom that was once in the
carbon dioxide molecule?
People Breathing
2.Look at the arrows going in
and out of the person. You
may have heard that people
and other animals breathe in
oxygen and breathe out
carbon dioxide. Where do you
think the carbon that is in the
carbon dioxide comes from?
Compost Decaying
3. Look at the arrows going
into and out of the
decomposers in the compost
pile. Decomposers need
oxygen to decompose dead
plants and animals. They give
on carbon dioxide. Where
does the carbon in the carbon
dioxide come from?
Candle Burning
4. Look at the arrows going
into and out of the candle.
Candles need oxygen to burn
and give off carbon dioxide.
Where does the carbon in the
carbon dioxide come from?
There are two important forms of carbon molecules: Organic forms of
carbon molecules and carbon dioxide molecules. Organic carbon
molecules contain carbon and are found in living and once-living things.
Carbon dioxide molecules contain carbon and are found as a gas in the air.
Think of places where you might find organic molecules and carbon
dioxide molecules. Complete the table below.
Organic Carbon
Carbon dioxide
Answer Alone
Look at your list of where you
would find “Carbon dioxide”.
What do you think are the main
processes that put carbon
dioxide into the air?
Look at your list of where you would
find “Organic Carbon”. What do you
think are the main processes that
take change carbon dioxide into
organic carbon?
Group Activity
Warm Up
1) If the arrows that go in and out of
the biosphere were equal, what do you
think would happen if we then decided
to cut down trees to make room for a
new neighborhood?
2) What would happen to the arrow
from the fossil fuel reservoir if we
choose to have more cars running on
gasoline, and use more fossil fuels to
power our homes?
Carbon in the Oceans
• Most carbon in the ocean is dissolved
carbonate and bicarbonate
• Ocean currents carry dissolved carbon
Summary of Carbon in Atmosphere
• Atmospheric carbon is mainly carbon
dioxide
• Carbon dioxide is added to atmosphere
– Aerobic respiration, volcanic action,
burning fossil fuels, decomposition of
organic materials
• Removed by photosynthesis
Carbon Cycle Drawing
• Write a paragraph (4 sentences)
about your Carbon Cycle drawing.
Within it you must include all places
where Carbon is in a CO2 form and
Organic Carbon(OC) form. Also,
include what process is changing it
from OC to CO2. Then include what
process is changing it from CO2 to
OC.
System:
System
Components
Inputs
Outputs
Effects on
other Systems
Nitrogen Cycle
•
Nitrogen is used in amino acids and nucleic acids
(all living organism need nitrogen to make
proteins)
•
Main reservoir is nitrogen gas in the atmosphere
•
Decomposers are vital to convert ammonia into:
1. usable nitrites & nitrates for plants (nitrogen
fixation)
2. nitrogen gas (denitrification = puts it back into the
atmosphere)
Nitrogen Struck by
lightning makes
nitrogen oxides, mixes
with water and makes
nitrates.
• Show video
NO3-
System:
System
Components
Inputs
Outputs
Effects on
other Systems
Phosphorus Cycle
• Phosphorus is part of phospholipids and all
nucleotides
– What are these?
• It is the most prevalent limiting factor in
ecosystems
• Main reservoir is Earth’s crust; no gaseous
phase (it never enters the atmosphere – like
carbon and nitrogen)
System:
System
Components
Inputs
Outputs
Effects on
other Systems
Phosphorus Cycle
mining
excretion
FERTILIZER
GUANO
agriculture
uptake by
autotrophs
MARINE
FOOD
WEBS
weathering
DISSOLVED
IN OCEAN
WATER
uptake by
autotrophs
weathering
DISSOLVED IN
SOILWATER,
LAKES, RIVERS
death,
decomposition
sedimentation
death,
decomposition
leaching, runoff
setting out
uplifting over
geolgic time
MARINE SEDIMENTS
ROCKS
LAND
FOOD
WEBS