Download Cycles in the Environment Topic #5

Cycles in the
Environment
Topic #5
The Carbon Cycle
• Every single living organism contains carbon (C)
• Plankton are microscopic plants and animals that
float in the ocean.
• Once they are dead, decomposing plankton are
buried and compressed over time and changed into
fossil fuels
• These fossil fuels will contain the carbon that was
present in the original organisms
The Carbon Cycle (cont.)
• Carbon is necessary for all life to exist
• Plants use carbon dioxide from the air in order to
make their food
• Moose, mice and many other organisms eat the
plants and release the carbon dioxide when they
exhale
• Wolves, foxes and other organisms eat the moose,
mice and other organisms and obtain their stored
carbon. They also exhale carbon dioxide CO2
The Carbon Cycle (cont.)
The Carbon Cycle (cont.)
• The carbon cycle includes:
-
photosynthesis – plants creating food
decomposition of living things – death and decay
respiration – breathing
extraction and burning of fossil fuels (coal, gas, etc)
dissolved carbon dioxide in oceans, lakes, rivers
plus all the carbon dioxide in the atmosphere
NO carbon molecule is ever destroyed – just reworked
and moved throughout the carbon cycle
The Water Cycle
• Like carbon, all living things require water
• An apple is 84% water, a carrot is 88% water, a
tomato is 94% water
• Human bodies are 60-70% water
• Water is used for carrying food to cell’s in an
organism’s body and for carrying away waste
The Water Cycle (cont.)
• The water cycle is the continuous movement of
water through an ecosystem
The Water Cycle (cont.)
• The water cycle involves 4 main processes
• The first two processes (evaporation and
transpiration) move water up from the Earth into
the atmosphere
• Evaporation is the process in which liquid water
changes into water vapour (gas)
• Transpiration is the process in which water that is
taken through a plant’s roots, evaporates from the
leaves, stem and flowers.
The Water Cycle (cont.)
• The second set of processes (condensation and
precipitation) return water to the Earth.
• Condensation is the process in which water vapour
(gas) changes into a liquid. Warm air cools the
vapour. As the air cools, it is able to hold less water
and water is released, forming clouds, fog or dew
• Precipitation is the process in which liquid water
forms from condensation occurring inside clouds
and then falls as rain, sleet, snow or hail.
The Water Cycle (cont.)
• The other components of the water cycle are ground
water and run-off
• Ground water is the water in the soil and rocks
below the surface of the Earth. People reach ground
water by digging wells.
• Run-off is water that doesn’t soak into the ground.
It runs off the ground into lakes, rivers, streams and
oceans.