Transcript Cycles in Nature

Cycles
That
Occur in
Nature
Water cycle
 Moves between atmosphere,
oceans & land
 1 – water evaporates from the
ocean
 2 – water also evaporates from
plants during the process of
transpiration
 3 – The evaporated water then
enters atmosphere as a gas
(water vapor)
 4 – Vapor condenses to form
clouds
 5 – when large enough, water
will fall back to earth as
precipitation
 6 – Water travels along the
surface as runoff or seepage
 7 – Plants remove water by
root uptake
 Water is always equal in the
cycle.
 The amount never changes
 Concerns(due to humans)
 Groundwater depletion due to
irrigation
 Unsafe drinking water due to
pollution or animal waste.
(causes 80% of diseases in
undeveloped countries)
Carbon cycle
Where is carbon stored?
Carbon cycle
Where is carbon stored?
In EVERY LIVING THING!!!!
 Photosynthesis: taken in by
plants & converted to sugar
 Cellular Respiration:
released
 Erosion & volcanoes:
releases CO2 in the air &
ocean
 Decomposition: released
(may be stored underground
as fossil fuels)
Human Activities:
 Mining
 Burning fossil fuels
 Cutting / burning down
forests
Nitrogen cycle
 Nitrogen –make up proteins
and DNA
 Where is most of it stored?
 In the atmosphere!! (79%)
 Plants and animals cannot take
nitrogen from the atmosphere
 1. Bacteria converts nitrogen gas
into ammonia in a process called:
 nitrogen fixation.
 2. A different bacteria converts
ammonia into nitrates and nitrites
needed by plants to make proteins
 3. Plants take in nitrogen (as
nitrates or nitrites)
 4. Consumers get nitrogen by
eating producers
 5. Organisms die, and return
nitrogen to soil as ammonia
 6. Some ammonia taken up by
producers
 7. Nitrates are converted into
nitrogen gas by bacteria in a
process called denitrification
 8. Nitrogen gas returns to the
atmosphere
 Human activities can also add
Nitrogen:
 Use of fertilizers (travel by
runoff)
 Dumping raw sewage
 Burning fossil fuels & wood
 Leads to eutrophication (the
end result is loss of oxygen
from the water)
Phosphorus Cycle
 1 – stored in rock (land &
ocean floor) & soil
 2 - Released by weathering &
erosion
 3 – travels in runoff
 4 – enters the ocean & gets
used by some marine
animals
 5 – travels through the food
web
 6 – returned to soil through
waste
Phosphorous Cycle

Human Activities