Transcript Nutrient Cycles

Nutrient Cycles
Reduce, Reuse, Recycle!!
I. Biogeochemical Cycles
a. a.k.a. nutrient cycles
b. Nature does not throw anything away
c. Cycle – the path from nonliving
environments to living organisms and
then back to the nonliving environments
again
d. Energy and nutrients move through the
trophic levels together.
I. Biogeochemical Cycles
e. Energy and nutrients move differently through the
biosphere
f. Nutrients are used over and over by living systems
– recycled!
g. Recycled nutrients
include: water,
carbon, nitrogen,
sulfur, calcium,
& phosphorus
II. The Water Cycle
Begins with water vapor
in the atmosphere condensing and falling
to the ground as rain or snow
– Condensation – changing from a vapor (gas) form
into a liquid or solid form
– Some water is stored as ground water – water
retained beneath the surface of the Earth that
supplies wells and springs
II. The Water Cycle
Remaining water is heated by the sun and reenters the atmosphere through evaporation
and transpiration
– Evaporation – changing from liquid form into
gas (vapor) form
– Transpiration –
the evaporation
of water from
plant leaves
II.
The
Water
Cycle
III. The Carbon Cycle
The movement of carbon through the
environment
– Carbon dioxide in the air or dissolved
in water is used by photosynthetic
plants to build organic molecules
– Carbon atoms return to the air and
water three main ways:
i.
Respiration – the use of oxygen to
make organic molecules during cellular
respiration; carbon dioxide is a byproduct of this reaction
III. The Carbon Cycle
Carbon atoms return to the air and water three
main ways:
– Combustion – the burning of carbon stored in
wood or fossil fuels (coal, oil, and natural gas)
III. The Carbon Cycle
Carbon atoms return to the
air and water three main
ways:
– Erosion – the breakdown
of limestone which releases
stored carbon; limestone is
formed from the shells of
dead organisms built into
sediments over millions of
years
III.
The
Carbon
Cycle
IV. The Nitrogen Cycle
The movement of nitrogen through the
environment.
– The atmosphere is about 78% nitrogen gas
– Nitrogen – needed to build proteins (muscle is
protein) and nucleic acids (DNA)
– Nitrogen fixation – changing free N2 gas in the
atmosphere into compounds; microorganisms in
soil combine nitrogen with hydrogen to form
ammonia
IV. The Nitrogen Cycle
The nitrogen cycle has four
important stages:
Assimilation – absorption and incorporation
of nitrogen into organic compounds by
plants
Ammonification – the production of
ammonia by bacteria during the decay
of organic matter
Nitrification – the production of nitrate from
ammonia
Denitrification – the conversion of nitrate
into nitrogen gas
IV. The Nitrogen Cycle