Download Biogeochemical Cycles

Biogeochemical
Cycles
Cycling of Matter in Ecological
Systems
Cycles of Matter
• Unlike the one-way flow of energy,
matter is ______________
Cycles of Matter
• Unlike the one-way flow of energy,
matter is recycled within and between
ecosystems.
Cycles of Matter
• Biogeochemical cycles –
Cycles of Matter
• Biogeochemical cycles –
Process in which elements, chemical
compounds, and other forms of matter
passed from one organism to another and
from one part of the biosphere to another
Cycles of Matter
• Biogeochemical cycles –
Biological
Geological
Chemical
Cycles are all connected
Water Cycle
• involves the processes of photosynthesis,
evaporation, transpiration, condensation,
respiration, and excretion
1. Photosynthesis – the process of plants (and
algae) converting the sun’s energy into food.
1.
+ CO2 + H2O  C6H12O6 + O2
2. Evaporation – The changing of liquid “water”
into the gaseous form
3. Transpiration – Is the evaporation of water
from a plant leaf
4. Condensation – The changing of gaseous
“water” to a liquid form.
5. Respiration – Plants using oxygen and
converting their food into energy they use.
1. C6H12O6 + O2  CO2 + H2O +
6. Excretion – The removal of waste products
(such as urine and sweat) from the body.
1. Water in the air falls to the Earth as rain or
snow (Precipitation).
2. Some water runs off the land into rivers, ponds
lakes, or oceans.
3. Water from rain may soak into the soil.
4. Some of this water is taken up by plants
through their roots. Animals may drink some of
the water on the ground. The rest flows into
underground lakes and rivers.
5. Excess water passes out of plants through
their leaves. Animals lose water through
body openings or as wastes are removed.
The water evaporates into the air. Water is
present in the air as a gas.
6. Water from lakes, rivers, and oceans also
evaporates into the air.
· The Water Cycle (Video Clip)
Carbon Cycle
• Carbon (C) is the basis of life on Earth.
• Scientists consider 99.9% of all organisms
on the planet to be carbon based life.
• Those organisms need carbon to survive.
• Whether the carbon is in the form of a
sugar or carbon dioxide gas, we all need
it.
· The Carbon Cycle--Recycling matter (Video Clip)
Carbon Cycle
1. Absorption of carbon by plants from
atmosphere.
2. Movement of carbon from plants into
the animal world.
3. Movement of carbon from living things
to the atmosphere.
Carbon Cycle
4. Movement of carbon from living things
to the land.
5. Movement of carbon from fossil fuels
to the atmosphere.
6. Movement of carbon from the
atmosphere to the oceans.
Carbon Cycle
involves the processes of respiration and
photosynthesis.
In respiration, oxygen and glucose are
combined releasing energy and producing
water and carbon dioxide.
Carbon Cycle
In photosynthesis water and carbon dioxide
along with the energy from the sun are
combined to produce glucose (containing
energy) and oxygen.
Each process compliments the other and the
ecosystem maintains its balanced
communities.
· The Carbon Cycle--Recycling matter (Video Clip)
The Nitrogen Cycle
• Organisms require nitrogen to produce
amino acids.
• Nitrogen makes up 78% of the
atmosphere, but most organisms can not
use this form of nitrogen, and must have
the fixed form.
• The nitrogen cycle produces the fixed form
of nitrogen these organisms need.
The Nitrogen Cycle
The Nitrogen Cycle Steps
• Step 1: A special type of bacteria called
nitrogen fixing bacteria take in
atmospheric nitrogen and produce
ammonia (NH3).
1. Nitrogen fixation
• Step 2: Other bacteria use this ammonia
to produce nitrates and nitrites, which are
nitrogen and oxygen containing
compounds.
2. Nitrification
Nitrogen Cycle Steps
• Step 3: The nitrates and nitrites are used
by plants to make amino acids which are
then used to make plant proteins.
Assimilation
• Step 4: Plants are consumed by other
organisms which use the plant amino
acids to make their own.
Nitrogen Cycle Steps
• Step 5: Decomposers convert the
nitrogen found in other organisms into
ammonia and return it to the soil. A few of
these type of bacteria return nitrogen to
the atmosphere by a process called
denitrification, however this amount is
small.
Root nodules
Alafalfa (Medicago sativa)
USDA - ARS
University of Sydney
The Phosphorous Cycle

essential but not found in atmosphere
 important part of DNA, RNA, and ATP
 Found in rock and soil
 Plants get it from soil; animals get it
from plants
 Effects rapid growth.
 Encourages blooming and root growth.
Steps of Phosphorus Cycle
1. Phosphates are removed by erosion
2. Phosphates enter the soil and water
3. Plants use them to make organic
compounds.
4. Consumers eat plants and obtain
phosphates
5. Organisms decompose and return
phosphates to the soil
Nutrient Limitation
• Primary productivity – rate at which
organic matter is created by producers.
Nutrient Limitation
• Limiting nutrient – single nutrient that
either is scarce or cycles very slowly,
limiting the growth of organisms in an
ecosystem
– Examples –
• farmers add fertilizers that contain nitrogen,
phosphorus, and potassium to their crops
• In freshwater aquatic environment, phosphorus is
usually the limiting nutrient
Nutrient limitation
• Algal bloom – immediate increase in the
amount of algae and other producers that
results from a large input of a limiting
nutrient
– Often results when runoff from heavily
fertilized fields increases amount of limiting
nutrient
Eutrophication - Algal Bloom
Algal Bloom