WATER AND NUTRIENT CYCLES
STANDARD
SB4. Students will assess the dependence of all organisms on
one another and the flow of energy and matter within their
ecosystems.
b.Explain the flow of matter and energy through ecosystems by
 Comparing the quantity of energy in the steps of an energy pyramid
 Explaining the need for cycling of major nutrients ( C, O, H, N, P).
ESSENTIAL QUESTION
How is energy transformed as it
flows through organisms and
ecosystems
WHAT ARE THE MAJOR NUTRIENTS?
C
 Carbon
 Found in lipids (make up the cell membrane) & carbohydrates
H
 Hydrogen
 Found in all macromolecules and water
N
 Nitrogen
 Found in Proteins
O
 Oxygen
 Found in water
P
 Phosphorus
 Found in Nucleic Acids
Nutrients are necessary to survive
NUTRIENT CYCLES
Carbon
Plants and algae
absorb carbon dioxide
(CO2) to use in
photosynthesis and
release oxygen (O2)
(CO2) is recycled into
the atmosphere during
cellular respiration,
through burning, and
through decay
NUTRIENT CYCLES
Nitrogen
Bacteria fix
atmospheric
nitrogen in plant
roots
returned to the soil
• urination
• Death
• Denitrification
• Fixed nitrogen is converted
back into nitrogen gas
plants absorb
nitrogen from soil
Consumers eat
plants or animals
and reuse the
nitrogen
NUTRIENT CYCLES
Rocks weather and
break down releasing
phosphorus into the soil
Phosphorus
moves from the short term cycle
to the long term cycle through
precipitation and sedimentation
to form rocks
Plants absorb phosphorus
from the soil and pass it
on to consumers
consumers produce waste
products or die the
phosphorus is returned to the
soil
WHY ARE THESE NUTRIENTS CYCLED?
 The 5 nutrients make up several molecules essential to life
What is cycling?
 Energy is recycled
 Nutrients are used by organisms, delivered back to the environment,
and used again.
 Ex: water cycle
Water
Rain
 90% of water evaporates from oceans, lakes, and rivers
 10% evaporates from the surface of plants
 called transpiration
Freshwater is about 3% of all water on Earth
WATER CYCLE
Flows into streams, rivers,
lakes, and oceans
Only to evaporate and
continue the cycle
Water is
constantly
evaporating into
the atmosphere
Water vapor
rises and begins
to cool in the
atmosphere
Ground water
and runoff
In form of rain, sleet,
or hail
Transferring water to
the earth’s surface
From bodies of water,
soil, and organisms
Water falls from
clouds as
precipitation
Clouds form when the
cooling water vapor
condenses into droplets
around dust particles in the
atmosphere
CHECKING FOR UNDERSTANDING #5
Directions: Label the top of your paper as ‘Checking for Understanding’.
Put today’s date as indicated below. Write the questions and the answer to
the following questions:
9/11/15
1. Explain how carbon and oxygen are cycled in an ecosystem
2. Why must nitrogen be cycled through an ecosystem?
3. Where does the phosphorus cycle begin?
4. Why is it important that phosphorus is cycled through the ecosystem?
Keep this paper in your notes until the next ‘Check for Understanding’.
This is for a grade!