1. 2.3 Cycling of Matter

2. 3 Important Materials That Cycle
Through Ecosystems
 Water
 Carbon
 Nitrogen
 As well as sulfur, calcium, and
phosphorus among others

3. Energy is lost:
 at each transition from one trophic
level to the next
 But the sun replenishes the energy
 Matter is recycled!

4.  Matter in the form of nutrients
also moves through the
organisms at each trophic level
 The atoms of elements that
make up the bodies of organisms
alive today are the same atoms
that have been on Earth since
life began

5. Water cycle
 plants absorb water through roots
 animals drink water or get it from food
 water is lost through respiration, excretion
and decomposition of dead organisms
 Animated water cycle
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7. The Carbon Cycle
 carbon is found as CO2 in the
atmosphere & ocean
 producers (terrestrial & aquatic) use CO2
in photosynthesis to make sugar
 photosynthesis = CO2 + H2O -> carbs.
 respiration & decay return CO2 to the
atmosphere
 burning returns CO2 to atmosphere

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11. The Nitrogen Cycle
 makes up 78% of the atmosphere
 living things cannot use nitrogen in
atmospheric form
 lightening and bacteria “fix’ into usable
compounds called nitrates
 plants convert nitrates into molecules
containing nitrogen

12. The Nitrogen Cycle (cont.)
 animals change these molecules into
animal proteins
 during digestion, humans convert
plant & animal proteins into human
proteins
 decay returns nitrogen to the
atmosphere

13. The nitrogen cycle (cont.)

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16. The Phosphorus Cycle
 short term cycle - plants use
phosphorus from the soil into body
tissues
 animals get phosphorus by eating
plants
 decay returns phosphorus to the
soil

17. The Phosphorus Cycle
 long term cycle - phosphorus
washed into the sea becomes
incorporated into rock
 years later rock containing
phosphorus is exposed -
phosphorus is released