Download Energy Flow Through an Ecosystem

Cycles of
Matter
in an
Ecosystem
Lesson 5
copyright cmassengale
1
Do Now – What is Ecology?
DO Now:
1. What are decomposers?
2. Give two examples
3. Can energy be recycled or re-used?
Essential Question:
How is matter cycled in an ecosystem?
Objective:
SWBAT identify and describe the three cycles of matter
in an ecosystem.
Lesson Overview
AGENDA
Finish Owl Pellet Lab
Discussion: Cycles of Matter
Water
Carbon
Nitrogen
•
HOMEWORK
Finish Nutrition & Energy
Reading and Vocabulary
Cycles of matter
How much do you know?
• How much do you know about
biogeochemical cycles and the impact that
humans have on these cycles?
• Can you provide any examples of human
activities that result in the alteration of the
water or nutrient cycles?
•
Eutrophic lake
Healthy lake
(high primary productivity
due to excessive nutrients)
What are the differences??
What types of processes are occurring in
each of these pictures? Which are natural?
Which are man-made?
Biogeochemical Cycles
• “Bio”
• “Geo”
• “Chemical”
-Biology
-Geology
-Chemistry
• Elements, chemical, compounds,& other
forms of matter passed from one organism
to another.
– How is this different from energy flow?
Recycling in the biosphere
Matter is recycled within & between
ecosystems
Biological systems don’t use up matter,
they transform it
Inhaling atoms that dinosaurs did!!!
The Water Cycle
• All living things require water
to survive
• Where does water come from?
-Moves between ocean,
atmosphere, & land
• Evaporation
-Water changes from liquid to gas
• Transpiration
-Water evaporates from the leaves into
the atmosphere.
• Condensation
- Water vapor (gas) turns into liquid
water forming clouds.
• Precipitation
-Water droplets become large
enough to fall to Earth
-Rain, snow, sleet, or hail
• Surface Runoff - Rain, snow, that flows
into streams, rivers, or canals.
Condensation
Evaporation
Transpiration
Precipitation
Run off
Seepage
Root uptake
Nutrient cycle
• Nutrients- all chemical substances that an
organism needs to sustain life
• Every organism needs nutrient to build
tissues and carry out essential life functions
• AKA Carbon, Nitrogen, and Phosphorus
cycles
Carbon Cycle
• Carbon is a key ingredient of living tissue
• CO2 (Carbon dioxide)
– Given off by plants & animals during
respiration
– Makes up atmosphere
– Released into atmosphere by volcanic activity,
burning fossil fuels and vegetation
– Decomposition of organic matter
– Taken in by plants in photosynthesis
More info
• 4 main processes move Carbon
through the cycle
1. Biological- photosynthesis, respiration,
decomposition
2. Geochemical – Erosion & volcanic activity
3. Mixed biogeochemical- burial & decompostion
4. Human Activities-mining, cutting & burning
forest, burning fossil fuels
CO2 in atmosphere
CO2 in ocean
Increased CO2 & the Greenhouse Effect
http://environment.nationalgeographic.com/environment/global-warming/gwoverview-interactive.html
Nitrogen cycle
•All organisms require Nitrogen to make amino acids
(which are used to make proteins)
•N2 makes up 78% of Earth’s atmosphere
•Humans add Nitrogen thru Nitrate (fertilizers)
•Found in waste –
-Ammonia (NH3), nitrate ions (NO3-),
& nitrite ions(NO2-)
More on Nitrogen Cycle
• Only certain types of bacteria can use nitrogen gas
directly
• They are found in soil and on roots of plants called
legumes (“magical fruit”)
• They convert it to ammonia through Nitrogen
Fixation
• Other bacteria convert ammonia into nitrates &
nitrites
• Producers use it to make proteins
• Consumers eat producers and reuse
nitrogen to make proteins
DEATH!!!
• When organism die, decomposers return
nitrogen to soil as ammonia
• Ammonia taken up by producers (again)
• Denitrification -other soil bacteria convert
nitrates into nitrogen gas. Releases nitrogen
into atmosphere.
Simplified
Nitrogen
Cycle
1.Organic wastes(from plants and animals) add nitrogen to the soil.
2.Bacteria in the soil convert the nitrogen into forms plants can use.
3.Plants use nitrogen in the soil to grow, develop, and produce seeds.
4.Plants are eaten by animals and people. The organic waste (which
contains nitrogen) is returned to the soil again.
Human Impacts
Phosphorus in runoff causes algal blooms
and eutrophication (oxygen depletion in
water)
Humans contribute to this by over
fertilizing, mining, and the use of sewage
treatment plants.