Chapter 55. 1. I can explain how energy regulates the amount and sizes of trophic levels. 1. I can describe the fundamental relationship between autotrophs,

Ecosystems & Restoration Ecology

Chapter 55

1. I can explain how energy regulates the amount and sizes of trophic levels.1. I can describe the fundamental relationship between autotrophs, heterotrophs and decomposers in an

ecosystem.2. I can explain how decomposition connects all trophic levels in an ecosystem.3. I can explain why the amount of energy used in photosynthesis is so much less than the amount of solar

energy that reaches the Earth.4. I can summarize the 10% rule.5. I can explain why worldwide agriculture could feed more people if all humans consumed only plant

material.

2. I can explain how limiting factors affect ecosystem dynamics. 1. I can explain how nitrogen and phosphorous limit the structure of an ecosystem.2. I can explain how cultural eutrophication can alter freshwater ecosystems.3. I can explain how it is that eutrophic bodies of water are both nutrient rich and oxygen poor.4. I can use my understanding of photosynthesis to explain how light limits ecosystems.

3. I can explain how primary productivity impacts the ecosystem structure.1. I can describe how to calculate gross and net productivity.2. I can compare gross to net productivity3. I can explain the influence of cellular respiration on net productivity.4. I can design a lab that measures gross and net productivity.

4. I can explain how nutrients cycle through an ecosystem.1. I can describe how water, nitrogen, carbon, and phosphorous cycle.2. I can identify the reservoirs of nitrogen, phosphorous and carbon.3. I can describe how living organisms assimilate and release the different nutrients in each cycle.4. I can explain the role of bacteria in the nitrogen cycle.5. I can explain how the phosphorous cycle is local.

5. I can describe the role of photosynthesis, and cellular respiration in the carbon cycle.

Learning Targets

Trophic efficiencies:10% rule◦ Generally, only 10% of

energy is transferred between trophic levels

◦ Remaining 90% is lost as heat from metabolism

Energy in Ecosystems




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Learning Targets

If there is not enough of a resource available, the organisms in the ecosystem are impacted◦ Nitrogen, phosphorus deficiencies◦ Used by plants in photosynthesis◦ Reduced PS = reduced plants = reduced animals

If there is too much of a resource available, the organisms in the ecosystem are impacted◦ Eutrophication – addition of sewage, fertilizer run

off to aquatic ecosystems◦ Boom in algae, cyanobacteria = less dissolved

oxygen for other organisms (fish) = death of fish

Limiting Factors




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Learning Targets

Key Terms

Primary productivity

Gross Primary Productivity

Net Primary Productivity

Rate at which plants convert sunlight energy into chemical energy

Rate at which plant produces organic material through photosynthesis

Net gain of dried mass stored in plant after respiration

MUST KNOW….

Net = gross - respiratory

Production production losses

NPP = GPP - R




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Learning Targets

Biogeochemical Cycles of Matter

Biotic factors are made up of matter (CHNOPS)

This matter cycles in our biosphere

4 Cycles Water cycle Carbon cycle Nitrogen cycle Phosphorus cycle Nicely reviewed on pages 1228-1229!

Water cycle

Key processes:◦ Transpiration

Evaporative loss of water through leaves

◦ Condensation Water vapor forms

clouds◦ Precipitation

Returns water to land

Carbon Cycle

Key processes:◦ Photosynthesis

Removes atmospheric CO2

◦ Cellular respiration Returns CO2 to

atmosphere◦ Burning of fossil fuels

Adds significant CO2 to atmosphere

Nitrogen Cycle Key processes:

◦ Nitrogen fixation Conversion of atmospheric

N2 to usable forms by bacteria

◦ Ammonification Decomposes organic

nitrogen to NH4+

◦ Nitrification NH4

+ is converted to NO3-

by nitrifying bacteria◦ Denitrification

Anaerobic bacteria convert NO3

- to N2

Phoshorus Cycle

Key processes:◦ Weathering of

rocks Adds phosphorus

to soil◦ Uptake by

producers◦ Producers eaten

by consumers◦ Decomposers

return phosphorus to soil




material.





Learning Targets

Documents

Chapter 55. 1. I can explain how energy regulates the amount and sizes of trophic levels. 1. I can describe the fundamental relationship between autotrophs,