Download Ecosystems

AP Biology
Ecosystems
Studying organisms in their environment
organism
population
community
ecosystem
AP Biology
biosphere
Essential questions
 What limits the production in ecosystems?
 How do nutrients move in the ecosystem?
 How does energy move through the ecosystem?
AP Biology
Ecosystem
 All the organisms in a community plus abiotic
factors

ecosystems are transformers of energy
& processors of matter
 Ecosystems are self-sustaining

what is needed?
 capture energy
 transfer energy
 cycle nutrients
AP Biology
Ecosystem inputs
constant
energy flows
input
of
through
energy
nutrients cycle
Matter
cannot
Don’t forget
laws of or
bethe
created
Physics!
destroyed
AP Biology
nutrients
can only
cycle
biosphere
inputs
 energy
 nutrients
Generalized
Nutrient
cycling
consumers
producers
consumers
decomposers
nutrients
nutrients
ENTER FOOD
CHAIN
made
available
= made available
to producers
to producers
Decomposition
connects all
trophic levels
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return to
abiotic
reservoir
abiotic
reservoir
geologic
processes
Carbon cycle
CO2 in
atmosphere
Diffusion
Respiration
abiotic reservoir:
 CO2 in atmosphere
enter food chain:
Combustion
of fuels =
 photosynthesis
carbon fixation in
Industry and home
Calvin cycle
Photosynthesis recycle:

return to abiotic:
 respiration
Plants
 combustion
Animals
Dissolved CO2
Bicarbonates
Photosynthesis
Animals
Plants and algae
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Carbonates in sediment
Deposition of
dead material
Deposition
of dead
material
Fossil fuels
(oil, gas, coal)
Nitrogen cycle
Carnivores
abiotic reservoir:
 N in atmosphere
enter food chain:
 nitrogen fixation by
soil & aquatic bacteria
recycle:
Herbivores
 decomposing &
nitrifying bacteria
return to abiotic:
 denitrifying bacteria
Birds
Plankton with
nitrogen-fixing
bacteria
Atmospheric
nitrogen
Plants
Death, excretion, feces
Fish
excretion
Decomposing bacteria
amino acids
Ammonifying bacteria
loss to deep sediments
Nitrogen-fixing
bacteria
(plant roots)
Nitrogen-fixing
bacteria
(soil)
Nitrifying bacteria
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soil nitrates
Denitrifying
bacteria
Phosphorus cycle
Plants
Land
animals
Soluble soil
phosphate
Loss in
drainage
fungi)
Rocks and
minerals
Decomposers Phosphates
(bacteria & fungi) in solution
Animal tissue
and feces
abiotic reservoir:
 rocks, minerals, soil
enter food chain:
 erosion releases
soluble phosphate
 uptake by plants
recycle:
 decomposing bacteria
Animal
tissue
&
fungi
Urine and feces
return to abiotic:
 loss toDecomposers
ocean
(bacteria and
sediment
Aquatic
animals
Plants and
algae
Precipitates
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Loss to deep sediment
abiotic reservoir:
 surface & atmospheric
water
enter food chain:
 precipitation & plant
uptake
Solar energy
recycle:
 transpiration
return to abiotic:
Evaporation
 evaporation & runoff
Water cycle
Transpiration
Water vapor
Precipitation
Oceans
Runoff
Lakes
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Percolation in soil
Groundwater
Aquifer
Transpiration
Remember
transpiration?
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Breaking the water cycle
 Deforestation breaks the water cycle

groundwater is not transpired to the
atmosphere, so precipitation is not
created
forest  desert
desertification
AP Biology
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Repairing the damage
 The Greenbelt Movement




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planting trees in Kenya
restoring a sustainable ecosystem
establishing democracy
empowering women
Wangari Maathai
Nobel Peace prize 2004
Studying ecosystems
Hubbard Brook
Experimental Forest
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7800 acres
38 acre deforestation
Effects of deforestation
40% increase in runoff

loss of water
 60x loss in nitrogen
 10x loss in calcium
loss into
surface water
Concentration
of nitrate (mg/l )
80 nitrate levels in runoff
AP Biology
40
loss out of
ecosystem!
4
Deforestation
2
Why is
0
nitrogen
1965 so
important?
1966
1967
Year
1968
Ecosystem inputs
energy flows
through
nutrients cycle
AP Biology
biosphere
inputs
 energy
 nutrients
Energy flows through ecosystems
sun
secondary
consumers
(carnivores)
primary consumers
(herbivores)
producers (plants)
AP Biology
loss of
energy
loss of
energy
Food chains
 Trophic levels
feeding relationships
 start with energy from
the sun
 captured by plants



1st
sun
top carnivore
Level 3
Secondary consumer
carnivore
Level 2
Primary consumer
heterotrophs
herbivore
level of all food chains
food chains usually go Level 1
Producer
up only 4 or 5 levels
 inefficiency of energy
transfer

Level 4
Tertiary consumer
all levels connect to
decomposers
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autotrophs
Decomposers
Bacteria
Fungi
sun
Inefficiency of energy transfer
 Loss of energy between levels of food
chain

To where is the energy lost? The cost of living!
17%
growth
only this energy
moves on to the
next level in
the food chain
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energy lost to
daily living
33%
cellular
respiration
50%
waste (feces)
sun
Ecological pyramid
 Loss of energy between levels of food
chain

can feed fewer animals in each level
1
100
100,000
1,000,000,000
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Humans in food chains
 Dynamics of energy through ecosystems have
important implications for human populations
 how much energy does it take to feed a human?
 if we are meat eaters?
 if we are vegetarian?
What is your
ecological
footprint?!
AP Biology
Food webs
 Food chains are

linked together into
food webs
Who eats whom?

a species may
weave into web at
more than one level
 bears
 humans
 eating meat?
 eating plants?
AP Biology
Any
Questions??
We’re working
on a lot
of them!
AP Biology
2006-2007