Ecosystems
Organisms that use inorganic nutrients
and an outside energy source to produce
sugars and other organic nutrients for
themselves and other members of the
community are _____.
A) autotrophs
B) producers
C) heterotrophs
D) both A and B
Organisms are classified into trophic
levels according to _____.
A) where they live
B) the source of their nutrients
C) how much they weigh
D) all of the above
Essential questions
What limits the production in ecosystems?
How do nutrients move in the ecosystem?
How does energy move through the ecosystem?
Inorganic nutrients are released from
dead organic matter and animal wastes
by _____.
A) decomposers
B) secondary consumers
C) producers
D) autotrophs
Energy _____ an ecosystem.
A) flows through
B) cycles within
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
In a balanced ecosystem you would
expect the see the biomass of the
_____ to be greater than the biomass
of any other groups of organisms.
A) producers
B) primary consumers
C) secondary consumers
D) top predators
Ecosystem inputs
constant
energy flows
input
of
through
energy
nutrients cycle
Matter
cannot
Don’t forget
laws of or
bethe
created
Physics!
destroyed
nutrients
can only
cycle
biosphere
inputs
 energy
 nutrients
1.Which level of the energy pyramid below
would contain the plant species of this salt
marsh?
Carbon dioxide enters the carbon cycle
of an ecosystem through which group of
organisms?
A. Decomposers
B. Detritus feeders
C. Producers
D. Secondary consumers
As nutrients cycle through an
ecosystem inorganic nutrients are
returned to autotrophs by _____.
A) producers
B) primary consumers
C) top predators
D) detritivores
Nitrogen is needed to produce _____.
A) amino acids
B) nucleic acids
C) both A and B
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
return to
abiotic
reservoir
abiotic
reservoir
geologic
processes
Which of the following activities would
help to reduce global warming?
A. Using gasoline as a fuel in cars
B. Using coal to generate electricity
C. Planting trees
D. Raising livestock for food
An example of a detritus feeder is
_____.
A) a diatom
B) a photosynthetic bacterium
C) an earthworm
D) an elk
Eutrophication _____.
A) is caused by runoff of nitrogen
and phosphorous
B) causes algal blooms
C) results in massive fish kills
D) all of the above
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
Carbonates in sediment
Deposition of
dead material
Deposition
of dead
material
Fossil fuels
(oil, gas, coal)
1.Which processes indicated on the carbon
cycle below will contribute towards increased
global warming?
Can have
more than
one answer.
Which of the following nutrients can be
a limiting nutrient because of plants'
inability to use its gaseous form?
A) nitrogen
B) phosphorous
C) hydrogen
D) carbon
The conversion of nitrate to nitrous
oxide and nitrogen gas is called _____.
A) denitrification
B) nitrification
C) nitrogen fixation
Use of agricultural fertilizers adds
excess _____ to ecosystems.
A) phosphorous
B) nitrogen
C) both A and B
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
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
Loss to deep sediment
The evaporation of water from plants is
called ____.
A) respiration
B) distillation
C) transpiration
D) fermentation
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
Percolation in soil
Groundwater
Aquifer
Transpiration
Remember
transpiration?
Which of the following activities would
help to reduce global warming?
A. Using gasoline as a fuel in cars
B. Using coal to generate electricity
C. Planting trees
D. Raising livestock for food
Breaking The Water Cycle
Deforestation breaks the water cycle
groundwater is not transpired to
the atmosphere, so precipitation is
not created
forest  desert
desertification
Repairing the Damage
The Greenbelt Movement
planting trees in Kenya
restoring a sustainable ecosystem
establishing democracy
empowering women
Wangari Maathai
Nobel Peace prize 2004
Studying Ecosystems
Hubbard Brook
Experimental Forest
7800 acres
38 acre deforestation
Effects of Deforestation
40% increase in runoff
loss of water
loss into
surface water
80 nitrate levels in runoff
Concentration
of nitrate (mg/l )

 60x loss in nitrogen
 10x loss in calcium
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
biosphere
inputs
 energy
 nutrients
Energy Flows Through Ecosystems
sun
secondary
consumers
(carnivores)
primary consumers
(herbivores)
producers (plants)
loss of
energy
loss of
energy
Food chains
Level 4
Tertiary consumer
top carnivore
Trophic levels
Level 3
feeding relationships
Secondary consumer
start with energy from
carnivore
the sun
Level 2
captured by plants
Primary consumer
1st level of all food
heterotrophs
herbivore
chains
1
food chains usually go LevelProducer
up only 4 or 5 levels
inefficiency of energy
autotrophs
transfer
all levels connect to
Decomposers
decomposers
Bacteria
sun
Fungi
Inefficiency of Energy Transfer
sun
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
energy lost to
daily living
33%
cellular
respiration
50%
waste (feces)
Ecological Pyramid
sun
Loss of energy between levels of food chain
can feed fewer animals in each level
1
100
100,000
1,000,000,000
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?!
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?
Any
Questions??
We’re working
on a lot
of them!
2006-2007