Download Ecology Notes 2

Ecology Notes 2
The sun is the ultimate
source of energy
Autotrophs (producers) trap the sun’s
 _________
photosynthesis – the
energy to carry out _____________
changing of energy to sugar
 Other autotrophs use chemosynthesis to
make organic molecules from chemicals
Heterotrophs (consumers) feed upon
 __________
producers and each other and transfer
the stored energy
What is a food chain?
 This is the transfer of materials and potential
energy from organism to organism
grass
mouse
**a food chain
always begins with
a producer!!
snake
owl
decomposer
(bacteria)
What is a food web?
 Interacting
food chains
What is a trophic level?
3rd order
consumers

A feeding step in
the passage of
energy and
materials
1. 4th level
2. 3rd level
3. 2nd level
4. 1st level
5. Decomposer
Video clip
2nd order
consumers
1st order
consumers
producers
1. 1st trophic level
 autotrophs – trap
sun’s energy
3rd order
consumers
2nd order
consumers
1st order
consumers
autotrophs
2. 2nd trophic level
 first order
consumers
feed on producers
3rd order
consumers
2nd order
consumers
1st order
consumers
producers
3rd trophic level
 Second order consumer
– feed on 1st order
consumers
3rd order
consumers
2nd order
consumers
1st order
consumers
producers
4. 4th trophic level
 third order consumer
– feed on 2nd order
consumers
3rd order
consumers
2nd order
consumers
1st order
consumers
producers
5. Decomposers (aka
saprophyte) & Scavengers
 Found at all trophic
levels!
 Ex- earthworms,
mites, crabs,
vultures, fungi,
bacteria
Ecological Pyramids
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this
energy for
life processes.
The rest is lost
as heat.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.
Nutrient Cycles
 Nutrients, like water, carbon,
phosphorus, and nitrogen are cycled
between organisms and the environment.
Video clip: water cycle on Internet
The Water Cycle
Condensation
Precipitation
Evaporation
Transpiration
Runoff
Seepage
Root
Uptake
The Carbon Cycle: carbon is found in all living things
6CO2 + 6H2O  6CO2 + C6H12O6
CO2 in
Atmosphere
CO2 in Ocean
Video clip
The Nitrogen Cycle: nitrogen is used to make amino acids &
proteins. It must be “fixed” by bacteria before we can use it.
N2 in Atmosphere
NH3
NO3and NO2-
Video clip
The Phosphorus Cycle
 Important in making DNA & RNA
 Not very common in the biosphere
 Can be found in small quantities in water and
on land, but not in the air
 Phosphorus is often a limiting nutrient,
meaning that the growth of organisms is limited
by how much phosphorus is available. (That’s
why we use fertilizers).
 If a pond suddenly receives an excess of the
limiting reagent (pollution, runoff…), it can
cause algal blooms (bad for environment).