Transcript 2010: Ecology- Energy Flow

Energy Flow
Laws of
Thermodynamics…
• 1. Energy is neither
created or destroyed,
only transferred
• 2. With every transfer,
some energy is lost to
HEAT (or other less
available form of
energy)
BIOTIC COMPONENTS of an
ECOSYSTEM
PRODUCERS
(produce food)
Chemoautotrophs- bacteria
that use inorganic chemicals
like ammonia, nitrites, sulfides
to make food)
Photoautotrophs-use energy
from the sun…produce most of
the organic nutrients for the
biosphere
CONSUMERS
DECOMPOSERS
(consume food)
Need a preformed souce of
organic nutrients
(Break down dead organic matter)
VALUABLE- release inorganic
nutrients for plants to take up
Consumers can be :
Primary/Secondary/
Tertiary
(See next)
Ex- nonphotosynthetic
bacteria, fungi
DETRITUS=
partially decomposed
matter in the water or
soil
What does
each arrow
represent?
Kinds of Consumers
•
level
• Secondary/ 2nd level
• Tertiary/ 3rd level
st
Primary/1
FOOD CHAINS
• Show how matter and
energy move through
an ecosystem
All food is NOT created equal…
• TROPHIC LEVELS: All the organisms that
feed at a particular link in a food chain
• 10% rule: In general only about 10% of
the energy from one trophic level is
available to the next!!!
A weakness in the chain…
• Food chains can only have up to about 5
links
• Animals at the end of the chain wouldn’t
get enough nutrients and energy.
• Most animals are part of more than one
food chain
• This creates…
FOOD WEBS!
• Interconnected food chains. They express
all the possible feeding relationships at
each trophic level in a community.
• Arrows are drawn from food source to
consumers (substitute “eaten by” for
arrows)
Which of the following organisms
are producers?
6
7
1
8
2
5
0%
9
0%
0
0%
9
0%
8
0%
7
0%
6
0%
5
0%
4
0%
3
0%
2
1
2
3
4
5
6
7
8
9
0
1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
4
3
10
Which of the following organisms
are consumers?
6 6
7
1 1
7
8
2 2
5
5
9
0%
0%
4
0
0%
9
0%
8
0%
7
0%
6
0%
5
0%
4
0%
3
0%
2
1
2
3
4
5
6
7
8
9
0
1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
3 3
4
10 0
Which of these are primary
consumers?
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
1
2
3
4
5
6
7
8
9
0
6
7
1
8
2
5
9
4
3
10
Biomass Pyramid
• The total amount of living material present
in each trophic level (a feeding step in a
food chain).
NOTE: are there
more autotrophs
or heterotrophs?
WHY?
Pyramid of Numbers
Each bar in the
pyramid represents the
size of the population
at that trophic level
Pyramids of Energy
• Each bar in the
pyramid represents
the energy
available within that
trophic level
• Remember the
10% rule!!!