Energy Flow in Ecosystems
I. Thermodynamics
A.
„
= the study of energy transfer that occurs in
matter
matter = anything that has mass &
takes up space
The Laws of Thermodynamics
B. The Laws of Thermodynamics
1. First Law of thermodynamics
2. Second Law of thermodynamics
Energy can neither be created
nor destroyed.
destroyed.
Energy transformations lead to an increase
in ENTROPY in a system.
However:
„
It can change form……
..
form……..
Light ->->Heat
II. Energy transformations in an
ecosystem
A. Producers (primary energy sources)
Plants are producers.
producers.
1. E travels via UltraUltra-violet light
from Sun to plants
2. Plants (by photosynthesis)
make own food
to store E
as glucose (sugar)
(E = energy)
Entropy = disorder (chaos)
Order ->->-> Disorder
„ Entropy always increases.
increases.
„
II. Energy transformations in an
ecosystem
B.
Consumer
=
organism
that eats
plants or
other
organisms
to get E
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Energy transformations in an
ecosystem
C. Detrivore
= breaks dead matter into smaller
„
pieces to help recycle it
E.g. worms, maggots, crabs, millipedes
„
Energy transformations in an
ecosystem
Energy transformations in an
ecosystem
D. Decomposer
= agent of decay
Recycles the nutrients in dead bodies
to return them to the
ecosystem
E.g. bacteria,
fungi
Energy Flow
in an
Ecosystem
IV. Energy Loss
Between Trophic Levels
III. Trophic levels
(-troph=
troph= feeder)
Trophic level =
feeding level;
levels of an
ecosystem that E
flows through
Energy pyramid
„
Only 10% 0f E moves from one trophic level to
the next
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∴(therefore) 90% of E is lost to heat for
each trophic level we go up
¿Why does it take so many mice to feed one hawk?
90% E lost each trophic level we go up
V. Food Chains
Food chain =
the path that E takes through the
trophic levels
Note: Food webs are what we really have…
have…
Food Chain Examples
VI. Feeding patterns
pattern
definition
example
VI. Feeding patterns
pattern
definition
example
herbivore
carnivore
omnivore
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VI. Feeding patterns
pattern
definition
example
herbivore
Plant eater
Deer, mouse
carnivore
Meat eater
Lion, dog
omnivore
Eater of plants
& animals
Bear, pig,
human
VI. Feeding patterns
pat
VI. Feeding patterns
pattern
definition
example
Filter feeder
Filters food
from water
Baleen whales,
flamingoes
Detrivore
Eater of dead
organic matter
Decomposer
Breaks dead matter to
the molecular level,
returns nutrients to
the envt.
envt.
Maggots, crabs,
worms,
millipedes
Bacteria, fungi
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