Download Food_Energy_through_Ecosystems

Energy Flow in
an Ecosystem
1
Energy Flow
• Energy in an ecosystem originally
comes from the sun
• Energy flows through Ecosystems
from producers to consumers
– Producers (make food)
– Consumers (use food by eating
producers or other consumers)
2
Producers
• Sunlight is the main
source of energy
for most life on
earth.
• Producers contain
chlorophyll & can
use energy directly
from the sun
3
Autotrophs
• An Autotroph is any organism
that can produce its own food
supply!
• Autotrophs are also called
Producers
• Plants, algae, some protists, &
some bacteria are examples
4
Niche of a Producer
• Captures energy and transforms
it into organic, stored energy for
the use of living organisms.
• May be photoautotrophs using
light energy (e.g. plants)
• May be chemoautotrophs using
chemical energy (e.g.
cyanobacteria)
5
Photoautotroph
Producer That Captures Energy
from the sun by:
– Photosynthesis
• Adds Oxygen to the
atmosphere
• Removes Carbon Dioxide from
the Atmosphere
Algae
6
Habitat of Photoautotrophs
• On Land
– Plants
• In The Sea
– Algae
• Tidal Flats & Salt Marshes
– Cyanobacteria
7
Chemoautotrophs
• Capture energy from
the bonds of inorganic
molecules such as
Hydrogen Sulfide
• Process is called
Chemosynthesis
• Often occurs in deep
sea vents or gut of
animals
Called a Black
smoker (thermal
vent)
8
Tube Worms living in Black
Smoker
9
Consumers
Heterotrophs eat other organisms
to obtain energy. (e.g. animals)
• Herbivores
– Eat Only Plants
– 1st Order or Primary Consumer
• Carnivores
– Eat Only Other Animals
– 2nd Order or Secondary
Consumer
– Could also be a 3rd Order or
Tertiary Consumer
10
Consumers
Heterotrophs eat other organisms
to obtain energy.
• Omnivores (Humans)
– Eat Plants & Animals
• Detritivores (Scavengers)
– Feed On Dead Plant & Animal
Remains (buzzards)
• Decomposers
– Fungi & Bacteria
11
Energy Transfer
Most
of the energy the primary consumer
gets from the producer is used by the
consumer.
Some of the energy moves into the atmosphere
as heat.
Some energy in the primary consumer is
STORED & not lost to the atmosphere or used
by the consumer itself. This energy is available
for another consumer (predator).
12
Energy Transfer
Most of the energy the secondary
consumer gets from the primary
consumer is used by the secondary
consumer.
Some of the energy is lost as heat,
but some energy is stored and can
be passed on to another consumer.
13
Feeding Relationships
Energy flows
through an
ecosystem in
one direction
from producers
to various
levels of
consumers
14
Feeding Relationships
• Food Chain
– Simple Energy path through an
ecosystem
• Food Web
– More realistic path through an
ecosystem made of many food
chains
15
Food Chain
1st
order
Consumer
2nd Order
Consumer
3rd
Order
consumer
4th Order
Consumer
Producer (trapped
sunlight & stored food)
16
Name the Producer, Consumers
& Decomposers in this food
chain:
17
18
Food Web
19
20
How Many Chains are in
this web?
21
Identify the Producers, Consumers,
& Decomposers:
Count
the
Food
Chains!
22
Trophic Levels
Each Level In A Food Chain or Food
Web is a Trophic Level.
• Producers
– Always The First Trophic Level
– How Energy Enters The System
• Herbivores
– Second Trophic Level
23
Trophic Levels
• Carnivores/Omnivores
– Make Up The Remaining
Trophic Levels
Each level depends on the
one below it for energy.
24
Ecological Pyramids
Graphic Representations Of The
Relative Amounts of Energy or
Matter At Each Trophic Level
May be:
Energy Pyramid
Biomass Pyramid
Pyramid of Numbers
25
Energy Pyramid
How much energy is used, stored and/or given
off at each level?
26
Biomass Pyramid
What can you determine from the biomass
pyramid?
27
Energy Pyramids Show
•Amount of available energy
decreases for higher consumers
•Amount of available energy
decreases down the food chain
•It takes a large number of
producers to support a small number
of primary consumers
•It takes a large number of primary
consumers to support a small number
of secondary consumers
28
Pyramid of Numbers
At each level, what happens to the number of
organisms?
29