Download 13.3 Energy in Ecosystems - Biology with Ms. Murillo

13.3
Energy in Ecosystems
The student is expected to:
11C summarize the role of
microorganisms in both maintaining
and disrupting the health of both
organisms and ecosystems
and
12C analyze the flow of matter and
energy through trophic levels using
various models, including food chains,
food webs, and ecological pyramids
TEKS 11C, 12C
13.3
Energy in Ecosystems
TEKS 11C, 12C
KEY CONCEPT
Life in an ecosystem requires a source of energy.
13.3
Energy in Ecosystems
TEKS 11C, 12C
Producers provide energy for other organisms in an
ecosystem.
• Producers get their energy from non-living resources.
• Producers are also called autotrophs because they make
their own food.
13.3
Energy in Ecosystems
TEKS 11C, 12C
Producers provide energy for other organisms in an
ecosystem.
• Consumers are organisms that get their energy by eating
other living or once-living resources.
• Consumers are also called heterotrophs because they feed
off of different things.
13.3
Energy in Ecosystems
TEKS 11C, 12C
Almost all producers obtain energy from sunlight.
• Photosynthesis in most producers uses sunlight as an
energy source.
• Chemosynthesis in prokaryote producers uses chemicals
as an energy source.
carbon dioxide + water +
hydrogen sulfide + oxygen
sugar + sulfuric acid
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
The student is expected to:
11C summarize the role of microorganisms in
both maintaining and disrupting the health of
both organisms and ecosystems
and
12C analyze the flow of matter and energy
through trophic levels using various models,
including food chains, food webs, and
ecological pyramids
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
KEY CONCEPT
Food chains and food webs model the flow of energy
in an ecosystem.
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
A food chain is a model that shows a sequence of feeding
relationships.
• A food chain links species by their feeding relationships.
• A food chain follows the connection between one producer
and a single chain of consumers within an ecosystem.
GRAMA GRASS
DESERT COTTONTAIL
HARRIS’S HAWK
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
• Consumers are not all alike.
– Herbivores eat only plants.
– Carnivores eat only animals.
– Omnivores eat both plants and animals.
– Detritivores eat dead organic matter.
– Decomposers are detritivores that break down organic
matter into simpler compounds.
carnivore
decomposer
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
• Specialists are consumers that primarily eat one specific
organism or a very small number of organisms.
• Generalists are consumers that have a varying diet.
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
• Trophic levels are the nourishment levels in a food chain.
– Primary consumers are herbivores that eat producers.
– Secondary consumers are carnivores that eat
herbivores.
– Tertiary consumers are carnivores that eat secondary
consumers.
– Omnivores, such as humans that eat both plants and
animals, may be listed at different trophic levels in
different food chains.
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
A food web shows a complex network of feeding
relationships.
• An organism may have multiple feeding relationships in an
ecosystem.
• A food web emphasizes complicated feeding relationships
and energy flow in an ecosystem.
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
What is the significance of arrows in a food chain?
They show the direction of the energy flow
producer
consumer 1
consumer 2
consumer 3
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
If all of the snakes in this chain died, what would
happen to the hawk?
•They would have to find a new food supply,
such as the mouse or they would not be able to
survive
decomposer
producer
consumer 1
consumer 2
consumer 3
13.4 Food Chains And Food Webs
TEKS 11C, 12,C
If all of the mice in this chain died, what would happen
to the web?
•The web would become unsustainable as a
vital part of it would be missing.
decomposer
producer
consumer 1
consumer 2
consumer 3
Ecological
Pyramids
Ecological Pyramids
• Instead of
representing
trophic levels in a
food web, an
ecological
pyramid can be
used.
Hawk
(1 kcal)
5
4
Snake (10 kcal)
Frog (100 kcal)
3
Grasshopper (1,000 kcal)
2
Grass (10,000 kcal)
1
Ecological Pyramids
• Does this pyramid represent a food chain
or web?
Hawk
(1 kcal)
• A chain,
because there is
only one
organism at
each level
5
4
Snake (10 kcal)
Frog (100 kcal)
3
Grasshopper (1,000 kcal)
2
Grass (10,000 kcal)
1
Pyramid of Energy
Pyramids of energy
show the relative
amount of energy
available at each trophic
level of a food chain or
food web.
kcal = kilocalories
Hawk
(1 kcal)
5
4
Snake (10 kcal)
Frog (100 kcal)
3
Grasshopper (1,000 kcal)
2
Grass (10,000 kcal)
1
Pyramid of Energy
• What happens to the energy as you go up
the pyramid?
• It decreases as it is either lost
as heat energy or used in
metabolism
• Only about 10 percent
of energy is passed on
to the next trophic
level.
4
Hawk
(1 kcal)
5
Snake (10 kcal)
Frog (100 kcal)
3
Grasshopper (1,000 kcal)
2
Grass (10,000 kcal)
1
Pyramid of Biomass
Pyramid of Biomass represents the
relative amount of
living organic matter
available at each
trophic level
Pyramid of Numbers
Pyramids of
Numbers show the
relative number of
individual
organisms at each
trophic level.
Ecological Pyramids
Correctly label each pyramid shown at
the top of the pyramid section.