Transcript Energy and Feeding Relationships power point

Energy Transfer in
Ecosystems
Terms to be Familiar with
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Ecosystem
Biotic
Abiotic
Producer
Consumer
Herbivore
Carnivore
Omnivore
Scavenger
Decomposer/Detritovore
Parasite
A step-by-step
sequence linking
organisms that feed
on each other.
A food chain always
begins with
producers (plants).
Arrows are used to
show direction of
energy transfer.
Trophic Levels
• Feeding level
• Producers = 1st trophic level
(most energy available)
Quartenary
consumer
Primary
• Primary consumers feed on
producers (2nd trophic level)
• Secondary consumers feed
on primary consumers (3rd
trophic level)
• Tertiary consumers (4th
trophic level)
Secondary
Tertiary Consumer
Energy Transfer
• The sun provides energy for producers to
grow. Producers use the sun’s energy to:
– Perform photosynthesis –
Transforms Solar E -- Chemical E (glucose)
- Plants use the stored chemical energy to “fuel”
their metabolism.
– (Run chemical reactions which result in Growth,
Make nectar, Active transport)
• This Chemical E is transferred from
producer to consumer when a consumer
eats a plant.
Energy Transfer
• Animals do not store all of the energy they
obtain from a plant. They use it to:
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Move
Pump blood
Digest food
Other Chemical reactions
Most E from food is “burned” to maintain our
body temperature
• Once the energy has been used, it is not
available to be transferred.
• Only ~10% of the energy at each trophic
level gets transferred to the next one.
Energy Transfer
• A food chain is usually limited to 5
trophic levels.
100% of original energy
Sun
2% of original energy
Phytoplankton
0.2% of original energy
Zooplankton
0.02% of original energy
Smelt
(fish)
salmon
0.002% of original energy
humans
Food Webs
• A diagram that shows the
feeding relationship between
organisms in an ecosystem.
• The arrows indicate the
direction of energy transfer.
Source of E -> Recipient
• A food web consists of many
food chains.
• More chains and
interconnections supports a
more stable ecosystem
Keystone Species
• A species that plays a vital role in
stabilizing the ecosystem. Removal of a
keystone species will cause a chain reaction
involving many other species in the
ecosystem.
Wolves of Yellowstone
Wolves of Yellowstone
• Trophic Cascade powerful interactions that
can control entire ecosystems.
• Occur when predators limit the density
(#/area) and/or behavior of their prey and
thereby enhance survival of the next lower
trophic level.
• Effects of the presence/absence of the
keystone species “cascades” down the food
chain
Check your Understanding
• Food Chain Gizmo | ExploreLearning
Try This
• In a forest community, green plants of many types form the
start of the food web as the producers. One small food web
that can be identified is one starting with these green plants that
are eaten by the cankerworm. The cankerworm is eaten by the
red-eyed vireo (a bird). Rabbits also feed from the green
plants, and they are eaten by the bobcats. Both the rabbit and
the bobcat are eaten by lice which live in their fur. These lice
are eaten by the red-eyed vireos in the forest. It has been
noted that both the red-eyed vireos and the rabbits are eaten by
sharp-shinned hawks in the area.