Trophic Level Diagrams
MS / Science
Balance, Cycle, Ecology, Energy, Relationships,
Transference
(Students have a very basic understanding of trophic levels, including producers,
consumers, and decomposers.)
Start by doing a 4-corner rotation: Sun, Producers, Consumers, Decomposers.
Ask students, “What role do you feel you understand best in relation to trophic levels?”,
and have them choose a corner. There, they turn and talk, explaining to their partners
one thing they understand. Students should be listening for new ideas and
understanding.
Then ask, “What role do you feel you understand least in relation to trophic levels?”
Students choose a corner. There, they turn and talk, sharing a question or point of
uncertainty. The partners listen not to give an answer, but to name the confusion or
uncertainty. (Questions are celebrated!) The partners paraphrase back what they heard,
and then roles proceed in turn.
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Students return to their seats and write:
 a fact they know about trophic levels that shows understanding;
 a question that they hope to refine and then answer by the end of the seminar
cycle.
Distribute both diagrams.Have students examine them and label the Pyramid diagram
‘A’; the Sun diagram ‘B’. Ask what they expect studying these texts to be like. What will
make them easy to approach, as well as (for some) perhaps a challenge?
Mark the text in quadrants 1, 2, 3, 4 for reference.
The trophic level of an organism is the position it occupies in a food chain. The word
trophic comes from the Greek (trophē) referring to food or feeding. A food chain
represents a succession of organisms that eat another organism and are, in turn, eaten
themselves. The number of steps an organism is from the start of the chain is a
measure of its trophic level. Food chains start at trophic level 1 with primary producers
such as plants, move to herbivores at level 2, predators at level 3 and typically finish
with carnivores or apex predators at level 4 or 5. The path along the chain can form
either a one-way flow or a food "web". Ecological communities with higher biodiversity
form more complex trophic paths.
Retrieved from Wikipedia, March 2015: http://en.wikipedia.org/wiki/Trophic_level
Provide (or mine participants for) definitions for the following: solar energy, carnivore,
herbivore, tertiary, primary, secondary, detritivores
Study both diagrams. Add commentary that helps describe relationships and/or
connections between what is happening between the different trophic levels. Ask
students to find two relationships that they really understand and mark them with
commentary and an asterisk (*). Have them find two relationships or sections in the
diagrams that leave them with puzzlement or wonder, and mark those with commentary
and a question mark (?). These annotations will help in the Post-Seminar writing.
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 What could be another name or title for these diagrams? (round-robin
response)
 Explain your thinking. (spontaneous discussion)
 Are food webs more about balance, organization, importance—or
something else?
 Where might someone look first at these diagrams? What order or lack of
order do you see in the diagrams?
 What part does the sun play in understanding the different trophic levels of
a food web?
 What are some relationships or connections represented in the texts that
may be overlooked or underappreciated by middle-school students?
 What is most important to remember in order to further understand food
webs and trophic levels?
 How should understanding food webs and trophic levels impact how
humans live?
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Remind students of the Launch Activity. Ask whether any progress was made toward a
deeper understanding of what they knew; and whether they any closer to answering the
question they constructed. Utilize personal reflection (have students write down new
thoughts immediately following seminar) as well as small and whole-group sharing.
Consider your audience to be younger students who have not yet studied trophic levels,
and their teachers as they prepare students for this unit.
After reading and discussing trophic levels, including a closer look at both diagrams,
write a short essay in which you:
a) Define trophic levels in a new way; and
b) Explain several important relationships you see within trophic levels.
Support your paragraphs with evidence from the texts.
(Informational & Explanatory/Description)
(LDC Task#:
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Review students’ annotations from the Analytical Read as well as the writing
immediately following seminar. Use these notes in addition to classroom discussion to
support the writing.
Allow a few minutes for all to revisit the text (diagrams), draft an outline/web for their
writing, and refine their thinking. Have students use an organizational template as
needed. A four-paragraph essay may work best for most: An opening, a body that
explains trophic levels and highlights relationships with example(s), and a closing.
(Make sure the writing task is visible for all.)
Challenge all to draft their essays by writing the paragraphs defined by their
outlines/webs. Refer to the texts in order to illustrate key points. Encourage several
references to the text.
Have participants work in pairs to read their first drafts aloud with emphasis on reader
as creator and editor. The reader should make a special note to signify to the listener
the definition of trophic levels and the relationships highlighted, with corresponding
support selected from the text. The listener should say back one point heard clearly,
how it is supported by the text, and ask one question for clarification. Roles are then
switched. Give time for full revisions resulting in a second draft.
Once the second draft is complete, have participants work in groups of three-four and
this time take turns reading each other’s second drafts slowly and silently, marking
spelling or grammar errors they find, with a limit of 5-per page. (Have dictionaries and
grammar handbooks available for reference, as well as these directions for editing.)
Take this opportunity to clarify/reteach any specific grammar strategies you have
identified your students needing. Give time for full revisions and editing, resulting in a
third and final draft.
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Students should deliver the essays to teachers of science in the previous grade,
encouraging those adults to share general feedback by way of a visit or email, as time
permits.
Kelly Foster
National Paideia Center
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Both Images Retrieved March 2015; this page from: http://pixshark.com/trophic-levels.htm
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