Succession Review
Answer Key
1. Draw a picture of primary succession. Tell
what types of plants/trees are in each stage.
Tell whether each stage has pioneer,
intermediate, and/or climax community.
2. You have inherited a fifty-acre abandoned farm field from a tree
hugging back-to-nature woman who insists that the property be
maintained in such a way that it will revert to the condition it
was in prior to human intervention.
A. How would the property move through the stages of
succession?
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Follow the pattern of secondary or old field
succession.
Grasses would first overtake the plowed land.
Shrubs would start to come in, and eventually
take over the grass.
Shrubs would then be replaced by softwood trees
that favor sunlight, like pines and cedars.
Eventually hardwood trees would take over, like
maples and oaks, forming a climax community.
2. You have inherited a fifty-acre abandoned farm field from a tree
hugging back-to-nature woman who insists that the property be
maintained in such a way that it will revert to the condition it
was in prior to human intervention.
B. How would you protect the area from the modern problems
that would affect it? Consider nonnative species and other
factors that did not exist prior to human intervention.
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Refrain from planting ornamental plants, allowing
the native species more space to thrive
Clean up trash and food around the area to
preserve the natural habitats and eating patterns
of the wildlife.
Prevent deer from eating the saplings
Remove invasive plants
3. What are two ways that you can recognize if
a species is a dominant species in a
community?
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How much ground it covers (Ex. Trunks of trees)
How much light it captures (Ex. Leaves of trees)
4. Explain how the BHT, frequency, and abundance can help
you figure out what stage of succession the community is in.
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The BHT will tell you which species is dominant,
and the frequency and abundance will give you
an idea of how many of the different types of
trees there are.
• For example:
• If softwood trees are more abundant and
dominant, you can tell that the forest is at an
intermediate stage.
• The presence of young hardwood trees (low
BHT) tells you that the forest is transitioning
into a climax community.
5. Which type of succession would occur
faster… primary or secondary? Give reasons
to support your answer.
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Secondary succession will occur faster.
Soil or bottom sediment is already in place from
an earlier existing ecosystem (possibly destroyed
by a fire or flood).
Seeds of earlier plants might still exist in the soil
and can quickly grow into new plants, given
enough water and sunlight.
6. A forest fire just wiped out our plot next to
the Timberlane tennis courts. What are two
positive scenarios that could come out of this?
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Increased levels of biodiversity if the plants are
allowed to grow back naturally
More stable environment because of the
increased biodiversity.
7. Which stage of succession demonstrates the
most stability? Explain your reasoning.
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The climax community demonstrates the most
stability.
These stage of succession has the greatest
variety of living things.
If some organisms are affected by disease (or
some other condition), it will have less of an
impact on the ecosystem as a whole because
there are other organisms there to help fulfill the
role of the afflicted organisms.
8. Name three abiotic factors that play a role in
forest succession, and describe their possible
effects.
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Sunlight: Plants have varying tolerances for
shade. As succession progresses, there is more
shade from the larger plants, and so the smaller
grasses and weeds that need sunlight tend to die
off.
Space: As larger plants move into an area, there
is physically less space for the smaller plants to
grow and develop.
Nutrients: The amount and type of nutrients
available changes with the different types of
plants.
9. Describe how wildlife can also change with
the stages of succession.
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Plants determine the types of wildlife you will
see in an area.
Certain types of herbivores eat certain types of
plants, so they will go where the food is.
Certain types of plants provide shelter for
different types of animals as well.
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Ex. Squirrels live in trees and eat nuts. You will only
find them in mature forests where they find their
preferred shelter and food.
10. Are the Timberlane and Hopewell woods in
the same stage of succession?
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Timberlane has more softwood trees that are
indicative of earlier succession.
11. Why is only 10% of the energy passed on from
one trophic level to the next?
• Energy is lost to respiration
• Energy is lost to build the body
• Not all of the prey is consumed
12. Why is an ecosystem more sensitive to
disruption from the top than it is from the bottom?
• The top has more diversity
13. How do detritivores fit into the ecosystem?
• They recycle material- not energy
• They are essential in a forest, almost all of the
nutrients are in the biomass and need to be
processed back into the soil.