Principles of Ecology, Guangxi University, College of Forestry
Final exam, May 16, 2015
Your name in Chinese
Your name in Pinyin
Score:
I) Species interactions
___________(of 14)
II) Introduction to communities
___________(of 12)
III) How and why species diversity varies.
___________(of 21)
IV) Introduction to ecosystems
___________(of 13)
V) Nutrient cycling and environmental crises
___________(of 9)
VI) Conservation biology and landscape ecology
___________(of 10)
VII)
Course-wide subjects
___________(of 9)
VIII)
Essay on primary readings
___________(of 12)
TOTAL
____________ (of 100)
Principles of Ecology
Your name in Chinese Characters_________________
Final Exam May, 2015, p. 2
Your name in Pinyin________________
I) Species interactions
1) Fill in the blank: Competition is a __-/-_____ interaction. Predator/prey is a _____+/-_____
interaction. Commensalism is a ____+/0____ interaction. Mutualism is a ____+/+_______
interaction.
Choose from: +/-, +/0, +/+, -/-, -/0. (8 points)
2) Give an example of a (a) a commensalism and (b) an obligatory mutualism. One sentence for
each. (6 points)
Commensalism: a person who seeks shade under a tree. There’s no effect on the tree.
Obligatory mutualism: coral and zooxanthellae, figs and fig wasps or more generally flowers and
pollinators. Obligatory means neither partner can live without the other.
II) Introduction to communities
3) Look at the following species accumulation curves:
DOTS
Which kind of animals (that shown by the line with dots [circles] or that shown by the line with
dashes [lines]) has the most species? (Name which kind of animals: dots or dashes; 4 points).
4) There are two communities. (a) Just by looking at them, which has the highest diversity (A or B)?
(Circle one) A
s
H     p loge p
i
i1 i
(b) Now, remember that the Shannon-Wiener index equation is:
Calculate the index for the two communities and show your work (use back of paper if necessary;
8 points for whole question).
Principles of Ecology
Your name in Chinese Characters_________________
Final Exam May, 2015, p. 3
Your name in Pinyin________________
Community A
species
#
%
log
(%)
1
4
0.33
-1.11
-0.37
2
4
0.33
-1.11
-0.37
3
4
0.33
-1.11
-0.37
12
% log
(%)
-1.11
H' =
1.11
H' =
0.56
Community B
species
#
%
log
(%)
1
10
0.83
-0.19
-0.16
2
1
0.08
-2.53
-0.20
3
1
0.08
-2.53
-0.20
12
% log
(%)
-0.56
Principles of Ecology
Your name in Chinese Characters_________________
Final Exam May, 2015, p. 4
Your name in Pinyin________________
III. How and why species diversity varies.
5)
In the 1800’s Alfred Lloyd Wallace discovered something unusual: the mammals of the
Philippines were more different from those of Papua New Guinea (750 km away) than from
Africa (5500 km away). What do we know now about the physical processes on earth that
Wallace did not know, and that explain this finding? One sentence answer. Include in your
answers something about the relationship between the Philippines and Papua New Guinea (5
points).
Plate tectonics explain this finding: the Philippines and Papua New Guinea (PNG) were originally very
far apart and thus had very different mammals. But PNG, as part of the Austalian plate, has been moving
towards the Philippines.
6) Name three reasons why there is more diversity in the tropics than in the temperate regions. One
sentence answer for each of the three explanations (6 points).
Possible answers:
1) The tropics has more land area
2) The tropics have been around longer (because the temperate areas have been covered by ice off
and on).
3) The tropical climate is better for organism’s survival and reproduction.
4) The tropics are more productive
Answers that include “more rainfall” and “more sunshine” don’t get full points because they do not fully
explain diversity, though they do underlie answers 3 and 4 above.
7) Below are three graphs of island biogeography theory. In graph A, write above the two curves
which one is immigration and which one is extinction. In graph B, make two new curves for an
island that is farther away than the island already shown on the graph. In graph C, make two
new curves for an island that is larger than the island already shown on the graph. For graphs B
and C, show with arrows where the species equilibrium number was for the original island, and
then for the new one (the one that’s farther away or larger). Whole question = 10 points.
THE LINE ON THE LEFT IS IMMIGRATION, ON THE RIGHT IS EXTINCTION
Principles of Ecology
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Final Exam May, 2015, p. 5
Your name in Pinyin________________
Question 7 continued (see p. 2)
FOR B, THE IMMIGRATION LINE IS SMALLER (ISLAND HARDER TO GET TO)
THE EXTINCTION LINE IS HIGHER (SPECIES THAT GO EXTINCT UNLIKELY TO
RECOLONIZE FROM MAINLAND). THE SPECIES EQUILIBRIUM POINT IS SMALLER.
FOR C, THE IMMIGRATION LINE IS BIGGER (LARGER ISLAND, BIGGER TARGET) AND THE
EXTINCTION LINE IS LOWER (LARGER POPULATIONS ON BIGGER ISLAND), SO THE
SPECIES EQUILIBRIUM POINT IS LARGER.
IV. Introduction to ecosystems
8) Define what an ecosystem is (one sentence answer; 5 points)
An ecosystem is all the members of a biological community and the physical environment they live in.
9) One of the most common patterns in a food web is called the “biomass pyramid”. This describes
how there are many species and many individuals at the bottom of the food web (low trophic
level) and there are only a few species and individuals of those species at the top. Write 2-3
sentences that explain this pattern. Include in your answer a discussion of what happens to the
biomass of autotrophs, and what proportion is captured in the biomass of the heterotrophs that eat
them, as opposed to being lost (what is it lost to?). (8 points)
Transfer between trophic levels is inefficient. Specifically, not all the energy stored at one trophic level is
consumed by the one above it. And of the energy that is consumed, much of it is wasted, either excreted
(feces and urine) or metabolized (used in respiration, movement), and only a little bit is assimilated (made
into tissue). Since there’s not so much energy to go around at the top trophic levels, there are not many
individuals that can live.
Principles of Ecology
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Final Exam May, 2015, p. 6
Your name in Pinyin________________
V. Nutrient cycling and environmental crises
10) Below is a picture of the global Nitrogen (N) Cycle. (Whole question 9 points).
(a) First, circle the parts of this chart that summarize processes that are human made. CIRCLE
ALL THE ORANGE ARROWS.
(b) Second, with a dark, continuous arrow, point to a figure that represents the amount of N in a
reservoir. THIS WOULD BE ANY FIGURE INSIDE A BOX.
(c) Third, with a dashed arrow (- -- - -- - -- ->), point to a figure that represents the amount of N
in a flux. THESE ARE THE FIGURES NEXT TO THE (RED OR ORANGE) ARROWS.
Principles of Ecology
Your name in Chinese Characters_________________
Final Exam May, 2015, p. 7
Your name in Pinyin________________
VI: Conservation biology and landscape ecology
11) What kind of species should a conservation biologist prioritize? What kind of areas should a
conservation biologist prioritize? Write one sentence for each of these questions. For the areas
question, mention two characteristics of areas that are good to prioritize. (Whole question 5 points)
Species: we should prioritize those species that are rare and threatened.
Areas: we should prioritize ‘hotspots’ which are places where there are a lot of threats and where
there are a lot of species that are endemic (only found in that area).
12) Look at the figure below. Explain why the theory of island biogeography informs us how to best
plan reserves in terms of reserve size, number of reserves, reserve proximity and reserve
connectivity (2-3 sentences). (Whole question 5 points)
Island biogeography tells us that large islands, and ones that are close to the mainland, have more species.
This theory can be applied to reserves, because reserves are islands of undisturbed lands in disturbed
habitats. So we need large reserves, not small or fragmented ones (top two lines of figure). When
reserves are fragments those fragments should be close together (third line), and connections between
fragments are also good (fourth line).
Principles of Ecology
Your name in Chinese Characters_________________
Final Exam May, 2015, p. 8
Your name in Pinyin________________
VII. Course-wide subjects
13) In class, we talked about the beaver, a mammal that eats tree bark, cutting down trees to dam
rivers and therefore make small lakes, in which it builds a kind of house called a lodge (whole
question 9 points).
a) What might a populations ecology study about beavers? Give an example of a project he or
she might work on (one sentence). Any project that is about the abundance or densityof
beavers.
b) What might a community ecologist study about beavers? Give an example of a project he or
she might work on (one sentence). Any project that looks at interactions between species in
the beaver’s ecosystem.
c) What might an ecosystem ecologist study about beavers? Give an example of a project he or
she might work on (one sentence). Any project that looks at how the beavers affect or are
affected by the physical environment. For example, how does the presence of beavers affect
nutrient cycling?
VIII. Essay on primary readings.
14) Pick one of the following three questions and write a one paragraph essay. Write on this page,
and, if necessary on the back of this page. (whole question 12 points).
a) About the Isack and Reyes (1989) article on mutualisms, what data do they show to establish that
both sides (humans, honeyguides) benefit? What data do they show to establish that honeyguides
communicate information about the hive to humans?
b) About the Terborgh et al. (2001) on “ecosystem collapse”, why would you call this a natural
experiment? Describe what happened at the site where the scientists worked before they started
collecting data.What happened ecologically on islands without predators (big cats and ant-eating
armadillos)?
c) About the Jackson et al. (2001) article on marine communities, what kind of scientists wrote this
article? What do they study and what kind of data did they collect? What kind of marine habitats
do they review? What’s their conclusion as to what has been the most important human activity
that has harmed these ecosystems?
a) In the beginning of this article the authors compare the time it takes humans to find a bee hive by
themselves and then when they are following a honeyguide. They find hives much quicker when
following the guide. Then in the rest of the article they show evidence that honeyguides give
information to the human followers about the location of the nest. They lead the humans in the
correct direction and as they get closer, the birds perch closer and closer to the ground.
b) This article is a “natural experiment” because what happened – the flooding of an area to make
islands – did not occur because the scientists wanted to design an experiment, but for other
reasons (the making of a hydroelectric dam). Nevertheless, by making the dam, people imposed
an interesting scientific treatment: the absence of predators (leopards and armadillos) on small
islands (because they couldn’t swim well and small islands didn’t have enough food for them).
On these small islands the herbivorous animals became very abundant and eat the small plants,
hence radically changing the vegetation.
Principles of Ecology
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Final Exam May, 2015, p. 9
Your name in Pinyin________________
c) The scientists who wrote this article specialize on fossil animals and the history of the
environment. They present data on what animals were historically (~ 5000 years ago) in these
ecosystems and what ones are there now. They studied coral reefs, kelp forests and estuaries.
They conclude that the first and most important human effect on these ecosystems was
overfishing.