Download 31 May 2004 1 Tropical Ecology and Conservation ENVS122 Final

31 May 2004
Tropical Ecology and Conservation ENVS122
Final Exam Study Questions
Review Session Monday 7 June 12:00-1:30 in 071 Soc Sci 2
The final exam is cumulative, and we have covered a lot of material in this course. The
exam will be similar in flavor to the midterm; mostly short answers, maybe a longer
answer or two, some diagrams to work off of, and some thought-provoking multiple
choice. I’m interested in you showing me that you understand the main concepts,
patterns, processes, and theories that we’ve talked about, and can explain them in
CONCRETE terms – either with specific examples or with enough detail to show that
you understand how it really works. You should be able to use specific terms correctly –
and provide an unambiguous definition of it. I am not interested in answers that put
down everything you think might be related to the question, but rather that you read the
question carefully and answer it directly. Be complete but concise. I want you to show
that you can explain to your family or roommates what something you see on the
Discovery channel means in the big picture, and how you know what it means. You
should understand the process behind doing ecology in the tropics, and the limitations.
You should be able to interpret clearly graphs and tables of the kinds we’ve talked about
in class and those that you’ve studied in the readings. Most of the questions will come
from this list and from the reading questions.
Some terms and tools you should be comfortable with:
Insolation • Cation Exchange Capacity
• Prop roots
• Richness •
Inter-Tropical Convergence Zone
• Evenness • Alpha, Beta, and Gamma
Diversity • Endemism • Species Accumulation Curves
Palm • Epiphyte • Hemiepiphyte
• Epiphyll • Buttresses
Pneumatophores • Net Primary Productivity • Photon Flux Density
Guild •
Symbiosis • Parasitism • Commensalism • Mutualism
Endophyte • Competitive Exclusion
Some questions about the main ideas of the course.
1. What climatic factors would you expect to change seasonally, and what would you
not expect to change, in a lowland moist season forest at 9° N latitude? What drives
seasonal changes in the tropics and how? Be able to give a description to someone
who is going to the tropics for the first time what do expect for temperature range,
rain patterns, and day length.
2. What tropical/subtropical American countries experience regular hurricane damage
and which do not?
3. How do the following change with elevation? Temperature, Total Precipitation,
Direct deposition of moisture? Why does precipitation change?
4. Be able to sketch on a map of South and Central America general areas where you
would find rain forests (wet and moist forests), Dry forests (including Caatinga and
Chaco), Savannah (Llanos, Cerrado), Flooded forests (Mangroves, Pantanal), and
Montane forests.
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5. What are the three determinants or axes used in the Holdridge Life Zone system?
What do each mean, specifically?
6. What were the spatial relationships between North America, South America, and
Africa: 135 MYBP (Jurassic), 65 MYBP (Cretaceous), 15 MYBP (Miocene), 3
MYBP (Pliocene), 12,000 YBP (Pleistocene)? What is the evolutionary significance
to tropical ecology of today?
7. In particular, what is the importance of a) the Central American Land bridge and b)
the Pleistocene to mammals in the Americas?
8. Which are myths and which apparently true and WHY (be specific).
• All tropical soils are nutrient poor.
• Tropical soils are fragile.
• Cutting tropical forests leads to Laterization, preventing plant growth in the
future.
• Tropical soils are very heterogeneous.
• Ultisols and Oxisols are the most common tropical soils, and are characterized
by a high Cation Exchange Capacity
• Spodosols are typical of most tropical soils.
• Nitrogen and phosphorus are limiting factors in most tropical soils.
• Cutting and removing trees from a tropical forests removes the majority of
nutrients from the system.
• Above-ground biomass generally increases as soil fertility increases.
• Root allocation is greater in Spodosols than in Ultisols.
9. Draw a typical (a) species-area curve and (b) frequency plot for plants or insects in a
typical lowland moist tropical forest. Label the axes appropriately.
10. In a large sample from a lowland moist tropical forest community (of plants or insects
or fungi or birds), would you be more likely to find 10% or 70% of the species in that
community represented by a single individual?
11. Draw a graph indicating the relationship between (a) plant diversity and precipitation,
(b) plant diversity and elevation in the tropics.
12. In what four kinds of tropical environments would you most expect high levels of
plant endemism? Why?
13. What kinds of forests would you expect to hold the greatest diversity of epiphytes and
hemiepiphytes? Why?
14. What do pollen records from the tropics tell us about the evolutionary constancy of
association among different plant species in the tropics?
15. Within the context of tropical diversity, be able to provide a succinct description for
each of the following theories, specifically discussing if it explains genesis or
maintenance of diversity, how it accounts for differences between the tropics and
temperate systems, and what empirical evidence is available and relevant.
• Stability-time hypothesis
• Refugia hypothesis
• Interspecific competition/niche partitioning hypothesis
• Productivity/Resource-complexity hypothesis
• Predation hypothesis
• Neutral Theory
16. Describe the life cycle of a strangler fig.
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17. Describe the light environment for an understory plant in a lowland moist tropical
forest. How does it compare to the environment in a forest gap? in a large clearing?
What special physiological adaptations to many such understory plants have to
maximize their energy-capturing ability?
18. Describe three ways in which tropical plants avoid cope with drought stress and give
a specific example or life form to go with each strategy.
19. Why is CAM photosynthesis common among epiphytes in wet forests? How does it
work as a water conservation strategy?
20. How are deciduousness of trees and depth of water acquisition related in tropical
trees? How do we know?
21. Would you expect higher beta diversity in tropical plants or mammals?
22. What are the three most diverse groups of neotropical mammals?
23. Describe Terborgh’s and Dirzo’s arguments for the importance of top-down
regulation of tropical plant communities. What data do they present to support their
arguments? What experiment did Wright and Terborgh do that relates to the issue?
Be able to summarize the arguments in a succinct statement about what is the
importance of mammals in neotropical forests.
24. For each of the following, be able to provide a brief physical description, what they
eat, if they are arboreal or terrestrial, and anything particularly noteworthy about their
social structure: Coati mundi, White-lipped peccary, Collared peccary, Tamandua, 3toed sloth, Agouti, Paca, Capybara, Ocelot, Jaguar, Tapir, Kinkajou.
25. Why are frugivorous birds colorful and insectivorous ones generally not in the
neotropics? Give a specific examples (Family level or more specific) of antbirds,
aerial insectivores, gleaners, frugivores, nectarivores, and granivores among tropical
birds.
26. What were the main differences and main similarities between tropical and temperate
bird communities?
27. Why do tropical birds participate in mix-species flocks? How do mixed-species
flock affect the evenness of bird diversity in tropical forests?
28. What kinds of animals are primarily responsible for the observed latitudinal gradient
in predator diversity? What is the main food chain that supports those predators?
29. Describe four reproductive strategies found in tropical frogs, and give a specific
example of each.
30. Contrast tropical and temperate snake communities in terms of density, diversity, and
habit.
31. What are the two major groups of venomous snakes in the tropics? How are they
different? Give a specific example of each.
32. Be able to define Batesian and Müllerian mimicry, and give a specific neotropical
example of each, including both partners.
33. Describe each of the following insect sampling methods, and their pros and cons:
Light traps, Fogging, Berlese funnel, Malaise traps. If you were assigned to do as
complete an inventory of the arthropod community of a tropical forest patch as
possible but only had funds for two methods, which would you employ and why?
34. One of the most famous numbers in tropical ecology in Terry Erwin’s 30 million
kinds of insects. How did he arrive at that number? Does it make sense? What are
the assumptions? are they valid?
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35. In what season would you sample a seasonal tropical forest to capture the greatest
diversity of insects?
36. Compare guild composition of temperate and tropical arthropod communities in terms
of species and numbers. How are they similar and how different? Why?
37. How are arthropods distributed vertically in a rain forest in terms of numbers? What
are the most numerous and most diverse arthropod groups in rain forests? Do they
differ in their microsite distribution?
38. Describe the life history of Atta ants.
39. What are the components of the disease triangle? In the complex 3-dimensional
structure of a moist tropical forest, where would you expect to find the most foliar
disease an why?
40. Describe or draw a generalized life cycle of a fungal disease of plants. How does
each stage interact with the environment of a moist tropical forest? How would you
expect disease development to differ in a dry forest?
41. Begin with a tree seed, and follow it through until the tree that grows from it produces
seeds and then dies. Describe how, in each stage – germination, seedlings, saplings,
adult, flowering, fruit production, decomposition – fungi affect the host.
42. What is the Janzen-Connell hypothesis? What are the key patterns that must be
present to recognize if a system is behaving according to the hypothesis? How can it
help maintain plant community diversity?
43. What are three possible ecological roles for leaf endophytic fungi?
44. What are the two main kinds of mycorrhizal associations? In what kinds of tropical
forests would you expect each? What kinds of fungi are associated with each?
Which exhibits more host specificity? How do mycorrhizae in tropical forests differ
from those in California forests?
45. What is coevolution? What is the scale on which it takes place? What do we need to
be able to say that two organisms are coevolved?
46. What are the major differences in patterns of herbivory between temperate and
tropical zones? How does herbivory differ among different forest types? Pioneer and
shade-tolerant species? Seasonally? What are the impacts of herbivory on plant
dynamics?
47. What are the key organisms that consume plant material in tropical forests? How
important are they and in what ways to plant population dynamics?
48. What are the major kind of defenses that plants have evolved against pests and
pathogens in the tropics? What trade-offs are involved in evolving defenses? What is
the defense-resource availability theory?
49. How would you use an understanding of evolution of host defenses in a biological
prospecting program for pharmaceuticals?
50. Be able to describe a range of types of disturbance important in tropical forests, and
how they differ in their impacts.
51. Describe what a treefall gap in a tropical forest is like. How big are most gaps? What
is the importance of lianas in gap formation? What is the return interval between gaps
in tropical forests outside the hurricane belt?
52. Be able to describe the life cycle of a gap in a lowland tropical moist forest, and
discuss why gaps have been suggested as the key to maintenance of plant diversity.
What observations led to the idea that gaps are important for diversity? How does the
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measurement of diversity in gaps on a per area versus per stem basis change the
picture about the importance of gaps in forest diversity?
53. What are the premises that must be confirmed to demonstrate niche partitioning in
gaps, and what evidence supports or refutes each? How does this relate to the key
theories of genesis and maintenance of tropical diversity that we have discussed?
54. How do tropical trees exchange genes? How is this similar to or different from
California forests? What is the scale of gene flow in tropical trees? How do we
know? What are the effects of fragmentation on gene flow and plant reproduction?
55. How do tropical trees move their seeds around? What are the effects of fragmentation
on seed dispersal?
56. How does seed dispersal limitation relate to maintenance of diversity of trees in
tropical forests?
57. Once seeds are dispersed, how does density-dependent mortality affect seedling
diversity? How do we know? How is this related to the maintenance of diversity of
trees in tropical forests?
58. Be able to describe the differences between an equilibrium and non-equilibrium
model of tropical forest dynamics.
59. What did Hubbell (1979) say about the spatial pattern of tropical tree species, and the
mechanisms that drive species dynamics?
60. Be able to summarize the view of Clements and Gleason on plant communities, and
discuss the importance to understanding forest dynamics.
61. How did Hubbell and Terborgh et al. each approach looking at forest dynamics?
How were they different, and how do those differences affect how we interpret their
results? What were the key findings of each study?
62. How do the world views of Hubbell and Terborgh affect the approach to explaining
how tropical forests work?
63. What is the importance of Edenic narratives to tropical conservation biology? Be able
to give specific examples.
64. What specifically did the Rio Convention accomplish with respect to tropical
biodiversity?
65. How have anthropogenic effects on tropical forests changed over the last few
thousand years, particularly pre- and post-conquest? How do we know? How old are
the oldest tropical forests in Central America?
66. How can a novel disease of coconuts affects Kuna society and forest conservation in
the Comarca of Kuna Yala?
67. Why is shade coffee an important conservation concern in Latin America? What
biological information supports their importance? What social/political/economic
structure have evolved to support them? What factors have led to the decline of
shade coffee?
68. What are the major threats to the Amazon forest? How have the threats changed over
time? How do the different threats interact?
69. What are key factors to consider in designing conservation efforts in tropical habitats?
What are major limitations and opportunities? What are some of the reasons that
parks work or don't work as conservation tools?
70. What are some of the major constraints to natural regeneration of forests after
deforestation? What restoration tools can help facilitate forest recovery?
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71. What are some of the benefits and costs of biological prospecting? Ecotourism? How
can they be useful conservation tools? (or can they?)
72. What are the important biological features of mangrove forests? Freshwater flooded
forests? Cloud Forests? What special threats do these forests face? Why are they of
such conservation importance?
73. Think synthetically about tropical dry forests and moist forests. What are the key
similarities and differences between them in ecological, evolutionary, and
conservation terms? What kinds of research questions would you most want to ask
that would specifically compare wet and dry forests?
74. Be able to describe an important contribution of each of the following tropical
ecologists: Steve Hubbell, John Terborgh, Phyllis Coley, Paul Collinvaux, Julie
Denslow, Al Gentry, Robin Chazdon, Nigel Stork, Terry Erwin, Rodolfo Dirzo, Allen
Herre, Dan Janzen.
75. Be able to describe the kind of forest you would find at La Selva Biological Station,
Barro Colorado Island, Manu National Park, Los Tuxtlas Biosphere Reserve, Manaus
Forest Fragmentation Project. Know what country each site is in.
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