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SCIENCE OLYMPIAD 2016 ISLIP INVITATIONAL
ECOLOGY DIVISION C TEST
All answers must be written on the answer sheet. Answers written on this test copy will not be graded.
1.
The boundary between the taiga and tundra is known as the:
A. Foliage partition
B. Fall line
C. Continental divide
D. Timber line
E. Frost line
2.
The tundra is far less extensive in the ________ Hemisphere due to ______________.
A. Southern/less land presence in the 60 to 70 degree South latitude range.
B. Southern/warmer and wetter climate in the 60 to 70 degree South latitude range.
C. Northern/thawing of Arctic ecosystems due to a changing climate.
D. Northern/encroachment of the boreal forests due to a changing climate.
E. Southern/rugged, elevated terrain unsuitable for tundra flora.
3.
The following biomes are correctly listed in order of decreasing net primary productivity:
A. Taiga, Tundra, Temperate Deciduous Forest
B. Tundra, Taiga, Temperate Deciduous Forest
C. Temperate Deciduous Forest, Taiga, Tundra
D. Temperate Deciduous Forest, Tundra, Taiga
E. Taiga, Temperate Deciduous Forest, Tundra
4.
New York’s forests are mostly, if not all located in the:
A. Temperate deciduous forest
B. Taiga
C. Tundra
D. Temperate rain forest
E. Temperate grassland
5.
Over the last 1000 years this biome has experienced the greatest degradation due to human activity:
A. Temperate deciduous forest
B. Taiga
C. Tundra
D. Temperate rain forest
E. Temperate grassland
6.
This biome covers the most land area on earth:
A. Temperate deciduous forest
B. Taiga
C. Tundra
D. Temperate rain forest
E. Temperate grasslands
7.
Climate change is having the largest impact on the soils of the:
A. Tundra
B. Taiga
C. Temperate deciduous forest
D. Temperate grasslands
E. Temperate rain forest
Questions 8 – 10 refer to the tree pictured here.
8.
This kind of tree is known as a(n):
A. Douglas fir
B. Norway spruce
C. Larch
D. Scotch pine
E. White birch
9.
The largest stands of these trees in the North American taiga are found in:
A. Western Canada and the northwestern U.S.
B. Eastern Canada and Quebec
C. Surrounding the northern coasts of the Great Lakes.
D. Southern Alaska and the Yukon
E. In the U.S. Rocky Mountains in Montana
10. This tree’s superlative is:
A. It’s the most resistant to rot and water
B. It’s is the tallest of all conifers
C. Its wood is the most resistant to fire
D. It yields more timber than any tree in North America
E. It’s the fastest growing tree in North America
11. In a typical forest ecosystem, dead trees and fallen trees are most important because of their role in
which of the following:
A. Providing a valuable source of timber
B. Providing habitats for wildlife
C. Contributing to soil erosion
D. Preventing runoff during rapid snowmelt
E. Removing carbon dioxide from the air
12. A large forested area is fragmented into small forest tracts separated by agricultural areas. This change
will most likely lead to:
A. An increase in the population of top carnivores
B. An improvement in the dispersal mechanisms of forest species
C. A more stable regional climate
D. A decrease in the amount of edge habitat
E. A decrease in the gene flow within species of the original forest
13. Which of the following can be used to assess the biological diversity of an area?
A. Population size of each species and area occupied by each population
B. Minimum population area and minimum viable population size.
C. Ratio of K-strategists to r-strategists and life expectancy of K-strategists
D. Number of individuals under 10 years old and number of individuals over 60 years old
E. Genetic variation within each species and number of species present.
14. The process in the hydrologic cycle in which water vapor Is released from leaves into the atmosphere is
called:
A. Infiltration
B. Transpiration
C. Sublimation
D. Dispersion
E. Diffusion
15. Which of the following is a common characteristic of lakes undergoing cultural eutrophication?
A. Decreased rates of sediment accumulation and phosphates
B. Decreased amounts of green and blue-green algae
C. Decreased oxygen levels to 15-20 ppm.
D. Increased water clarity in the epilimnion
E. Increased levels of nitrates
16. Lakes that are characterized by high water clarity and low concentrations of dissolved nutrients are
classified as:
A. Haloclinic
B. Pycnoclinic
C. Eutrophic
D. Oligotrophic
E. Stratified
17. When logging occurs in a watershed, a likely effect on the local streams is:
A. Mitigation of anoxia
B. Decreased nutrient levels
C. Decreased turbidity
D. Increased oligotrophic conditions
E. Increased water temperature
18. Eutrophic lakes are most commonly found in which of the following:
A. Temperate deciduous forests
B. Taiga
C. Tundra
D. Both tundra and taiga
E. Answers A, B, and C equally
19. In a river ecosystem, dissolved oxygen concentrations drop quickly downstream from a point-source input
of poorly treated sewage into the river. This effect is due to:
A. Increasing populations of mayfly and stonefly larvae
B. Increasing activity of trout and black bass
C. Increasing bacterial activity as organic matter decays
D. Decreasing bacterial activity as turbidity increases
E. Decreasing water temperature as surface evaporation increases
20. Which of the following is most likely to increase both the nutrient levels and the bacterial content of lake
water?
A. Runoff from a nearby cattle feedlot
B. Thermal pollution from a nearby power plant
C. Increased aeration of the lake water
D. Percolation of the water through soil and sand to groundwater
E. Acidification of the lake water by acid deposition
21. Which of the following is a major goal of the program begun in the 1990s to reintroduce the gray wolf into
Yellowstone National Park?
A. Decrease the number of grizzly bears because their population as a tertiary consumer was too high.
B. Enable the removal of the gray wolf from the endangered species list
C. Increase the dwindling numbers of tourists that visit the park each year.
D. Upset the natural predator-prey balance between coyotes and elk
E. Decrease the number of sheep and cattle that wander into the park and overgraze the vegetation.
22. Sustainable use of forests in the United States and Canada would likely be encouraged by:
A. Cutting small groups of medium- and large- sized trees in uneven-aged forests
B. Clear-cutting old-growth forests to allow for secondary succession
C. Allowing road building in wilderness areas so that older, clear-cut forests have time to regenerate.
D. Logging on steep slopes in designated wilderness areas
E. Enforcing all provisions of the Resource Conservation and Recovery Act (RCRA)
23. Losses of usable energy between successive trophic levels in an ecosystem are best accounted for by:
A. The 1st Law of Thermodynamics
B. The 2nd Law of Thermodynamics
C. The law of conservation of matter
D. The process of ecological succession
E. Narrow ranges of tolerance among species in the ecosystem.
24. In the northeastern U.S. forests the problem of acid rain has:
A. worsened due to rising human population in the U.S.
B. worsened due to rising global temperatures.
C. improved due to more strict emission standards and reduction of coal-burning industries.
D. improved due to cleaner types of coal burned in U.S. industries.
E. worsened due to accelerated coal use in the eastern and central U.S.
25.
Which of the following would most likely have the greatest positive impact on the quality of the natural
environment worldwide in the next 100 years?
A. Discovery of new reserves of fossil fuel in coastal areas
B. Increased agricultural production in forest edge communities
C. Increased life expectancy in more developed nations
D. Increased reliance on food from ocean ecosystems
E. Stabilization or slow reduction of the size of the human population
26.
The single largest reason for the current decline in forest biodiversity is:
A. alteration of habitats
B. overuse of animals for human consumption
C. climate change
D. poaching/illegal hunting
E. introduction of exotic/invasive species
27.
Generally, which of the following is the best long-term method of preventing extinctions?
A. Breeding endangered species in captivity
B. Providing food to endangered species in the wild
C. Protecting the habitats of endangered species
D. Removing predators from areas that contain endangered species
E. Paying people not to kill endangered species
28.
The Rule of 70 is a very good estimate of doubling time IF:
A. growth rates remain lower than 5%.
B. you are measuring biological/population growth only.
C. a nation’s population is very large.
D. the growth rate remains constant.
E. None of these
29.
30.
Questions 29 -31 refer to the graph on the right.
The diagram to the right shows how the number of
individuals in a population changed with time as a
result of external stresses and resource limitations.
Which part of the curve corresponds to the carrying
capacity of the ecosystem?
A. A
B. B
C. C
D. D
E. E
Resources for the population are at a maximum at point:
A. A
B. B
C. C
D. D
E. E
31.
If the graph was applied to humans, at which point would our species currently be?
A. A or B
B. C
C. D
D. E
E. it cannot be determined from the information provided here
Questions 32 – 36 refer to the lynx/hare chart below.
32.
The lynx population can’t stay above that of the hare for very long due to:
A. the second law of thermodynamics
B. the shorter life expectancy of the lynx
C. the shorter life expectancy of the hares
D. the larger habitat range of the lynx
E. the law of conservation of mass
33.
In most cycles the positive slopes on the prey’s population curve are steeper than that of the predator’s
curve because:
A. the prey tends to reproduce faster.
B. the prey can find a mate faster.
C. the predators have a more difficult time finding a mate
D. Choices A, B, and C are all correct
E. None of these
34.
In North America this predator/prey relationship can be found in which of the following:
A. tundra
B. taiga
C. temperate deciduous forest
D. only B & C
E. choices A, B, & C are correct
35.
Wabakimi Park in Ontario, Canada measures 3,444 mi2 in area. Using the chart above, calculate the
approximate hare population in the park at year 60. Show your work on the answer sheet.
36.
Calculate the approximate lynx population in the park at year 60. Show work on the answer sheet.
37.
In a stable, long-existing community, the establishment of a single species per niche is most directly the
result of:
A. Competition
B. Interbreeding
C. Commensalism
D. Overproduction
E. Effective protection in reserves and sanctuaries
38.
Explain why most ecologists would agree with the statement “A forest ecosystem is more stable than a
cornfield.” Use the answer sheet.
39.
Which statement describes all stable ecosystems?
A. Herbivores provide energy for the autotrophs.
B. The populations of predators are dependent on the populations of their prey.
C. The number of autotrophs equals the number of heterotrophs.
D. Incoming solar energy equals the outgoing, reflected energy from the earth and atmosphere.
E. At least 3 foundation species are abundant in that ecosystem.
Questions 40 & 41 refer to the graph and the explanation below.
A population of paramecia (single-celled aquatic organisms) was grown in a sample of lake water placed in
a 200 mL beaker containing some smaller single-celled organisms. Population growth of the organisms
for 28 hours is shown in the graph below.
40.
Which factor most likely accounts for the change in the paramecium population from 8 to 20 hours?
A. an increase in the nitrogen content of water
B. an increase in wastes produced
C. an increase in water pH
D. a decrease in water pH
E. an increase in available food
41.
One likely explanation for the change in the paramecium population from 26 hours to 28 hours is that the:
A. carrying capacity of the beaker was exceeded
B. rate of reproduction increased
C. time allowed for growth was inefficient
D. oxygen level was too high
E. light levels entering the beaker were changed
Questions 42 & 43 refer to the diagram below. This diagram shows various ecological communities that occupied
an area over a period of 300 years.
42.
What has happened over this 300-year time period?
A. Primary progression
B. Secondary progression
C. Primary succession
D. Secondary succession
E. None of these
43.
Which statement best describes the diagram?
A. Community A is the most stable community.
B. Community B replaced community C after a period of 100 years.
C. Community C developed into community A after a period of 75 years.
D. Community D modified the environment, making it more suitable for community E.
E. All communities on the diagram have equal stability.
Questions 44 & 45 refer to the diagram below. The data was taken from a lake near a resort in Maine.
44.
Which relationship can correctly be inferred from the data presented in these graphs?
A. Trout and Whitefish are likely to be indicator species.
B. Trout and Whitefish are likely to be specialist species.
C. Carp and Walleye are likely to be keystone species.
D. Both A & B are correct
E. Both B & C are correct
45.
The graph on the left shows the relationship between the oxygen in the water and the level of sewage in
that water. The change in oxygen content over time is due to:
A. warmer water being able to hold less oxygen
B. increased turbidity cooling the water
C. decreased bacterial activity in the water
D. increased bacterial activity in the water
E. more fish consuming oxygen over time
46.
For many decades, certain areas of New York State have remained as hardwood forests containing
predominantly ____ and ____trees.
A. oak/hickory
B. maple/pine
C. larch/spruce
D. oak/pine
E. larch/hickory
47.
Which human activity has probably contributed most to the acidification of lakes and soils in the
Adirondack and Catskill regions of New York?
A. relaxation of Clean Air Acts from the 1970s.
B. using pesticides for the control of harmful insect herbivores.
C. poisoning of groundwater due to hydraulic fracturing in neighboring Pennsylvania.
D. burning sulfur and nitrogen-containing fossil fuels upwind from New York.
E. cultural eutrophication due to decades of chemical fertilizing of lawns and farms.
Questions 48 & 49 refer to the graph and information below.
A small community that is heavily infested with mosquitos was sprayed weekly with a powerful insecticide
for several months. Daily counts providing information on mosquito population size are represented in
the graph.
48.
Which statement best explains why some mosquitos survived the first spraying?
A. The weather in early summer was probably cooler than average.
B. Most of the mosquitos were of reproductive age.
C. Natural variation existed within the population.
D. Environmental factors varied slightly as the summer progressed.
E. Some of the insecticide may have been applied incorrectly.
49.
Mosquito populations rebounded even after several months of spraying this powerful insecticide. A likely
reason for this is:
A. Survivors of the first spraying were able to breed and pass along inherited resistance to their offspring.
B. Warmer temperatures weakened the effectiveness of the insecticide.
C. Mosquitos from other places moved into the affected area.
D. Many mosquitos were in their resistant larval stage at the time of the first spraying.
E. Predators of mosquitos like bats and birds were more severely affected by the insecticide.
50.
Communities have attempted to control the size of mosquito populations to prevent the spread of certain
diseases like malaria and zika. Which control method is most likely to cause the least ecological damage?
A. draining the swamps where mosquitos breed.
B. spraying swamps with chemical pesticides to kill mosquitos
C. spraying oil over swamps to suffocate mosquito larvae.
D. increasing populations of native fish that feed on mosquito larvae in the swamps.
E. burning the swamp plants in spring to kill the mosquito larvae.
51.
Which statement does not represent an example of bioremediation?
A. Duckweed removes heavy metals from ponds and lakes.
B. Ladybugs eliminate insect pests from plants.
C. Bacteria break down hydrocarbons in oil.
D. Ragweed plants remove lead from the ground around factory sites.
E. All of these are examples of bioremediation.
52.
Which of the statements below is an example of the “tragedy of the commons”?
A. Treaties allowing for the limited taking of whales for research purposes.
B. Offshore clam beds in public areas depleted below replenishment levels by overfishing.
C. Individuals catching their legal limit of fish on a daily basis.
D. Shrimp boats accidently catching turtles in their nets.
E. A large storm smothering a large oyster bed with a new sand bar.
Questions 53 – 55 refer to the diagram below.
53.
Which part of the diagram shows the resource use that would be in competition if a new species moves
into an area and is in direct competition with another species?
A. A
B. B
C. C
D. D
E. E
54.
The niche of the black bear (omnivore) is best represented as:
A. A
B. B
C. C
D. D
E. E
55.
The area under the curve shown by letter B is best described as:
A. the productivity of a producer such as grass.
B. the productivity of a tropical rain forest.
C. the niche of a specialist like a panda bear.
D. the competition between a producer and a consumer.
E. how far the niche of two species of animals are separated from each other.
56.
Which of the following has NOT contributed to the explosion of the white-tailed deer population in the
northeastern U.S.?
A. Many people planting their properties with edible flowers and shrubs.
B. Trapping of deer and moving them out of areas where they are not wanted.
C. Suburbanization eliminating many forests and creating many edge habitats.
D. Hunting laws restricting their hunting.
E. Elimination of many of their natural predators.
Base your answers to questions 57 & 58 on the graphs below which show changes in the number of aspen trees
and the beaver population in an area over a 50-year period.
57.
State one possible reason for the relationship between the aspen tree and the beaver populations. Write
your answer on your answer sheet.
58.
Predict how the number of aspen trees would change if a parasite that targets the beaver population
were introduced into the area during year 5. Explain your answer on your answer sheet.
Questions 59 and 60 refer to the climate charts below. The red line represents temperature and the blue line
represents precipitation.
A
B
C
D
59.
Which of these climate charts best represents the climate of the taiga?
A. A
B. B
C. C
D. D
E. None of these
60.
Chart B best represents the climate found in the:
A. Tundra
B. Taiga
C. Temperate deciduous forest
D. Temperate rain forest
E. None of these