1. Review Which of the following is NOT true about ecosystems?
A. They include biotic components B. They can be a wide range of sizes C. They include no human components D. Many species interactions occur in them E. They include abiotic components
2. How many hectares of land is a 500-acre park? (1 acre = ha)
3. In 2011, 640,000 ha of Amazon rainforest were cleared. Approximately how many hectares is that each hour?
4. What type of species is most sensitive to environmental stresses?
5. What is the smallest structure that can carry on all life processes?
6. The removal of this type of species would have the greatest negative impact on an ecosystem.
7. A group of organisms that are genetically similar enough to breed in nature and produce live, fertile offspring is called: C
500 x = 202.5ha
640,000 ha/year X 1 year/365 days X 1 day/24 hours = 73 ha
Indicator
Cell
Keystone
Species

2. Review
Autotrophs
A. Use photosynthesis B. Are able to survive without oxygen C. Are primary consumers
D. Are at the top of the food chain E. Cannot assimilate carbon.
2. A zebra is an example of
A. A secondary consumer B. A producer C. A detritivore D. A primary consumer
E. A scavenger
3. If gross primary productivity in a wetland is 3 kg C/m2/year and respiration is 1.5 kg C/m2/year, what is the net primary productivity of the wetland?
A. 1.5 kg C/m2/year B. 2 kg C/m2/year C. 3 kg C/m2/year D. 4.5 kg C/m2/year
E. Impossible to determine from the given information.
The gross primary productivity of an ecosystem is
A. The total amount of biomass B. The total energy captured by photosynthesis
C. The energy captured after accounting for respiration D. The biomass of the producers E. The energy available to primary consumers
5. Roughly what percentage of incoming solar energy is converted into chemical energy by producers?
Which of the following is not an example of an abiotic component of an ecosystem?
A. Water B. Minerals C. Sunlight D. Fungi E. Air
7. At which trophic level do organisms use a process that produces oxygen as a waste product?
8. At which trophic level are dragonflies that consume mosquitoes that feed on herbivorous mammals? A D
NPP = 3 – A B 1% D
Primary producers
Tertiary consumers

3. Review
The average efficiency of energy transfer between trophic levels is approximately
A. 1% B. 4% C. 10% D. 50% E. 90%
2. Human construction of buildings and pavement affect the hydrological cycle by (choose all that apply) A. Increase runoff B. Increase evaporation C. Increase percolation D. Decreasing recharge areas
3. If the producer level of an ecosystem contains 10,000 kilocalories of energy, how much energy does the tertiary consumer level contain? C
A and D
10 kilocalories
4. The hawk is:
5. The corn is:
6. The snake is:
7. The rabbit is:
Tertiary consumer
Producer
Secondary consumer
Primary consumer
8. Animals that feed on the dead carcasses of other animals are called:
9. Fungi and bacteria, which breakdown organic matter and return nutrients to the soil, are called:
Detritivores
Decomposers

4. Review
Which of the following is fixed from the atmosphere by bacteria?
A. Magnesium B. phosphorous C. Sulfur D. Nitrogen E. Potassium
2. The largest carbon sink in found in the:
3. Phosphorus
A. Is a limiting nutrient in many aquatic systems B. Has an important gaseous stage
C. Is easily lost from soils due to leaching D. Is often produced by volcanic eruptions
E. Changes chemical form often during its biogeochemical cycle
4. Acid rain is associated with which geochemical(s) cycle(s)?
5. Which of the following processes is also known as ammonification?
A. Nitrogen fixation B. Nitrification C. Assimilation D. Mineralization
E. Denitrification
5. Which of the following statements about the carbon cycle is true?
A. Animals cause an increase in atmospheric carbon dioxide through cellular respiration.
B. Coal, oil, and natural gas are the remains of ancient plants.
C. Plants remove carbon dioxide from the atmosphere during photosynthesis.
D. Carbon dioxide can become dissolved in ocean water, where it may be incorporated into the shells of marine organisms.
E. all of the above
6. Which of the following statements is true regarding the sulfur cycle?
A. Sulfur is an important component of carbohydrates.
B. Sulfur is an important component of lipids.
C. Sulfur is not found in living organisms.
D. The burning of coal leads to acid rain. D
Ocean A E

5. 7. Briefly describe a strategy that uses integrated pest management for the control of the black-legged tick population.
Physical controls: habitat management
Shorten grass and brush reduction: Eliminates ticks habitat
Expose areas to more sunlight: increase soil temperature, lower soil moisture killing tick pupa.
Control burning of brush: eliminate ticks and habitat
Introduce a plant that repels ticks: ticks leave.
Biological controls:
Introduce a tick predator: birds, wasps or ant kill ticks
Introduce a disease: must only kill ticks
Introduce a tick competitor: Reduces tick numbers due to competition for limiting factors.
Sterilize male ticks: less reproduction
Decrease the host organisms: introduce a mouse or deer predator. Lengthen the hunting season for deer.
Pesticide use:
Use tick pesticide: kill ticks directly must be used in moderation and at the beginning of the ticks life cycle
Use herbicides: Kill plant in turn killing tick habitat. Must be used in moderation.

6. Worm Invasion
A researcher studying the ecology of the deciduous forest outside of Fremont has made an alarming discovery. While taking an inventory of the species present on the forest floor. Professor Peter Tate discovered many earthworms of an Asian species not previously known to live in this area. The Asian worms, unlike native worms, have voracious appetites.
The forest floor is home to a myriad of species that live in the leaf litter, which is composed of several years’ accumulation of slowly decomposing leaves. Dr. Tate explained that “the leaf litter is critical to the survival of local species of forests plants.” Dr. Tate has found the Asian worms, unlike their indigenous cousins, consume the entire layer of leaf litter in a single season. He said, “This sets the stage for the takeover by invasive exotics such as Japanese stilt grass.” Dr. Tate and other scientists are exploring strategies for the control of the Asian worms.
a. Support Dr. Tate’s assertion that “the leaf litter is critical to the survival of local species of forests plants.” Include in your discussion the roles of leaf litter in a deciduous forest ecosystem.
Role of the leaf litter:
Provides shelter for seedlings
Allows germination of seedlings
Reservoir for many nutrients to absorbs and releases them for plant and other organisms
Provides shelter for other organisms
Helps retain moisture near the ground
Helps reduce erosion
Contributes to humus production
The bold statements relate to plants and can be used to support Tate’s assertion.

7. b. Describe THREE abiotic changes that would be likely to result if the exotic worms consumed all the leaf litter in a single year.
Soil nutrient levels would decrease: nutrients move to the worms
Erosion of soil would increase: bare land erodes faster
Soil temperature would change: bare soil absorbs more solar radiation
Increased evaporation: bare soil loses water faster
Loss of topsoil: due to increased erosion
Soil moisture would decrease: more evaporation soil becomes drier
Decrease intensity and severity of fires: Less fuel
Reduced ground cover: leaf litter removed ground is exposed
c. For one of the changes you identified in part (b), explain how the change could set the stage for the takeover of Japanese stilt grass or other exotic species.
If soil temperature changes many native species would die out allow room for an invasive species like Japanese stilt grass.

8. d. Design a controlled experiment to determine whether the worms, in fact, do change the forest ecosystem. Identify the environmental factor you will measure, and include the specific hypothesis you will test and the data you will collect.
If the worms eat the leaf litter then the pH of the soil will increase.
Set up and area of equal size where the leaf litter is not invaded by the Asian Worms.
Set up a second area and remove the leaf litter as the Asian Worms would.
Test the pH of the soil at the begging of the study and every month for a year.
Must remove any excess leaf litter throughout the year that drops as the Asian Worms would.
Compare the pH numbers between the control and experimental plots.

9. Review
What is the correct order of the atmospheric layers starting at the Earth’s surface?
There are two solstice and two equinox. What are they, when do they occur in the northern hemisphere and what is special about them?
What is the main cause of the seasons? How is the Earth positioned in the northern hemisphere during summer and winter?
Which atmospheric layer contains the protective ozone layer?
What is the correct order of convection cells starting at the equator?
What suppresses rain? What promotes rain? Where do we get rain? Where is it dry?
Which of the following BEST explains why polar regions are colder than tropical regions? a) polar regions have lower albedo values b) polar regions receive less solar energy per unit of surface area c) tropical regions receive less direct sunlight thru the year d) sunlight travels thru more atmos. and loses more energy in tropical regions e) tropical regions rotate faster than polar regions
Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere
Summer solstice/June 21/longest daylight
Winter solstice/December 21/Shortest daylight
Autumnal equinox /September 21/equal day and night
Vernal equinox/March 21/equal day and night
Earth is tilted 23.5 degrees/Summer tilted towards sun winter tilted away
Stratosphere
Hadley, Ferrel and Polar
Descending air/Ascending air/0 degrees and 60/30 degrees and 90 B

10. 8. which of the following statements about patterns of temperature and precipitation is NOT correct? a) the air on a Hadley cell rises where sunlight strikes earth most directly b) the greatest amount of precipitation occurs at the intertropical convergence zone (ITCZ) c) the air in a Hadley cell descends near 30 degrees N and S, causing the formation of deserts d) the air of a polar cell rises near 60 degrees latitude e) along earths surface, the air of a Hadley cell moves away from the equator E
Predators questions

11. i. According to the data, what are the optimal temperature and relative humidity for termite activity?
Temperature = 30 degrees C
Humidity = 90%
ii. Given a density of 4.5 x 107 termites per hectare and optimal conditions, calculate the annual amount of methane emitted, in kilograms, by the termites inhabiting a 2,000 hectare tropical rain forest.
2,000 hectares x 4.5 x 107 termites x 70 kg CH4/year = 6.3 x 109 kg CH4/year
1 hectare ,000 termites
iii. Suppose the temperature increases to 35 degrees C and the relative humidity decreases to 50 %. Using the data provided, determine the amount of methane, in kilograms, that would be emitted by the termites in the 2,000 hectare tropical rain forest.
0.09 (current conditions) x 6.3 x 109 kg CH4/year = 2.1 x 109 kg CH4/year
0.27(optimal conditions)
iv. Explain why the population size of termites is also affected by temperature and humidity.
Reasons: Temperature and humidity are limiting factors for termite populations
There is a range of tolerance for temperature and humidity for termites and their symbionts
Explanation: At 40 degrees wood consumption stops and at 20 degrees activity is lowest, regardless of humidity.
At a humidity less than 90% termite wood consumption decreases regardless of temperature

12. b. It has been observed that soon after a tropical rain forest is cleared, termite density increases to an estimated 6.8 x 107 termites per hectare. Thereafter, the termite population size decreases dramatically.
i. What is the most likely reason that the density of the termites increases when a tropical rain forest is cleared?
An increase in dead plant material
Increased food source can support larger populations of termites
ii. Why do the termite populations eventually decrease dramatically?
Exhausts food source and die off
Termite exceed the carrying capacity of the forest and the population crashes (overshoot and crash)
Without trees the surface temperature increases and may get higher than the termites can survive.
Increased competition for a limited resource
c. Describe one way, other than changes in termite activity, that tropical rain forest destruction contributes to anthropogenic climate change.
Reduction in photosynthesis: Less carbon dioxide removed from atmosphere
Loss of carbon sink: increased amounts of carbon dioxide and or methane in atmosphere
Lack of shade: warmer surface temperatures
Pollution from trucks, saws, bulldozers used: increase carbon dioxide

13. Strange Days on Planet Earth: Predators
Surface water runoff
Carried by rain, snow, or dust that falls into the water
Can be carried by groundwater from a polluted aquifer
b. Draw a food chain that illustrates the correct trophic order in the pond. Include the concentrations of compound “X” for each part of the chain.
Water(0.1 ppb)----Zooplankton(0.2 ppb)----small fish(0.1 ppm)-----Predatory fish(1.0 ppm)------Hawk(3.0 ppm)

14. c. Describe a process that would explain the different concentrations of compound “X” in each organism.
Bioaccumulation: Fat-soluble molecules accumulate and stay in the fatty tissues of animals.
Biomagnification: Occurs when compounds are passed from prey to predator. As the predator eats many contaminated prey the accumulated pollutant becomes magnified in the predator at much higher concentrations than in the environment.
d. Describe one real life example of a substance that behaves like compound “X” in the oceans. Give one negative effect that the substance might have on humans.
Mercury, PCB’s (polychlorinated biphenyl) and DDT (Pesticide) are common molecules that bioaccumulate and biomagnify.
PCB’s-skin irritation (rashes), Studies in workers exposed to PCBs have shown changes in blood and urine that may indicate liver damage. Common symptoms included dermal and ocular lesions, irregular menstrual cycles and lowered immune responses. Other symptoms included fatigue, headaches, coughs, and unusual skin sores. Additionally, in children, there were reports of poor cognitive development.
DDT have been linked to diabetes. DDT, like other organochlorines, have been shown to have xenoestrogenic activity, meaning they are chemically similar enough to estrogens to trigger hormonal responses in animals. It is a carcinogen.
Mercury-itching, burning pain, skin discoloration, swelling, desquamation( shedding of skin), sweating, increased salivation, and hypertension.

15. Review On the lee side The rain shadow causes desserts to form:
Trade winds/0-30 degrees
Westerlies/30-60 degrees
Easterlies/60-90 degrees
Of atmospheric lifting (air rising)
Of subsidence (air sinking)
The rain shadow causes desserts to form:
What are the major prevailing winds of the Earth? Where do they occur?
Low pressure systems are associated with rain because:
High pressure systems are associated with dry climates because:
5. The atmosphere is one important carbon reservoir. Describe a biological process by which carbon is removed from the atmosphere and converted to organic molecules.
6. Describe a biological process by which carbon is converted from organic molecules to a gas and returned to the atmosphere.
Photosynthesis: the process by which plants/autotrophs take in carbon dioxide from the atmosphere and convert it into glucose/sugar.
Respiration breaks down food/glucose/sugar/complex carbohydrates and releases CO2 into the atmosphere
Animals digest food and produce gases such as methane that can be emitted either through belching or flatulence
Decomposition of organic material by bacteria or fungi converts organic carbon into gases such as methane

16. 7. Oceans and terrestrial systems are also important carbon reservoirs
7. Oceans and terrestrial systems are also important carbon reservoirs. Explain how atmospheric carbon is incorporated into two oceanic sinks.
8. Identify one terrestrial sink, other than fossil fuels, that stores carbon for thousands to millions of years.
9. Phosphorus is another element important to all organisms. Describe one major way in which the phosphorus cycle differs from the carbon cycle.
10. Identify one reason that phosphorus is necessary for organisms
Carbon (CO2) can be taken up by organisms like phytoplankton for photosynthesis
Carbon can be taken up by marine organisms and used for shells, skeletons, coral, etc.
Biological pump (organisms in the upper ocean sink to the bottom of the ocean)
Atmospheric CO2 can dissolve directly into ocean water
Old growth forests/trees that live for thousands of years (just “forests” does not earn credit)
Trapped/incorporated into ice caps/glaciers
Limestone or sedimentary rocks
Incorporation into soil
Freshwater wetlands/bogs
Peat formation/burial of plant material under anaerobic conditions
Dissolved in aquifers
Phosphorus cycle does not typically have a gas/atmospheric phase
Phosphorus is a component of nucleotides/ATP in cells - It is necessary for the formation of DNA and RNA-Phospholipids are a major component of all cell membranes

17. Review
Desert owls are inactive during the day and active at night. They also have small bodies. This describes _____ adaptation to the hot and dry desert. A. anatomical B. behavioral C. physiological D. anatomical and behavioral E. anatomical, behavioral, and physiological
Horned lizards are desert animals that are active during the day. Their skin and kidneys are efficient at conserving water; when they get hot, they move to the shade so they can cool off. This describes _____ adaptation to the hot and dry desert. A. anatomical B. behavioral C. physiological D. anatomical and behavioral E. anatomical, behavioral, and physiological
What are the two major factors determining the distribution of terrestrial biomes? A. temperature and light B. temperature and rainfall C. light and rainfall D. plants and animals E. temperature and plants
Which aspects of a region's climate have the most impact on plants and animals? A. Soil composition and temperature. B. Moisture and wind. C. Sunlight and moisture. D. Sunlight and wind.
Which action influences the abiotic components of an organism's environment? A. Water pollution. B. Extinction of predators. C. Interactions with offspring. D. Introduction of exotics. D E B C A

18. Review
Which of these biomes is characterized by little rainfall? A. temperate broadleaf forest B. coniferous forest C. desert D. temperate grassland E. tropical rain forest
Which of these is the largest terrestrial biome on Earth? A. tundra B. coniferous forest C. temperate broadleaf forest D. temperate grassland E. desert
Which biome is characterized by an extensive canopy that allows little light to penetrate to the ground and by the presence of epiphytes? A. temperate grassland B. coniferous forest C. tropical rain forest D. desert E. tundra
Which biome is characterized by the presence of permafrost? The melting of this releases which greenhouse gas?
In which of the following terrestrial biome pairs are both dependent upon periodic burning? A. tundra and coniferous forest B. chaparral and savanna C. tropical forest and temperate broadleaf forest D. grassland and tundra E. desert and savanna
Which type of biome would most likely occur in a climate with mild, rainy winters and hot, dry summers?
Why are experiments that involve transplanting species seldom conducted today? A. Species transplants still are a popular experimental tool. B. The transplanted species are often disruptive to their new communities. C. There are no criteria to determine if they are successful. D. The success of the transplant cannot be measured in one researcher's lifetime. E. The potential range of a transplanted species can never be greater than its actual range C B
Tundra and to a lesser extent the boreal forest/methane B
Chaparral B

19. Review
Farmers are buying mango tree saplings for $10 each, and the full-grown trees produce $75 of fruit each year. If a farmer whishes to earn $1,500 per year when the trees are grown, how much will the farmer have to spend on saplings?
An ecosystem that rapidly returns to its original state after a disturbance is
A. Resistant B. Vigorous C. Resilient D. Stable E. Adaptable
3. The intermediate disturbance hypothesis states that intermediate levels of disturbance will
A. Increase runoff B. Increase ecosystem nutrient cycling C. Decrease primary productivity D. Increase species diversity E. Decrease biomass
4. Which is a measure of how much a disturbance can affect the flows of energy and matter in an ecosystem? A. Diversity B. Intensity C. Resistance D. Resilience E. Homeostasis
5. Which is true of primary succession? Choose all that apply
A. It starts with bare soil B. As it progresses the number of species decreases C. It occurs after forest fires D. If begins with colonization of lichens and mosses E. It results in an ecosystem of grasses and small plant.
6. Which of the answer(s) in number 5 are true of secondary succession?
$1500 per year x 1 tree/$75 per year x $10/1 tree = $200 C D
B and C
A, B and C

20. Review
Farmers are buying mango tree saplings for $10 each, and the full-grown trees produce $75 of fruit each year. A village of 225 people decides to pool its resources and set up a community mango plantation. Their goal is to generate a per capita income of $300 dollars per year for everyone in the village.
A. How many mature trees will the village need to meet this goal?
B. Each tree requires 25 square meters of space. How many hectares must the village set aside for the plantation (1 square meter = hectares)?
C. Each tree requires 20 L of water per day during the 6 hot months of the year (180 days) and 10 L a day for the remaining days. The water must be pumped to the plantation from a nearby stream. How many liters of water are needed each year to water the plantation?
$300/person x 225 people = $67,500 dollars per year
$67,500 dollars per year/$75 per tree = 900 trees
900 trees x 25 square meters x hectares/1 square meter = 2.25 ha
20 L x 180 days (hot months) = 3600 L
10 L x 185 days (rest of year) =1850 L
3600 L L = 5450 L

21. Review What is the difference between a rangeland and a pasture?
Which of the following is not a problem in rangeland management?
A. Fire B. Overgrazing C. Poor soil conditions D. The high cost of grazing permits
E. Inconsistent management standards and guidelines?
3. Which is used to reduce the impact of timber harvesting? Choose all that apply
A. Tree plantations B. Selective cutting C. Prescribed burns D. Mechanized logging
E. Clear-cutting
Which of the following is not an example of the tragedy of the commons?
A. Overgrazing by sheep on community-owned pastures
B. Depletion of fish stock in international water
C. Automobile congestion in Yellowstone National Park
D. Depletion of soil minerals by farmers on private land
E. Tropical deforestation due to clearing public lands for agriculture
For many years, forest fires were suppressed to protect lives and property. This policy has led to: A. A buildup of dead biomass that can fuel larger fires. B. Many forest species being able to live without their habitats destroyed C. Increased solar radiation in most ecosystems D. soil erosion on steep slopes E. Economic instability
Which of the following is not an environmental consequence of clear-cutting?
A. Increase soil erosion B. Decreased biodiversity C. Increased fish populations due to the influx of nutrient D. Decreased tree species diversity due to loss of shade tolerant species E. Stands of the same age trees
Natural vs. Managed D
A and B A C

22. Review
Which of the following are environmental impacts of urban sprawl? I Greater reliance on the automobile and increased fossil fuel consumption II Increased consumption of land for housing and highway construction III Loss of valuable farmlands
all
Matching
2. also known as autotrophs, they are responsible for
producing usable forms of energy
3. a process in which producers use solar energy to
convert CO2 and H2O into glucose (C6H12O6)
4. heterotrophs that consume producers
5. the successive levels of organisms consuming one another
6. the GPP (total energy captured) - the energy from the respiration of producers
7. the movements of matter within and between ecosystems that involve biological, geological, and chemical processes
8. single essential nutrient that limits productivity in an ecosystem
9. process of converting nitrogen gas (N2) into ammonia (NH3)
Photosynthesis
Trophic levels
Nitrogen fixation
NPP
Limiting factor
Primary consumer
Biogeographical cycles
Producers 3 5 9 6 8 4 7 2

23. 10. an event caused by physical, chemical, or biological agents that results in changes in population size or community composition
11. the rate at which an ecosystem returns to its original state after a disturbance
12. when plants release water from their leaves into the atmosphere
13. organisms that specialize in breaking down dead tissues and waste products into smaller particles
14. carnivores that eat secondary consumers
15. The tendency of a shared, limited resource to become depleted because people act from self-interest for short-term gain
16. dominated by trees and other woody vegetation (if you got this wrong, that's really sad)
17. Removes single trees or relatively small number of trees from among many in a forest
18. dry, open grasslands
19. large areas typically planted with a single rapidly growing tree species
20. has a goal of maintaining all species, both plants and animals, in a close to a natural state as possible
21. creation of urbanized areas that spread into rural areas and remove clear boundaries between the two
22. The limiting nutrient of freshwater systems.
Transpiration
Selective cutting
Resilience
Tertiary consumers
Rangelands
Eutrophication
Phosphoros
Disturbance
Sustainable forestry
Tragedy of the
commons
Detritivores
Urban sprawl
Tree plantations
Forests 12 17 11 14 18 23 22 10 20 15 13 21 19 16
23. Nutrients in freshwater lakes and ponds that leads to an increase in the growth of algae.

24. Forests are an example of natural capital by providing many valuable economic services. However, due to harvesting forests for these resources we have greatly reduced to important ecological services they also provide to the ecosystem.
Identify TWO ecological services that forest ecosystems provide.
Explain how clear cutting is an example of a positive feedback loop for erosive processes.
Describe TWO environmental impacts deforestation practices have on the ecosystem.
Discuss how human activities are threatening to the survival of available forested area.
Identify a potential economic impact of losing our forests.
Humans currently dominate the majority of the planet. Is it estimated that humans use, waste, and/or destroy up to 55% of the net primary productivity of the planet’s terrestrial ecosystems and is increasing around the world. (give 2 reasons for each)
What harmful impacts have humans had on the deserts that have caused concern?
What harmful impacts have humans had on the grasslands that have caused concern?
What harmful impacts have humans had on the forests that have caused concern?
What harmful impacts have humans had on the mountains that have caused concern?
Differences in average annual precipitation and temperature largely determine the location and lead to the formation of our biomes. Desert biomes typically experience larger evaporation than precipitation. Annual precipitation in desert ecosystems is low and often scattered unevenly during the year.
Describe how the rain shadow effect has played a role in forming some major desert ecosystems in the world.
Explain why desert ecosystems take a long time to recover from any environmental disturbance.
Identify some adaptations a plant and animal may utilize to be successful in the desert ecosystem.
Discuss TWO anthropogenic factors that lead to an increasing distribution of deserts globally.