Unit 2 APES - FRQs

1 (c) explain how the change could set the stage for the takeover of Japanese stilt grass or other exotic species.

"the exotic species are often more tolerant than native species of drier soils, and therefore, out-compete native species"

5 (c) In order to model the effects of ocean acidification on coral reefs, some simplifying assumptions can be made. Use the assumptions in the table below to perform the calculations that follow. Assume that the total global area of corals growing in reefs is 2.5 × 1011 m2 . Assume that corals grow only vertically and that the average vertical growth rate of corals is 3 mm/year. Assume that the average density of CaCO3 in corals is 2 × 103 kg/m3 . (iii) Because of ocean acidification, it is expected that in 2050 the mass of CaCO3 deposited annually in coral reefs will be 20 percent less than is deposited currently. Calculate how much less CaCO3 , in kg, is expected to be deposited in 2050 than would be deposited if ocean water pH were to remain at its current value.

0.2 x 1.5 x 10^12 kg = 3 x 10^11 kg

12 a. Describe the critical processes by which nitrogen is cycled through the biotic and abiotic components of Earth's ecosystems and identify the primary storage sink for nitrogen.

1) atmospheric nitrogen is fixed by bacteria in soil and in root nodules to produce ammonia/ammonium (some by lightning). 2) Ammonia is oxidized in soil by nitrifying bacteria to nitrites and then to nitrates. 3) Plants take up soluble nitrogen compounds through roots. 4) In plants, nitrogen compounds are used to produce biochemicals like protein, DNA, chlorophyll. 5) Denitrifying bacteria break down nitrogen compounds in the process of decomposition and release elemental nitrogen back into the atmosphere; or nitrifying decomposers break down organic nitrogen compounds, making them available to plants in the form of nitrates.

1 (b) Describe THREE abiotic changes that would be likely to result if the exotic worms consumed all the leaf litter in a single year.

1. erosion of soil would increase 2. changes in soil temperature 3. loss of soil coverage

4 (c) As the article states, the number of managed honeybee colonies has dropped significantly over the past few decades. Describe TWO specific economic consequences of the collapse of the managed honeybee colonies.

1. increased prices for food crops 2. loss of jobs because of lower crop yields

7 (c) The burning of fossil fuels has been shown to increase the concentration of carbon in the atmosphere. Discuss TWO other human activities that increase the concentration of carbon in the atmosphere.

1. production of cement releases co2 2. destruction of wetlands (releases co2)

6 (e) Describe TWO ecological benefits that greater biodiversity provides.

1. stability of ecosystems 2. control of pest species

2 (a) The United States consumes approximately 20 million barrels of oil per day. According to the USGS estimate, for how many days would the technically recoverable oil resource in ANWR supply the total United States demand for oil?

10,000,000,000 barrels / 20,000,000 barrels per day = 500 days

5 (c) In order to model the effects of ocean acidification on coral reefs, some simplifying assumptions can be made. Use the assumptions in the table below to perform the calculations that follow. Assume that the total global area of corals growing in reefs is 2.5 × 1011 m2 . Assume that corals grow only vertically and that the average vertical growth rate of corals is 3 mm/year. Assume that the average density of CaCO3 in corals is 2 × 103 kg/m3 . (i) Calculate the current annual global increase in volume, in m3 , of CaCO3 in coral reefs. Show all steps in your calculation.

2.5 x 10^11 m^2 x 3mm/year x 1m/1x10^3mm = 7.5 x 10^8 m^3 / year

5 (c) In order to model the effects of ocean acidification on coral reefs, some simplifying assumptions can be made. Use the assumptions in the table below to perform the calculations that follow. Assume that the total global area of corals growing in reefs is 2.5 × 1011 m2 . Assume that corals grow only vertically and that the average vertical growth rate of corals is 3 mm/year. Assume that the average density of CaCO3 in corals is 2 × 103 kg/m3 . (ii) Calculate the current annual global increase in mass, in kg, of CaCO3 in coral reefs. Show all steps in your calculation.

7.5x10^8 m^3 / year x 2x10^3kg/1m^3 = 15 x 10^11 kg

13 (c) A science class wanted to test the effects of an intensifying El Niño event on the amount of rainfall in their local area in the southeastern United States. For a measure of El Niño intensity, they monitored sea surface temperatures off the coast of Ecuador for a six-month period by consulting an oceanography Web site. They measured rainfall locally with rain gauges for the same six-month period. The table below shows the results compared to a typical or non-El Niño year. Sea surface temperature increase over six-month period Total rainfall over six-month period Typical normal (non-El Niño) year Current El Niño year (i) Identify a dependent variable in the study.

Amount of rainfall

13 (b) The model below shows a cross sectional view of El Niño conditions. (i) Describe a change in ocean circulation that results from an El Niño event that is represented in the model.

During an El Niño event, the surface waters in the central and eastern Pacific Ocean become significantly warmer than usual. That change is intimately tied to the atmosphere and to the winds blowing over the vast Pacific. Easterly trade winds falter and can even turn around into westerlies.

13 (b) The model below shows a cross sectional view of El Niño conditions. (ii) Explain how a change in the atmosphere that results from El Niño conditions represented in the model would affect Australia.

El Nino causes droughts in the Western Pacific. These conditions cause brush fires in Australia; The El Niño phase has extensive warming of the central and eastern tropical Pacific Ocean which leads to a major shift in weather patterns across the Pacific Ocean. El Niño conditions generally result in below average rainfall over much of eastern Australia. The La Niña phase has extensive cooling of the central and eastern tropical Pacific Ocean and generally leads to above average rainfall over much of Australia.

13 (b) The model below shows a cross sectional view of El Niño conditions. (iii) Describe one environmental effect resulting from the conditions represented in the model that could have a negative effect on humans in western South America.

Over the US and Canada there will be lower than average precipitation and this pattern follows the coast southwards where the western portion of South America will also experience lower than average rainfall.

7 (a) The atmosphere is one important carbon reservoir. (i) Describe a biological process by which carbon is removed from the atmosphere and converted to organic molecules.

Photosynthesis: the process by which plants take in co2 from the atmosphere and convert it into glucose.

10 (b) Describe the process of primary productivity.

Primary productivity is a term used to describe the rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem.

6 (b) Identify TWO specific human activities that result in a loss of biodiversity, and explain how each activity lowers biodiversity.

activity: clearing land for construction explanation: reduces habitat for many species activity: overfishing explanation: reduces top predators

6 (c) For each human activity, you discussed in (b), propose a practical strategy (other than simply banning the activity) to reduce the loss of biodiversity.

activity: clearing land for construction solution: habitat-conservation areas activity: overfishing solution: regulate activities

2 (c) Identify TWO activities that would be associated with the development of ANWR petroleum resources and describe a substantial environmental impact of each in ANWR.

activity: increased air traffic environmental impact: disruption of migration routes activity: construction on airstrips environmental impact: displacement of populations

13 (a) There is evidence that global climate change over the past 100 years has led to an increased warming of Earth because of the greenhouse effect. (ii) Identify one human activity that could directly contribute to global climate change.

burning of fossil fuels

3 (a) Identify TWO characteristics of forests that develop when fires are suppressed, and explain why the practice of fire suppression does not reduce, but actually increases, the risk of intense and extensive forest fires.

characteristic of forest: larger trees develop explanation for increased fire risk: adds to fuel load [intensity] - increased size of trees characteristic of forest: tree density increases explanation for increased fire risk: adds to spreading of fire [extent] - increased density of trees

2 (b) Describe TWO characteristics of arctic tundra that make it fragile and explain how these two characteristics make the tundra particularly susceptible to damage from human impacts.

characteristic: (biological) slow growth / decomposition rates susceptibility to damage: slow recovery rates characteristic: (climatological) short growing seasons susceptibility to damage: slow recovery rates

7 (b) Oceans and terrestrial systems are also important carbon reservoirs. (i) Explain how atmospheric carbon is incorporated into two oceanic sinks.

co2 can be taken up by organisms like phytoplankton for photosynthesis

8 (e) Many species, including some whales and birds, will travel thousands of kilometers during annual migrations. (ii) The North Atlantic right whale migrates between subtropical and polar waters annually. Nearly 50 percent of right whale deaths are due to human activities. Describe one commercial activity, other than whaling, that may result in the death of right whales.

commercial activity: fishing gear can accidentally trap

6 (a) Describe TWO characteristics shared by ecosystems that have high biodiversity.

complex food webs

14 b. Describe the connection between the climate change associated with an El Niño and the transmission of diseases. Explain whether the article is correct in its reporting of the various disease epidemics that occur in response to an El Niño.

connection 1: Climate change of wetter conditions promote transmission of disease by increasing the regions where mosquitoes breed — some mosquitoes are carriers of diseases such as malaria, dengue fever, or yellow fever. connection 2: Climate change of warmer water promotes transmission of disease because bacterial growth increases in warm water connection 3: Climate change of higher air/land temperatures promote transmission of disease because increased temperatures may mean increase breeding and feeding of insects

8 (a) Refer to the food web above to complete the following table. Organism from Arctic food web (i) identify a primary producer

diatom (phytoplankton)

12 d. Describe ONE way in which humans have disrupted the natural cycling of carbon and TWO major environmental consequences of that disruption

disruption: burning of fossil fuels 1. consequence: global warming - weather disruptions - heat waves (for ex) 2. consequence: increased rates of photosynthesis

3 (c) Describe TWO ecosystem services provided for humans by forests. Explain how clear-cutting would affect each ecosystem service you describe.

ecosystem service: forests provide oxygen (via photosynthesis) impact of clear-cutting: some loss of oxygen, without which we cannot live ecosystem service: forests provide habitat for many species, some of which provide food and goods for humans, some of which cause harm impact of clear-cutting: loss of habitat (biodiversity)

4 (d) Pollination by native insects is considered an ecosystem service. Identify a different ecosystem service and explain how that service benefits human society.

ecosystem service: release of oxygen by plants (oxygen cycle) benefit: necessary for human survival

7 (d) Identify an environmental problem that results from elevated atmospheric carbon concentrations. Discuss one consequence of the problem you identified.

environmental problem: sea level rise environmental consequence: coastal habitats will be flooded

10 (a) Refer to the food web above to identify the following organisms. (iii) Identify two organisms that compete for the same food source.

fish and sea snail (compete for seaweed)

3 (d) Identify a specific type of plant community or biome (other than a forest) that is naturally maintained by fire. Explain how the fire maintains the community or biome.

grasslands (savannah, steppe) - fire helps the seeds of native grasses to germinate

10 (a) Refer to the food web above to identify the following organisms. (ii) Identify a tertiary consumer.

herring gull

4 (a) As mentioned in the article, there are several possible explanations for the increase in mountain pine beetles. (ii) Reduced winter mortality of beetle larvae is likely a consequence of global climate change. Describe TWO ways that the activities of the beetles might enhance climate change.

higher levels of dead tree matter release more co2 through decomposition burning of forests as a result of infestation (dead trees) releases co2

8 (c) Describe how the change in sea ice habitat is affecting polar bears' ability to hunt and feed.

increasing the time between successful krills results in bears spending more time waiting/hunting for prey

14 c. People in what part of the world would be most likely to be affected by this link between El Niño and disease?

islands in the tropical Pacific (e.g., Papua New Guinea, Galapagos islands)

8 (a) Refer to the food web above to complete the following table. Organism from Arctic food web (ii) identify a primary consumer

krill (zooplankton)

7 (b) Oceans and terrestrial systems are also important carbon reservoirs. (ii) Identify one terrestrial sink, other than fossil fuels, that stores carbon for thousands to millions of years.

limestone

5 (d) Identify and describe one likely negative environmental impact of the loss of coral reefs.

loss of habitat - loss of shelter/hiding places

2 (d) Identify and describe TWO major end uses of the 20 million barrels of oil that the United States consumes each day and for each use describe a conservation measure that would substantially reduce United States consumption.

major end use: non fuel products (asphalt) conservation measure: reduction in use (less roadway building) major end use: petroleum fuel products (heating uses) conservation measure: reduction in use (turn down thermostat (heating), turn up thermostat (cooling), insulation)

8 (d) Explain how melting sea ice leads to a feedback loop that increases Arctic warming.

melting of sea ice leads to a decrease in albedo, or reflectivity, leads to water surfaces absorbing more of the sun's energy AND Increasing absorbption of sun's energy wars the water surface further, which leads to further ice melt

12 c. Identify EITHER one nitrogen compound OR one phosphorus compound that is considered a pollutant when released by human activity into the environment. For the compound you identified, describe the human activity and a specific environmental problem that results.

nitrogen compound: nitrates in commercial fertilizers human activity: application of fertilizer in farming and subsequent runoff problem: Nitrogen pollutants affects groundwater pollution and toxic

5 (e) Identify one environmental problem (other than one due to ocean acidification or loss of coral reefs) that affects marine ecosystems on a global scale.

overfishing

7 (e) Phosphorus is another element important to all organisms. (i) describe one major way in which the phosphorus cycle differs from the carbon cycle

phosphorus cycle does not typically have a gas phase

7 (e) Phosphorus is another element important to all organisms. (ii) identify one reason that phosphorus is necessary for organisms

phosphorus is a component of nucleotides

4 (b) The widespread death of trees leads to a series of changes in a forest ecosystem. Identify TWO physical changes that occur in the forest ecosystem as the result of the death of mature trees. For each physical change you identify, describe an impact of that change on the forest ecosystem.

physical change: increased flooding impact on ecosystem: loss of nutrients (leaching) physical change: increased soil temperature ecosystem: changes in plant growth

3 (b) The effects of the HFI are expected to extend beyond fire reduction. Excluding fire reduction, describe ONE positive and ONE negative effect likely to result from the implementation of the provisions of the HFI.

positive effect: increased removal of medium and large trees will lower the cost of timer negative effect: the removal of medium and large trees will reduce public input

8 (e) Many species, including some whales and birds, will travel thousands of kilometers during annual migrations. (i) Provide one reason a species may migrate a long distance.

protection of offspring from predators

1 (a) Support Dr. Tate's assertion that "the leaf litter is critical to the survival of local species of forest plants." Include in your discussion the roles of leaf litter in a deciduous forest ecosystem.

provides shelter for seedlings

Read the following article from the Fremont Examiner. file:///Users/logan_mckeown/Downloads/ap2003_frq_1.pdf

question 1

An aquatic food web includes the following organisms.

question 10

The Alaskan National Wildlife Refuge (ANWR) on Alaska's North Slope is frequently in the news because petroleum geologists estimate that there are billions of barrels of economically recoverable oil beneath the surface of its frozen tundra. According to a 1998 United States Geological Survey (USGS) estimate, ANWR could contain up to 10 billion barrels of technically recoverable oil. Oil company officials advocate opening the refuge to oil exploration and the subsequent development of its petroleum resources. Environmentalists argue that oil exploration and development will damage this fragile ecosystem and urge Congress to protect ANWR by designating it as a wilderness area.

question 2

For decades, forest fires in the United States have been suppressed. In 2003 legislation was passed under the Healthy Forests Initiative (HFI) in response to the record-breaking wildfires that had occurred in the early 2000s. Some environmental and conservation groups fear that negative impacts could result if timber companies are encouraged to harvest medium- and large-size trees in federally owned forests while clearing away the smaller trees and underbrush.

question 3

Read the following article from the Fremont Inquirer and answer the questions that follow. file:///Users/logan_mckeown/Downloads/APES_2011_1.pdf ->Article

question 4

Coral reefs are produced when corals acquire calcium ions (Ca2+) and carbonate ions (CO3 2−) from seawater and deposit solid CaCO3 to form their exoskeletons. Scientists are concerned that relatively rapid decreases in ocean water pH will hinder the deposition of CaCO3. The graph above shows the amount of CO2 dissolved in ocean water and ocean water pH (shown in parentheses) since 1850 and the predicted changes through 2100.

question 5

Biological diversity, or biodiversity, has become a topic of great concern among conservationists. Biodiversity is often used by scientists and policymakers to help determine the health of ecosystems.

question 6

Biogeochemical cycles describe the movement of certain elements (typically bound with other elements in compounds) through Earth's atmosphere, hydrosphere, biosphere, and lithosphere. These elements and their compounds are necessary components of all life, and because they cycle, they can be used repeatedly by new generations of organisms. Each biogeochemical cycle has different pathways with various reservoirs (sources and sinks) where elements may reside for days or millions of years.

question 7

An Arctic food web includes the following organisms.

question 8

The Anolis genus consists of many colorful lizard species that inhabit warm, tropical environments. Recently, researchers noticed that the leg lengths of these lizards seem to vary depending on the size of branches on which they crawl. When living on islands with small, narrow branches, these lizards have short legs. When living on islands with large, wide branches, the lizards have long legs. Researchers have hypothesized that this difference occurs as a result of natural selection. Below is a summary of their experiment.

question 9

7 (a) The atmosphere is one important carbon reservoir. (ii) Describe a biological process by which carbon is converted from organic molecules to a gas and returned to the atmosphere.

respiration breaks down glucose and releases co2 into the atmosphere

8 (a) Refer to the food web above to complete the following table. Organism from Arctic food web (iii) identify a secondary consumer

seal

10 a) Refer to the food web above to identify the following organisms. (i) Identify a primary producer.

seaweed

8 (b) Other than showing which organisms are consumed by other organisms, describe what is indicated by the direction of the arrows in the diagram.

shows the flow of energy among trophic levels

8 (e) Many species, including some whales and birds, will travel thousands of kilometers during annual migrations. (iii) Describe one strategy that could reasonably be implemented to decrease right whale deaths caused by the commercial activity you described in part (ii).

strategy: fines for discarded fishing gear so less gear is discarded reducing the number of whales trapped in gear

12 b. Explain ONE major way in which the phosphorus cycle differs from the nitrogen cycle.

that the major sink in the phosphorus cycle is the lithosphere

5 (b) Explain why the movement of carbon into the ocean has been increasing since 1850.

the concentration of co2 in the atmosphere has increased.

14 a. Describe what an El Niño is and clearly indicate where it occurs.

what it is: development of warm ocean waters where it occurs: tropical pacific ocean

6 (d) Describe ONE naturally occurring factor that could lead to a loss of biodiversity.

widespread wildfires can wipe out small populations

13 (c) A science class wanted to test the effects of an intensifying El Niño event on the amount of rainfall in their local area in the southeastern United States. For a measure of El Niño intensity, they monitored sea surface temperatures off the coast of Ecuador for a six-month period by consulting an oceanography Web site. They measured rainfall locally with rain gauges for the same six-month period. The table below shows the results compared to a typical or non-El Niño year. Sea surface temperature increase over six-month period Total rainfall over six-month period Typical normal (non-El Niño) year Current El Niño year (ii) Identify the control group in the study.

Intensification of El Niño

13 (c) A science class wanted to test the effects of an intensifying El Niño event on the amount of rainfall in their local area in the southeastern United States. For a measure of El Niño intensity, they monitored sea surface temperatures off the coast of Ecuador for a six-month period by consulting an oceanography Web site. They measured rainfall locally with rain gauges for the same six-month period. The table below shows the results compared to a typical or non-El Niño year. Sea surface temperature increase over six-month period Total rainfall over six-month period Typical normal (non-El Niño) year Current El Niño year (iv) Describe how the results of the study would differ in total rainfall over a six-month period in the southeastern United States if the data were collected during a La Niña year rather than an El Niño year.

La Niña is the build up of cool waters in the equatorial eastern Pacific to a slightly lesser degree. La Niña's impacts are opposite to those of El Niño. The atmosphere cools in response to the cold ocean surface, and less water evaporates. The cooler, dry air is dense. It doesn't rise or form storms. As a result, less rain falls over the eastern Pacific. Southeastern United States are correspondingly dry.

13 (a) There is evidence that global climate change over the past 100 years has led to an increased warming of Earth because of the greenhouse effect. (iiii) What could affect the relative abundance of the major greenhouse gases in the atmosphere?

Larger emissions of greenhouse gases lead to higher concentrations in the atmosphere. Each of these gases can remain in the atmosphere for different amounts of time, ranging from a few years to thousands of years. All of these gases remain in the atmosphere long enough to become well mixed.

4 (a) As mentioned in the article, there are several possible explanations for the increase in mountain pine beetles. (i) Provide one reason why fire-suppression policies lead to increased beetle activity.

Suppression leads to increased numbers of trees

13 (a) There is evidence that global climate change over the past 100 years has led to an increased warming of Earth because of the greenhouse effect. (i) Describe how the solar radiation that arrives at the equator is redistributed around the Earth through atmospheric circulation.

The energy from the sun is distributed by Radiation and Convection. Some of the radiation is absorbed by the atmosphere, while some is reflected by the atmosphere and clouds. Convection is heat transfer affecting the atmosphere, waters, and solid earth. In convection the heated fluid itself is moving. The flow of heated fluid in this situation is called a convection current.

13 (a) There is evidence that global climate change over the past 100 years has led to an increased warming of Earth because of the greenhouse effect. (iii) Describe how the activity identified in part (a):

When fossil fuels are burned, they release carbon dioxide and other greenhouse gases, which in turn trap heat in our atmosphere, making them the primary contributors to global warming and climate change.

10 (c) Describe one short-term, direct effect that over harvesting crabs would have on the food web shown above.

The overharvesting of crabs would cause the crabs to be extinct. This directly affects the sea snail population, as it would overpopulate because they are not being eaten by the only consumer which consumes them to maintain a balanced population and ecosystem.

10 (d) Besides banning all harvest of crabs, describe one potential realistic strategy to increase the population of crabs.

To increase the population of crabs, a realistic strategy involves implementing fishing restrictions/regulations.

13 (c) A science class wanted to test the effects of an intensifying El Niño event on the amount of rainfall in their local area in the southeastern United States. For a measure of El Niño intensity, they monitored sea surface temperatures off the coast of Ecuador for a six-month period by consulting an oceanography Web site. They measured rainfall locally with rain gauges for the same six-month period. The table below shows the results compared to a typical or non-El Niño year. Sea surface temperature increase over six-month period Total rainfall over six-month period Typical normal (non-El Niño) year Current El Niño year (iii) In addition to direct measurements, relative sea surface temperatures can be inferred with radar measurements from satellites. Cold sea surface water will be further away from the satellite than warm sea surface water. Explain why this occurs.

Upwelling is characterized by cold waters that rise up from the depths, often near the coasts; and warm water currents, such as the Gulf Stream.

5 (a) Explain how an increase in the amount of dissolved CO2 in ocean water results in a decrease in the pH of ocean water.

When co2 dissolves in the ocean, it forms an acid (carbonic acid or H2CO3).