1.
(a)
It has been suggested that “extinction is a natural process therefore we should not worry
about the loss of biodiversity”. Give two reasons why you either agree or disagree with
this statement.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(b)
List two advantages and two disadvantages of the role of captive breeding programs and
zoos in the conservation of endangered species.
(i)
Advantages
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Disadvantages
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
1
(c)
Evaluate the strengths and weaknesses of the Convention on International Trade in
Endangered Species (CITES).
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 8 marks)
2.
“Protecting the environment is a luxury that only the most economically developed countries of
the world can afford.”
(a)
State whether an ecocentrist or a technocentrist is more likely to agree with the statement
above. Justify your answer.
(2)
(b)
Discuss the arguments for and against the statement above. In your answer you should
refer to examples from both more economically developed and less economically
developed countries.
(10)
(c)
For an environmental issue you have studied, describe the roles of different groups in the
management of this issue. In your answer you could consider local, national and
international groups.
(5)
Expression of ideas (3)
(Total 20 marks)
2
3.
(a)
Describe the process of soil degradation and explain the direct and indirect consequences
to the environment.
(4)
(b)
Explain, using a named farming system, how
(7)
(i)
a technocentric approach can aid soil conservation.
(3)
(ii)
an ecocentric approach can aid soil conservation.
Expression of ideas (3)
(Total 17 marks)
4.
The pie charts below show the relative contributions of different sources of commercial energy
for less economically developed countries (LEDCs) and more economically developed countries
(MEDCs).
Commercial Energy Use by Source in LEDCs
Commercial Energy Use by Source in MEDCs
biomass 3 %
oil 26 %
biomass 35 %
oil 37 %
coal 25 %
nuclear power
1%
natural gas 7 %
hydropower,
geothermal &
solar 6 %
coal 25 %
nuclear power 5 %
natural gas 23 %
hydropower,
geothermal &
solar 7 %
[MILLER, Living in the Environment, 15E. © 2007 Brooks/Cole, a part of Cengage Learning, Inc.
Reproduced by permission. www.cengage.com/permissions]
3
(a)
State and explain the differences shown in the two pie charts.
(5)
(b)
Compare the advantages and disadvantages of fossil fuels and solar energy with respect to
efficiency and sustainability.
(6)
(c)
Discuss the Cornucopian view of the environmental challenges posed by the extensive
use of fossil fuels.
(6)
Expression of ideas (3)
(Total 20 marks)
5.
The figure below contains an ancient Chinese proverb.
Proverb
If you are thinking a year ahead,
sow seed
If you are thinking ten years ahead,
plant a tree
If you are thinking a hundred years
ahead, educate the people
Chinese poet Kuan Tzu 500 BC
4
(a)
The poet Kuan Tzu could be seen as an ecocentrist or a technocentrist. Justify whether
you think his views are ecocentric or technocentric.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(4)
(b)
Outline two factors which may affect someone’s environmental philosophy.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 6 marks)
5
6.
“The ecological footprint rests on a restrictive understanding of sustainability and it makes use
of questionable assumptions – the most serious being that we should raise forests in order to
solve the problem of carbon dioxide emissions.”
[Danish Environmental Assessment Institute (2002) Assessing the Ecological Footprint: A Look
at the WWF’s Living Planet Report]
(a)
Explain the concept of the ecological footprint and evaluate the usefulness of the concept
in global conservation.
(7)
(b)
Explain how societies can reduce their ecological footprint through technological
advancement.
(6)
(c)
Environmental philosophies can be classified as ecocentric (nature centred) and
technocentric (technology centred). Evaluate which environmental philosophy you think
is best suited to achieving long term sustainability.
(5)
Expression of ideas (2)
(Total 20 marks)
6
7.
Figure 1 — Fact File on Glen Canyon
Initial cost: $300 million (in 1963)
Ongoing costs: estimated between $11 and $29 million
Height: 216 m
Completed: 1963
Amount of Glen Canyon flooded by Lake Powell: 299 km
Economic benefits:
•
The Colorado River provides water for more than 30 million people and without Glen
Canyon Dam a lot of this water would be “wasted”.
•
Glen Canyon Dam allows the southwest of the United States to be developed and populated
far more than the pre-dam conditions.
•
85 % of the water is used for irrigation for agricultural production enabling arid regions to
become fertile agricultural lands and economically viable.
•
Because of the high productivity of these areas, many people in the United States are
provided with fruits and vegetables all year round.
•
The Glen Canyon Dam power station represents a cheap source of hydroelectric power for
much of the southwestern United States and for parts of Mexico, including many poor rural
and Native American communities.
•
The water supply enabled development of the town of Page, Arizona, which currently has
over 8,200 residents.
•
4 million visiting tourists (often en route to the Grand Canyon and Monument Valley) bring
in $2.5 million each year.
•
Many jobs depend on the tourist industry. The largest employers are the National Park
Service and the Navajo Generating Station.
•
Lake Powell itself provides fishing, boating, water-sports and camping to tourists each year.
•
Downstream, recreational fisheries have been improved. Non-native trout have done
especially well, further attracting tourists to one of the finest trout fishing sites in the
southwest.
•
Altered flows provide excellent rapids and runs for rafters and kayakers each year.
[Source: Adapted from the article “Large Dams in the Western United States”, produced by Environmental Science
students at Kenyon College in 1989, www2.kenyon.edu/Projects/Dams/index.html]
7
Figure 2 — Map of the Lower Colorado River
[In public domain, US Gov: http://www.saltonsea.water.ca.gov ]
8
Figure 3 — Photograph of Glen Canyon Dam, Lake Powell is behind
[http://commons.wikimedia.org/wiki/File:Glen_Canyon_Dam.jpg]
9
Figure 4 — The Advantages of Hydroelectric Power (HEP)
Adapted from a website produced by the National Hydropower Association (US).
A major source of energy
•
The United States is the second largest producer of hydroelectric power (HEP) in the
world.
•
HEP contributes 8–12 % of the United States’ electrical generation.
•
Globally, one-fifth of electricity is generated from HEP.
Clean and renewable – a sound environmental choice
•
93 % of Americans believe HEP is important for meeting future electricity needs.
•
HEP is a renewable source of electricity. HEP accounts for 80 % of the United States’
total renewable electricity generation making it the leading renewable energy source.
•
In 1999, HEP avoided the release of an additional 77 million metric tons of carbon
equivalent into the atmosphere. This is equivalent to the annual exhaust of half of the cars
on United States roads.
•
HEP projects can enhance wetlands and support healthy fisheries. Wildlife preserves can
be created around reservoirs, which can provide stable habitats for endangered or
threatened species.
Reliable, efficient, secure… and fun!
•
Today’s HEP turbines are capable of converting 90 % of available energy into electricity that is more efficient than any other form of generation.
•
HEP’s operational flexibility – its unique ability to change output quickly – is highly
valued and will become even more so in a competitive market. Its unique voltage control,
load-following and peaking capabilities help maintain the stability of the electric grid
ensuring economic growth and a high quality of life.
•
HEP adds to national security. Water from rivers is a purely domestic resource that is not
subject to disruptions from foreign suppliers, production strikes or transportation issues.
•
There were a total of 81 million recreation user days provided by licensed HEP projects in
1996. Boating, skiing, camping, picnic areas and boat launch facilities are all supported
by HEP.
[Source: Adapted from: United States National Hydropower Association www.hydro.org, Idaho National Laboratory]
10
Figure 5 — Historical water discharge and suspended sediment discharge trends as a
result of the construction of dams along the Colorado River (including Glen Canyon Dam)
40
(a) Water discharge
billions of m3
30
20
10
1910
1920
1930
1940
1950
1960
years
400
(b) Suspended sediment discharge
billions of kg
300
200
100
1920
1930
1940
1950
1960
1970
years
[Source: The United States Geological Survey in Schwarz et al. (1991), published in Goudie, The Human Impact on
the Natural Environment, Blackwell, 1993, page 182]
11
Figure 6 — The Chief Environmental Impacts of Dams
Impacts due to existence of dam and reservoir:
1.
Reservoir in place of a river valley (loss of habitat).
2.
Changes in downstream morphology of riverbed, delta, coastline due to altered sediment
load (increased erosion).
3.
Changes in downstream water quality: effects on river temperature, nutrient load,
turbidity, dissolved gases, concentration of heavy metals and minerals.
4.
Reduction of biodiversity due to blocking of migration of fish (e.g. salmon) and because
of above changes.
Impacts due to pattern of dam operation:
1.
Changes in downstream hydrology:
(a) change in total flows;
(b) change in seasonal flows (e.g. spring flood becomes winter flood);
(c) short-term fluctuations in flows (sometimes hourly);
(d) change in extreme high flow and low flow.
2.
Changes in downstream morphology caused by altered flow pattern.
3.
Changes in downstream water quality caused by altered flow pattern.
4.
Reduction in riverine/floodplain habitat diversity, especially because of elimination of
floods.
[P McCully (1996), ‘Silenced Rivers, The Ecology and Politics of Large Dams’, London, Zed Books]
12
River Otter and Muskrat are now absent from the
Grand Canyon.
Squawfish, Roundtail Chub and several other species
have disappeared.
Many birds (e.g. Western Willow Flycatcher), lizards
and invertebrates have been lost from the system.
Non-indigenous, generalist, plant and animal species
are invading including fish: several exotic trout
species, Bluegill, Sunfish and Channel Catfish are now
present in the system.
The truncation of the habitat corridor between the
Hoover and Grand Canyon Dam has interrupted
migration routes and is leading to genetic isolation of
certain indigenous species.
Due to the constant cold temperature of the river
downstream Blue Green Algae and Cladophora
have replaced the natural warm water food web.
The temperature variation would previously trigger
native fish reproduction and maintain native insect
populations.
The Colorado River runs through Mexico and its delta
area was classified as an International Biosphere in
1992. Since the Glen Canyon Dam was built water
rarely reaches the delta area.
Biological Habitats
Grand Canyon
and
Glen Canyon Dams
Indigenous Havasupi people inhabit the Grand Canyon basin.
Navajo and Hualapai people possess land in the Grand Canyon.
Hopi and Zuni have sacred rites in the Grand Canyon.
The presence of the dams have made indigenous people dependent
on its water; a trait not previously apparent in their culture.
River erosion is causing the destruction of archaeological sites.
People and Culture
The Grand Canyon is 446 km long, 1.5 km deep and 30 km wide.
Shaped by the Colorado River the Grand Canyon was declared a
world heritage site in 1919.
Hoover Dam was created in 1941 flooding the lower 20 % of the
Grand Canyon.
Glen Canyon Dam was completed in 1963, 24 kms upstream from
the Hoover Dam.
No formal environmental impact study was carried out on either
of the dams.
Glen Canyon Dam now traps 95 % of the sediments carried by the
Colorado River.
Downstream, soil and river fertility is compromised by a lack of
organic enrichment from sediment deposition.
River beach and bar erosion is now a problem downstream.
Water temperature downstream is a constant 8  C because water is
extracted from the dams at a depth of 60m – this water is cold, not
having been heated by the sun as surface water would be.
Prior to damming water temperature ranged from 3  C to 27  C.
Regulated flows currently keep the Colorado River in Grand
Canyon fluctuating between 228 – 570 cubic meters per second
(m3 s–1). Before the Glen Canyon Dam, flows fluctuated between
86 – 2571 m3 s–1.
Physical Properties
Figure 7 — Dam Impacts
13
Figure 8 — What is a good dam? A checklist
The following is an edited list of suggestions from International Dams Newsletter, 1986.
1.
No dam should be built until an adequate assessment of its likely environmental effects
has been undertaken and made available to the public.
2.
Water-development projects should only be undertaken if they can be shown to benefit
large sectors of the population instead of the urban elite.
3.
Schemes should favour labour-intensive rather than capital-intensive economic
activities.
4.
They should produce food crops for feeding the local population rather than for export.
5.
They should not compromise public health and safety.
6.
They should not adversely affect national parks, heritage sites, areas of scientific and
educational importance, tropical rainforests or areas inhabited by species threatened with
extinction.
7.
They must be viable for a minimum of 100 years. They should only be built where it can
be guaranteed they will not silt up.
8.
They should not be built if their associated irrigation schemes are likely to lead to the
salinisation of agricultural land.
9.
The funding should be based on sustainable long-term resource enhancement rather than
short-term resource exploitation.
10. They should not involve displacing indigenous people from their homelands and
endangering their culture, unless compensation is provided and they are better off than
before the project.
11. There must be no potential significant engineering or safety problems.
12. They should not be built where they are likely to inflict significant damage to estuarine
or ocean fisheries.
13. They should not be built if they are likely to significantly harm the environment of a
neighbouring country without its full consent.
[Source: Edited from International Dams Newsletter, 1986. Permission granted by International Rivers]
14
8.
The data in table 1 show the ecological footprints for people in various countries of the world. A
five hectare footprint would mean that five hectares of biologically productive space (including
land and sea) are in constant production to support the average individual of that country.
Available capacity is the total amount of biologically productive space for each country. If the
footprint exceeds the biologically productive area of the country, the country has an ecological
deficit.
Table 1
Population in 1997
Ecological
footprint /
–1
hectares person
Available capacity /
–1
hectares person
Ecological
difference (deficit
if negative) /
–1
hectares person
Australia
18 550 000
9.0
14.0
5.0
Ethiopia
58 414 000
0.7
0.5
–0.3
Germany
81 845 000
5.3
1.9
–3.4
India
790 230 000
0.8
0.5
–0.3
Indonesia
203 631 000
1.4
2.6
1.2
Japan
125 672 000
4.3
0.9
4 375 000
6.2
6.3
0.1
146 381 000
6.0
3.7
–2.3
2 899 000
7.2
0.1
–7.1
6.7
–3.6
Norway
Russian Federation
Singapore
United States
268 189 000
United Kingdom
58 587 000
5.2
1.7
–3.5
Venezuela
22 777 000
3.8
2.7
–1.1
5 892 480 000
2.8
2.1
–0.7
WORLD
[Source: The Earth Council, Ranking the Ecological Impact of Nations,
http://www.ecouncil.ac.cr/rio/focus/report/english/footprint/ranking.htm]
(a)
(i)
Calculate the ecological deficit for Japan.
...........................................................................................................................
...........................................................................................................................
(1)
15
(ii)
Calculate the ecological footprint of a person in the United States.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
If the Earth’s resources were equally shared, there would be a total of 2.1 hectares
of space available for each person. State how many countries in table 1 have an
available capacity greater than 2.1 hectares.
...........................................................................................................................
(1)
(iv)
Suggest why Indonesia is not in ecological deficit despite the fact that its
population is so large.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
16
(b)
Gross Domestic Product (GDP) is a measure of the economic wealth of a country divided
by the number of people in that country. Table 2 shows the GDP for various countries.
Table 2
Country
GDP per person in 1999 / US$
Australia
21 300
Ethiopia
560
Germany
22 100
India
1720
Indonesia
2830
Japan
23 100
Norway
24 700
Russian Federation
4000
Singapore
23 300
United States
31 500
United Kingdom
21 200
Venezuela
8 500
[Source: based on data from the 1999 CIA World Factbook,
http://www.photius.com/wfb1999/rankings/gdp_per_capita_0.html]
17
(i)
Complete table 3, using the data from tables 1 and 2 to rank the countries according
to the size of their ecological footprints and GDP.
Table 3
Rank
Size of ecological footprint
(country with largest footprint first)
1
2
GDP
(country with highest GDP first)
United States
Australia
3
Norway
Singapore
4
5
Russian Federation
6
Germany
7
United Kingdom
8
9
10
11
12
Indonesia
India
Ethiopia
(2)
(ii)
State what relationship (if any) your ranking in table 3 shows between ecological
footprint and GDP.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Explain how it is possible for some countries, such as Singapore, to have such a
high GDP despite the fact that they have so little biologically productive space.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
18
(c)
(i)
Using data from table 1 only, state whether or not the current global use of
resources is sustainable. Justify your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Describe two ways in which a country might be able to descrease its ecological
footprint through technological development.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(4)
19
(iii)
Compare the attitudes of an ecocentrist and a technocentrist towards ecological
deficit.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(4)
(Total 20 marks)
9.
(a)
Describe the purpose of an Environmental Impact Assessment (EIA).
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
20
(b)
At the time of construction of Glen Canyon Dam no EIA was undertaken. Outline, giving
reasons, three variables which should have been measured as part of a baseline study
prior to starting construction.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(c)
With reference to Figure 5 and other resources in the booklet describe and explain how
water discharge and suspended sediment discharge changed as a result of the construction
of dams along the Colorado River.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(5)
21
(d)
Use the resource booklet to complete the table below to show how abiotic conditions
have changed as a result of the construction of Glen Canyon Dam
Abiotic factor in the
Colorado river
Increased or decreased
after construction of
Glen Canyon Dam
Size of the beach and sand bar habitats
decreased
Reason for change
Replenishing sediment
held back behind dam
Riverine habitat diversity
Water temperature range
Nutrient content of water in river
(3)
(e)
Identify a non-native species now present within the Colorado River because of the
construction of Glen Canyon Dam, and suggest possible impacts this might have on
native species.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
22
(f)
Discuss, using evidence from the resource booklet, why the decision to construct dams
along the Colorado River could be described as a “technocentric” approach to resource
management.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
23
(g)
With reference to the checklist for “good” dams in Figure 8 and the information from the
resource booklet, justify to what extent you consider Glen Canyon Dam to be a “good”
dam.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(6)
(Total 25 marks)
24
10.
(a)
Evaluate the role of socio-cultural factors in the development of different food production
systems.
(8)
(b)
Compare the attitudes towards the natural environment of two named contrasting
societies, and discuss the consequences of these attitudes to the way in which natural
resources are used.
(10)
Expression of ideas (2)
(Total 20 marks)
11.
(a)
Explain the increasing global demand for water and discuss the problems this causes for
managing water resources sustainably. Support your answer with reference to examples.
(5)
(b)
Describe the concept of an ecological footprint and evaluate its role as a model for
assessing the demands of humans on their environment.
(5)
(c)
Compare the approaches of technocentric and ecocentric resource managers to the issue
of an increasing demand for water resources.
(8)
Expression of ideas (2)
(Total 20 marks)
12.
While much attention has been focused on the impending planet-wide oil shortage, a far
greater problem awaits us. Arguably the next world war will be fought over water
resources not oil reserves.
[Source: adapted from www.waterconserve.org]
25
(a)
Describe the Earth’s water budget and explain why the distribution of water resources
could be a source of conflict in the future.
(7)
(b)
Discuss how ecocentric solutions to water resource needs can be applied on a local scale.
(5)
(c)
Describe and evaluate the role of technocentric solutions in meeting the demand for food.
(6)
Expression of ideas (2)
(Total 20 marks)
13.
(a)
(i)
Explain why phytoplankton is found mainly near the surface in ocean ecosystems.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
State an abiotic factor responsible for the zonation observed in the deep ocean.
...........................................................................................................................
(1)
(iii)
With reference to Figure 1, state which trophic level is occupied by the seagull.
...........................................................................................................................
(1)
(b)
With reference to Figure 2, identify two adaptations of the deep-ocean prawn to life on
the ocean floor.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
26
(c)
(i)
Sun
A simplified energy flow diagram for a tropical forest food chain is shown below.
Strangler fig
Fruit bat
Snake
Harpy eagle
Decomposers
In the space provided below, sketch a simplified energy flow diagram to show how
energy flows through the food chain at a deep-ocean vent.
(1)
(ii)
Suggest which features of deep-ocean food webs make them particularly
vulnerable to disturbance.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
State one way in which organic matter leaves the deep-ocean ecosystem.
...........................................................................................................................
...........................................................................................................................
(1)
27
(d)
(i)
With reference to Figure 5, describe and explain the pattern shown in the graph of
catches of Orange roughy during the 1990s.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
Suggest how the problem of unsustainable fishing practices might be overcome,
from an ecocentric viewpoint and a technocentric viewpoint.
Ecocentric .........................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Technocentric ...................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(4)
(e)
(i)
With reference to Figure 6, state the amount of carbon stored in the world’s
oceans.
...........................................................................................................................
(1)
28
(ii)
Suggest why scientists are increasingly interested in the role that oceans play as
carbon sinks.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Describe two reasons why ocean levels are expected to increase as a result of
global warming.
...........................................................................................................................
...........................................................................................................................
(1)
(f)
Suggest why there is relatively little public pressure to conserve deep-ocean ecosystems
and justify the need for them to be conserved.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(4)
(Total 23 marks)
29
14.
(a)
Define what is meant by the term sustainability.
(2)
(b)
Explain, with reference to a case study, how the concept of sustainability applies in the
exploitation of water resources.
(6)
(c)
Compare the environmental value systems of two named societies and describe how these
societies might differ in the way that they exploit their resources.
(10)
Expression of ideas (2)
(Total 20 marks)
15.
(a)
Distinguish between pyramids of numbers and pyramids of biomass, and outline two
consequences of pyramid structure in ecosystems.
(4)
(b)
Evaluate the advantages and disadvantages to ecosystems and societies of banning the
pesticide DDT.
(6)
(c)
With reference to examples other than pesticide use, describe the ways in which farmers
can improve the productivity of their soil, and discuss how the strategies adopted may
differ between technocentric and ecocentric farmers.
(8)
Expression of ideas (2)
(Total 20 marks)
30
The diagram below shows the effects of two different fishing policies on fish stocks over four
years.
High intensity fishing policy
Low intensity fishing policy
200
36
28
18
20
1
24
32
36
48
2
3
4
48
Weight of fish / tonnes
200
Weight of fish / tonnes
16.
36
168
16
6
1
2
3
4
Year
Key:
(i)
56
20
Year
(a)
120
Catch
Stock of fish
Define the term sustainable yield.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Calculate the total catch over four years in each fishing policy in the diagram
above.
High intensity: ...................................................................................................
Low intensity: ...................................................................................................
(1)
(iii)
Calculate the percentage difference between the year 4 catch for the high intensity
fishing policy and the year 4 catch for the low intensity fishing policy.
...........................................................................................................................
...........................................................................................................................
(1)
31
(iv)
Predict, giving two reasons, which fishing policy would probably give the greater
profit over 20 years.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Outline two reasons why hunting and fishing may not be controlled by legislation.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(c)
Compare the energy efficiency of terrestrial and aquatic food production systems.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
32
(d)
Suggest one possible solution that a technocentrist might give to the problem of
overfishing.
......................................................................................................................................
......................................................................................................................................
(1)
(Total 10 marks)
33