1. (a) (i) Outline the Gaia philosophy. ....................................................... ................................................... ................. ....................................................... ................................................... ................. (1) (ii) Explain the difference between an open system and a closed system. ....................................................... ................................................... ................. ....................................................... ................................................... ................. (1) (b) The first and second laws of thermodynamics suggest that energy is neither made or lost, merely transformed. Using a named ecosystem, outline how this occurs. ............................................................ ....................................................... .................. ............................................................ ....................................................... .................. ............................................................ ....................................................... .................. ............................................................ ....................................................... .................. ............................................................ ....................................................... .................. 1
(b) The first and second laws of thermodynamics suggest that energy is neither made or lost, merely transformed. Using a named ecosystem, outline how this occurs.
2. The pedosphere can be defined as “that shell or layer of the Earth in which soil forming processes occur”. [Bates and Jackson, 1980]
(a) State how the pedosphere forms an integral part of the environmental system and outline the interactions between the hydrosphere, atmosphere, biosphere and pedosphere.
(5)
(b) Compare the agricultural properties of sand and clay soils.(5)
(c) Compare and evaluate soil conservation measures for a named commercial farming system and a named subsistence farming system.
(7)(Total 17 marks)
3
3. The Inuit are indigenous aboriginal people of Northern Canada. The data below come from a study of a Inuit fish farming community. The Inuit fish in the open sea but have also sectioned off a large fjord (a long narrow inlet of the sea) which they use for farming salmon and shrimps. The shrimps eat microscopic plants in the sea called phytoplankton. Salmon and kawai (a wild fish) both eat shrimps.
Figure 1
All units in KJm–2 yr–1
Insolation on fjord 185000.0
Insolation on open sea 1972000.0
Farmed shrimp consumed by Inuit 26.0
Gross primary production by phytoplankton 3470.0
Shrimp consumed by kawai 847.0
Respiratory loss by kawai (open sea) 572.0
Shrimp consumed by salmon (farmed) 461.0
Respiratory loss by salmon 410.0
Kawai consumed by Inuit 6.2
Salmon consumed by Inuit 4.3
Energy used in managing salmon farm 4.1
Energy used in fishing for kawai 6.7
Energy used in managing shrimp farm 14.0
Energy used in other human activities including trading furs 12.5
4
(a) Use the data in figure 1 to complete the diagram below.
S u n
F jo rd O p en sea
F a rm ed sh rim p 8 4 7
2 6
4 1 0
F ish in g fo rk aw a i 6 .7
(6)
(b) (i) Define what is meant by the term gross primary productivity (GPP).
(e) Calculations based on the data in figure 1 would suggest that farming and eating shrimp is the most energy efficient food source for the Inuit. Suggest why the Inuit continue to farm salmon.
4. (a) Distinguish between global warming and the greenhouse effect.(3)
(b) Explain what is meant by the systems concept and suggest how it can be applied to global warming.
(6)
(c) Reducing the impact of global warming is extremely difficult. Explain why this is the case. In your answer you should refer to the strategies for managing pollutants in the model below.
H U M A N A C T IV IT YP R O D U C IN GP O L L U TA N T
R E L E A S E O FP O L L U TA N T IN T OE N V IR O N M E N T
L O N G -T E R MIM PA C T O FP O L L U TA N T O N E C O S Y S T E M
A lte rin g h u m an ac tiv ity th ro u g h in cen tiv es an dp en a ltie s to p ro m o te th e :– d ev e lo p m en t o f a lte rn a tiv e tech n o lo g ie s– ad o p tio n o f a lte rn a tiv e life s ty le s– recy c lin g .
R eg u la tin g an d red u c in g th e p o llu tan t a t th e p o in t o f em iss io n b y :– se ttin g an d im p o sin g s tan d ard s– in tro d u c in g m easu re s fo r ex trac tin g th e p o llu tan t fro m w aste em iss io n s .
C lean in g u p th e p o llu tan t an d re s to rin geco sy stem s b y :– ex trac tin g an d rem o v in g th e p o llu tan t fro m th e eco sy stem s– rep lan tin g an d re s to ck in g w ith an im a l p o p u la tio n s .
The diagram below represents a coal fired power station.
sm o k e
co a l
. . . . . . . . . . . . . . . . .
w arm w a te r
[Source: Adapted from D D Kemp, Global Environment Issues, A Climatological Approach, (Taylor & Francis,1994) p. 7. Reproduced by permission of Cengage Learning]
(c) Complete the diagram above by naming the missing input and the two missing outputs.(2)
(Total 5 marks)
6. (a) Discuss the value of age-sex pyramids in analysing population change.(6)
(b) Outline the concept of an ecological footprint and discuss the relationship between socio-economic level and footprint size. Refer to examples in your answer.
(5)
(c) As the human population increases there is concern that we may ultimately out-grow our resource base. Evaluate the arguments for and against population control.
(6)Expression of ideas (3)
(Total 20 marks)
10
7. The figure below shows a model of the climatic system.
C L IM AT E
R ad ia tio n o u tp u ts fro mE arth -a tm o sp h ere
S o la r in p u ts toE arth -a tm o sp h ere
A tm o sp h e ric c ircu la tio n an dco m p o sitio n
H u m anac tiv ity
E arth -a tm o sp h e re system
L an d an dte rre s tria lfea tu res
A tm o sp h ere
O ceanO cean icc ircu la tio n
Ice
E x te rn a l in p u ts an d o u tp u ts o f th e c lim a tic sys tem
In tern a l in te rac tio n s o f th e c lim a tic sys tem
[Source: O’Hare and Sweeney, The Atmospheric System, (1986), Oliver and Boyd, page 189]
Size of organisms ............................. .............................
Life-cycles Simple Complex
Growth form r-species K-species
Stability Poor Good
[Source: D Briggs et al., Fundamentals of the Physical Environment, (Routledge, 1997) page 380.Reproduced by permission of Taylor & Francis Books UK (Cengage Learning)]
(a) Complete the figure above for diversity and size of organisms.(2)
10. (a) Describe the role of greenhouse gases in maintaining mean global temperature.(4)
(b) Discuss the impact of global warming. Consider the potential effect on biomes, global agriculture and human society.
(7)
(c) Predictive models of climate change may give very different results. Explain this statement with reference to the limitations of models and the contrasting arguments about global warming.
(6)Expression of ideas (3)
(Total 20 marks)
11. (a) A tree can be thought of as a system. Draw and label a systems diagram of a tree that shows inputs, outputs and storages of matter and energy.
(3)
19
(b) State two functions of producers in an ecosystem.
(f) Suggest what effect a significant and prolonged decrease in the pH of rainfall would have on primary productivity in a terrestrial ecosystem. Explain your answer.
12. The graph below shows the interdependence of population size of two species of mites. Eotetranychus sexmaculatus serves as the food supply for Typholodromus occidentalis.
E. s
exm
acul
atus
5 1 5 2 5 3 01 0 2 0
Ju ly A u g u st S ep tem b er O c tob er N ovem b er D ecem b er Jan u a ry F eb ru a ry
Chesapeake Bay is the largest estuary in the United States. Human population in the area grew from 3.7 million in 1940 to 15 million in 1995. Levels of phosphates and nitrates have risen considerably in Chesapeake Bay over the last four decades. Studies show that point sources contribute about 60 % of the phosphates and non-point sources contribute about 60 % of the nitrates. Commercial harvests of oysters, crabs and several important fish have fallen sharply since 1960. As a result of cleanup programs, between 1985 and 1992 phosphate levels declined by 16 % and nitrate levels by 7 %. These decreases led to a 75 % increase in submerged vegetation during the same time period.
(a) Describe the process which causes the presence of anoxic areas (no oxygen) and low oxygen areas in Chesapeake Bay. Include references to positive feedback in your answer.
(6)
24
(b) Evaluate the impacts of the process given in (a) on the aquatic environment of Chesapeake Bay.
(5)
(c) Describe the types of action that could have led to the improvements in water quality described above in recent years. Your response should include actions from all three levels of the pollution management model.
(6)Expression of ideas (3)
(Total 20 marks)
14. (a) Outline two management strategies for dealing with solid waste.
(iii) A model is a simplified description designed to show the structure or workings of an object, system or concept. Discuss the strengths and limitations of the model shown in the figure above.
15. “...loss of biological diversity around the world, from a multitude of causes, is correlated with decreasing productivity, increasing fragility in systems and increasing exposure of farming families to uncertainty, poverty and hunger. Reversing these trends will require a huge effort to understand the ecological, economic and social problems, while at the same time educating people from all walks of life – producer, consumer, scientist, policy maker and farmer.”[Food and Agriculture Organization (FAO)].
(a) With reference to examples of specific ecosystems you have studied, outline the factors which can lead to a loss in biodiversity.
(6)
(b) Describe and explain the relationship between biodiversity and “increasing fragility” in ecosystems.
(5)
(c) Evaluate the importance of educating “people from all walks of life” in reversing the loss of biodiversity.
(7)Expression of ideas (2)
(Total 20 marks)
16. “...there is constant interchange of … various kinds within each system, not only between the organisms but between the organic and inorganic. These ecosystems, as we may call them, are of ... various kinds and sizes.” Tansley (1935)
(a) Compare the characteristics of ecosystems and social systems.(5)
(b) Describe how populations of individual species interact within an ecosystem, using named examples to support your answer.
(6)
(c) Explain the relationship between climate and net primary productivity in two contrasting biomes you have studied.
(7)Expression of ideas (2)
(Total 20 marks)
27
17. Figures 1 and 2 represent the food webs for two ecosystems.
Figure 1. Terrestrial Grassland
S u n lig h t
G rass au to tro p h
H erb iv o re h e te ro tro p h
C arn iv o re h e te ro tro p h
D ea th
In o rg an ic m a te ria l
D ecay an d m in e ra liza tio n
28
Figure 2. Marine Food Web
H u m an
B a leen w h a leS m a ll-to o th ed w h a le
S p erm w h a le
E lep h an t sea l
L eo p a rd sea l
S q u id
C rab ea te r sea l
S eab irdF ish
C arn iv o ro u s p lan k to n
P h y to p lan k to n
H erb iv o ro u s p lan k to n
K rill
[Source: Tudge, C (1991) Global Ecology, The Natural History Museum, pp. 112–113]
(a) (i) State, giving two reasons, which of the food webs, Figure 1 or Figure 2, is likely to be more stable.
(iii) In table 2 below, list the farming systems (from table 1) as either low input or high input systems.
(2)
Table 2
Low Input Systems High Input Systems
(b) (i) State how MEDCs (more economically developed countries) and LEDCs (less economically developed countries) differ in terms of their dietary composition.
19. Four main factors affect the erosion of soil: crop type, climate, soil type and topography (landscape shape). The figure below shows the interactions between these factors.
Soil Erosion Model
AC ro p
BC lim a te
CS o il Ty p e
In fu en ces s tru c tu re an d co h es io n o f so il. A lso
p ro tec ts so il su rface .
R a in fa ll m ag n itu d e an d freq u en cy.
C lay, san d , s ilt an d lo am a ll h av e d iffe ren t q u a litie s .
DTo p o g rap h y
S lo p e an g le an d len g th a ffec t so il e ro s io n ra te .
S o il lo ss
[T O’Riordan, Environmental Science for Environmental Management, 1995, p. 233.Reproduced by permission of Pearson Education]
36
(a) Suggest how humans may have an impact on soil loss with reference to factors A, C and D in the figure above.
20. Figure 1 shows a farming system and Figure 2 outlines the activities for the farm in areas A, B and C over a year.
Figure 1
seed b ed s fo r to b acco an d rice
fru it tre e s :m a n g o es , ja ck fru it, co co n u t p a lm an d b e te l n u t
k itch en g a rd en :v eg e tab le s , sp ice s ,su g a r c an e
w o rk in g an im a ls , m a in ly ca ttle , u se fo o d in w e t seaso n ro u n d v illag e , b u t g raze s tu b b le a fte r h a rv es t
fam ily lab o u r, seaso n a l ro ta tio n o f c ro p s
h eav ie s t, p lo u g h ed lan d fo o d ed an d rice p ad d ie s . B as ic irr ig a tio n te ch n o lo g y u sed in d ry sea so n .
A rea Alig h te r so il b e tte r
d ra in ed ab o v e fo o d in g
A rea Bo p en fe ld s
A rea Cp o o rly d ra in ed lan d liab le to
fo o d in g
Figure 2
M o n th M arch A p ril M ay S ep tem b er M arch
S ea so n P re– m o n so o n Wet seaso n D ry seaso n
A rea Aca ttle in y a rd , m an g o es ,
v eg e tab le srep a irin g an d th a tch in g , g reen
co co n u ts , b e te l n u ts
A rea B ju te w h ea t, to b acco , m u sta rd
A rea C g raz in g , r ice (fo o d in g ) g raz in g
[Source: Adapted from M Carr, Patterns, Process and Change in Human Geography, Macmillan, (1987), page 142]
39
(a) State, giving two reasons, whether this system is more typical of farming in a more economically developed country (MEDC) or a less economically developed country (LEDC).
(c) With reference to Figure 1 and Figure 2, describe two ways in which the farming system has been developed in response to variations in the local environment.
21. (a) Describe the typical features of a climax community.(4)
(b) With reference to a named ecosystem describe the natural and human threats it faces and discuss the consequences for its future equilibrium.
(10)
(c) Explain, with the aid of an example, the role of feedback mechanisms in the regulation of ecosystem equilibrium.
(4)Expression of ideas (2)
(Total 20 marks)
42
22. (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)
23. Diagrammatic representation of a eutrophic lake:
The Asian tsunami* on 26 December 2004 was caused by an undersea earthquake and had a devastating impact across the Indian Ocean, causing unprecedented human, economic and environmental damage to those countries in its path.
The Maldives are a chain of 200 inhabited islands, with a maximum land height above sea level of just 4 metres. The country suffered relatively small human losses, but per capita has sustained the largest economic damage of any country. More than 70 islands were directly affected.
* tsunami: a giant wave caused by earthquakes, volcanic eruptions or undersea landslides associated with active plate margins
Figure 1 — Freshwater supply in the Maldives
Freshwater lens formation on islands
A proportion of the freshwater falling as rain on an island infiltrates into the sandy soils and accumulates as fresh groundwater. The freshwater, being less dense than saline seawater, floats on the saline groundwater that infiltrates the island laterally at depth from the sea. Because of density differences, a freshwater lens develops, which in general is thickest at the centre of the island, where groundwater levels are highest (compared to mean sea level). The typical ratio between the height of freshwater above mean sea level compared to the depth of freshwater below mean sea level is of the order of 1:20. Groundwater levels above mean sea level on small islands may be 0.10 metres to 0.50 metres above sea level, resulting in a freshwater lens depth of 2 metres to 10 metres thick.
In the Maldives 99 % of local households use rainwater as their drinking supply and groundwater for other uses. When rainwater dries up, they use groundwater for everything. The tsunami flooded many islands with seawater which contaminated groundwater supplies. Sewage also leaks into groundwater supplies.
45
Figure 2 — Hydrological model of coral islands
ev ap o tran sp ira tio n ra in fa ll
m ean sea lev e l w e ll
lag o o n o cean
fre sh w a te r(g ro u n d w a te r)
seaw a te r(sa lin e g ro u n d w ate r) co ra l
ro ck
Figure 3 — Desalination prospects for the Maldives
There is a common misconception that, for small marine islands, desalination (the removal of salt from seawater) is an ideal source of freshwater. The experience throughout the small island regions of the world is that with a few exceptions, Male (the capital island) being one of them, the operation of desalination plants is in fact unsustainable.
Desalination is expensive (up to US $8/m3 in Male) and likely to be higher on the outer islands; it requires advanced technical training not commonly available in the outer islands, it needs good cost-recovery to support complex spare part maintenance and it requires the import and storage of diesel fuels. Some or all of these factors that are required to sustain desalination are absent in small islands.
Outside of Male, resorts routinely use desalination plants. This is because tourists use large volumes of water and rainwater cannot meet demand. The small size of the islands means there is no groundwater available. The money generated by the resorts ensures engineers can adequately service the desalination plant, without which the resorts would close.
46
Figure 4 — Well water quality in three Maldivian islands after the 2004 tsunami and the WHO (World Health Organisation) recommended maximum background levels
Island Nitrate/mg l–1 Ammonia/mg l–1 Phosphate/mg l–1 Chloride/mg l–1
Kulhuduffushi 29.2 2.4 0.5 529
Filladhoo 32.9 6.8 0.9 1200
Dhidhdhoo 43.8 0.7 0.3 402
WHO guidelines 50.0 1.50 Background < 0.1 250
47
Figure 5 — Climate of the Maldives
M o n th ly av e rag e ra in fa ll an d su n sh in e
S u n sh in e / h o u rs
3 0 0
2 5 0
2 0 0
1 5 0
1 0 0
5 0
0
2 5 0
2 0 0
1 5 0
1 0 0
5 0
0
R a in fa ll / m m
J F M A M J J A S O N D
M o n th s
K ey : ra in fa ll su n sh in e
48
Figure 6 — Climate change and sea level rise in the Maldives
The islands of the Maldives rise, on average, up to 4 metres above sea level. In 1987 and 1991, storm surges flooded a large number of islands, including one-third of the capital where one-quarter of the country’s population lives. Unusually high waves forced the international airport to close, causing great damage to tourism and constraining emergency relief operations. Recent surveys have shown that almost one-third of the 200 inhabited islands were faced with serious beach erosion problems.
Sea level rise is not a fashionable scientific hypothesis but a fact. Already in this century, the seas have risen between 10 cm and 25 cm. The prevailing scientific consensus holds that human action, affecting the world climate, will cause the seas to rise more rapidly in the future.
Countries need to pursue immediate measures by relocating their populations away from areas of risk and taking protective measures to prevent flooding. For small island countries relocation is not possible and because defences against flooding are prohibitively expensive to construct, considerable external assistance would be needed.
49
Figure 7 — Trends in island tourism, adapted from www.ourplanet.com
Tourism is expected to go on growing by approximately 5 % per year. World Tourism Organization (WTO) projections suggest that international arrivals will rise to 800 million in 2007 and one billion in 2010. The vast majority of tourists will continue to come from the developed world, but economic expansion and per capita income growth in developing countries – such as Brazil, China and India – will, over the long term, add to the upward trend. This outlook makes tourism one of the most economically strong sectors of the global economy.
In order to enhance the long-term viability of the tourist sector, many small island developing countries have embarked on forward-looking strategies to improve efficiency.
50
Figure 8(a) — Outline map of an atoll island, indicating land above sea level airstrip
a irs trip
d eep w a te r n a tu rech an n e l re se rv e
h o te l
to u ris t b each 0 .5 k m
51
Figure 8(b) — Cross-section of an atoll island
5 m e tre s
p re sen t sea lev e l
52
Figure 9 — Countries with chronic water scarcity (below 2740 litre capita–1 day–1) in 2000, 2025 and 2050 compared to a number of other countries
CountryAvailable water /
litre capita–1 day–1
in 2000
Available water /
litre capita–1 day–1
in 2025
Available water /
litre capita–1 day–1
in 2050
Saudi Arabia 325 166 118
Israel 969 738 644
Somalia 3206 1562 1015
Malawi 4656 2508 1715
UK 3337 3270 3315
India 5670 4291 3724
China 6108 5266 5140
USA 24420 20405 19521
[Source: B Lomborg, The Skeptical Environmentalist, (2001). Reproduced by permission of Cambridge University Press]
53
Figure 10 — Percentage of people living with chronic water scarcity
2000 2025 2050
3.7 % 8.6 % 17.8 %
[Source: B Lomborg, The Skeptical Environmentalist, (2001). Reproduced by permission of Cambridge University Press]
54
25. (a) What geographical features make the Maldives susceptible to damage from a tsunami?
(f) Tourism is an important economic activity in the Maldives. Construct a model (diagram) that demonstrates the range of impacts tourism may have both directly and indirectly on Maldivian ecosystems.
26. The Gaia Hypothesis proposes that our planet functions as a single organism that maintains conditions necessary for its survival by feedback mechanisms. It was formulated by James Lovelock in the mid-1960s. In his recent book The revenge of Gaia, he suggests that we have passed the “tipping point” on global warming and that feedback mechanisms will speed up the rate of global warming.
(a) State what type of system the Earth is and what the inputs and outputs are(3)
(b) Using positive and negative feedback models explain the process of climate change.(7)
(c) Scientists use computer simulations to model the effects of changes in the temperature of the Earth. Discuss the advantages and disadvantages of this modelling.
(4)
(d) Describe your personal viewpoint on the global warming issue and justify your position based on the evidence.
(4)Expression of ideas (2)
(Total 20 marks)
62
27. The diagram below shows succession in a sand dune ecosystem.
(b) State what is happening within a system when a decrease in variable “P” leads to a decrease in variable “Q” which in turn leads to a further decrease in variable “P”.
Madagascar has an astounding total of eight plant families, four bird families, and five primate families that are endemic, that is they live nowhere else on Earth.
Madagascar’s more than fifty lemur species are the island’s charismatic worldwide ambassadors for conservation, although, tragically, fifteen more species have been driven to extinction since humans arrived.
Madagascar broke off from the Gondwanaland super continent more than 160 million years ago and is an example of species evolution in isolation. Despite close proximity to Africa, the island does not share any of the typical animal groups of nearby Africa. Instead, Madagascar has evolved unique species, with high levels of endemism (species unique to a geographical location).
The natural vegetation of the island is diverse. On Madagascar, tropical rainforests in the east give way to dry deciduous forests along the western coast. A unique spiny desert covers the extreme south. The island also has several high mountain ecosystems, which are characterized by forest with mosses and lichens.
The geographic isolation that allowed Madagascar to evolve diverse and unique species also contributed to its environmental degradation. Because humans did not arrive on the islands until 1500–2000 years ago, the native animals were not initially afraid and were easily hunted by the colonists.
The Malagasy people came to Madagascar from Africa and Asia and imported rice cultivation, slash-and-burn farming and cattle grazing, which are inappropriate for infertile, lateritic soils and were devastating to the fragile ecosystems of the island. The central plateau of Madagascar is almost completely deforested – and is now a lifeless land of infertile, baked red earth. It is estimated that only about 17 % of the original vegetation of Madagascar remains.
The 18 million people who live in Madagascar today do not represent a very large number considering the land area of the island. However, the population is growing at more than 3 % per year and is expected to double by the year 2025. In an area that is already one of the most economically disadvantaged in the world, this growth rate is putting tremendous pressure on the natural environment. In addition to agriculture, hunting and logging, industry and small-scale mining are growing threats.
On the other Indian Ocean Islands, these same threats have been worsened by the introduction of invasive alien species, brought as food sources, pets or for pest control. Rats, cats and mongooses have devastated populations of birds and small reptiles, while grazing rabbits, goats, pigs, and deer have stripped many landscapes. In addition, exotic plant species such as water hyacinth (Eichhornia crassipes) threaten the biodiversity of freshwater ecosystems.
Madagascar suffers from some of the worst land degradation and erosion in the world as seen by the dark areas of the aerial photograph below.
[Source: www.photos.wildmadagascar.org]
77
Figure 7 Logging tables
Conventional logging
• Too many roads and skidtrails
• Too many landings that are too large
• Substantial canopy opening
• Subsequent invasion by vines and pioneer plant species
• Significant damage to other vegetation, including future crop trees
• Large number of lost logs
Reduced-impact logging
• Reduces soil disturbed in roads, landings, and skidtrails by almost 50 %
• Significantly less canopy opening
• Better survival of residual trees
• Faster recovery; shorter cutting cycles
• Total cost is 10–15 % lower
• Wood waste is reduced by more than 60 %
[Source: Tropical Forest Foundation]
78
Figure 8 Conservation in Madagascar
About 2.7 % of Madagascar’s land area is officially protected in national parks, strict nature reserves established to conserve ecosystems and special reserves designed to protect a particular species or a group of species.
Attempts to identify and safeguard the areas remaining natural habitats are being implemented with projects that demonstrate the value of this conservation to the country. For example, in much of Madagascar the economic value of the remaining forests is of enormous importance. Eco-tourism has provided a source of income for local communities.
Efforts at species-focused conservation represent important progress for the future of several unique species. A number of lemur species have been bred successfully in captivity, and, in 1997, the first lemur reintroduction program introduced captive-born black and white ruffed lemurs into the Betampona Nature Reserve.
The diagram below represents a tropical forest ecosystem on the north east coast of Madagascar.The climax vegetation type up to the coastal margin is mixed tropical forest.
Table of surveyed animal groups present at the three sites shown on the map above.
Number of species
Animal group Site 1 Site 2 Site 3
Lemurs
Tenrecs (rodent-like insectivores)
Geckos and chameleons
Carnivores (fossa, fanaloka, mongoose)
Frogs
Insects
Scorpions
0
1
3
0
0
2
3
9
7
12
1
5
14
0
2
3
5
0
2
9
1[Source: adapted from www.europe.2007-aliens.org]
35. “The first law of thermodynamics concerns the conservation of energy, whilst the second law explains the dissipation of energy not available for work.”
(a) (i) State, giving the reason, which of these laws explains why natural systems are never “isolated”.
(ii) In the space below, draw a flow diagram model to illustrate an example of negative feedback within an ecosystem.
(2)
93
Figure 1 The image below shows heather (Calluna vulgaris) which is a pioneer plant species in moorland succession
94
Figure 2 The table below shows the growth stages of heather
Life stage Height / cm Cover / % Biomass / g m–2 Productivity / g m–2 yr–1
Early 24 12 290 150
Building 52 94 1500 440
Mature 63 78 1900 360
Degenerate 55 41 1000 140
[Source: Table showing growth stages of heather from Biological Sciences Review, (Philip Allan Updates, (November 2005).Reproduced by permission of Philip Allan Updates.]
95
(b) (i) Construct an appropriate graph to illustrate the relationship between biomass and productivity within the development of heather moorland.
(4)
96
(ii) Describe and explain the trend in percentage cover for heather shown by the data in Figure 2.
Uganda is a relatively small country in east Africa with a rapidly growing and ethnically diverse population. The economy of the country is heavily dependent on farming which employs 83 % of its workforce. While rainforests have extraordinary global significance, conservation efforts in Uganda clearly need to take into account the needs of both the local communities and the national economy as a whole. Management of their forest reserves has moved toward meeting social, economic and conservation needs within the country. In Kibale National Park, for example, the protected area is surrounded by 7 “parishes” (areas of local government with strong family and tribal ties) where approximately 150 000 people live. These boundary communities extract more than 20 different products from the park to meet some of their subsistence, commercial, cultural and medicinal needs.
98
Figure 1 Map showing the location of Kibale National Park in Uganda
S U D A N
K E N YA
K ab a le
Z A IR E
RW A N D A
TA N Z A N IA
U G A N D A
K ab a le
M b ara ra
M asak a
E n teb b e
K am p a la J in ja
M b a le
M o ro lo
H o lm aM asin d i
G u lu
K itg u m
A ru a
F o rtP o rta l
K ib a leN a tio n a lP a rk
L ak eVic to ria
L ak eAlb ert
eq u a to r
[Source: www.usu.edu. Reproduced by permission of Utah State University]
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Figure 2 Map of Kibale National Park and surrounding parishes
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Figure 3 The model on which the original proposal for the Kibale National Park was based
K ey :
T h e U g an d a s tra teg y fo r m an ag in g th e ir tro p ica l fo re s t w as s ta rted b y th e W o rld B an k F o res try R eh ab ilita tio nP ro g ram m e an d th e o rig in a l p ro p o sa l fo r K ib a le N a tio n a l P a rk w as b ased o n th e ir “M an an d th e b io sp h e rem o d e l” sh o w n b e lo w.
P ro d u c tio n zo n e 5 0 %
B u ffe r zo n e 3 0 %
S tric t re se rv e 2 0 %
S tric t re se rv e –
B u ffe r zo n e –
P ro d u c tio n zo n e –
(0 % o f th e fo re s t a rea ) w h e re a ll d irec t h u m an im p ac t is p ro h ib ited
(3 0 % o f th e fo res t a rea ) m an ag ed fo r e co to u rism , ed u ca tio n , re sea rchan d co n tro lled h a rv es tin g b y lo ca l co m m u n ity o f m in o r fo res t p ro d u c ts
w ild co ffeee .g .
(5 0 % o f th e fo res t a rea ) m an ag ed fo r su s ta in ab le fo re s try an d lo ca lco m m u n ity u se
[Source: adapted from D Earl, (1992), Wise Management of Tropical Forest for Timber Production, Tourism and Wildlife, Wise Management of Tropical Forests, Oxford University Press, Oxford]
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Figure 4 Data showing diameter and abundance of Ficus* species in logged and unlogged Ugandan rainforest
Forest Type Number of Ficus species trees / km2 by diameter class (cm)
* Ficus species are fig trees that grow by attaching themselves to the main trunks or stems of other forest trees. The trees that they grow against are very often those that provide timber for the loggers. In a typical rainforest they provide abundant food for many fruit-eating birds and insects, particularly at times when there are very few alternative food sources available. Many other trees and shrubs depend on these bird populations for dispersal of their seeds. Because so many species depend upon Ficus species, they are frequently referred to as “keystone species” in a forest ecosystem.
[Source: adapted from D Alder, (1991), Uganda Forestry Rehabilitation Project Data Processing for the Budongo Forest Inventory, report DA-UG-4]
Figure 5 Figure showing relative abundance of seven primate species in adjacent areas ofmechanically logged and undisturbed forest at Kibale National Park
M ech an ica lly logged forest U n d istu rb ed forest
R ed co lo b u s
R ed ta il m o n k ey
B lu e m o n k ey
C h im p an zee
B lack an d w h ite co lo b u s
M an g ab ey
L’H o est’s m o n k ey
6 5 4 3 1 0 1 3 4 5 6
In d ex o f ab u n d an ce (n u m b er o f p rim a te g ro u p s/k m )(n u m b er o f in d iv id u a ls /k m in case o f ch im p an zees)
2 2
[P Howard (1991) Nature Conservation in Uganda’s Tropical Forest Reserves, IUCN Publishers.Reproduced by permission]
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Figure 6 Conservation and indigenous peoples
The removal of people in establishing protected areas in Africa is the most basic form of ecological restoration, and is based on the idea that human occupation is “unnatural”. In some instances this may be true, but in most it is not, and serious questions of human rights are raised by the imposition of “wilderness conditions” through the eviction of farmers, hunter-gatherers or pastoralists. Many institutional and legal problems arise, but are typically met through various forms of community outreach programmes, sometimes with revenue sharing, development aid and access for resource use.
[M Penrow and A Davy, Handbook of Ecological Restoration, (2002).Reproduced by permission of Cambridge University Press.]
Figure 7 Sample letters received by the Kibale chief warden from parish members aroundthe park
“This is to tell you that when we went in the park we saw four people pit-sawing timber around Lake Kiribwato. We are therefore calling you to come and patrol the area. The resource users reported to me of that illegal activity.”
General Secretary, LC II, Nyabweya Parish, 6 June 2000
“There are five people who are in the park, hunting. We saw them while we were checking coffee areas. Bring rangers and we will arrange to catch them. Come quickly before they come out of the forest.”
Resource User, Nyakarongo Parish, 2 March 2000
“Madam, we are informing you that people are burning charcoal in the park. Please arrange to send rangers for patrolling. We shall guide you to show the areas and the people involved.”
LC II Office, Kiziba Parish, 8 November 2000
“I hereby inform you that after Mweya coordination meeting we patrolled the park and found that pit sawyers had split a tree in the park but upon seeing us they ran away. So, we collected their tools and took them to the office of LC II. We wanted someone to come so that we could hand them in to your office. But they never showed up. We still have in our possession two machetes, one rope and one file for sharpening.”
User Group Member, Kakooga
[Adapted from P Chhetri, A Mughisa, and S White (2003), Community resource use in Kibale and Mount Elgon National Parks, Uganda. In: G Borrini-Feyerabend and T Sandwith (eds) Conservation Partnerships in Africa, Parks journal, IUCN Gland,
Switzerland, 13:1, pages 28-38 – Box 1]
Figure 8 A selection of strategies employed to develop a cooperative partnership between the
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local population and the management of Kibale National Park
Strategy 1 – allowing local people access to park resources
Cooperative resource management allows people access to selected resources under certain conditions. In return the resource users undertake to monitor and regulate resource-harvesting levels and to protect the resource use areas. Formal agreements are negotiated and signed by Uganda Wildlife Authority (UWA) and by resource users. Kibale National Park has entered into a number of agreements, involving 29 % of surrounding parishes. Of these, three agreements were for harvesting wild coffee in the park by people in Mbaale, Kabirizi and Nyakarongo parishes, one agreement allowed extraction of multiple resources such as papyrus, craft materials, medicinal plants, grass for thatching and access to crater lakes for fishing at Nyabweya.
Strategy 2 – problem-animal management
In Kibale National Park, the loss of crops to park animals is perhaps the biggest source of conflict between local communities and park managers. UWA, working with local communities, tested a number of deterrents to keep the park animals from entering the farmers’ fields. They included digging a trench, live fencing with Mauritius thorn (Caesalpinia decapetala), placing sharp objects, scare-shooting and growing buffer crops such as tea and soybean that are not easily eaten by wild animals. Of these, the trench and Mauritius thorn fencing were found to be the most effective measures to keep bush pigs and elephants out of crops.
Strategy 3 – partnerships to reduce pressures on protected areas
Unsustainable development outside the parks forces people to turn to park resources for food, other subsistence products and even to generate cash income. By cooperating with the district authorities to promote environmentally sustainable development outside the parks, UWA is helping to reduce pressures on the parks. These projects, which are also working with local NGOs, include a variety of activities e.g. beekeeping (honey production) under managed conditions within the park, domestic pig farming, coffee and fruit growing.
Strategy 4 – revenue sharing
UWA’s policy of allocating 20 % of the entrance fees to surrounding local authorities is a good example of sharing benefits from conservation. However, the actual amounts shared are small, as they are limited to gate fees only and do not include a wide range of other sources of revenue such as trekking fees, camping fees, etc. For example, Kibale National Park earned a total of US $116 300 in the year 2002 but only US $7800 was given to nearby communities.
[Source: adapted from P Chettri, A Mughisa, and S White, (2003), Community Resource Use in Kibale and Mount Elgon National Parks, Uganda Parks, 13:1, pages 28–38]
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Figure 9 Decentralization
Decentralization is the process whereby a central government gives up some of its management powers to local government, local leaders or community institutions. Central governments have often found it hard to enforce some policies – such as grazing allocations, fishing quotas and forest use – because of resistance in local communities. Decentralization can bridge this gap by creating ways for people to negotiate mutually acceptable environmental goals with governments.
The first wave of decentralization was seen in developing countries in the late 1980s and early 1990s, frequently resulting in some form of decentralized natural resource management. Uganda tried to recreate its government in a way that was responsive to citizens and would promote local governments after years of repressive rule. From the mid-1990s onward, a second form of decentralization became popular thanks to the efforts of donor agencies targeting aid toward specific environmental and social sectors. For instance, donor agencies supported the establishment of forest and wildlife committees in Uganda.
[Source: adapted from World Resources 2002–2004, (2003), World Resources Institute]
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Figure 10 The roles of local organizations in the decentralization of forest management inUganda
A survey was carried out of local organizations and governmental bodies associated with forest management in Uganda in order to identify the roles each played. The organizations were considered in three categories – district governments, parish authorities and support organizations (e.g. NGOs, research institutes). The table below records results of this survey where the figures represent the percentage of responses from each category that considered themselves to contribute to the given role.
Note: N = the number of organizations surveyed in each category.
RolesDistrict
governments(N = 47)
Parishauthorities(N = 169)
Support organizations
(N = 20)
Promotion of tree-planting 98 95 90
Promotion of energy conservation technologies 9 43 35
Monitoring illegal forest use 57 23 20
Promotion of bee-keeping 30 23 20
Formulation of policies and local laws 47 19 15
Promotion of ecotourism 17 10 15
Promotion of forestry research 9 4 35
Seeking funding for forestry activities 4 3 5
[Source: adapted from N Turyahabwe, C Geldenhuys, S Watts, and J Obua, (2007), Local Organizations and Decentralised Forest Management in Uganda, International Forestry Review, 9:2, page 588]
37. (a) Suggest two ways in which the buffer zone of the “Man and the biosphere model” (Figure 3) may contribute toward achieving effective conservation of the forest ecosystem.
(b) Identify one way in which the Kibale National Park differs significantly from the model on which it was based, and state how that difference may influence the success of conservation within the park.
(c) (i) Calculate (to the nearest whole number) the percentage of Ficus species trees (Figure 4) that have a diameter of 50 cm or less in unlogged and in logged forest.Show your calculations.
(e) (i) Outline the differences in abundance of primate species between mechanically logged and undisturbed parts of Kibale National Park forest (Figure 5).
(iii) Assuming that the recording of data in the study was completely reliable, state one other assumption that must be made in order to conclude that the differences found in primate abundance between the two areas is due to logging activity.
(f) From your own study, or from the information provided in the resource booklet, state one way in which logging may not be considered a truly sustainable activity even when harvesting is kept to below maximum sustainable yields.
(g) Four parishes are specifically referred to in Figure 8 as entering into agreements with the UWA. From an examination of the location of these four and the other parishes on the map, suggest two reasons why other named parishes may be less willing to enter into such agreements.
(h) Identify one cause for indigenous people to have negative attitudes toward the establishment of the Kibale National Park, and explain how one of the strategies adopted by the park management may help to overcome it.
(i) In the study reported in Figure 10, identify one role in which the three groups show a significant difference in their contribution and suggest a reason for this difference.
(j) From the information given in the resource booklet, identify and discuss two pieces of evidence that could be used to suggest the Kibale National Park has achieved a degree of success in its conservation aims. (Use the figure numbers to refer specifically to any evidence you identify.)
38. (a) Distinguish between the terms renewable, replenishable and non-renewable natural capital.
(3)
(b) With reference to a named example of replenishable natural capital, explain how human actions are damaging the resource and discuss the possible effects of this.
(8)
(c) Describe the Gaia hypothesis and evaluate the usefulness of a global perspective for managing resources sustainably.
(7)Expression of ideas (2)
(Total 20 marks)
39. Some people believe that population control should be given equal weight to resource use in environmental management.
(a) Discuss, with reference to the statement above, the relationships which exist between human population growth, resource consumption and carrying capacity.
(5)
(b) Describe and compare the role of density-dependent and density-independent factors in the regulation of animal populations.
(4)
(c) Explain why an understanding of equilibrium is important for the successful management of ecosystems. In your answer you should refer to examples of ecosystems where this equilibrium has been upset by human activities.
(9)Expression of ideas (2)
(Total 20 marks)
40. The table below gives a list of energy sources used to generate electricity and their cost per kilowatt hour.
Energy source Unit cost / kw hr–1
Coal 4.8 – 5.5
Natural gas 3.9 – 4.4
Nuclear 11.0 – 14.5
Wind 4.0 – 6.0
Hydro electric 5.1 – 11.3
Solar 15.0 – 30.0
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(a) Identify the two energy sources with the average lowest cost in the table above, and state one advantage and one disadvantage of each.
41. Figure 1 shows two wildlife reserve models. Model A has two isolated reserves whilst Model B has a corridor connecting the reserves. Species X, Y and Z are found in all three reserves.
Figure 1
M od el A M od el B
R o ad
S p ec ie sX ,Y, Z
S p ec ie sX , Y, Z S p ec ie sX , Y, Z
S p ec ie sX ,Y, Z
1 k m 1 k m
(a) In Figure 1, state, giving a reason, whether Model A or Model B is better for the conservation of genetic diversity of species X.
(b) Figure 2 is a nutrient model for a rainforest ecosystem. The size of the circles represents the amount of nutrients stored and the width of the arrows represents size of the flow of nutrients.
(i) Explain why the nutrient store for the biomass is so large.
Svalbard is a group of islands within the Arctic Circle and 1000 km north of Norway. For nearly four months of the year it is in complete darkness. Glaciers and snowfields cover 60% of the total area. The sea freezes for part of the year. Spitsbergen is the largest island in the group, with the only permanent settlements. There are no roads except within and close to these settlements.
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Figure 2 Fact file on Svalbard
• the warm, North Atlantic Current flows along the west and north coasts of Spitsbergen
• Svalbard has a permafrost layer 450 metres deep, only the top metre of soil melts during the summer
• natural resources include coal, iron ore, copper, zinc, phosphate, wildlife and fish
• reserves of oil and gas are believed to lie beneath the seas round Svalbard
• there are no trees
• many scientists come to the islands to study the glaciers and the region’s unique wildlife
• a global seed store for conserving seeds collected from all over the world has recently been built on the island
• tourism is becoming increasingly important
Figure 3 Temperature and precipitation data for Svalbard
The mean monthly air temperature for two consecutivetime periods (1961–1990 and 1991–2004)
Tem
pera
ture
/°C
5
0
- 5
- 1 0
- 1 5
- 2 0
K ey :
1 9 6 1 – 1 9 9 0
1 9 9 1 – 2 0 0 4
Janu
ary
Feb
ruar
y
Mar
ch
Apr
il
May
June
July
Aug
ust
Sep
tem
ber
Oct
ober
Nov
embe
r
1 0D
ecem
ber
M o n th
[Source: data adapted from Norwegian Meteorological Institute]
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The mean monthly precipitation for two consecutivetime periods (1961–1990 and 1991–2004)
Pre
cipi
tati
on/m
m
4 5
4 0
3 5
3 0
2 5
2 0
1 5
1 0
5
0
K ey :
M ean p rec ip ita tio n1 9 6 1 – 1 9 9 0
M ean p rec ip ita tio n1 9 9 1 – 2 0 0 4
Janu
ary
Feb
ruar
y
Mar
ch
Apr
il
May
June
July
Aug
ust
Sep
tem
ber
Oct
ober
Nov
embe
r
Dec
embe
r
M o n th
[Source: data adapted from Norwegian Meteorological Institute]
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Figure 4 Plants and animals of Svalbard
Svalbard reindeer(Raingifer tarandus
platyrhynchus)
[Marius Fiskum, www.fotopia.no]
Arctic fox(Alopex lagopus)
[Source: Mr Per Herald Olsen, no.wikipedia]
Purple Saxifrage, Saxifraga oppositifolia, Svalbard, July 2002, Michael Haferkamp.This file is licensed under
the Creative Commons Attribution ShareAlike 3.0
Rock ptarmiganhttp://en.wikipedia.org/wiki/Rock_ptarmigan
[Sources: www.wikipedia.org and www.arcticphotos.co.uk]
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Figure 5 Reindeer on Svalbard
Some of the animals and plants found on Svalbard are unique. The Svalbard reindeer (Rangifer tarandus platyrhynchus) is a different subspecies to the wild reindeer of Scandinavia and Russia and the caribou of North America (Rangifer tarandus). Svalbard became an island about 40 000 years ago when sea levels rose, leaving a small reindeer population trapped on the island.
WILD REINDEER / CARIBOU
IMAGE REMOVED FORCOPYRIGHT REASONS
[Source: www.uncommonyukon.com]
SVALBARD REINDEER
IMAGE REMOVED FORCOPYRIGHT REASONS
[Source: www.sciencemuseum.org.uk]
Physical features • long legs• lean body• large antlers
• short legs• large amounts of body fat stored
for winter• small antlers• extra large stomachs to digest
poor quality food
Behaviour • live in large herds• move frequently while grazing
as food supply is rapidly exhausted
• can run fast, even when very young
• live singly or in small herds• remain in the same grazing area
for long periods• move slowly
Food • a lichen called reindeer moss, often found beneath snow cover in winter
• small Arctic flowering plants of very low nutrient value, containing natural toxins
Intraspecific competition • compete for food and mates with other members of herd
• little direct competition for grazing because animals are widely dispersed in their habitat
Predators • wolves • none
Parasites • warble flies burrow under their skin and lay eggs, that then hatch into maggots
• no warble flies live on Svalbard
Common causes of death • predation, parasites, injuries caused by fighting other reindeer
• starvation when teeth are lost or worn out
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Figure 6 Coal mining on the coast of Svalbard
Coal has been mined on Svalbard for over 100 years. There are plans to open a new coal mine. The diagram below shows the potential environmental problems of opening a new coal mine.
Figure 7 Model to show fate of coal extracted from mines on Svalbard
C o a l so ld(1.2 × 10 6
to n ne s y r –1 )
C o a l ex cav a tedin m in e
B lo w n aw ayas d u s t
C o a l d u s t(0 .0 2 5 × 1 0 6
to n n es y r )
D ep o s ited lo ca llyo n so il, ic e an dv eg e ta tio n
– 1
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Figure 8 Svalbard International Seed Vault
S eed v au lts
B rid g e
Tu n n e l en tran ceS leev e to p ro tec t tu n n e l fro mero s io n an d c lim a tic ch an g es
O ffice an d h an d lin g a rea
A irlo ck d o o rs
[Diagram of Svalbard International Seed Vault - www.croptrust.org/main/arctic]
Species are becoming extinct at an alarming rate. The Svalbard international seed vault has been built to preserve up to 2 billion seeds from around the world, because other seed collections elsewhere could be lost. Threats to other seed banks include war, natural hazards, power cuts and poor management.
The Svalbard seed vault has been dug out of a permanently frozen hill side. Even without electricity the samples will remain frozen because of the permafrost. Seeds will only be released from the vault if all other seed sources have been lost.
Figure 9 Arctic polar projection
IMAGE REMOVED FOR COPYRIGHT REASONS
[Source: adapted from www.britannica.com/eb/art-58/Southern-limit-of-Arctic-tundra-and-approximate-line-of-demarcation]
43. (a) (i) State which major biome is found on Svalbard.
(ii) Coal dust and gases from mining may affect local or global climate.Using Figure 6 and Figure 7, describe and explain one example of positive feedback and one example of negative feedback caused by coal mining emissions that may affect the climate.
