Calculating Rates
Example1 : calculate the CBR of the USA in 2005 if the there were 4 138 349 births out of a total population of 295 895 897.
4 138 349 x 1000 = 13.98 per 1000
295 895 897
Example 2 : calculate CDR of a country that had 2 448 017 deaths out of a population of 295 895 897.
2 448 017 x 1000 = 8.27 per 1000
295 895 897
General Questions
1. AIDS pp. 83-84 : what is the impact of AIDS on human populations ?
AIDS has killed more than 20 million people in the past 20 years and will lower the avg. life expectancy, mainly in developing countries of Asia, Latin America and especially Africa.
2. Social security p. 84 : What is the problem with social security ? too many old people and not enough young people to make money and taxes that will take care of the old people.
3. Fertility p. 85 : what type of countries have high fertility rates ? low fertility rates? Why?
LEDCs = high MEDCs = low probably because of money, education - socio – cultural economic factors but hard to prove.
1

4. Education p. 86 : Higher education = ___less_______ children. Poor people have ___large______ families. The Middle class have high aspirations but have no ____money_________ and have the _____smallest_______ families. It is important to __________make______ ______money_________.
5. Economic prosperity p. 86 : Economic prosperity leads to an
____increase__________ in the birth rate while increasing costs of living lead to a _____decline______ in the birth rate. In the UK it costs __200 000 lbs.______________ to raise a kid. Basically if parents believe _______will not have money________________ they will _____not have kids_____________________.
IB 1 What does the term carrying capacity refer to? D
A. The optimum reproductive rate for sustainability.
B. The maximum size any given population reaches.
C. The minimum area of land required to support a given population sustainably.
D. The maximum population size an environment will sustainably support.
IB 2 Fertility rate is C
A. the total number of births minus the total number of deaths in a country.
B. the number of births per thousand individuals in a population per year.
C. the number of births per thousand women of child-bearing age per year.
D. the average number of children a woman has in her lifetime.
IB 3 Natural Increase Rate of a human population is C
A. number of immigrants per year.
B. number of immigrants – number of emigrants per year.
C. crude birth rate
 crude death rate
.
10
2

D. crude birth rate

10 crude death rate
.
IB 4 The table below shows demographic data for the human population of a country in
2004. Notes
Birth rate/1000 Death rate/1000
Number of live children per female
Mean age of mother at first live birth/years
13 16 1.2 29
(a) (i) Define the term natural increase rate .
(ii) Calculate the percentage natural increase rate for the data above.
(b) (i) Predict how the population of the country is likely to change over the next 5 years.
(ii) Identify two pieces of data that support your prediction in (b) (i) above.
(c) Outline two reasons why women in developing countries usually have children at a younger age than those in developed countries. a) (i) natural increase rate = birth per thousa nd natural increase rate =
 death per thousa nd crude birth
10 rate
 crude death rate
/
/
10
(percentage) rate at which a population increases per year;
(ii)
13
–
16
10
=
–
0 .
3 % (minus sign not required)
(b) (i) decrease;
Allow: decline/fall/go down.
(ii) death rate exceeds birth rate/negative rate of increase; number of children per female too low for replacement; relatively long generation time (of 29 years);
(c) In developing countries: lack of access to contraceptives; lack of education about family planning; lack of educational opportunities other than about family planning;
1 max
1
1
2 max
3

culture/religion e.g.
women’s perceived role in Islamic societies; lack of employment opportunities;
In developed countries: better access to contraceptives; good education about family planning; many education opportunities; culture e.g.
women expected to have a career and bring up a family; wider employment opportunities; women reluctant to sacrifice affluent lifestyle to have children
(dependent on 2 incomes for mortgage etc .);
Accept other relevant points
Do not credit the same point from different lists twice.
2 max
[7]
4

Questions
IB 5 - D
5

IB 6 D
6

IB1 Which list below contains only components of renewable natural capital? A notes
A. Fish, timber, cattle
B. Methane, the ozone layer, water vapour
C. Nuclear fuel, hydroelectric power, solar energy
D. Rice, whales, diamonds
IB 2 Which could not be described as natural capital? C notes
A. A forest on a hillside
B. The fish stocks of a fish farm – stock NOTE not harvest
C. The fish harvested from the inshore waters of one country in one year
D. A waterfall
IB 3 With the help of examples, distinguish between the terms natural capital and natural income natural capital = natural resources, e.g. forest; that (if properly managed) can provide a long-term supply of goods and/or services, the natural income; yield of timber/recreation/game = natural income;
[1] for each definition, with appropriate example. Award [0] if no
2 max examples given.
2. Fill in the blanks ( answers may vary a little) : Sustainability is living within
___the means or limits of nature__________ so that this will ensure that
7

____natural resources (natural capital) _________ are/is not
___depleted/degraded/used up______. This is important so that future
_______generations________ can continue to use _____the natural resources__________.
3.Explain sustainable development . Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
4. Why is sustainable development considered, by many economists, contradictory and really not achievable?
Population growth is not being slowed down putting more pressure on natural capital ( resources). People want to develop economically , especially in the
LEDCs ( less developed countries) and there simply isn’t enough pie to go around. So MEDCs ( more developed countries) will need to lower their standard of living.
5. Why do some people see sustainable development as the only way out of our present problems with population growth, economic stability and energy solutions?
Technology can allow the use of renewable resources and energy and will also reduce pollution. Governments must enforce radical legislation on recycling and population control and develop people’s attitudes toward sustainable development as the only way to save the planet for future generations.
6. Know the basics of the following: a) Rio Earth Summit 1992 : changed attitudes to sustainability on a global scale mainly about economic growth and environmental loss. b) Kyoto Protocol 1997 : Agreements made to reduce greenhouse gases and reducing carbon emissions to 1990 levels. Should be reduced by 2012. c) Johannesburg World Summit 2002 : mainly looked at social issues; targets were set to reduce poverty and increase people’s access to safe drinking water and sanitation.
IB 4 Distinguish between the terms sustainability and sustainable yield
IB 4 sustainability is the exploitation of natural income without causing long-term deterioration of natural capital/ OWTTE ;
8

sustainable yield is the rate of increase of natural capital which can be exploited without depleting the original stock/ OWTTE ;
IB 6 Outline two factors that may undermine the ability of a country to maintain or develop a policy of sustainable development. notes
IB 6 A range of answers may be acceptable e.g. war; countries’ resources are diverted to armies rather than invested in education/agriculture/development projects; population expansion; more resources must be put into sustaining the population rather than development; national debt; paying off heavy foreign debts means less money left over for inward investment; cultural inertia; culture may not have a philosophy of sustainability (consumerist culture of west or nomadic culture of Africa); political unrest; short-term thinking predominates but sustainable development is a long-term goal;
IB 7 Compare the probable size of the ecological footprint of an inhabitant of a developed country with that of an inhabitant of a less developed country.
Explain your answer. notes
IB 7 [1] for size of footprint the size of the footprint of an inhabitant of a developed country will be larger;
[2] for explanation inhabitant of developed country has higher standard of living/ higher income; and thus will consume more food; and probably higher proportion of meat; taken from higher in food chain/requiring larger area to produce;
9

and so will require larger area per capita to support an individual; higher car ownership/greater use of power; implies more CO
2
production; requiring larger area for assimilation;
Any other appropriate points
C
Which of the following most correctly represents characteristics of each type of soil? B
Sandy soil Clay soil
A. Good water-infiltration capacity Good water-infiltration capacity
B. Poor nutrient-holding capacity Good nutrient-holding capacity
C. Good aeration Good aeration
D. Good water-holding capacity Poor water-holding capacity
Which of the combinations in the table below correctly completes the following sentence?
B
Human activities such as . . . I . . . can cause soil . . . II . . .
I II
10

A. Overgrazing
B. Deforestation
C. Urbanisation
Conservation
Degradation
Conservation
D. Addition of organic material Degradation
Which of the following is most likely to lead to desertification? C
A. Eutrophication
B. Use of organic fertilizers
C. Irrigation
D. Ozone depletion
IB Extended Response Question - know
(a) Compare soil management strategies in a named commercial farming system, for example the U.S, with those in a named subsistence farming system for example Thailand.
(8)
(b) Discuss how viewing soils as systems can help farmers to understand and reduce the causes of soil degradation .
Answer :
(a) USA - commercial
* large-scale cereal cultivation in the prairies, USA – high technology
* approach to minimizing wind erosion;
* use of specially adapted ploughs;
* shelterbelts of trees planted;
* GM ( genetically modified) crops with shorter stalks to minimize wind damage and exposureof soil;
*application of fertilizer to retain fertility of soil;
11

Thailand – subsistence
 small-scale agriculture e.g.
vegetable farming in Thailand
 manure from working livestock allowed to fertilize soil;
 terraces built by hand to reduce run-off;
 fields allowed to be fallow/rest by crop rotation/soil is rested;
 variety of crops grown reduces the likelihood of exposure of soil at different times; commercial farming system relies on a technological approach to managing the soil (technocentric), whereas subsistence farming depends more on traditional practices, which have evolved over time as people live on the land (ecocentric)
(b) Discuss how viewing soils as systems can help farmers to understand and reduce the causes of soil degradation .
Answer : systems are models with inputs, outputs and storages
 activities such as overgrazing, deforestation, unsustainable agriculture and irrigation cause processes of degradation which include soil erosion, toxification and salinization;
 systems approach stresses the interconnectedness of soils with overgrazing an understanding of the balance of animals that can be supported before the critical threshold is reached will help farmers plan herd size;
 seeing soils as renewable resources in equilibrium (inputs of nutrients through rain and organic matter) and outputs through natural leaching will help farmers to compensate for the losses to overall nutrient balance by removing crops, and the importance of returning nutrients through the use of fertilizers;
12

 understanding that soils are living systems which are integral parts of ecosystems will help farmers to take a broader perspective when managing their land e.g.
deforestation on nearby slopes can have an impact on water flows and likelihood of soil erosion in flash flood conditions
 some processes of degradation are examples of positive feedback e.g.
less vegetation → greater wind speeds → more soil erosion → less top soil → less vegetation etc ., understanding this can help farmers to break the cycle;
Miscellaneous Questions
Which of the combinations in the table below correctly completes the following sentence?
B
Human activities such as . . . I . . . can cause soil . . . II . . .
A. Overgrazing
B. Deforestation
I II
Conservation
Degradation
C. Urbanisation Conservation
D. Addition of organic material Degradation
Which of the following is most likely to lead to desertification? C
A. Eutrophication
B. Use of organic fertilizers
C. Irrigation
D. Ozone depletion
13

1) 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 beds for tobacco and rice
Area A lighter soil better drained above fooding
Area B open felds
Area C poorly drained land liable to fooding fruit trees: mangoes, jack fruit, coconut palm and betel nut kitchen garden: vegetables, spices, sugar cane working animals, mainly cattle, use food in wet season round village, but graze stubble after harvest heaviest, ploughed land fooded and rice paddies.
Basic irrigation technology used in dry season.
family labour, seasonal rotation of crops
14

Figure 2
Month
Season
March April May September
Pre–monsoon Wet season Dry season
March
Area A
Area B
Area C cattle in yard, mangoes, vegetables jute grazing, rice (fooding) repairing and thatching, green coconuts, betel nuts wheat, tobacco, mustard grazing
[Source: Adapted from M Carr, Patterns, Process and Change in Human Geography , Macmillan,
(1987), page 142]
(a) State, giving one reason, whether this system is more typical of farming in a more economically developed country (MEDC) or a less economically developed country (LEDC).
LEDC basic/lack of technology generally; rice farming is typical of LEDCs/where rice is often the staple crop; cash crops for export such as sugar cane, tobacco; houses look fairly simple and made from local/cheap materials/ thatched roofs; dependence on working animals; labour intensive (family labour); mixed cropping on small scale;
(b) Complete the systems diagram below to show three inputs, processes and outputs for the farming system shown in Figure 1 and Figure 2 .
15

Inputs
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Processes
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
FARM
Outputs
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . inputs : [1 max] water/technology/cattle (livestock)/sunlight/rain/manure/ seed/labour/soil;
Award [1] for any three of the above. processes : [1 max] planting/ploughing/harvesting/irrigating/repair/respiration/ run-off/labour;
Award [1] for any three of the above. outputs : [1 max] jute/vegetables/mangoes/Jack fruit/Palm/coconut/sugar cane/spices/crops/waste/income/energy/rice/food/
Betel nuts/tobacco/cattle (livestock)/heat/oxygen/carbon dioxide/wheat/mustard;
(c) With reference to Figure 1 and Figure 2 , describe one way in which the farming system has been developed in response to variations in the local environment. different crops planted at different levels; rotation of crops to match seasonal rainfall patterns; monsoonal climate so main crop is rice; irrigation technology used in dry season; livestock fed differently at different times of year; different jobs done at different times of year;
16

Figure 3 below shows nutrient cycling in a terraced paddy. irrigation canal rice paddy nitrogen fxation by decay of rice stubble releases blue-green algae nutrients rice water terrace lower rice paddy little soil erosion dead organic material rapid breakdown slow breakdown NO
3 oxidised zone reduced zone (little O
2
) little leaching
(d) With reference to Figure 3 define
(i) leaching . when nutrients, dissolved in water, wash down through the soil/paddy and are lost;
(ii) nitrogen fixation . process by which nitrogen in atmosphere is fixed to form nitrate by blue-green algae (and converted into a useable form for plants);
(e) With reference to Figure 3 explain the following.
(i) There is very little soil erosion in this farming system.
(ii) The dead organic material breaks down more rapidly in the oxidized zone.
17

(e) (i) because the terraces are level there is little run-off by water so soil is not washed away/terraces prevent soil erosion/ soil collects in paddies;
(ii) oxygen is required by decomposers to break down organic matter (the oxidized zone is closer to the surface and richer in oxygen)/higher BOD in oxidized zone as more decomposers, thus more decomposition;
2) The data in Figures 1 and 2 show differences in nutrition between more economically developed countries (MEDCs) and less economically developed countries (LEDCs).
Figure 1
Item LEDCs
Energy intake / calories per person per day 2210
Total protein / g per person per day
Animal protein / g per person per day
63
10
MEDCs
3340
90
40
Population (U .N . estimates for 1985) 3487 million 1100 million
Figure 2
Consumption of animal protein / g per person per day
New Zealand
Uruguay
United Kingdom
74.8
61.9
53.4
Austria
Israel
47.5
36.3
Chile
Spain
Mexico
Japan
29.2
23.4
23.4
16.9
Egypt
Guatemala
Pakistan
India
12.2
8.5
7.7
5.9
18

(a)
(a)
[Source: J H Lowry, World Population and Food Supply , (Edward Arnold, 1986) p. 24.
Reproduced by permission of Edward Arnold (Publishers) Ltd.]
Using the data in Figure 1, calculate the percentage of total protein that animal protein represents for MEDCs and LEDCs. b) A healthy human diet will include at least 70 g of protein and
2500 calories of energy per day. Use this information and the data in Figures 1 and 2 to describe the differences in the diets of
MEDCs and LEDCs.
MEDCs 44.4 % (accept 44 %) ;
LEDCs 15.9 % (accept 16 %) ; b) MEDCs: eat more calories/energy intake higher than they need;
LEDCs: do not eat enough calories/energy intake too low;
MEDCs: eat a lot of protein; high % of protein from animals;
LEDCs: not enough protein; protein mainly non-meat;
3. The diagram below shows some of the environmental problems caused by a demand for greater agricultural production. increased soil erosion loss of species diversity reduction of long-term productivity danger to human health loss of species diversity narrowing of genetic base soil compaction loss of hedgegrows and walls eutrophication high nitrate concentrations in drinking water increasing use of fertilizer damage to SSSIs* residues on monocultures food harm to nontarget species increasing use of pesticides organic pollution of fresh water indoor rearing of animals animal and plant breeding mechanisation demand for greater production
* Sites of Special Scientific Interest
[Source: Kevin Byrne, Environmental Science , (Nelson Thornes Ltd., 1997) p. 167.
Reproduced by permission of Nelson Thornes Ltd.]
19

a) According to the concept map above what sequence of events leads to soil erosion. Explain each event clearly, i.e. don’t just state the event. b) How does this relate to the “ Dust Bowl” that occurred during the 1930s in the USA.
(a) Answer will, of course, depend on the problems chosen. [4] for each problem. Credit should be given for use of examples and case studies.
e.g. soil erosion: use of heavy machinery leads to compaction of soil, so soil structure is lost; top soil is more easily removed by the agents of erosion
(wind or water); even more erosion likely if wind breaks (hedgerows and walls) are removed; once top soil is lost, organic material is gone and the fertility of the soil is reduced;
(b) this occurred during the 1930s in the US due to intensive farming on the prairies; leading to the dust bowl as vast quantities of soil were blown away; leads to lower yields and a vicious cycle as remaining soil may be even more intensively farmed by farmers to compensate;
4. a) Draw an MED food production system that clearly shows : 3 inputs, 3 outputs and 3 processes. b) Fill in the following concept map according to your drawing.
Inputs
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Processes
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
FARM
Outputs
1.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
(5)
Various Answers
20

5. The table below shows the productivity of different farming systems.
Table 1
System
Migratory pastoralist, Kenya
Shifting cultivation, Papua New
Guinea
Cattle, UK
Wheat, UK
Maize, USA
A
0.025
1.5
3.5
97
104
B
0.01
0.5
0.7
20
18
C
0.004
0.3
A = harvested food energy (GJ ha
–1
yr
–1
), expressed as total food energy land area
B = food energy used per person in the area (GJ ha
–1
yr
–1
)
C = if food energy use per person were equivalent to that used by an average
American in the 1990s
[Source: adapted from Primack, R B (1993), Essentials of Conservation Biology , OUP, pp. 111]
(a) State which farming system produces the greatest amount of food energy. maize, USA; b) Suggest two reasons why the farming system you identified in (a) has such a high productivity. intensive agricultural system; high levels of inorganic fertilizer used per unit area; high yielding/management-intensive crop varieties
(possibly GM types); extensive and intensive weed, pest and disease control; efficient harvesting; possibly irrigation;
0.6
17
18
21

c) Fill in the following table based on table 1 above.
Low Input Systems migratory pastoralists, Kenya shifting cultivation, Papua New
Guinea
High Input
Systems cattle, UK wheat, UK maize, USA
22

6. The figure below shows data for farming labour and tractor use in an economically developed country.
2.5
2.0
1.5
1.0
0.5
5.0
4.5
4.0
3.5
3.0
1950 1955 1960
Year
1965 1970 1975
[Source: Kevin Byrne, Environmental Science , (Nelson Thornes Ltd., 1997) p. 188.
Reproduced by permission of Nelson Thornes Ltd.]
(a) Suggest what the figure above implies about changes that have taken place in agriculture.
(b) Outline two strategies for increasing agricultural production in less economically developed countries (LEDCs).
(a) as tractor use increase farm labour use goes down; agriculture is becoming more mechanized; agriculture may be more intensive; less need for labour on farm; farms becoming larger require more machinery; farming/agriculture is becoming more technocentric; tractors farming labour
400
300
200
100
900
800
700
600
500
23

(b) greater use of pesticides to protect crops and livestock; use of high yielding crops and livestock; the use of GM crops and livestock; greater agricultural industrialization/mechanization; improving irrigation; soil management techniques e.g.
terracing; agroforestry;
7. MEDCs vs. LEDCs : Know the following a) MEDCs have a greater proportion of animal protein in their diet (approx 26%), whereas LEDCs are more dependant on grain crops;
MEDCs generally have greater variation in their diets than
LEDCs; b) MEDCs tend to have larger ecological footprints than LEDCs; because they have high “grain equivalent” food consumption lifestyles; they consume high levels of fossil fuel; high CO
2
emissions; produce larger amounts of waste; higher lifestyle expectations and possess more consumer goods; use proportionately more raw materials; c) MEDC farming does the following : limits biodiversity because of herbicide and pesticide elimination of non-crop species; introduces toxins through fertilizers/irrigation; limits habitat type because of monoculture; eutrophication due to fertilizer application; risk of hybridization from GM maize; aesthetic impact on landscape;
2
24

1. The amount of water present in the hydrosphere as freshwater is approximately A
A. 3 %.
B. 6 %.
C. 10 %.
D. 20 %.
2. The percentage of the earth’s surface covered by oceans is about B
A. 90 %.
B. 70 %.
C. 50 %.
D. 45 %.
3. Which of the following contains the greatest proportion of the world’s fresh water? C
A. Organisms
B. The atmosphere
C. Ice-caps and glaciers
D. Streams, rivers and lakes
4. Which of the following is most likely to lead to an overall increase in the Earth’s freshwater storages? C
A. Removal of forests
B. Melting of polar ice caps
C. Increase in evaporation rates from the oceans causing increase in precipitation over the continents
D. Discovery of new underground aquifers
25

5. What proportion (by volume) of the Earth’s water is fresh? C
A. 0.026 %
B. 0.26 %
C. 2.6 %
D. 26 %
6.
P = precipitation (rain, snow) falling on the surface of the lake
E = evaporation from the surface of the lake
I = inflow from streams
Lake R = run-off in a stream flowing out of the lake
S = loss by downward movement into the rocks
Assuming there is neither a rise nor a fall in the level of the lake, and there are no other inputs or outputs, what is the value of R? A
A. P + I – E – S
B. I + P + E + S
C. (S + E) × (I + P)
D. I + P + E – S
7. Which of the following contains the greatest proportion of the world’s freshwater? A
A. Ice caps and glaciers
B. Rivers
C. Lakes
D. Groundwater
26

8. Which row correctly shows the storages of the water in order of decreasing size? D
LARGEST
                      
SMALLEST
A.
B.
Oceans
Oceans
Groundwater
Lakes, rivers and atmosphere
Glaciers and ice caps
Glaciers and ice caps
Lakes, rivers and atmosphere
Groundwater
C.
D
Lakes, rivers and atmosphere
Oceans
Oceans
Glaciers and ice caps
Groundwater
Groundwater
Glaciers and ice caps
Lakes, rivers and atmosphere
9. Which of the following statements is correct? C
A.
Less than 0.1 % (by volume) of the Earth’s water is freshwater.
B. The hydrological cycle is independent of solar energy.
C. The main reservoir of the Earth’s freshwater is in ice caps and glaciers.
D. Only abiotic storages are involved in the hydrological cycle.
27

10. The pie charts below show the usage of water in the United States and China.
United States
Industry
49 %
Agriculture
41 %
Domestic
6 %
China
Industry
7 %
Domestic
10 %
Since 1950 the global rate of water withdrawal from surface and groundwater sources has increased almost fivefold and per capita use has tripled.
[Source: Worldwatch Institute and World Resources Institute, 2000]
Agriculture
87 %
(a) Discuss two reasons for differences in water usage between the United States and
China.
(b) Describe, with examples, three ways in which human population growth affects the world’s fresh water resources.
(a) Differences
USA uses more water for non-essential purposes ( e.g. car washing, gardening, washing machines etc.
); industry represents 50 % of usage in USA and only 7 % in China because China is still developing; agriculture is the base of China’s economy, so substantial amounts of water are needed for irrigation; power plant cooling is less significant in China;
Changes availability of water: e.g. enormous increase in number of reservoirs and dams since 1950; applies to both developed and developing countries/specific examples; average figures may conceal enormous local differences as withdrawal rates have increased 5-fold, but per capita use has only tripled; so population must have increased; increases in standard of living account for increase in water demand;
Credit other valid responses.
(b) an increase in the following activities makes demands on the supplies of fresh water:
28

agriculture (irrigation); provision of water for stock; increased industrialization (manufactured products); public uses such as street cleaning, watering of parks; enlargement of urban areas;
Any other reasonable points, e.g. increase in population has contributed to large increase in pollution e.g. eutrophication; industrial and sewage pollution of rivers; contamination of aquifers by industrial activities e.g. leaking fuel tanks, heavy metals; excessive water pumping of aquifers leading to salination of water in coastal areas; in some areas water use is exceeding available supplies; this leads to political difficulties;
29

11. The diagram below shows storages (in percentage of total water) and flows in the global water cycle. The rates of flow are given in 10
15
kg yr
–1
.
CLOUDS
0.001 %
Precipitation
100
Condensation
400
ATMOSPHERIC
WATER VAPOUR
0.001 %
Evaporation
64
Evaporation
336
Precipitation
300
SURFACE WATER 0.001 %
ICE 2 %
GROUND WATER 1 %
Run-off/groundwater flow OCEAN
97 %
(a) (i) What is the source of energy which drives the water cycle? .
(ii) In which of the processes given in the diagram does this energy enter the cycle?
(b) (i) What percentage of all precipitation falls directly into the oceans?
(ii) What percentage of all evaporated water comes from the oceans?
(c) (i) Assuming the cycle is in steady state, what mass of water flows into the oceans through run-off and groundwater flow per year?
(ii) Explain why this figure might increase in the future, as a result of burning fossil fuels.
(d) Name a storage of water in the biosphere that is not shown in the diagram, and explain how water is transferred in and out of this storage.
(e) (i) State briefly one way in which one of the other flows in the diagram might change if evaporation rates were to increase.
(ii) Describe how two changes in the flows shown on the diagram could lead to a fall in global temperatures and reduce global warming.
(iii) Name the type of feedback involved in this reduction in global warming.
(f) Identify each of the different processes referred to on the diagram as either transfer or transformation processes.
30

(a) (i) solar energy/the sun
(ii) evaporation
(b) (i)
300
400
× 100 = 75% need correct answer for the mark, not necessarily working.
1
1
(ii)
336
400
× 100 = 84%
(c) (i) 100 – 64 or 336 – 300 = 36 × 10
15
kg
Award [1] for correct answer (36) and [1] for units (10
15
kg).
1
2
(ii) Burning fossil fuels releases more carbon dioxide/greenhouse gases [1]
; … which increases global temperatures [1]
; … which melts ice
[1] ; increased temp. → increased evaporation → increased cloud cover [1] . max 3
(d) Vegetation/plants/animals/organisms/biomass/soil water [1] ;
Appropriate mechanisms for transfer [2] / e.g. organisms – water enters by absorption through roots or digestive system [1] ; water leaves by transpiration or excretion (sweating, urination) [1] . max 3
(e) (i) Condensation/precipitation/run off/groundwater flow would increase (because of extra water in atmosphere) [1]
Or: run off/groundwater flow would decrease (because of extra evaporation from warmer surfaces)
(ii) (accept any two of)
• increase in evaporation/condensation leads to increased cloud cover [1] ; leads to increased reflection of solar radiation/higher albedo [1] ;
• increase in precipitation leads to more snow
[1] ; leads to increased reflection of radiation [1] ;
• decrease in the rate of evaporation decreases amount of water vapour entering the atmosphere [1] ; water vapour is a greenhouse gas (so reducing it will reduce the greenhouse effect) [1] and/or reducing atmospheric water vapour will reduce cloud cover [1] ; and hence increase radiation loss to space [1] .
1
(One change in flow [3 max], two changes in flow [4 max])
(iii) (Response must follow on from (e) (ii))
For increases in flow given above; feedback is negative [1]
For decreases in flow given above; feedback is positive [1]
4
1
31

(If part (ii) is not answered or answer does not mention a direction of change in flow and its consequences, no credit
can be given here.)
(f) Transformation = condensation and evaporation [1] ;
Transfer = precipitation and run off/groundwater flow [1] .
12. The diagram below shows some of the material flows which affect food production and fresh water resources.
2
[20] atmosphere rivers food production systems available fresh water resources soil
(a) Distinguish between the terms sustainability and sustainable yield . aquifers
(b) Describe and explain two ways food production systems can be managed sustainably.
(c) Describe and explain two ways fresh water resources can be managed sustainably.
(a) sustainability is the exploitation of natural income without causing long-term deterioration of natural capital/ OWTTE ; sustainable yield is the rate of increase of natural capital which can be exploited without depleting the original stock/ OWTTE ;
(b) food production : crops or animals are renewable resources; food can be produced sustainably provided that farming procedures do not cause long-term damage to soil; e.g. use of contour plowing techniques; salinisation of soils can be caused by excessive irrigation; restrictions on hunting/fishing of wild populations ( e.g. fish) may be needed to conserve breeding stock;
32

lower density stocking of animals needed to minimize damage to soil/vegetation;
Any other appropriate examples .
( c) fresh water : fresh water resources are replenished by the water cycle; fresh water is used sustainably if the rate of extraction is no greater than the rate of replenishment; e.g. by aquifer recharge, rainfall etc .; over-exploitation of aquifers in coastal areas can cause intrusion of salt water; lowering of water table; e.g. parts of coastal western Australia; over-extraction of river water reduces flow downstream/ affects ecosystems/affects fishing; e.g
. Murray River; water can be used more sustainably by reducing wastage; e.g. more water-efficient appliances (low flush toilets, water saving taps etc .); use of grey or recycled water for purposes other than drinking and cooking; mending leaks; drip irrigation systems;
Allow any other valid points and examples.
Award [7 max] if only food or water are discussed.
10 max
13. Why is it difficult to calculate carrying capacities for human populations? B – key word resource
A. Human populations have increased greatly over the last 50 years.
B. Resources can be imported and exported and the level of technology can influence carrying capacity.
C. Human populations can move more rapidly than the populations of other organisms.
D. Pollution has damaged certain environments and reduced the carrying capacity.
33

14. Which of the following does not influence human carrying capacity? A – key words : resource and technology
A. Birth rate
B. Resource consumption rate
C. Resource exploitation rate
D. Level of medical technology
15. It is difficult to estimate accurately the global carrying capacity for the human population because B- key word technology
A. population densities vary from country to country.
B. technological developments may lead to changes in rates of resource consumption.
C. birth and death rates in different countries vary greatly.
D. humans produce more waste products than any other species.
16. The carrying capacity of a country depends mostly on D – key words economic, technological
A. the rate of increase of its population.
B. the amount of insolation it receives.
C. the quantity of its mineral resources.
D. its state of economic and technological development.
17. Overpopulation occurs when D – key words : available resources can NOT support
A. the population level allows resources to be used sustainably, giving a good standard of living to all.
B. there are too few people in an area to use the resources.
C. resources are being used at a rate that allows them to be replaced for further harvesting.
D. the available resources cannot support the number of people in the area at a reasonable standard of living.
34

18. Which combination of characteristics is most likely to be associated with a stable or falling human population? B
I. Increase in the proportion of women receiving higher education
II. Increase in average income
III. Decrease in the average age of marriage
IV. Increase in birth rate
V. Decrease in death rate
VI. Increase in the average age of marriage
A. I, II and III
B. I, II and VI
C. I, II, III and IV
D. III, IV and V
19. These statements describe changes taking place in the populations of two different countries:
• Country X begins to import a resource from another country.
• Country Y increases its birth rate through a population policy.
Which of the following predict the most likely effects these changes will have on the carrying capacity of each country? B – X IMPORTS RESOURCES so it increases its carrying capacity. BIRTH RATE doesn’t really have an effect.
A.
B.
C.
D.
Increase in carrying capacity
X
X
Y
—
Decrease in carrying capacity
Y
—
—
X, Y
No change in carrying capacity
—
Y
X
—
35

1. The diagrams below represent the area inhabited by, and the ecological footprint of, two human populations. One population is from a developed country and the other from a developing country. The diagrams are drawn to the same scale.
= Area
= Ecological footprint
Population A Population B
(a) Which of the populations is most likely to be a developing country? Explain your answer.
(b) State three pieces of information that would be necessary to calculate the ecological footprint for any human population.
(c) Explain two ways in which the latitude of a country might affect the size of the ecological footprint.
(d) Which of the populations, A or B , is exceeding the carrying capacity of the area? Explain your answer.
(e) (i) Suggest two ways in which the food production of the two populations might differ.
(ii) Explain how these differences could influence the size of the ecological footprints of these two populations.
(f) Compare the sustainability and environmental impacts of fossil fuels and hydroelectricity as sources of energy.
36

(a) Population B : as ecological footprint is smaller than population [1]/ are living sustainably [1] .
(b) Award [1] for each two correct items.
Per capita CO
2
production/ per capita land requirement for absorbing waste CO
2
from fossil fuels/rate of absorption of
CO
2
by local vegetation per unit area/ per capita food consumption/rate of food production locally per unit area/ population number.
(If candidate states total population CO
2
production and food consumption, then population number is superfluous.)
1 max
Other correct answers are acceptable but those above are on syllabus.2 max
(c) Any two of: lower latitudes – higher net productivity in local vegetation – so smaller ecological footprint for the same CO
2 output [1]/ low latitudes may provide better conditions for food production – so smaller ecological footprint to supply same food production [1]/ higher latitudes have lower temperatures – greater need for energy sources – greater CO
2 wastes – larger ecological footprint [1] . 2
(d) Population A [1] ; because it takes a greater area than that available to sustainably supply its resources [1] .
(e) (i) Allow any two of: one population might use intensive farming techniques [1]/ monoculture [1]/ use of fertilizers [1]/ pesticides [1] .
Allow for ECF from (a) and (d).
2
2 max
(ii) intensive farming techniques would lead to greater food production per unit area [1] ; so smaller footprint [1]/ eating more food or more meat would require more agricultural production [1] ; so larger footprint [1] OWTTE. 2 max
(f) Sustainability up to [2] fossil fuel use is unsustainable as a non-renewable resource [1]/ as rate of consumption > rate of renewal [1] ; hydroelectricity – sustainable as replenishable [1]/ water cycle continues through input of solar energy [1] ;
37

Impacts up to [2] fossil fuels – CO
2
release increases global warming [1]/ SO x and NO x
causing acid rain [1]/ NO x
causing ozone depletion [1] ; hydroelectricity – building of dams floods and destroys ecosystems [1]/ reduces downstream flow rates [1]/ reduces downstream flood plains [1]/ blocks fish migration [1] . 4 max
[15]
[20]
2. The graphs below show the world demand for meat and cereals for the years 1974, 1997 and the projected demand for 2020.
Meat Cereals
250 2000
200
150
1500
1000
100
50
0
500
0
Developed countries
Developing countries
Developed countries
Developing countries
Key : 1974 1997 2020
[IFPRI, IMPACT projections, "2020 Global Food Outlook", Trends, Alternates and Choices (June
2001).
Courtesy of the Food and Agricultural Organization of the United Nations.]
(a) For both developed and developing countries, calculate the percentage increase in demand for cereals from 1974 to 1997.
Developed countries:
Developing countries:
(b) Explain the trends in the demand for meat and cereals as shown in the graphs above.
(c) Suggest, giving a reason, how the ecological footprint of developing countries might change by the year 2020.
38

(a)
Developed countries cereals 100 × ( 750

700 )
700
= 7 %; (accept 6 to 8%)
Developing countries
100 ×
( 1200

600 )
600
= 100 %; (Accept 98 to 102
%)
2
(b) demand for meat and cereals both increasing as human population increases; developing countries have a larger increase than developed countries as the rate of population increase is greater; demand for meat in developing countries is increasing more than the demand for cereals as demographic transition progresses/GNP increases and more people can afford meat;
Any other reasonable points.
Must have an explanation. A simple description of the graphs or restatement of the data is not sufficient.
2 max
(c) increase in ecological footprint; gap between developed and developing countries is diminishing; footprint depends on population and per capita consumption; both these are increasing in developing countries; need for developing countries to import food;
39

.
3. Discuss whether or not the world’s total human carrying capacity can continue to increase through the use of technology. carrying capacity - maximum population that can be sustained without permanent damage to life supporting systems/OWTTE; technology requires exploitation of a range of natural resources often at unsustainable rates; up until now technological solutions have always been found to solve problems; technology has enabled humans to increase food production by using fossil fuels to mechanise farming, increasing yields; but fossil fuels will eventually run out; but mechanised cultivation methods often damage or destroy soil; use of pesticides and fertilizers to increase yields may permanently pollute/damage water and soil; transport systems allow goods to be distributed across the globe; technology and transport enable humans to live in cities at higher densities; but transport releases carbon dioxide increasing global warming/ climate change etc .; technology can destroy natural systems that may absorb waste; but technology can be used to clean up waste and pollution; information age has enhanced remote communication, (in theory) reducing need for global travel; toxic pollutants have ( e.g.
radionuclides, heavy metals, organic chemicals) spread throughout ecosystems; changes in global temperature could damage food production systems; rises in sea level may destroy major cities;
40

4. The graph below shows the growth of the human population over the last one thousand years.
World population (×10)
3
2
1
6
5
4
1000 BP
BP = before present
Using this graph alone, it can be concluded that C
A. birth rate is increasing.
B. death rate is decreasing.
C. population growth rate is increasing.
D. fertility rate is increasing.
500 BP
Time/years present
5. Which of the following populations are most likely to be sustainable? A
Population density
Mean individual consumption
High dependence on
A. high low renewable resources
B.
C.
D. high high low high high low renewable resources non-renewable resources non-renewable resources
41

1. Total World Biodiversity
A)
How many “known” species? – 1.4 – 1.8 million
B) How many estimated species? 100 million or 8- 10 million
C) List 4 kingdoms of organisms – Animalia, Plantae, Fungi, Bacteria
D) Which major group of which kingdom has highest % identified ? vertebrates = 93 % ;
E) Which major group of which kingdom has lowest % identified? algae( plantae) = 3 %
F) Plants = 85 % vs. Insects at 11% ?
2. Background and Mass Extinctions
A) Define background rate and approximate number - natural extinction rate
.
It’s about 10 – 100 species per year.
B) What are some factors surrounding the background rate that are difficult to explain?
- Some species will be extinct before we even know they existed
- some believe the current rate is about 1000 times the background rate
- extinction rates depend on location, hotspots for example
- Mass extinctions may be causing the rate to be much greater than the background rate
- Homo sapiens
3. Geological Time Scale
Know the following:
A) age of earth and the universe – 4. 6 billion, 13.7 billion
B) extinction date of dinosaurs – 65 million years ago
C) when humans appeared
– 200 000 years ago
D) Sequence of major eras : Precambrian, Paleozoic, Mesozoic and
Cenozoic
E) Over how many years did the last 5 mass extinctions occur ? 500 million
42

4. The Sixth Mass Extinction
A) What is the cause? humans
B)
What is a “weedy” species? – successful species in today’s current mass extinction
C) Are we a “weedy” species? – no one is really sure
D) List 4 things humans do to be the direct cause of ecosystem stress :
- transform the environment- with cities, roads and industry
- overexploit other species – in fishing, hunting, harvesting
- introduce alien species – which may not have natural predators
- pollute the environment
– which may kill species directly
E) Hotspots : Define the criteria that determines if an area is a Hotspot or not. threatened areas where 70% or more of the habitat has been lost and which contains more than 1500 species of plants which are endemic.
F) Define endemic species – species only found in that area- unique
5. Keystone Species
– Types of Diversity
A) Define Keystone species and give 2 examples.
Important species that many other species and the ecosystem depend on. If lost of this one species may lose many other species.
Ex. A small predator may keep herbivore in check. If not herbivore could go rampant and wipe out many other plant species
EX. Beavers ( engineer species) make dams that create swamps that create huge number of swamp species
B) Explain biodiversity . Define two types of biodiversity with one example of each.
1. Species diversity – both range and number ex. forest has 15 diff. species with 100 individuals of one species and one individual of the other 14 species. Low on habitat spread diversity.
Another forest has 15 species and 7 individuals of each species. Better on habitat spread diversity. Higher species diversity
2. Genetic diversity – the range of genetic material present in a species or a population, the gene pool. It reflects the genetic variety that exists within a species, which determines the amount of variation between different individuals.
43

A small population usually has less genetic diversity.
3. Habitat diversity
– number of different habitats per unit area. Tropical rainforests high, Tundra low.
6. How New Species Form / Plate Influence on Biodiversity
A) Explain speciation related to NATURAL SELECTION . Use the following in your explanation :
- geographical or reproductive barriers
- genetic variation and competition among individuals and how this may lead to speciation
- limited resources
- natural selection as a major force for speciation and EVOLUTION.
- how fast is speciation?
- briefly explain 2 specific examples of speciation
- Isolation leads to new species in general
B) Plate Influence and Continental Drift on Biodiversity
Explain effect of plate tectonics and continental drift on
Llamas and camels
– both have similar ecological roles as pack animals and for meat. Had a common ancestor but due to plate tectonics were separated – geographical isolation – and developed into new species.
Kangaroos and cattle – both have similar ecological roles as herbivores to eat grass and convert to meat. Australia separated via plate tectonics and developed unique species . Cattle , placental animals, outcompeted the marsupials in other parts of the world. Thus you can only find kangaroos in
Australia.
Basically had similar ecological roles and common ancestors
7. Factors that affect Biodiversity
A) List the factors that maintain biodiversity : complexity of ecosystem, stage of succession ( few species at first , then more diversity , then community climax) , limiting factors ( biotic factors
– predators, humans; abiotic
44

factors
– water, climate) , inertia ( ecosystems that resist change when subjected to a disruptive force)
B) List the factors that lead to a loss of biodiversity : natural hazards ( volcanic eruptions, NATURAL fires, tsunami) not by humans;
Humans : loss of habitat ( biggest cause) by fragmentation, pollution, overexploitation, introducing nonnative ( exotic) species, spread of disease, modern agricultural practices
C) Vulnerability of tropical rainforests:
- what may happen in 50 years ( be completely gone
- contain __50_ % of earths’ timber ( timber # 2 natural resource after oil)
- once cleared rain forest can only grow crops for about two years , why? - fast rate of respiration and decomposition means that the forests APPEAR to be very fertile, HOWEVER, most of the nutrients are in the huge trees and plants and NOT in the soil. Once cleared, soil is not really fertile and will only last about 2 years. Fertile soil is like the Midwest US ,valleys in china , Nile river valley, which will support farming for 100s of years.
8. Extinction
List the factors that make some species vulnerable to extinction ( make sure you understand them). Think of some examples. a) Narrow geographical range - ( species can only live in 1 type of area) ex. p.115 Golden Lion Tamarin only found in atlantic rainforest, pandas in N. china bamboo) b) Small population – ( less genetic variation and can not adapt to change very well) c) Low population densities and large territories
– ( individual species requires large territory to hunt and only meets mate for reproduction once in a while – mountain lions, pumas, humpback whales) d) Few populations of the species e) Large Top predators ( p. 48 biomass pyramid , only 10% is passed to next level so top predators have large ranges , low densities and need a lot of food f) Low reproductive potential - reproduce slowly ( whales , penguins only 1 egg per year) g) Seasonal Migrants – species that migrate have more problems: long routes, mating habitat destroyed , weather, h) Poor dispersers - species that are not mobile, example plants, flightless birds, cannot escape if habitat goes bad. i) Specialized feeders or niche requirements - due to lack of natural selection pandas can only eat bamboo shoots, koala bears can only eat eucalyptus leaves, the sundew plant can only live in very humid places
45

j) hunted for food or sport k) Human activity causes extinction to occur faster vs. slower extinction rates due to natural causes
9. Case Studies
Find an example of one that is not in the textbook. Write description, ecological role, pressure, method of restoring population
46

1. Definitions a) Red lists b) Bio right c) Conservation d) Preservation e) CITIES f) UNEP, WWF, GREENPEACE,IUCN g) NGO
– GO h) Corridor
2. Why Conserve Biodiversity? Arguments
– Economic Reasons a) Explain direct value and give one example of a food source and one example of a natural product .
Direct value are goods harvested which are eaten or sold. For example a food source
– crops , rice. There are big environmental pressures due to farming and controversial technology( ex. Genetically modified organisms- gmos) used to feed the planet. Natural products , such as medicines, fertilizers etc. are derived from plants or animals. For example guano = bird droppings high in phosphate and used for fertilizing; rubber from rubber trees, honey etc. b) Explain indirect value and give 1 example : harder to calculate. They provide goods and are services or processes that do not appear in a country’s economic figures yet are vital to the economy. For example climate regulation or water quality. c) Make sure you know and understand the following types of indirect values: i) Ecosystem productivity
– what is the main topic sentence?
“ecosystem productivity gives us environmental stability and recycles materials .
“
They are very complicated and rely on many species, biotic and abiotic factors. Pollination depends on insects, plants capture carbon and
47

release oxygen. Climate is regulated by rainforests and vegetation cover. ii) Scientific and educational value : make sure you know and understand examples listed in textbook. Add aesthetic values ( not in textbook).
Biological control agents- ladybirds eat pests called aphids
Genes- hybrids, gmos, genetic engineering
Environmental monitors
– miners used canaries to test for toxic gases
Recreational – parks, ecotourism
Human health – medicines, medicinal plants, cure for cancer – amazon
Human rights
– preserve rainforests to preserve Indians
Ethical/ aesthetic/ intrinsic value – humans are responsible for nature
Biorights – preserve ecosystems as a whole and reduce $$ and need to concentrate on single species later on
3. Conserving and Preserving Biodiversity
Conservation biology vs. preservation biology : explain the difference and give an example.
Conservation biology is the sustainable use and management of natural resources. They do not want to exclude humans and understand that human interaction is needed . They will seek ways to involve humans such as creating local income for local natives. Example: hunting guides, ecotourism
Preservation biology attempts to exclude human activity. This is a nonanthropocentric viewpoint. Whatever the costs , species should be preserved regardless of humans.
4. Methods : explain each
A) Conservation Organizations- GOs, NGOs , WWF, IUCN,
GREENPEACE, UNEP. Do Which is which research p. 122 of text.
Table 6.1 good : how GOs and NGOs compare :
Media – GO prepare and read written statements – typical politicians.
NGOs use media to gain attention – typical journalists
Speed of response - GOs slow as always. NGOS faster
48

Political constraints
– GOs a lot .NGOs none
Enforceability – GOs International agreements and laws. NGOs none, use public opinion to put pressure on GOs.
WWF and GREENPEACE – NGOS
UNEP ( from Wikipedia) - The United Nations Environment Programme
( UNEP ) coordinates United Nations environmental activities, assisting developing countries in implementing environmentally sound policies and practices . It was founded as a result of the United Nations Conference on the . Its activities cover a wide range of issues regarding the atmosphere , marine and terrestrial ecosystems . It has played a significant role in developing international environmental conventions, promoting environmental science and information and illustrating the way those can work in conjunction with policy, working on the development and implementation of policy with national governments and regional institution and working in conjunction with environmental Non-Governmental
Organizations (NGOs). UNEP has also been active in funding and implementing environment related development projects.
IUCN ( from Wikipedia) - The International Union for Conservation of
Nature and Natural Resources ( IUCN ) is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." [1] The organization publishes a " Red List " compiling information from a network of conservation organizations to rate which species are most endangered.
[
B) Red Lists – produced by the IUCN is a collection of threatened species lists under varying levels of threat to their survival.
C) Species based conservation – the CITIES agreement
The Convention of International Trade in Endangered Species. Species were becoming extinct due to buying and selling on a global scale for example, selling Blue Parrots from Brazil. Has about 5000 animal species and 28 000 plant species on list against law to sell. Since 1975 has been the most effective international wildlife agreement in the world .
49

D) Captive breeding programs and zoos
Not very successful. Zoos are nice but not effective. Reintroducing animals into wild is expensive and only a few successful stories ( eg.
Condor in California, Tamarin Lion in Atlantic Rain forest). Sometimes reintroducing an animal is impossible because original habitat has been wiped out.
But what are the alternatives? Text doesn’t give any.
E) Botanical gardens and seed banks ( basically gene banks)
Plants are definitely easier to reintroduce to wild than animals. There are many seed banks and botanical gardens around the world and the future for preservation and conservation is much brighter than for animals.
However , entire forests and ecosystems still have a huge problem.
F) Gene banks – may keep DNA for recreating later on but technology still far away.
G) Designing Protected Areas – Criteria
Read pp. 128 – 129 of text; See fig. 6.6 explain following criteria:
50

Size – bigger is usually better because it minimizes edge effects. Smaller sometimes better due to more diversity in habitat
Shape – circular usually better to minimize edge effects ( ectozones) .
Actually based on what is available so most parks are irregular in shape.
Edge effects- where 2 habitats meet and you get a mix of abiotic factors ( weather, precipitation wind etc. ) occurring at the ectozones. More different kinds of species will meet at the edges but this will create competition and predation which is not good for conservation of all species.
Corridors - narrow strips of land that connect different park reserves.
Worked well in Costa Rica and other countries but does have some disadvantages:
- diseases can spread form on reserve to another
- easy access by hunters and poachers
Proximity - basically the way areas are grouped together see fig. 6.6 above
51

5. Case Studies - know
52