A4 TRF/P.1 of 10
A 4 :Man-Land relationship : Tropical Rainforest
88#3; 94#4; 95#4; 96#2; 97#4; 00#4; 01#4; 02#4; 03#3
89+4; 90+4; 91+4; 93+4; 94+3; 95+4; 98+5; 03+5
I.
Spatial distribution of tropical rainforests
II. Human Activities in TRF / Causes of deforestation
94#4 + 95#4 + 96#2 + 00#4 + 01#4 + 02#4
Activities
A. Native tribes
1. shifting cultivation
For survival
2. nomadic herding
3. logging for firewood as fuel
4. fruit gathering
5. hunting
B. Multi-National Corporations 1. plantation,
For profit making
e.g. rubber, cotton, tea, coffee
+ oil palms
2. cattle ranching
3. growing of cash crops
4. commercial lumbering
5. mining
6. construction of roads and
railways
7. settlements
Examples
Amerindians of Amazon Basin
Rubber plantation in W. Malaysia
N. part of Brazillian Highland
Cassava in Thailand
Western Kalimantan (ramin)
Sulawesi, Indonesia (ebony)
Sungai Lembing (tin)
Gambang (iron)
Trans-Amazon Highway in Brazil
A4 TRF/P.2 of 10
III. Operation of shifting cultivation
97#4
1. Shifting cultivation is mainly carried out by native tribes,
e.g. Amerindians in Amazon Basin.
2. They find a small plot of land (1-2ha/family)
3. They clear the land by simple tools, e.g., sticks and hoes.
4. They slash and burn the vegetation and the ashes act as natural fertilizer.
5. Subsistent crops, e.g. rice, cassava, maize and manioc are grown.
6. Soil fertility decreases after 3-4 years because of successive cropping and weed invasion.
7. They abandon the land and shift to another site for cultivation.
8. This allows natural regeneration of the forest.
IV. Definition of sustainable development
97#4 + 00#4 + 01#4
1. Sustainable development is defined as the development that meets the needs of the present
without compromising the ability of future generations to meet their own needs.
2. It associates with the improvement of the quality of human life within the carrying capacity of
the supporting system.
3. Environmental resources are exploited / used at rates within their capacity for renewal.
i.e. exploitation rate kept within the earth’s carrying capacity.
4. It respects and works with nature’s limit
5. Depletion of non-renewable resources is minimized.
6. So, the earth’s biodiversity can be preserved.
7. Take shifting cultivation as an example:
a)
It is carried out by native tribes, e.g. Amerindians in Amazon Basin.
b)
They clear a small plot of land (1-2 ha./family) by “slash and burn”
c)
clearance done by simple tools, e.g., sticks + hoes
→ Tall trees with buttress roots have not been slashed and they act as buffer to speed up
regeneration.
d) low population density (<20 people /km2) → low pressure on land (<20 people / ha.)
e)
subsistent crops, e.g. rice, cassava and maize, are grown.
→ low yield + little harvest → ↓export of nutrient
f)
Traditionally, long-rotation shifting cultivation method is adopted.
g)
small population → long fallow period (≥ 25 yrs.) is allowed for natural regeneration, i.e.
natural replenishment of soil fertility (Fig. 1)
7. Other egs.:
collection of firewood as fuel, hunting and fruit gathering,
e.g. Aborigines in N. Australia.
Fig. 1
A4 TRF/P.3 of 10
V.
Reasons of why shifting cultivation is sustainable / maintains a harmonious relationship with man
94#4 + 97#4 + 01#4
1. The size of clearing is small.
2. Simple tools are used for clearing (sticks and hoes).
3. Population density is low (<20 people /km2).
4. Pressure on land is low since only subsistent crops are grown.
5. There is long rotation period.
6. Fallow period is long (20-25 yrs).
7. Natural Regeneration is allowed, and soil fertility can be restored.
8. Tall trees, which have not been slashed, act as buffer and speed up regeneration.
VI. Causes of deforestation
+ Egs. On P.1 94#4 + 95#4 + 96#2 + 01#4 + 02#4
Recently, the TRF is cleared at a fast rate (120,000km2/yr.)
A.
for LDC (less developed country)
1.  high natural increase + rapid population growth
 demand for food and fuel 
Shifting cultivators e.g. Ameridines in Amazon Basin shortens the fallow period. This starts the
vicious cycle of soil depletion (Fig. 2). Using fire and axe, shifting cultivators convert the
forest to farmland at a rate of about 90,000 km2/yr..
Fig. 2
2. LDC is greatly indebted to DC, e.g. Brazil is heavily indebted to foreign countries, e.g. US$270
billion in 2001 → aim at short term economic gain → welcome foreign “development” /
exploitation.
3. Political factor : mass migration
e.g. Transmigration in Indonesia
In 1950s, under government’s Transmigration Programme, some 3.6 million people were
redistributed from overcrowded islands of Java and Bali to densely forested areas in Kalimantan
and Sulawesi.
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B.
for MDC (more developed country)
1.  living standard & industrialization level
 demand for minerals ores, timber + farm produces (as raw materials + food).
2. Profit making activities for exploitation
a)
Commercial lumbering to meet the increasing consumption of valuable timber (hardwood for
furniture; softwood for paper products), e.g. ramin in Kalimantan, ebony in Sulawesi
b)
Mining minerals ores, e.g. tin in Sungai Lembing, iron ore in Gambang in Malaysia.
c)
Cattle ranching beef cattle are raised for export to the USA for fast food. Large areas
of the rainforest have been converted to
pasture land in Central America and Brazil, e.g. in Brazilian Highland
d)
Plantation
MDCs make use of the hot, wet climate of rainforests to grow commercial tropical cash
crops, e.g. coffee, oil palms and rubber, e.g. rubber plantation in W. Malaysia
3. Construction of roads, railways + highways, e.g. Trans-Amazon Highway in Brazil, to improve
accessibility for further resources exploitation.
4. These actions are allowed by the LDC's government who are interested in the short-term
economic gain.
C.
Deforestation is speeded up because of:
development in technology and the use of machinery.
VII. Environmental constraints faced by developers in TRF / Problems of development
95#4
1. Difficulty in clearance
- It is difficult to clear the dense forest.
-
Besides, thick tree trunks and buttress roots are difficult to cut
2. Poor working condition
- Hot and wet climate is not pleasant to work.
- Workers’ health is undermined by diseases and intestinal parasites, cut and wounds easily develop
into serious infections.
- Biting insects, wild animals and snakes bring discomfort and danger.
3. Poor soil for farming
- Soil is infertile because of serious leaching by heavy rainfall. This makes farming difficult.
- Tropical grass is too coarse for cattle. Pasture has to be grown especially for cattle.
- Flooding is a frequent hazard due to heavy rain.
4. Mixed stand
- Since the hot wet climate favours great species, there are few dominants in TRF.
A4 TRF/P.5 of 10
5.
Poor accessibility
- Accessibility is poor because of steep slopes, swamps, remote location and the lack of
infrastructure, e.g. roads and railways.
- Forest floor is too swampy and muddy to support buildings and bridges.
- Even roads are built, they are difficult to maintain because of rapid regrowth of vegetation.
Heavy rain often washes them away or trees grow up, forcing their way through the road surface
or pushing aside the railway sleepers.
- Besides, logs have high water content and are heavy, it is impossible to float in water or to be
transported by river.
6.
High cost of development
- The work of surveying, the making of maps and the development of infrastructure, e.g. roads,
railway and port facilities are not easy and very costly. The cost of development is too great to
be economically worthwhile. Capital and running cost are high.
- Money has to be spent to solve the problems. e.g. buying fertilizer to enrich the soil, construction
of roads to solve the problem of poor accessibility.
VIII.Solutions to overcome the development constraints 95#4
1.
Roads and railways should be constructed to improve accessibility.
2.
Heavy machines should be used to clear the forest.
3.
Fertilizers should be applied to enrich the soil.
4.
Afforestation can be practised to reduce soil erosion.
5.
Cattle pastures, especially for cattle should be grown.
IX. Impact of deforestation / Inevitable consequences /
Global problems caused by forest destruction 95#4 + 02#4
A.
Atmosphere : rainfall reduction, temperature change, oxygen depletion and greenhouse effect
1.
2.
Micro-climate
a.
enlarged daily and annual range of temperature  the loss of buffer
b.
stronger wind  reduced friction
Macro-climate
a.
increased temperature and greenhouse effect
- Owing to the reduction of vegetation, cooling effect, resulting from evapotranspiration,
drops.
- CO2 level increases due to reduced uptake of CO2 by the diminishing vegetation.
- Since CO2 absorbs heat, the rise of CO2 level results in global warming.
- Global warming causes the melting of ice caps and led to the rise of sea level, and so,
the risk of flooding in coastal areas increases.
A4 TRF/P.6 of 10
b.
increased occurrence of hail and thunderstorm
- increased temperature, convection currents increase.
c.
increased aridity / rainfall reduction
- deforestation, there is reduced evapotranspiration, which is a major source of rainfall.
Aridity increases globally. Drought and famine result.
d.
depletion of oxygen source
- Since 80% of the earth’s vegetation is in the rainforests, destroying them will deplete
the reserve of atmospheric oxygen. This has global implications on our oxygen source.
B.
Hydrosphere
1.
Removal of vegetation causes the decrease of infiltration and the increase of surface runoff.
Soil erosion is intensified. Silting results and risk of flooding increases.
2.
The hydrograph is modified as shown in the following figure. (Fig. 3)
Fig.3
C.
Lithosphere : Soil depletion
1.
Soil erosion :
a. Removal of vegetation causes the decrease of infiltration and the increase of surface runoff.
Soil erosion is intensified. Badlands and gullies may be formed.
b. Deforestation causes the lost of buffering effect. So, the soil is directly exposed to the
sun and attacked by rain splash effect. Soil structure and texture are destroyed.
c. There is lack of plants' roots to bind soil particles together.
2.
Soil depletion :
a.  intensified leaching
b. The land is cleared of nutrient-enriched vegetation. This results in a dry, barren
wasteland prone to severe erosion. The global effect is that the land will never fully
recover, i.e. land degradation occurs.
A4 TRF/P.7 of 10
D.
Biosphere : extinction of plants and animals
1.
Secondary growth replaces primary forest
Secondary growth with shorter trees, fewer species diversity, more open structure and
lower density replaces the primary forest.
2.
Breaking down of food chain
As a result of reduced food supply and the destruction of their natural habitat, smaller space
is available for animals. So, some animals are forced to leave or change the living patterns.
Number and species of plants and animals are reduced. The global impact of reduced
biodiversity is that : loss of pharmaceutical products and loss of medical value we haven’t
even assessed yet.
X.
Reasons for the concern about the rainforest 96#2 + 97#3
Value / Importance of rainforest /Importance of maintaining biodiversity 00#4 + 02#4 + 03#3
Def. Of biodiversity :
= variety and variability of all species of plants, animals and micro-organisms,
as well as the ecosystem they compose
Recent rate of biodiversity loss :
Rapid, e.g. the earth will lose about 20% of all its living species by 2020.
A.
TRF helps to maintain environmental / ecological stability
1.
Climatic stability :
i.e. plants absorb CO2 + turn it into cleaner air, fighting against pollution and greenhouse effect
deforestation →↑ CO2 level ∵
a)
↓ uptake of CO2 by the reduced vegetation cover
b)
burning produces CO2
Since CO2 absorbs heat →↑T°→ global warming
→ melting of ice caps → rise of sea level →↑ risk of flooding in low-lying areas
2.
Hydrospheric stability
a) water organisms can purify the water
b) regulate river regime
deforestation → modified hydrograph (Fig.3) + ↓infiltration + ↑surface runoff
→↑soil erosion →↑silting / sedimentation of rivers/ reservoirs →↑ risk of flooding
3.
Biological stability
TRF provides a favourable habitat for living organisms
B.
The need to maintain biodiversity / genetic diversity / conserve TRF
for scientific, educational, economic and recreational purposes and for our future generation
1.
TRF has a very large genetic pool of plants and animals. The genetic variety, which is neither
fully understood nor appreciated, should be conserved for future use, e.g. scientific study,
medical use. They may be useful economic resources, e.g. food, drinks, fuel, timber, shelter,
colourants, pesticides and medicines.
A4 TRF/P.8 of 10
2.
Besides, TRF provides wild areas for recreation and enjoyment. For many LDCs, it provides local
income and foreign exchange through tourism.
3.
In terms of aesthetic value, plants and animals together with landscapes are beautiful, enriching
human life on earth.
C.
Ethnic value
Wild species have a right to co-exit with us. We have no right to exterminate them.
D.
Cultural value
Deforestation destroy habitats of native tribes. Some may be forced to move to other forest
areas and some may even change their ways of living. The traditional life and culture of the
natives will disappear.
XI. Dilemma of conserving rainforest as a national park 97#4
E.g. The establishment of the National Park of Xingu in Brazil in 1961
Conflict of interests / different points of view : Dilemmas
Parties for the proposal : (refer to P.7)
1. Environmentalists : forest conservation helps to maintain ecological stability
2. Native tribes : protect their habitat from foreign encroachment
3. Scientists : biodiversity can be preserved for scientific study
4. Recreationalists : wild areas can be preserved for recreation and enjoyment
Parties against the proposal :
1. Indigenous people
Indigenous population suffer from poverty and poor economic development. Actually, they
can have a choice to consume their forest to facilitate economic development in farming,
industry and trade. By opening the forest for foreign development, more infrastructure will
be built and more job opportunities will be created. Their living standard can be raised in
that way. So, it is not justifiable to conserve the forest in national parks to protect for the
whole world while they are poor and hungry.
2. Government of LDCs
They are heavily indebted to foreign countries, e.g. Brazil is heavily indebted to foreign
countries, e.g. US$270 billion in 2001. It is not fair if asked to conserve the forest from
any exploitation without being given anything in return.
Although national parks may bring income from tourists provided that a large investment to
improve communications, building hotels and providing amenities are available. It may not be
a good option to most LDCs if the entire cost of foregoing exploitation is not accounted.
A4 TRF/P.9 of 10
XII. Definition and utilization of resources to developers 00#4
Developers = local government, overseas companies from developed countries
Def. Of resources = all the resources found from nature, e.g. timber, minerals
Utilization of resources :
1.
Aim :
exploit all the resources to maximize the economic return and for the growing pop.
2.
Utilization pattern:
don’t need to consider the carrying capacity of the land,
just focus on short-term production rather than long term development
3.
Means:
agricultural activities, e.g.
plantation Rubber plantation in W. Malaysia
cattle ranching Northern part of Brazillian Highland
mining, e.g. Sungai Lembing (tin) + Gambang (iron) in Malaysia
commercial lumbering, e.g. Western Kalimantan (ramin) + Sulawesi, Indonesia (ebony)
industrial development + settlement
built infrastructure,e.g. Trans-Amazon Highway in Brazil for the ease of further exploitation
4.
Consequences:
a)
exploitation > carrying capacity of the land  biodiversity loss
b)
upset the ecological balance
(atmosphere, e.g. greenhouse effect + pollution;
lithosphere,
hydrosphere, e.g. modified hydrograph +
biosphere, eg. habitat loss + secondary growth + brokening of food chain)
XIII. Definition and utilization of resources to environmentalists 00#4
Def. Of resources = environment : need to protect and maintain the environment we are living
Utilization of resources :
1. Utilization pattern: Sustainable development : (Refer to P.2)
a)
Resources are exploited within the carrying capacity of the land,
i.e. take no more from nature than nature can replenish
b)
It respect and work with nature’s limit.
c)
Resources are used and conserved wisely,
e.g. adopt selective cutting instead of clear felling for commercial lumbering
better farming methods/ soil conservation measures, e.g. crop rotation, are used
establish national parks for forest conservation
2. Consequence :
Balance relation can be maintained among 3Es: environment, economy and everyone
A4 TRF/P.10 of 10
XIV.
Ways to slow down biodiversity loss 00#4 + 01#4 + 02#4 + 03#3
1. Stabilizing population by birth control + family planning   pressure on land
2. Diversification of economy   dependency on lumbering activities
3. Afforestation should be practised to control soil erosion. Fast-growing seedlings should be
transplanted to the deforested regions.
4. Forest conservation and management projects should be carried, e.g. establishment of TRF
as national parks or nature reserves.
5. Legislation should be adopted to control forest destruction, e.g. pollution and illegal cutting.
6. Using resources wisely and efficiently, e.g. adopt selective cutting instead of clear felling
for commercial lumbering.
7. Better farming methods with soil conservation, e.g. crop rotation, contour ploughing and
adding of chemical fertilizers should be used.
8. In the long-run, the public should be educated on the importance of environmental
protection and having a harmonious relationship with the nature.
sustainable development should be adopted.
9. Campaign on paper recycling should be launched.
XV.
Ways for individuals to slow down biodiversity loss 94+3 + 03#3
1. Avoid buying furniture or wooden products made with tropical timber.
2. Avoid disposable wooden chopsticks and boxes.
3. Collect used paper for recycling.
4. Buy only recycled paper.
5. Use both sides of every sheet of paper.
6. Join organization against resources misuse.
The concept of