P.1
Section A3 :
Biotic System :
Ecosystem & Vegetation & Soils
Paper I :
88
89
90
91
92
93
94
95
96
97
98
99
3
2
3, 4
4
3
4
3
1, 4
3
2
3, 5
5
00
01
02
Paper II :
03#3:
TRF : climate  soil fertility + veg. productivity + importance of maintaining floral
diversity + ways to reduce biodiversity loss
97#3 : TD : rainfall pattern + vegetation adaptation + comparison of NPP with TRF
96#4 :
95#3 :
94#3 :
93#3 :
92#4 :
Ecosystem : physical, chemical and biological processes + human impact + measures
TRF & TD ecosystem : compare and contrast components and interaction
TD : vegetation adaptation + man’s impact
Tundra : environmental constraints on plants and animals
TD : vegetation adaptation (survival, structural forms + spatial characteristics)
91#3 :
89#3 :
Tundra : spatial variation in vegetation
TRF → TD : vegetation gradient + human impact on vegetation.
88#3 :
TRF : reasons of luxuriant vegetation + unfavourable factors for farming + impact
Past Exam Paper :
03#3
Topical rainforests have some of the world’s most luxuriant vegetation and yet some of the
world’s least fertile soil.
Discuss the different influences of climatic inputs on soil fertility and vegetation
productivity in the tropical rainforest ecosystem. Explain the importance of maintaining
floral diversity in the system and suggest ways to reduce the rate of biodiversity loss.
97#3
Describe and explain the pattern of rainfall in tropical deserts. In what ways do desert
plants adapt to the desert environment ? Discuss the primary productivity of a desert
ecosystem in comparison with other ecosystems in the tropics.
03
4
P.2
96#4
An ecosystem is a structural and functional unit involving the interplay of various physical,
chemical and biological processes.
Discuss this statement with reference to a biome with which you are familiar. Explain how
the ecosystem can be modified by human beings and suggest measures to alleviate the
problems arising from human impact.
95#3
Compare and contrast the tropical rain forest and tropical desert ecosystems in terms of the
components and the interactions among them. Illustrate your answer with examples.
94#3
Describe and explain the adaptation of vegetation to the climatic conditions in tropical arid
areas. How and in what ways might man change the ecological balance in such areas ?
93#3
Assess the effects of physical and ecological constraints on plants and animals lives with
reference to the harsh environmental conditions in tundra landscapes.
P.3
92#4
Survival of plants in arid zones is heavily dependent on avoiding desiccation.
Using examples of plants at the local scale, describe and explain how avoidance of
desiccation affects the survival, structural forms and spatial characteristics of desert
vegetation in the tropics.
91#3
Account for the spatial variations in vegetation characteristics in the tundra biome at the
global scale.
89#3
Describe and explain the changes in vegetation along the climatic gradient from tropical rain
forest areas to tropical desert areas. How has the impact of man changed the vegetation
pattern you have described ?
88#3
“ In terms of the amount of biomass, natural vegetation is very luxuriant in tropical rain
forests, but the natural conditions for developing farming in tropical rain forests are not so
favourable.” Explain this statement. With reference to a tropical rain forest area of your
choice, evaluate the impact on the natural ecosystem of any one attempt to develop
agricultural in that area.
P.4
Section A3 :
Biotic System :
Soils
Paper I :
88
89
3
3
90
91
3
92
93
94
4
95
96
2
97
98
99
00
01
02
3
Paper II :
02#3 : environmental gradient of climatic and soil conditions from the equator to the temperate lat.
01#3 : salinization + relative importance of physical and human factors
00#3 : Soils in TD + human & physical factors → soil degradation + ass. measures
99#1 :
98#2 :
5 soil formers + climate : less influential
laterization and salinization + compare biotic and climatic conditions + man → saline soil
96#1 :
95#2 :
92#3 :
90#3 :
weathering + soil formation
podzolization + gleying
Tundra : spatial variation of soil + role of vegetation in soil formation
soil formation processes + conditions hinder soil formation, i.e. factors
02#3
The changes of biomes, in which communities and environmental systems interact, are
related to environmental gradients.
Discuss the environmental gradients of climatic and soil conditions from the Equator to the
temperate latitudes. Using one specific biome as an example, illustrate how human
activities may disturb the ecological balance of the community.
01#3
Salinization is a common soil process in arid regions, but it is now also found in semi-arid regions.
Describe and explain the process of salinization. Evaluate the relative importance of
physical and human factors in contributing to this soil process in semi-arid regions.
00#3
Describe the characteristics of soils in the tropical desert region. How do human and
physical factors interact to trigger soil degradation at the desert margin ? To what extent is
soil conservation effective in slowing down the degradation process ?
03
4
P.5
99#1
Of the soil formation factors, namely climate, topography, parent materials, organisms and
time, climate is perhaps the most important.
Explain the statement. Under what circumstances may climate be less influential in soil
formation ?
98#2
The characteristics of soil are the results of the interaction of environmental sub-systems.
With reference to laterization and salinization and contrast the soil development process
with respect to their climatic and biotic conditions in a natural setting. Discuss with
examples how people who fail to manage the soil have led to an increase in producing saline
soil.
96#1
Weathering is often regarded as a prerequisite of soil formation. Explain the role of
weathering in the formation of soils in the humid tropics. Evaluate the importance of other
factors in the formation of these soils. Illustrate your answer with examples.
95#2
Podzolization and gleying are two distinctive soil forming processes under different
environment conditions. With the aids of diagrams, describe the major characteristics of
the two processes. Compare the ways in which climatic and other environmental factors
interact to produce the two processes.
92#3
Describe and explain the spatial variations of soil properties in the tundra ecosystem. To
what extent is vegetation a factor of soil formation in this ecosystem.
90#3
Explain the processes which organize soil into horizons, and illustrate your answer with
examples of soil from different environments. Account for the conditions where soil
horizons are unlikely to be present.