Geography - Paper 3

Describe the tropical rainforest biome (location, climate and vegetation)

• on or near the equator between the tropics

• rain all year (2000mm annually)

• hot all year (25 - 30 degrees)

• dense forests of evergreen trees in different layers

Describe the desert biome (location, climate and vegetation)

• no rain or clouds

• found 15-30 degrees N/S of the equator

• cool nights mean many nocturnal animals

• average precipitation <250mm / year

• plants are scarce and have water-storing features like spines and extensive root systems

Describe the taiga/boreal forest biome (location, climate and vegetation)

• below freezing up to 6 months a year

• no sunlight for several months

• coniferous, evergreen trees

• up to 300mm of precipitation a year, which often falls as snow

Describe the tundra biome (location, climate and vegetation)

• found in arctic and antarctic

• very cold and sun has little power

• temp below dressing and little sunlight for many months

• few plants can live here, only mosses and lichens

Describe the tropical grasslands biome (location, climate and vegetation)

• found 5-30 degrees N/S of equator

• hot all year, 25 degree average, 500-1000mm precipitation annually

• always has a dry season

• long grasses, some drought-resistant shrubs and trees with long roots to reach water underground

Describe the temperate grasslands biome (location, climate and vegetation)

• 40-60 degrees N/S of equator

• hot summers (25) and cool winters (-40)

• large herbivores (eg kangaroos and bison) and burrowing animals

• average precipitation 500-900mm a year

Describe the temperate forests biome (location, climate and vegetation)

• deciduous trees like oak

• warm summers (18) and cool winters (5)

• lots of precipitation all year (750-1500mm annually)

• 40-60 degrees N/S of equator

Describe the effects and causes of precipitation variations in biomes

• influenced by latitude, low in high pressure zones, high in low pressure zones

• forests found in areas of low pressure and high rainfall

• plants grow if precipitation is spread across all seasons, less if there is a wet and dry season

Describe the effects and causes of temperature variations in biomes

• sunshine hours and intensity affect photosynthesis and plant growth

• in polar areas, LI is low so a lack of heat and light limits growth

• temperature and sunlight hours are affected by latitude, as it increases winter becomes longer and colder, and the climate more seasonal

• most plants need temperatures above 5

Describe how climate and other factors affect plant growth

• temperature falls 1 degree for every 100m climbed

• impermeable rocks cause the surface to become waterlogged to peat bogs and marshlands form

• in areas regularly flooded by sea water, plants are adapted to salt

• clay soil holds onto water and nutrients well

• mountains are more exposed to wind, and precipitation is usually greater at higher altitudes

How is the biosphere used commercially for food?

• fish and meat farming

• natural vegetation replaced with crops

• sustainable harvesting of fruits and berries

How is the biosphere used commercially for fuel?

• animal dung is dried and burnt

• biofuels from plants

• wood from trees

• areas of vegetation cleared for mining of fossil fuels

How is the biosphere used commercially for medicine?

• poppies are the main source of morphine

• aloe has soothing properties

How is the biosphere used commercially for building materials?

• timber from trees

• straw used for roofing and insulation

• animal dung mixed with clay and used to make bricks

How do indigenous people use the rainforest?

• to find medicine: e.g. a bark is used to help headaches and fevers by some tribes

• to find food: e.g. duck and monkey can be eaten, and snare traps are used to catch small game

Describe commercial use of the rainforest

• farming, especially for cattle ranching or to grow crops like soybeans to feed cattle

• commercial crops like palm oil, cocoa or cereals

• timber to make furniture or construction wood

• mining of metal ores like copper and iron

• construction of dams and reservoirs to for HEP or to supply water to cities

Describe some factors that affect the nutrient cycle

• removing biomass takes a nutrient store out of the system

• heavy rain and surface run-off can wash away little, removing another essential nutrient store

• weathering breaks down rocks and releases mineral ions into the soil

• deforested areas are at risk of soil erosion, removing another store

Describe the nutrient cycle

1. When dead material is decomposed, nutrients are released into the soil.

2. They are then taken up from the soil by plants which may be eaten by consumers.

3. When the plants or consumers die, they are decomposed, and the nutrients are returned to the soil.

4. This transfer of nutrients is called the nutrient cycle.

Describe factors affecting the water cycle

• destroying a forest biome has serious impacts: less interception, etc

• mangrove trees on coasts of sub-tropical countries provide interception and reduce surface run-off to provide a natural flood defense

• in 2010, severe flooding in Bangladesh was partially blamed on illegal logging

Describe problems with population growth

• industrialisation and global shift (more factories)

• urbanisation (ruining habitats and more energy demand)

• food production (will need 2x as much food by 2050, but this will not be achieved)

• affluence (more disposable income leads to a growing middle class so consumption increases)

What are the two views on population growth that you need to know?

Malthusian view, Boserupian view

Describe the Malthusian view on population growth

• believed there was no way to provide enough resources for the growing population

• believed 'natural' checks would occur (eg famine or natural disasters) to reduce the population

Describe the Boserupian view

• believed population growth is a positive thing

• thought humans would invent ways around problems with shortages of resources

• population growth —> innovation

Describe the indirect threats of on the tropical rainforest

• warmer temps cause a shift in the weather systems that keep weather constantly wet so the plants and animals would not be able to cope in the drier and hotter climates

• stressed plants and animals would be more vulnerable to disease

• hotter and drier forests would be more vulnerable to forest fires

Describe the nutrient cycle in the rainforest

• decomposition occurs quickly in the warm and wet conditions

• releases nutrients into soil

• heavy precipitation leaches nutrients deep into soil and weathers rocks to release mineral ions

Describe the adaptations of animals in the tropical rainforest

• jaguars have dotted fur to blend in with dappled sunlight

• sloths have strong claws and green algae in their fur to blend in

• monkeys and lemurs have strong claws, and long tails for balance

• parrots have loud calls to find mates and strong beaks to open nuts

Describe the adaptations of plants in the tropical rainforest

• trees have flared bases and flexible trunks with visible buttress roots to provide extra stability

• leaves are waxy and have drip tips to allow water to run off easily

• trees grow no leaves or branches below the canopy to conserve energy where they cannot reach the sunlight

What are the layers in the tropical rainforest?

emergent layer, canopy, understory, forest floor

What are the two rainforest protection schemes you need to know?

REDD and CITES

Describe how CITES protects the tropical rainforest

• it is an international treaty protecting 35,000 species as countries agree to stop imports/ exports of endangered species

• hard to check that all 181 countries involved are doing what they should, and demand means illegal trade in increasing

Describe how REDD protects the tropical rainforest

• a UN scheme to support all projects aiming to reduce deforestation

• large sums of money available