2.5: Climate and Natural Vegetation (Paper 1 and 2)

Question 1

Explain the characteristics of desert climate: (4)

Answer 1

• Mean temperature of hottest month: 43 degrees celcious (1)
• Mean temperature of coolest month: 24 degrees celcious (1)
• Annual Range: 25 degrees celcious (1)
• Annual Precipitation: Below 250mm (1)

Question 2

Explain the characteristics of equatorial climate: (3)

Answer 2

Mean temperature: 26-28 degrees celcious annually (1)
Annual range: 1-2 degrees celcious
Annual precipitation: Over 2000mm

Question 3

Explain how the following factors influences the characteristics of climates: (10)

• Latitude: (1)
• Pressure systems: (2)
• Wind: (2)
• Distance from the sea: (2)
• Altitude: (1)
• Ocean Currents: (2)

Answer 3

• Latitiude: Areas that are close to the equator recieve more heat than areas that are close to the poles due to incoming solar radiation is more concentrated near the equator and insolation near poles need to pass through a greater amount of atmosphere and they also could be reflected back into space. (1)
• Pressure systems: Low-pressure systems are associated with uplifting of air. condensation cloud formation and rain. (1) High pressure systems are assosciated with descending air and dry conditions like hot deserts. (1)
• Wind: Prevailing winds are the most frequent winds and their effect depends on where they come from. (1) For example, the southwest winds that affect the British Isles bring warm air from the mid-atlantic. (1)
• Distance from the sea: It takes more energy to heat up water than it does to heat land and it also takes longer for water to lose heat. (1) Areas that are closer to the sea are hotter than the sea during the day and colder than the sea during the night. (1)
• Altitude: Temperature decreases with altitude and on average the temperature drops 1 degrees celcious every 100m because air at higher altitudes is thinner and less dense. (1)
• Ocean Currents: The effect of an ocean current depends upon whether it is a cold ocean current or a warm ocean current. (1) Cold ocean currents lower the temperature of coastlines they affect. (1)

Question 4

Explain the characteristics of tropical rainforests in terms of: (15)

• Vegetation (4)
• Soil (4)
• Wildlife (2)
• Climate (5)

Answer 4

• Vegetation: Vegetation in the rainforest is well adapted to the climatic conditions of rainforests. (1) Photosynthesis and growing can take place all year. (1) The vegetation is layered and the shape of the leaves varies within each layer in order to receive sunlight. (1) There are up to 200 species of tree per hectare including fig, teak, mahogany and rosewood. (1)
• Soil: Tropical soils are very deep and infertile. (1) The heavy rain washes out much of the clay salts and other nutrients. (1) Decaying vegetation is broken down rapidly under hot, wet conditions and releases some nutrients back into the soil. (1) As a result of poor soil. plants that grow throughout the year take up these nutrients before they are washed away. (1)
• Wildlife: Over 50% of all animal species on Earth are found in tropical rainforest areas and most of these alive in trees. (1) Many species are still yet to be identified. (1)
• Climate: Within the tropics 23.5 degrees north and south of the equator. (1) Diurnal range is 7 degrees celcious. (1). There are no seasons and it is hot and wet all year. (1) High humidity of 75-80%. (1) Winds blow into the tropical region from high pressure areas to the north and south of the equator. (1)

Question 5

Explain the causes of deforestation: (7)

Answer 5

• Mining: Land is cleared to obtain precious materials. (1)
• Settlements: As populations grow, more space is cleared for housing. (1)
• Logging: Trees are felled for timber. (1)
• Agriculture: Huge areas are cleared for plantations such as soy or palm oil as well as for grazing cattle. (1)
• Hydropower: Building of dams and and reservoirs to provide electricity. (1)
• Road building: Roads such as highways are built to provide further access to the forest. (1)
• Wildfires (1)

Question 6

Explain the effects of deforestation: (6)

Answer 6

• Disruption to the circulation and storage of nutrients. (1)
• Surface eriosion and compaction of soils. (1)
• Sandification: Selective erosion when rain falls. (1)
• Increased flood levels and sediment content of rivers. (1)
• Climate change (1)
• Loss of biodiversity: (1)

Question 7

Explain the characteristics of hot deserts in terms of: (14)

• Vegetation (4)
• Soil (1)
• Wildlife (5)
• Climate (4)

Answer 7

• Vegetation: Vegetation from desert margins is often referred to as scrub. (1) Plants adapt to life in hot deserts by growing long water-seeking roots, (1) producing only a few leaves to reduce transpiration, (1) storing water and prducing seeds that wait for rainfall before growing and completing a very quick lifecycle. (1)
• Soil: Soils are poor here because they contain very few nutrients and organic matter because they are very dry. (1)
• Wildlife: Hot deserts have one of the lowest biodiversity of plants and animals on Earth. (1)
  They are adapted to living in the desert by being nocturnal, (1) remaining undeground for much of the day, (1) having large ears (1) and becoming dormant during periods of extreme heat and moisture shortages. (1)
• They experience rainfall of less than 250mm per year, (1) they are found in subtropical areas between 20 degrees and 30 degrees north and south of the equator, (1) in areas of rain shadow, (1) and are at great distance from the sea. (1)

Question 8

Define the term specific heat capacity: (1)

Answer 8

The amount of heat needed to raise the temperature of a body by 1 degrees celcious. (1)