Topic 7.2 - The biosphere as a life support system for people (Finished)

Question 1

What is the biosphere?

Answer 1

The biosphere is all parts of the Earth that are occupied by living things. It includes animals, plants, soil, water, bacteria etc

Question 2

What four ways do indigenous people use forests?

Answer 2

Food, medicine, building materials, fuel

Question 3

How do indigenous people get food from the biosphere?

Answer 3

• Many get food directly from plants and animals
• Some may forage for food such as berries, nuts
• Animals are hunted and trapped (e.g. fish)

Question 4

How do indigenous people use the biosphere for medicine?

Answer 4

Lots of plants have medical properties which can be used to cure illness and keep people healthy. E.g. in trf plant species can be used to create over 7000 drugs

Question 5

How do indigenous people use the biosphere for building materials and fuel?

Answer 5

Trees and plants are often used as building materials for furniture and homes, sap from trees can make waterproofing etc. Indigenous people also rely on plants and animals for fuel for cooking and keeping warm, wood, moss, dry dung can all be burnt

Question 6

What are some supporting services of the biosphere?

Answer 6

• Nutrient cycling
• Photosynthesis for food webs
• Soil formation

Question 7

What are some provisioning services of the biosphere?

Answer 7

(Goods)

• Timber for building
• Fuelwood
• Food

Question 8

What are some regulating services of the biosphere?

Answer 8

• Storing carbon and emitting oxygen to keep the atmosphere in balance
• Purifying wager and regulating its flow in the hydrological cycle

Question 9

What are some cultural services of the biosphere?

Answer 9

• Recreation and tourism

- Spiritual well-being and happiness

Question 10

Why is demand for energy increasing?

Answer 10

More people have electronic devices such as laptops and phones and world population is increasing all needing more energy

Question 11

How is the biosphere being exploited for energy?

Answer 11

• Large areas of forest are cut down for the growing of crops for biofuel or making way for coal mines and power plants
• Some areas of tropical forest are flooded when HEP dams are built
• Drilling for oil and gas in tundra melts permafrost
• Clearing land for coal surface mines destroys landscape, cuts down forest

Question 12

How is the biosphere being exploited for water?

Answer 12

• Lakes, rivers and aquifers are over-exploited meaning they are drained faster than they can refill. Mainly in hot places like the Sahara Desert.
• water of irrigation

Question 13

How is the biosphere being exploited for minerals?

Answer 13

• Minerals are extracted by mining which releases toxic chemicals into streams killing animals + plants
• Open cast mining causes deforestation and large areas of surface removed

Question 14

Why is the biosphere being over-exploited for water?

Answer 14

A rising population means more people who need water for drinking washing etc. Also more food needed so more water to irrigate farmland etc

Question 15

Why is the biosphere being over-exploited for minerals?

Answer 15

Increasing demand for electrical appliances and scientific instruments

Question 16

What four main things is the biosphere bing over-exploited for?

Answer 16

Food, water, energy, minerals

Question 17

What are the four main services provided by the biosphere?

Answer 17

Provisioning services, supporting services, regulating services, cultural services

Question 18

What is the effect of over-exploiting the biosphere for water?

Answer 18

Plants and Animals can’t survive as there is no water left for them damaging the biosphere

Question 19

How is the biosphere being over-exploited for food and what is the effect?

Answer 19

• Cattle farming means large areas of forest/land are cleared to keep cattle
• Palm oil plantations mean that large areas of forest need to be cleared

Question 20

Statistic for exploitation of biosphere for food

Answer 20

6 million hectares of palm oil plantation in Indonesia

Question 21

Statistic for exploitation of biosphere for energy?

Answer 21

HE dam in Amazonia flooded 1750 km2 of rainforest

Question 22

How does slash-and-burn farming work?

Answer 22

1) Farmers cut down an area of forest and burn the biomass releasing nutrients into the soil
2) Nutrient-rich soil is farmed for a few years before it becomes useless
3) Once it has been used up they move into another area

Question 23

Is slash-and-burn farming sustainable?

Answer 23

Yes if few people do it, but because forest takes long to regrow and too many people are doing it it has become very damaging

Question 24

Are local tribes or slash-and-burn farmers more sustainable?

Answer 24

Local tribespeople are more sustainable as they use the forest on a much smaller scale and try to minimise damage to it as they know it will affect them much more.

Question 25

Who is generally responsible for commercial exploitation of the biosphere?

Answer 25

TNCs!

Question 26

How does the biosphere help control the proportion of different gases in the atmosphere?

Answer 26

Plants take in carbon dioxide and give out oxygen during photosynthesis. Animals take in oxygen from the air and give out carbon dioxide when they breathe. This mantains a constand balance of gases

Question 27

Why is maintaining the balance of gases in the atmosphere important?

Answer 27

• Most organisms need oxygen to survive
• Too much co2 causes global warming, but some is needed for keeping the Earth warm enough for life
• Too much co2 makes oceans acidic affecting organisms living there

Question 28

How does the biosphere mantain soil structure?

Answer 28

The roots of vegetation hold the soil together preventing it from being easily eroded by wind and rain

Question 29

How does the biosphere maintain nutrients in the soil?

Answer 29

Plant roots and animals (e.g. earthworms) spread nutrients through the soil maintaining it’s fertility, allowing plants to grow. Vegetation also intercepts rainfall before it reaches the ground preventing leeching (nutrients washed downwards in soil)

Question 30

What is leeching?

Answer 30

Leeching is where nutrients in the soil are washed downwards out of reach of plants

Question 31

What is the water cycle?

Answer 31

The water cycle is the movement of water between land, bodies of water and the atmosphere.

Question 32

How does the biosphere regulate the global water cycle and what is the benefit?

Answer 32

Plants store water and release it into the atmosphere slowly. Large areas of forest can reduce risk of drought and flooding in areas a long way away.

Question 33

How does the biosphere prevent flooding and soil erosion?

Answer 33

Water is taken up by plants, so less reaches rivers reducing flooding and soil erosion

Question 34

Briefly describe the nutrient cycle?

Answer 34

Plants absorb nutrients and use them to grow, animals eat plants taking in contained nutrients. Both die and decompose returning nutrients to soil. Leaves also fall and decompose.

Question 35

What are population projections?

Answer 35

Population projections are predictions of how many people there will be in the world in the future

Question 36

What world population does the highest of three predictions for population growth by the UN reach?

Answer 36

The highest prediction shows the world’s total population reaching 14 billion people

Question 37

Give an example of how increased demand for one resource can lead to increased demand for another?

Answer 37

More people means more food needs to be grown which increases demand for water to grow the food

Question 38

What four factors increase demand for resources?

Answer 38

Population growth, increasing wealth, urbanisation, industrialisation

Question 39

Why does increasing wealth mean a higher demand for resources?

Answer 39

Wealthier people have more disposable income so their resource consumption increases. They have more money to spend on food, buying more than they need. They can afford cars, televisions which use lots of energy. More can also afford toilets, showers etc using more water.

Question 40

Why does urbanisation create an increased resource consumption?

Answer 40

Cities are more resource intensive than rural areas (street lights, neon signs, fountains in parks needing water). Food and water also have to be transported long distances to meet increasing demand in cities, and waste removed using energy

Question 41

What is industrialisation?

Answer 41

Industrialisation is the shift in a country’s main economic activity from primary industry to secondary production

Question 42

Why does industrialisation create increasing demand for resources?

Answer 42

• Manufacturing goods uses lots of energy to run machines. It also uses lots of water for cooling and cleaning
• Industrialisation increases production of processed goods so increased demand for resources such as palm oil

Question 43

What was Malthus’s theory on population growth and resource availability?

Answer 43

Malthus thought that population is growing faster than supply of resources so eventually there would be too many people for resources. He believed when this happened people would be killed by catastrophes (e.g. war, famine, illness) and population would return to supportable level. This continues onwards.

Question 44

What is the point of catastrophe? (Malthus)

Answer 44

The point of catastrophe is where there is a equal resource supply to people

Question 45

What was Boserup’s theory on population growth and resource availability?

Answer 45

Boserup believed that if resource supplies became limited, people would come up with new ways to increase production (e.g. irrigation) to avoid hardship. However big the world population grew, people would always be able to produce sufficient resources.

Question 46

Has Malthus or Boserup theory turned out true?

Answer 46

Neither has proved completely right or wrong. There have been famine in some areas but globally food production has kept up so far.