Topic 7 - People And The Biosphere

Question 1

What is an ecosystem?

Answer 1

An ecosystem is made up of all of the living and non living things in an area and their interacts.

Question 2

What is a biome?

Answer 2

Large scale global ecosystems with distinctive vegetation.

Question 3

How does the climate effect biomes?

Answer 3

1. Temperature - Most plants need temperatures of over 5°C to grow, so length of growing season varies from place to place.
2. Precipitation and water availability are important as plants need water. Plants grow if precipitation is spread across all seasons, but not if there is a dry season or water is frozen in winter.
3. Sunshine hours and intensity affect photosynthesis and therefore plant growth.

Question 4

What Local factors affect where biomes are found?

Answer 4

Altitude
Rock type
Soil type
Drainage

Question 5

What does biotic mean?

Answer 5

The living components of an ecosystem: the plants (flora) and the animals (fauna)

Question 6

What does abiotic mean?

Answer 6

The non-living components of an ecosystem: soil, rocks, water and the atmosphere.

Question 7

What does Biodiversity mean?

Answer 7

The variety of biotic components in an ecosystem (high biodiversity = thousands of different plants and animals)

Question 8

What to remember about biotic and abiotic components?

Answer 8

They interact

Long cold winters, low precipitation and frozen soils —> Specialist plants, small amount of plant food so small number of animals —> low biodiversity.

Question 9

What does the biosphere provide us with?

Answer 9

Food
Medicine
Building materials
Sources of fuel

Question 10

What is the biosphere exploited commercially for?

Answer 10

Energy
Water
Mineral resources

Question 11

What does the biosphere do for us?

Answer 11

• Regulates the gasses that make up the atmosphere - plants absorb carbon dioxide and produce oxygen for us to breathe in.
• Regulates the water cycle - Plants slow the flow of water to rivers and filter water to make it clean.
• Keeps soil healthy for plants to grow - new nutrients are provided by rotting plant material.

Question 12

What was Malthus’ theory?

Answer 12

It was impossibile to increase food production as rapidly as population growth. Therefore if a population was allowed to grow too much, it was inevitable that food supply would run out and famine would result, reducing the population size.
Pessimist

Question 13

What was Boserup’s theory?

Answer 13

Boserup thought that human innovation will be sparked by demands on resources. So if there is high demand for food new techniques to increase food production will be invented. The same applies to water supplies and energy supplies.
Optimist

Question 14

What global and regional trends are decreasing the increasing for food, energy and water resources?

Answer 14

Population growth
Rising affluence
Urbanisation
Industrialisation

Question 15

How does affluence affect demand for resources?

Answer 15

People are getting richer. They have a higher disposable income so consume more resources. In developing countries more people can afford running water for toilets and showers.

Question 16

How does urbanisation affect demand for resources?

Answer 16

Movement from rural to urban areas means there is more resources used because food and water has to be transported there and waste had to be removed which uses energy. Urban areas use more resources than rural areas.

Question 17

How does altitude affect biome distribution?

Answer 17

• Temperature goes down higher up.
• Mountains are more exposed to wind and precipitation.
• Slopes are usually steeper and therefore soils are thinner.

Question 18

How does rock type affect biome distribution?

Answer 18

• Limestone rocks produce alkaline soils due to their permeability and are therefore dry.
—> These lead to beech trees replacing oak as the main species in some areas or even preventing tree growth altogether.