Biosphere - A Life Support System (Edexcel GCSE Geography B)

Resources for Indigenous & Local People

• The biosphere provides goods and services at both a local and global level 

Goods 

• Goods are tangible products which can be taken from the ecosystem

• Timber, food and water are all examples of goods 

• These can be sold or used to sustain communities in the ecosystem

• They are one of the four services ecosystems provide

Services

• The services provided by ecosystems are essential for life to survive

• There are four groups of services:

  • Provisioning

  • Regulating 

  • Cultural 

  • Supporting

Examples of Goods and Services

• Many indigenous communities are directly dependant on the ecosystem goods and services 

• The Awá in the Amazon rely on the rainforest in a range of ways including:

  • Branches and palm leaves for building shelters called Tapāí

  • Palm tree fibres to make rope and hammocks

  • Wood for fires 

  • Food sources include honey collected from bee nests in trees, fish and berries such as acaí; tapir, deer and howler monkeys

Commercial Exploitation

• Increasingly the biosphere is exploited for commercial gain including:

  • Mining

  • Agriculture

  • Logging (timber)

  • HEP

  • Other industries

Mining

• Minerals are used in many industries 

  • May lead to deforestation and clearance for access roads and the mines

  • Toxic chemicals are a waste product and end up in the water systems

    • This affects the river ecosystem and human health

Examples of Mined Minerals

Agriculture

• Large areas are cleared to make way for grazing and crops

• Monocultures reduce biodiversity and impact on the food web

• Use of pesticides may affect other animals as well as the ones targeted

• Use of fertilisers can lead to eutrophication

Logging

• Felling of trees leads to:

  • Reduced interception and increased soil erosion

  • Impact on the nutrient cycle due to a lack of organic matter to add nutrients back to the soil

  • Loss of habitats and food sources for wildlife

HEP

• Construction of dams and reservoirs provides electricity but impacts on the biomes in a number of ways including:

  • Clearance of forests to make way for the dam and reservoir

  • Flooding of habitats

  • Loss of food sources

  • Affects the river wildlife as the dam can form a barrier to fish that migrate such as salmon

  • Prevents the movement of sediment downstream which affects ecosystems 

• Most human activities involve the clearance of biomes

• Once they have been cleared it is difficult to restore them

• They cannot provide the goods and services as effectively or at all

Regulation of the Atmosphere, Soil & Water

• Biomes regulate the atmosphere, soils and water 

• Without this regulation there would be:

  • More flooding

  • Soils would be unhealthy

  • A different balance of gases in the atmosphere

Atmosphere

• To maintain the balance of gases in the atmosphere gas exchange happens continuously between the atmosphere, plants, animals and water

• An example of this is the carbon cycle

• The plants and soils in biomes are carbon sinks

• Plants absorb CO₂ from the atmosphere during photosynthesis

• When plants are eaten the carbon moves from the plant to the animal

• Some CO₂ is then returned to the atmosphere through respiration

• When the plants and animals die and decompose the carbon becomes part of the soil and over millions of years may be converted into fossil fuels

• As human activity increases, CO₂ in the atmosphere increases, this may be from:

  • Burning of biomass or fossil fuels

  • Deforestation: meaning less CO₂ is taken out of the atmosphere

Soils

• The nutrient cycle maintains the health and fertility of the soil

  

• Soils require nutrients from dead organic matter (plants and animals) to remain fertile and healthy

• Removal of the biomass means the supply of nutrients is disrupted 

• The lack of vegetation cover also leads to increased leaching and the litter may be washed away, further reducing the nutrient supply

• Tropical rainforests biomes are particularly vulnerable because most of the nutrients are held in the biomass

Regulation of water

• When trees and plants are cleared from a biome it impacts on the hydrological cycle and increases flood risk

  • Interception is decreased 

  • Soil erosion increases and soil is washed into rivers reducing their capacity

  • There is more surface run off, decreasing the length of time it takes rainfall to reach rivers

  • Infiltration decreases further increasing surface run off

• The lack of trees and plants also reduces transpiration which may then lead to less frequent and reliable rainfall

Resource Demand - Global & Regional Trends

Increased resource demands

• In 2022 the world's population reached 8 billion, this increases the demand for, and pressure on, natural resources

• Increasing areas of biomes are cleared for:

  • Settlements

  • Economic activities (farming, mining, manufacturing, logging)

• Increased numbers of animals are hunted or their habitats/food sources are destroyed

• Rivers, land and the atmosphere are polluted by waste

Urbanisation

• Urbanisation has increased to 55% leading to greater urban sprawl

Food and water

• More people leads to greater demand for food and water

• Land is cleared for both grazing and crops

• Commercial agriculture is increasing using larger areas across the world and more water

• Use of pesticides and fertilisers increases pollution of land and water

Industrialisation

• Increasing numbers of countries have industrialised 

• Recent industrial growth has been mainly in Asia - China and India

• Industrialisation increases wealth and resources consumption, as well as transport use

Wealth

• Average wealth has increased meaning that people have more money to spend on:

  • Food 

  • Water: appliances such as dishwashers/washing machines, more industries using water

  • Homes: larger homes taking up more land

  • Energy: production of energy uses large areas of land for power stations, extracting energy sources, wind and solar farms

  • Consumer goods: the demand increases industrial production and waste

• These all use natural resources and create waste which impacts on the biomes

Population & Resource Theories

Malthus theory

• Malthus proposed his theory in 1798

• A pessimistic view on the relationship between population and resources (specifically food) which states:

  • Population growth is increasing at a faster rate than the food supply

  • There will be times when there is not enough food to sustain the population

  • As a result, population growth will stop as a result of a Malthusian catastrophe - famine, disease or war

  • These are known as positive checks as they increase the death rate

  • Preventative checks are factors which decrease the birth rate 

  • These limiting factors maintain the balance between population and resources

• Malthus's predictions were incorrect as they came before much of the technological developments which have enabled food supply to be increased

• Neo-Malthusians today base their views on Malthus' theory. They argue that:

  • We have now used most of the available agricultural land 

  • The amount of fertile land is in decline

  • Food prices are increasing

  • The population continues to increase

• They suggest that famines are one example of how Malthusian theory has proved to be correct

• Neo-Malthusians argue that population control is essential to avoid Malthusian catastrophe

Boserup theory

• A Danish economist, Ester Boserup put forward her theory in 1965 

• An optimistic view of the relationship between population and resources (specifically food) which states that:

  • Population growth will stimulate developments in technology to increase food production

  • More efficient resources will be discovered/used

  • Renewable resources will replace non-renewable