Biosphere - A Life Support System (Edexcel GCSE Geography: B (1GB0))

• 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

• 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

• 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

Carbon cycle 

Soils

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

Tropical rainforest nutrient cycle

• 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

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

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

Graph to demonstrate Malthus's theory

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

Graph to demonstrate Boserup's theory