Land Use (AQA GCSE Biology): Revision Note

Land use

• The increasing human population of the planet means an increasing amount of land is required for activities such as building, quarrying, farming and dumping waste

• This is causing the destruction of many habitats, such as rainforests and woodlands

• This reduces the biodiversity of these areas and interrupts food chains and webs, meaning that more species may die because their prey is gone

• The main reasons for habitat destruction include:

Reasons for increasing human land use

• Clearing land for farming and housing

  • Crops, livestock and homes all take up a large amount of space

  • As there is an increasing population and demand for food, the amount of land available for these requirements must be increased by clearing habitats such as forests (deforestation)

• Extraction of natural resources

  • Natural resources such as wood, stone and metals are used to make many different products

  • Many trees are cut down, destroying forest habitats

  • Quarrying and mining take up a large amount of space and the land must be cleared first

• Landfill sites

  • Many materials cannot be recycled and are discarded when they have been used

  • Landfill sites take up a lot of room and their creation often results in the destruction of natural habitats

Peat bogs

• Bogs are areas of land that are waterlogged and acidic – plants living in bogs do not decay fully when they die due to a lack of oxygen

• The partly decomposed plant matter accumulates over very long periods of time and forms peat

• The carbon that would have been released into the atmosphere as carbon dioxide (if the plants had been able to fully decompose) is instead stored in the peat

• Peat bogs are also important habitats for many species (e.g. migrating birds)

Why they are being destroyed

• Peat bogs are drained so that the area can be used for farming

• Peat can be dried and used as a fuel

• Peat can be used to produce compost for gardens or farms to increase food production

Negative impacts

• Carbon dioxide is released into the atmosphere when peat is burned as a fuel, and when dug-out peat decays (the microorganisms breaking it down respire) – this contributes to global warming

• Similarly to fossil fuels, peat bogs take so long to form that peat is effectively a non-renewable energy source

• The available peat bog habitat area for many species of animals, plants and microorganisms is decreasing, so these species lose their food and shelter; their local populations die out or migrate, reducing biodiversity

• Peat bogs are being destroyed faster than they can form – they are being used unsustainably