GCSE Biology revision

Land use

Biodiversity and the effect of human interaction on ecosystems

AQA 4.1.1.1

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AQA student objectives

Learning pathway

All · Most · Some

ALL 🎯

Identify and describe Land Use and Its Consequences, What is Deforestation? and Deforestation and Carbon Dioxide in the context of land use.

MOST 🎯🎯

Explain the relationships between Land Use and Its Consequences, What is Deforestation? and Deforestation and Carbon Dioxide and how they contribute to land use.

SOME 🎯🎯🎯

Apply and analyse knowledge of Land Use and Its Consequences, What is Deforestation? and Deforestation and Carbon Dioxide to interpret unfamiliar information about land use.

Revision summary

Key knowledge

Read on screen, then print for Cornell-style active revision.

Land Use and Its Consequences

Humans use land for building, quarrying, farming, and waste disposal, but the more land we use, the less remains available for other organisms
Converting land for human use often causes knock-on environmental damage beyond just the loss of space for wildlife

What is Deforestation?

Deforestation is the cutting down of forests and occurs worldwide for reasons including farming, biofuel crop production, and logging
Forests are cleared to raise cattle, grow crops such as rice, or cultivate plants used to produce biofuels — plant-based fuels burned instead of fossil fuels
Logging refers specifically to clearing forest to obtain the wood itself, which can then be used as a building material or burned as fuel

2. What is Deforestation?AQA

Notes

Deforestation is the cutting down of forests and occurs worldwide for reasons including farming, biofuel crop production, and logging
Forests are cleared to raise cattle, grow crops such as rice, or cultivate plants used to produce biofuels — plant-based fuels burned instead of fossil fuels
Logging refers specifically to clearing forest to obtain the wood itself, which can then be used as a building material or burned as fuel

Deforestation and Carbon Dioxide

When trees are removed, they can no longer photosynthesise, meaning carbon dioxide is no longer absorbed from the atmosphere and locked inside plant biomass
Burning forests to clear land releases all the stored carbon directly into the atmosphere as carbon dioxide, contributing to global warming
The smoke produced by burning forests can suffocate animals and pollute nearby towns, causing serious environmental and health problems

3. Deforestation and Carbon DioxideAQA

Notes

When trees are removed, they can no longer photosynthesise, meaning carbon dioxide is no longer absorbed from the atmosphere and locked inside plant biomass
Burning forests to clear land releases all the stored carbon directly into the atmosphere as carbon dioxide, contributing to global warming
The smoke produced by burning forests can suffocate animals and pollute nearby towns, causing serious environmental and health problems

Deforestation and Biodiversity

Tropical rainforests have particularly high biodiversity, supporting vast numbers of different plant and animal species
Destroying forest habitats massively reduces local biodiversity, and as deforestation continues on a large scale, entire species are being driven to extinction

What are Peat Bogs?

Peat bogs are areas of land where the soil is both acidic and waterlogged, preventing microorganisms from fully decomposing dead plant material
The waterlogged conditions limit oxygen availability, making aerobic respiration impossible for decomposers, so plants only partially rot
Partially decomposed plant matter gradually accumulates to form peat, locking away the carbon that the plants absorbed during their lifetime

5. What are Peat Bogs?AQA

Notes

Peat bogs are areas of land where the soil is both acidic and waterlogged, preventing microorganisms from fully decomposing dead plant material
The waterlogged conditions limit oxygen availability, making aerobic respiration impossible for decomposers, so plants only partially rot
Partially decomposed plant matter gradually accumulates to form peat, locking away the carbon that the plants absorbed during their lifetime

Why Peat Bogs Matter for Climate

Because carbon is stored in peat rather than released as carbon dioxide, peat bogs act as important carbon stores that help reduce global warming
Peat bogs are often drained to create farmland; once drained, oxygen returns to the soil, allowing microorganisms to decompose the peat and release stored carbon as carbon dioxide
Peat is also deliberately removed to be burned as fuel or used as garden compost, both of which result in the release of carbon dioxide into the atmosphere
Peat bogs are being destroyed far more quickly than new ones can form, making this loss particularly difficult to reverse

6. Why Peat Bogs Matter for ClimateAQA

Notes

Because carbon is stored in peat rather than released as carbon dioxide, peat bogs act as important carbon stores that help reduce global warming
Peat bogs are often drained to create farmland; once drained, oxygen returns to the soil, allowing microorganisms to decompose the peat and release stored carbon as carbon dioxide
Peat is also deliberately removed to be burned as fuel or used as garden compost, both of which result in the release of carbon dioxide into the atmosphere
Peat bogs are being destroyed far more quickly than new ones can form, making this loss particularly difficult to reverse

Peat Bogs and Biodiversity

Just like deforestation, the destruction of peat bogs destroys the unique habitats of the specialised organisms that live there
Loss of peat bog habitats reduces biodiversity and may lead to the extinction of species that depend on these environments

Key Themes: Linking Land Use to Global Issues

Both deforestation and peat bog destruction increase atmospheric carbon dioxide levels, accelerating global warming
Both processes reduce biodiversity by destroying habitats, potentially causing species extinction on a large scale
Human demand for farmland, fuel, and resources is the common driving force behind both types of habitat destruction

8. Key Themes: Linking Land Use to Global IssuesAQA

Notes

Both deforestation and peat bog destruction increase atmospheric carbon dioxide levels, accelerating global warming
Both processes reduce biodiversity by destroying habitats, potentially causing species extinction on a large scale
Human demand for farmland, fuel, and resources is the common driving force behind both types of habitat destruction