Biodiversity and habitat destruction

Biodiversity and habitat destructionSpec 20.2.1, 20.2.2, 20.2.3

Biodiversity

The number of different species that live in an area.

A habitat is destroyed when it is changed so much that the organisms living there can no longer survive. This reduces biodiversity.

Reasons for habitat destruction

• Increased area for housing, crop plant production and livestock production: forests, grassland and wetlands are cleared to build homes and to grow food for a growing population.
• Extraction of natural resources: mining, quarrying and drilling remove soil and rock and destroy the habitat above.
• Freshwater and marine pollution: pollutants such as sewage, fertiliser and plastics make water unsuitable for the organisms that live in it.

Damage to food webs

Humans can also have a negative impact on habitats by altering food webs and food chains. Removing one species affects others. For example, if a predator is hunted out, its prey may increase in number and eat too much of the producers. If a producer is cleared, the animals that feed on it lose their food and may die or move away.