Habitat destruction
Section: Biology | Syllabus: Cambridge IGCSE Combined Science (0653)
Ecosystems and Biodiversity
- An ecosystem is a unit containing the community of organisms and their environment, interacting together
- Biodiversity is the number of different species that live in an area
Reasons for Habitat Destruction
- Increased area for housing, crop plant production and livestock production - expanding human populations require more land for homes and to grow food, clearing natural habitats such as forest
- Extraction of natural resources - mining, logging, and oil and gas drilling destroy habitats and pollute surrounding areas
- Freshwater and marine pollution - pollution from industry, agriculture and sewage destroys aquatic habitats
Deforestation
Deforestation is the large-scale removal of trees from a forested area. Its undesirable effects, as an example of habitat destruction, include:
| Effect of deforestation | Explanation |
|---|---|
| Reducing biodiversity | Loss of habitat means many species lose their food, shelter and nesting sites, causing population decline |
| Extinction | Species with very specific habitat requirements may disappear entirely |
| Loss of soil | Tree roots bind the soil together - without them, rain washes soil away (erosion), reducing soil fertility |
| Flooding | Trees absorb rainwater and slow surface runoff - without them, water runs off faster, causing flooding of low-lying areas |
| Increase of carbon dioxide in the atmosphere | Trees remove carbon dioxide by photosynthesis, and store carbon in their wood; fewer trees means less carbon dioxide is removed, and burning or decaying wood releases stored carbon back into the atmosphere |
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