The Importance of Biodiversity | Biology for GCSE/IGCSE - Year 11 PDF Download

Human Pressures on Other Species

Biodiversity

• Is defined as the number of different species that live in a particular area.
• Human activities have tended to decrease biodiversity, while high biodiversity is crucial for stable ecosystems.
• Habitat destruction by humans is a significant factor leading to decreased biodiversity.

• The global increase in human population is leading to the devastation of various habitats, including rainforests, woodlands, and marine ecosystems.
• Human activities such as deforestation, pollution, and land conversion for economic purposes are major contributors to habitat destruction, resulting in a decline in biodiversity.
• This disruption in ecosystems leads to the collapse of food chains and webs, causing the extinction of species due to the depletion of their prey.
• The main reasons for habitat destruction include:

Deforestation

• Deforestation involves the large-scale clearing of trees, often leading to detrimental environmental impacts.
• When trees are replanted after clearance, it can be considered sustainable; however, this is not commonly practiced.
• The primary reasons for deforestation include land conversion for construction, livestock grazing, and the establishment of monocultures like palm oil plantations.
• The reduction in global forest cover results in severe environmental consequences, exemplifying habitat destruction.
• Undesirable outcomes of deforestation encompass species extinction, soil degradation, increased flooding, and heightened levels of atmospheric carbon dioxide.

The Impact of Environmental Changes

• Extinction: Extinction refers to the permanent loss of a species. When a species goes extinct, it is lost forever, disrupting the balance of ecosystems.
• Loss of soil: Soil is a vital resource for agriculture and ecosystems. When soil is lost through erosion or degradation, it affects food production and leads to desertification.
• Flooding: Flooding can result from various factors like heavy rainfall or human activities. It causes damage to infrastructure, displaces communities, and leads to loss of life.
• Increase of carbon dioxide in the atmosphere: The rise in carbon dioxide levels is primarily due to human activities like burning fossil fuels. This leads to global warming, climate change, and impacts biodiversity.