Human Impacts on Biodiversity Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Explore how human activities can both positively and negatively affect biodiversity in ecosystems, understanding the range of impacts humans have on the...

• Describe positive and negative human interactions with ecosystems
• Explain how human activities affect biodiversity
• Evaluate the impact of conservation efforts on ecosystems
• Compare different approaches to protecting biodiversity

Key ideas to keep in view

Use this lesson to stay inside B6.1 Monitoring and maintaining the environment while connecting the detail back to the wider B6: Global challenges topic.

• B6: Global challenges
• B6.1 Monitoring and maintaining the environment
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Human Impacts on Biodiversity before testing yourself from memory.

• Every day, human activities change the natural world around us. Some changes help wildlife thrive, whilst others push species towards extinction. Understanding these impacts isn't just about saving pandas - it's about maintaining the complex web of life that keeps our planet functioning.
• Picture a rainforest being cleared for palm oil plantations. In one day, hundreds of species lose their homes. Now imagine a nature reserve being created in the same area. The contrast shows how human choices directly shape biodiversity - the variety of life on Earth.
• The process by which natural habitats are damaged or eliminated, making them unable to support the species that live there.
• The biggest threat to biodiversity comes from habitat destruction. When we clear forests for farmland, drain wetlands for housing, or build roads through wilderness areas, we fragment ecosystems into smaller pieces. Many species need large territories to survive - a single tiger needs up to 100 square kilometres of...
• Deforestation removes entire ecosystems. The Amazon rainforest loses an area the size of a football pitch every minute. Each cleared hectare eliminates habitat for countless species, from insects to jaguars. Trees also store carbon dioxide, so deforestation contributes to climate change.
• Pollution poisons ecosystems in multiple ways. Pesticides kill beneficial insects alongside pests. Plastic waste entangles marine animals. Chemical runoff from farms creates dead zones in rivers and seas where nothing can survive.
• Overfishing removes key species from marine food webs. When we catch too many large predatory fish, their prey species multiply rapidly, disrupting the entire ecosystem balance.
• Humans can also have positive effects on biodiversity through careful planning and conservation efforts. These approaches work by protecting existing habitats, restoring damaged ecosystems, and creating new spaces for wildlife.
• Nature reserves and national parks protect large areas of habitat from development. a habitat National Park in the USA covers nearly 9,000 square kilometres, providing safe space for wolves, bears, and hundreds of other species. In the UK, the New Forest protects ancient woodland and heathland.
• Captive breeding programmes save species from extinction. The California condor was reduced to just 27 birds in 1987. Through careful breeding in zoos and wildlife centres, over 500 now exist. Some have been successfully released back into the wild.

Continue through the topic

Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.