8.6 Biodiversity

Levels of diversity

Biodiversity is the variety of life, measured at three levels: genetic diversity (within a species), species diversity (number and variety of species), and ecosystem diversity (variety of habitats). More biodiversity generally means a more stable, resilient ecosystem.

Why it matters

Greater genetic diversity helps populations adapt to change. Ecosystems provide ecosystem services (clean water, pollination, climate regulation) that humans depend on. Losing biodiversity makes ecosystems more vulnerable to disturbance and collapse.

Key terms

Biodiversity

The variety of life, measured at genetic, species, and ecosystem levels.

Species / genetic / ecosystem diversity

The three levels of biodiversity: within a species, among species, and among habitats.

Diversity & stability

Higher biodiversity generally makes ecosystems more stable and resilient.

Ecosystem services

Benefits ecosystems provide humans, like clean water, pollination, and climate regulation.

Threats to biodiversity

Habitat loss, pollution, invasive species, and climate change reduce diversity.

Try an AP-style question

Which statement is correct?

1. Y is more diverse because one species dominates the community
2. Both have the same richness, but X is more diverse because it is more even
3. Both communities have exactly the same diversity since both have 5
4. X has greater species richness than Y because it is balanced