Species Diversity
Middle School
Definition
The variety and number of different species within a community or ecosystem. Greater species diversity generally makes an ecosystem more stable and better able to recover from disturbances.
Worked examples
A rainforest with 150 tree species, 80 bird species, and hundreds of insect species has high species diversity.
Many different species in one ecosystem increases its stability and resilience.
A wheat field with only wheat plants and a few pest insects has low species diversity.
Few species make the ecosystem fragile — a single disease can wipe out the crop.
Common mistakes
- Species diversity is just the total number of organisms in an area. → Species diversity is the number of different species, not total individuals. A million bacteria of one species has lower diversity than ten individuals from ten different species.
- High species diversity always means more animals. → High species diversity includes plants, fungi, microbes, and animals. All kingdoms of life contribute to species diversity, not just animals.
- Species diversity and genetic diversity are the same thing. → Species diversity counts different species; genetic diversity is variation within one species. They are both types of biodiversity but measure different levels of biological variety.
Where you'll use it next
You'll apply species diversity when studying ecosystem stability, food webs, conservation biology, and human impacts like habitat loss and invasive species in ecology and environmental science.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026