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Biodiversity and ecosystem health

Review your understanding of biodiversity and ecosystem health in this free article aligned to NGSS standards.

Key points:

  • Biodiversity is the variety of species in an ecosystem.
  • Biodiversity decreases when species go extinct, or die out. Extinction often happens when organisms can no longer survive because of changes to their ecosystems.
  • A decrease in biodiversity can be the result of human actions. For example, human actions are leading to habitat loss and climate change. These, in turn, are causing a decrease in Earth’s biodiversity.
  • When an ecosystem loses biodiversity, it doesn’t function as well. So, scientists often look at how complete an ecosystem’s biodiversity is in order to measure the ecosystem’s health.
A coral reef with orange and blue fish.
Coral reef ecosystems tend to have high biodiversity. However, their biodiversity is at risk due to human activities. Image credit: “Gulf of Eilat (Red Sea) coral reefs" by Daviddarom, public domain.

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