Biodiversity
Introduced| English | Meaning |
|---|---|
| biodiversity/ˌbaɪəʊdaɪˈvɜːsɪti/ | The variety of life, including genetic diversity, species diversity and ecosystem diversity. |
| ecosystem/ˈiːkəʊsɪstəm/ | A community of organisms interacting with each other and with their physical environment. |
| keystone species/ˈkiːstəʊn ˈspiːsiːz/ | A species whose effect on an ecosystem is unusually large relative to its abundance. |
The variety of life
- A rainforest teems with thousands of species; a car park has almost none.
- This variety of life is what we call biodiversity.
- More variety usually means a healthier, stronger ecosystem.
- Protecting it is one of biology's biggest challenges.
What biodiversity is
- Biodiversity 生物多样性 is the variety of living things in an area.
- It counts the number of different species and how even their numbers are.
- It also includes variety of genes and of whole ecosystems.
- A place rich in species has high biodiversity.
Biodiversity at three levels: genetic, species, and habitat
Biodiversity is…
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Biodiversity is the variety of species (and genes and ecosystems) in an area.
Why it matters
- High biodiversity makes an ecosystem 生态系统 more stable and resilient.
- If one species is lost, others can often fill its role.
- Diverse ecosystems also give us food, medicines, and clean air and water.
- A biodiverse world is more able to survive change.
Why does high biodiversity help an ecosystem?
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High biodiversity makes an ecosystem more stable — if one species is lost, others can fill the gap.
A species that has an especially large effect on its community is a ____ species.
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A keystone species holds the community together; losing it can collapse the whole ecosystem.
Keystone species
- Some species matter far more than their numbers suggest.
- A keystone species 关键种 holds its whole community together.
- Remove it, and the ecosystem can collapse.
- Threats like habitat loss, pollution, and climate change all reduce biodiversity.
High or low biodiversity?
Sort each place by how much variety of life it holds - high or low biodiversity.
Habitat loss and pollution are threats that can reduce biodiversity.
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Habitat loss, pollution, and climate change all reduce biodiversity by wiping out species.
Select all true statements about biodiversity.
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A car park has low biodiversity — almost no species. The other three are correct.
Biodiversity is not just a "nice to have". High biodiversity makes an ecosystem more stable — able to recover from disease, weather, or the loss of a species. A low-biodiversity system, like a single-crop field, is fragile: one pest can wipe out everything.
The sea otter, a keystone species:
- Sea otters eat sea urchins, which would otherwise devour the kelp forests.
- Remove the otters, and urchins explode and strip the kelp bare.
- The whole community — fish, seals, and more — collapses. A single keystone species held it all together.
Biodiversity is the variety of living things in an area. High biodiversity makes an ecosystem more stable and resilient, and supplies food, medicine, and clean air. A keystone species has an outsized effect — losing it can collapse a community. Habitat loss, pollution, and climate change all threaten biodiversity.
Write from a richness of 14
- A plot contains 14 species.
- Evenness, how equal their abundances are, is not counted yet.
What is the species richness?
Richness counts species. Evenness compares their abundances.
What is the richness of this plot?
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Richness is how many species are present. Other options — The evenness score (which was not given); The number of individual animals (which was not given).