The value of biodiversity
Look around your school's soccer field or the nearest park: no two people are identical, nor are any two oak trees, nor any two ponds. That variety is not a decoration on the planet: it is what keeps it standing. When it disappears, we feel the effects even if we do not notice straight away. Think of the Everglades or the Chesapeake Bay: why does it matter that so many different living things share them?
The three levels of biodiversity
If you walk along the Gulf Coast or the Maine coast, you see gulls with slight differences in their plumage, tide pools with different fish, crabs and algae, and cliffs bordering dunes and salt marshes. At what levels is all that variety of life organised?
Some species live in only one place on Earth. These are endemic species. The Hawaiian honeycreepers and the nene (Hawaiian goose) are examples of how isolated places like islands hold unique life: the nene lives wild only in Hawaii.
Explain what biodiversity is and name its three levels, giving an example of each.
Explain what biodiversity is and name its three levels, giving an example of each.
Explain in your own words the difference between species diversity and ecosystem diversity, and give an example of each.
Explain in your own words the difference between species diversity and ecosystem diversity, and give an example of each.
What is genetic diversity? Explain why a population with high genetic variety withstands a disease better than one with little.
What is genetic diversity? Explain why a population with high genetic variety withstands a disease better than one with little.
Name two products we obtain thanks to biodiversity (food, medicines, materials) and state which living thing each one comes from.
Name two products we obtain thanks to biodiversity (food, medicines, materials) and state which living thing each one comes from.
What biodiversity gives us
Ecosystems provide us with ecosystem services free of charge, such as crop pollination, water purification, or fertile soil formation. Name two of these services and…
Ecosystems provide us with ecosystem services free of charge, such as crop pollination, water purification, or fertile soil formation. Name two of these services and explain what one of them involves.
A large proportion of the crops we consume depend on pollinating insects such as bees. Explain what would happen to food production if they disappeared, and what this…
A large proportion of the crops we consume depend on pollinating insects such as bees. Explain what would happen to food production if they disappeared, and what this teaches us about the value of biodiversity.
Earthworms and soil fungi are not "attractive" species, but without them forests would not work. Use this example to explain why biodiversity is not valued only for its…
Earthworms and soil fungi are not "attractive" species, but without them forests would not work. Use this example to explain why biodiversity is not valued only for its best-known species.
Distinguish between the direct and indirect value of biodiversity and classify these examples: honey, the shade of a forest that cools a valley, the timber of an oak…
Distinguish between the direct and indirect value of biodiversity and classify these examples: honey, the shade of a forest that cools a valley, the timber of an oak tree, and the water purification carried out by a wetland.
Why variety provides stability
After a year of intense drought, a uniform plantation of poplars dries out completely, while a nearby riverside woodland with willows, ash trees, elms and shrubs survives with hardly any damage. A similar thing happens on farms: a field of one crop can be wiped out by one pest. Why do two plant communities respond so differently to the same adversity?
An ecosystem with many species tolerates a drought or a pest outbreak better than one with few species. Explain why, using the idea that if one species fails, others can…
An ecosystem with many species tolerates a drought or a pest outbreak better than one with few species. Explain why, using the idea that if one species fails, others can fulfill its function.
The graph shows the results of an experiment: two grasslands, meadow A with twelve plant species and meadow B with only three, experience the same drought, and the…
The graph shows the results of an experiment: two grasslands, meadow A with twelve plant species and meadow B with only three, experience the same drought, and the percentage of their initial production maintained by each is measured. Interpret the data in the graph and relate them to ecosystem stability.
The number of butterfly species is counted in three meadows under different management: an unmowed meadow (38 species), a meadow mowed once a year (25 species), and a…
The number of butterfly species is counted in three meadows under different management: an unmowed meadow (38 species), a meadow mowed once a year (25 species), and a lawn mowed every week (7 species). Interpret the data, relate them to the management of each meadow, and reason which one will provide better services such as pollination.