Biodiversity: The Variety of Life: Concept Map

Concept Map

Organise the vocabulary, quantities and relationships into a connected model.

This extension applies that lens specifically to Biodiversity: The Variety of Life.

Biodiversity is the variety of living things found in a place. It is measured at more than one level:

1. the number of different species present;
2. the variety within a species (think of all the different varieties of maize a farmer can plant);
3. the variety of habitats — the different kinds of places available for organisms to live.

A species is a group of organisms that are alike and can breed with one another to produce offspring that can themselves breed. Lions are one species; leopards are another.

South Africa is one of the most biologically diverse countries on Earth. We hold about 10% of the world's known plant species on roughly 2% of the world's land, along with a huge variety of birds, reptiles, insects and mammals.

Worked example — comparing two plots. A learner marks out two squares of 1 m × 1 m.

• Plot A, in a maize field, contains 40 maize plants — 1 species.
• Plot B, in Cape fynbos, contains 7 buchu, 5 erica, 3 restio and 1 protea — 4 species, 16 individual plants.

Plot A has more plants, but Plot B has far higher biodiversity, because biodiversity counts the number of different kinds, not the number of individuals.

Many fynbos species are endemic — they occur naturally in one place on Earth and nowhere else. Roughly two out of every three fynbos plant species are found only in the Cape.