Look outside your window and see how many different species of plants and animals you see. The number you see will depend on a host of factors. Do you live in a city, in a suburb, a town, or out in the country? Do you live in a region that is cold or hot? Do you live in a desert, a rainforest, or somewhere in between? In general, the number of different species, or biological diversity, in a region is highest where the resources necessary for life (water, sunlight, chemicals) are highest.

The biodiversity of a region is usually a measure of the health of the ecosystem. The greater the diversity, the less likely the region is to be radically upset by some small change. Humans can have a devastating effect on the biodiversity of a region. Cutting down a forest or mowing down grasslands in order to put a farm that grows only one crop reduces the biodiversity of a region radically. If a pest that feeds on that one crop is introduced, the entire ecosystem can fail.

The activities below look at biodiversity from a number of different angles.