Number of species in an ecosystem
Now you know bio means life or living, biodiversity is the life or living diversity, the measure of diversity within an ecosystem.
The coral reefs off the coast of Atauro Island in the region of the Banda Sea, Savu Sea and Flores Sea have the greatest marine biodiversity on the planet, with some reefs supporting over 300 reef fish species.
Rainforests are the most biodiverse habitats on land. Even though they make up just 2% of the Earth's surface rainforests account for 50% of life on land. It's not just the size of rainforests that accounts for their biodiversity – a single bush in the Amazon could be home to more species of ant than the whole of the British Isles.
Polar regions of the world are areas of low biodiversity. The frozen surface means plants find it difficult to survive in these regions and so there is less food for other organisms further up the food chain.