Question

Coral reefs and tropical rainforests are ecosystems known for what, contributing greatly to the species in existence on earth?

Answer 1

biodiversity

How many species actually exist in the world? No one knows for sure because only a small percentage of them have already been discovered. Estimates range from 5 to 30 million total species currently in existence. Many of them live on coral reefs and in tropical rainforests  see Figure below  . These two ecosystems have some of the greatest biodiversity on the planet.