What is the most biodiverse ecosystem in the world?

The most biodiverse ecosystem in the world is the Amazon Rainforest. It is home to approximately 10% of the world's known species and is considered one of the most important ecosystems on the planet. The Amazon Rainforest spans across nine countries in South America and is home to a wide range of animal and plant species, including thousands of species of birds, mammals, reptiles, amphibians, and insects. The Amazon Rainforest is also an important source of oxygen, carbon storage, and climate regulation.