The country considered to have the highest density of biodiversity in the world is Brazil. It is recognized as the Earth's biodiversity champion, hosting about one-tenth of the world's species. Brazil has the highest counts of both vertebrates and invertebrates and an estimated 55,000 species of plants, largely due to the Amazon rainforest, Mata Atlantica forest, and other diverse ecosystems within its territory. This makes Brazil the richest country in terms of biodiversity density globally.