Which biome has the greatest species diversity? Least diversity?
Tropical forests are widely considered to have the greatest species diversity of the terrestrial biomes and the tundra biome has the least.
As temperature and precipitation decrease, biodiversity generally decreases.
High species diversity :
Tropical forests are widely considered to have the greatest species diversity of the terrestrial biomes but diversity is also high in the temperate deciduous biome and
Low species diversity :
The tundra biome has the least biodiversity, but the northern coniferous biome also has low species diversity. Generally speaking, desert biomes have low species diversity, but pockets of localized high biodiversity do exist. You can read more about exceptions [here] (http://www.conservationmagazine.org/2015/03/deserts-teem-with-biodiversity-if-you-know-where-to-look/) and here.
You can read more about diversity in different terrestrial biomes here.
You can find global biodiversity maps for amphibians, mammals, and birds here. The map below is of amphibian species diversity.