New Ground: A World Tour of the Wave's Twenty Ecosystems

The biome: any land defined by scarcity of water rather than heat, from scorching to frigid.

The world's largest hot desert.

Home to the saguaro cactus, this desert's signature plant.

A cold desert, proof that the biome is defined by rainfall, not heat.

A semi-arid desert shared by Namibia, Botswana and South Africa.

North America's largest desert, spanning the US-Mexico border.

The biome: an unbroken belt of coniferous forest just south of the tundra.

The largest forest on Earth, across Russia's Siberian expanse.

Home to the gray wolf and the beaver, whose dams shape its wetlands.

The biome: open, grass-dominated terrain shaped by fire and grazing.

The American bison's defining home, after its near-extinction and recovery.

Eurasia's own vast grass sea.

The biome: tropical grassland with scattered trees and a sharp wet-dry season.

Roughly 13,750 elephants and over 1,600 lions by the park's own count.

The biome: the open and coastal ocean, seventy percent of the Earth's surface.

The only sea on Earth with no land boundary at all.

Ice-edge waters that draw both the pole-to-pole Arctic tern and the Antarctic blue whale in the austral summer.