North American rangelands are, in a word, DIVERSE. Huge areas in North America are classified as rangeland, from the rugged tundra of Alaska and Canada to the grasslands of the central United States to the arid deserts of southwestern United States and Mexico. These lands encompass a diverse range of temperatures and land uses. The vast open landscapes that constitute the rangelands of North America include tundra, with shallow soil, permafrost, and a short growing season, supporting resilient communities of mosses, willows, and forbs and migrating polar bears, foxes, and caribou. Across the core of North America are huge tracts of grasslands including the shortgrass, mixed-grass, and tallgrass prairie. These grasslands are some of the most fertile soils on earth and many areas have been converted to croplands and pastures. Many areas of rangelands are dominated not by grasses but by shrubs, including the saltbrush communities of the Great Basin, and the mesquite and creosotebush shrublands of the southwestern U.S. and Mexico. The driest areas in North America give rise to deserts that are characterized by extreme temperature ranges and chronically low precipitation, producing communities dominated by cactus, spiny shrubs, and animals with behaviors and morphology that help them survive in these dry climates. The woodland rangeland type is distinctive from traditional forest with its open canopy. Consider ponderosa pine and oak woodlands that grow widely spaced trees, permitting an understory of shrubs, grasses and forbs to flourish in the abundant light.