steppe
steppe, vast grassland, devoid of trees and with little diversity in vegetation, receiving around 25 to 30 cm (10 to 12 inches) of rain per year. The word “steppe” is derived from the Russian word for “flat grassy plain.”
The world’s most extensive flat steppes are in temperate Eurasia. Often referred to as the Steppe, this region in Eurasia extends some 8,000 km (5,000 miles), stretching from Hungary in the west, through Ukraine and Central Asia, to Manchuria in the east. Steppes can also be found in other regions, such as Patagonia in South America and the Great Basin region in the United States, where sagebrush is prevalent. Similar habitats have been identified in Spain and Italy, as well as in Namibia, Australia, and the Sahel in western and north-central Africa. Some authorities, however, regard these regions in North and South America and in Africa as “pseudo-steppes” and limit true steppes to those in Eurasia.
Regardless of their location, steppes typically have hot summers and cold winters that divide the year into sharply contrasting seasons. The amount of rainfall is a key feature, as less water would foster a desertlike habitat while more water would lead to a savanna or forest. Considered semiarid, steppes typically have low humidity and are located away from the world’s oceans, often isolated by surrounding mountains.
As grasslands, steppes are characterized by annual and perennial true grasses (such as Bromus, Festuca, and Stipa) and a number of grasslike plants that are similar in appearance. Such grasses and graminoids typically grow to no more than half a metre (1.5 feet) in height. Small flowering shrubs and low forbs are also common, with the specific community composition depending on the steppe. Chernozem, a type of arable soil, pervades many of the world’s steppes.
The wide open grasslands of the steppe are inhabited by a number of herbivores and their predators. Given the lack of hiding places in the low vegetation and the need to migrate to new pastures, the landscape supported the evolution of several large herbivores with sharp senses that are adept at running. The Eurasian Steppe is home to the horse, the bobak marmot, the gazelle, the wild Bactrian camel, the Caspian Sea wolf, the corsac fox, and the saiga antelope, among others. In North America, steppes host the pygmy rabbit, the sage grouse, the American bison, and the prairie dog. The camelid guanaco, the pampas deer, and the rodents tuco-tuco and viscacha inhabit the Patagonian steppe.
Steppes have been subject to pressing issues such as overgrazing and the conversion of wild areas to agricultural land. Conservation efforts have saved the American bison from extinction, though many other species, such as the South American bromeliad Puya raimondii, the Eurasian saiga antelope, and the onager of Iran and Turkmenistan, remain endangered.