Central Asia peoples of the vast region. Central Asia is sometimes referred to as Turkestan. There are several places that claim to be the geographic center of Asia, for example Kyzyl, the capital of Tuva in the Russian Federation, and a village north of Ürümqi, the capital of the Xinjiang region of China. Central Asia is an extremely large region of varied geography, including high passes and mountains (Tian Shan), vast deserts (Kyzyl Kum, Taklamakan), and especially treeless, grassy steppes. The vast steppe areas of Central Asia are considered together with the steppes of Eastern Europe as a homogeneous geographical zone known
Agriculture on the prehistoric Great Plains berlandieri"), marsh elder ("Iva annua"), and maize ("Zea mays"). Tribes periodically switched from farming to hunting throughout their history during the Plains Village period, AD 950–1850. The primary constraint on agriculture on the Great Plains is that precipitation is often deficient for growing maize, the primary crop of Indian farmers. In addition, on the northern Great Plains the growing season is short. Agriculture on the Plains seems to have had an ebb and flow, advancing westward into the drier areas in favorable wet periods and retreating in drier periods. The periodic abundance or scarcity of bison was also a factor