GREATER KHINGAN RANGE

Chinese (Wade-Giles romanization) Ta Hsing-an Ling, or (Pinyin) Da Hinggan Ling, major mountain system located in the Inner Mongolia Autonomous Region, northeastern China. The range extends some 750 miles (1,200 km) from north to south and constitutes the divide between the flat plains of the Northeast (Manchuria) to the east and the high Mongolian Plateau to the west. The Greater Khingan Range is bounded on the south by the Jehol Uplands and on the north by the Amur River. The range is an important watershed between the Liao River system and the Sungari and Nen (Nonni) river systems of the Manchurian Plain to the east and the headwaters of the Amur River and its tributaries in the northwest. The western slopes of the southern section of the range drain into the Mongolian Plateau. The Greater Khingan Range has an average elevation of from 3,950 to 4,250 feet (1,200 to 1,300 m), the highest peak reaching 6,673 feet (2,035 m). The range is much broader in the north (190 miles ) than it is in the south (60 miles ). It was formed during the Jurassic period, and it is essentially a tilted fault block; its ancient fault line forms its eastern edge, facing the Manchurian Plain. The ranges are markedly asymmetrical, with a sharp eastern face and a more gentle western slope down to the Mongolian Plateau, which at this point lies at an elevation of 2,600 to 3,300 feet (790 to 1,000 m). The eastern slopes are more heavily dissected by the numerous tributaries of the Nen and Sungari rivers, but generally the mountains are rounded with flat peaks. The ranges are composed largely of igneous rocks (i.e., formed from the molten state). The mountains form an important climatic divide. They take most of the precipitation from the southeasterly winds and produce a marked contrast with the arid region to the west. The climate of the whole region is comparatively wet (receiving more than 20 inches annually). The northern section of the mountains is the coldest part of eastern China, with extremely severe winters (mean temperature -18 F ) and with large areas under permafrost. This area is covered by forests of larch, birch, aspen, and pine, with shrub cover on the highest elevations. It is rich in wildlife, including deer, elk, marten, hare, and many fur-bearing animals. The central and southern sections of the range, however, are considerably warmer and drier than in the north, with January temperatures of about -5 F (-21 C), annual precipitation of 10-12 inches (250-300 mm), and comparatively light snowfalls. The coniferous forests of the north gradually give way in the south to broad-leaved forests and then to patches of grassland interspersed with woodland. In the south the forests cover the higher ground above 5,000 feet (1,500 m), while the greater part of the area is covered with tall grassland. In May 1987 a devastating fire swept the Greater Khingan forests, destroying perhaps 4,000 square miles (10,000 square km) of timber; it became known as the Black Dragon Fire, for the Hei-lung Jiang ("Black Dragon River," i.e., the Amur) that flows through the area. The Greater Khingan region was to a large extent unexplored until the 20th century. The exploitation of the northern area began with the construction early in the 20th century of the first railway across the mountains-the Chinese Eastern Railroad from Tsitsihar to Man-chou-li, the latter in extreme northwestern Manchuria on the Russo-Chinese frontier. Under the Japanese occupation of Manchuria (1931-45), a number of railways were constructed into the mountains north and south of this line in order to extract lumber, the most important being those running into the area north of T'u-li-ho. These lines were later extended eastward into the I-le-hu-li Mountains, which strike east and west and join the Greater Khingan Range proper to the Lesser Khingan Range. Further south a more recent line follows the T'ao-erh River valley northwest from Pai-ch'eng in Kirin province to So-lun and the hot springs at A-erh-shan in Inner Mongolia. Much of the area is inhabited by Mongol and (in the north) Manchu-Tungus peoples, such as the Orochon and Evenk. Logging continues to be the major economic activity.