The Qinling or Qin Mountains, formerly known as the Nanshan and sometimes called the "Szechuan Alps", are a major east-west mountain range in southern Shaanxi Province, China. The mountains mark the divide between the drainage basins of the Yangtze and Yellow River systems, providing a natural boundary between North and South China and support a huge variety of plant and wildlife, some of which is found nowhere else on earth. To the north is the densely populatedWei River valley, an ancient center of Chinese civilization. To the south is the Han River valley. To the west is the line of mountains along the northern edge of the Tibetan Plateau. To the east are the lower Funiu and Dabie Shan which rise out of the coastal plain. The northern side of the range is prone to hot weather, however the physical barrier of the mountains mean that the land to the North has a semi-arid climate, with the lack of rich, fertile landscape that can not support a wealth of wildlife. The mountains also acted as a natural defense against nomadic invasions from the North, as only four passes cross the mountains. In the late 1990s a railway tunnel and a spiral was completed, thereby easing travel across the range. The highest mountain in the range is Mount Taibai at, which is about west of the ancient Chinese capital of Xi'an. Three culturally significant peaks in the range are Mount Hua, Mount Li, and Mount Maiji.
The environment of the Qin Mountains is a deciduousforestecoregion. The Qin Mountains form the watershed between the Yellow River basin of northern China, which was historically home to deciduous broadleaf forests, and the Yangzi River basin of southern China, which has milder winters and more rainfall, and was historically home to warm temperate evergreen broadleaf forests. The low-elevation forests of the foothills are dominated by temperate deciduous trees like oaks, elm, common walnut, maple, ash and Celtis spp. Evergreen species of these low-elevation forests include broadleaf chinquapins, ring-cupped oaks and conifers like Pinus massoniana. At the middle elevations, conifers like Pinus armandii are mixed with broadleaf birch oak and hornbeam. From elevation, these mid-elevation forests give way to a subalpine forests of fir, Cunninghamia, and birch, with rhododendron abundant in the understory. The region is home to a large number of rare plants, of which around 3,000 have so far been documented. Plant and tree species native to the region include Ginkgo, thought to be one of the oldest species of tree in the world, as well as Huashan or Armand pine, Huashan shen, Acer miaotaiense and Chinese fir. Timber harvesting reached a peak in the 18th century in the Qinling Mountains. Home to the Qinling pandas, a sub-species of the giant panda, which are protected in the region with the help of the Changqing and Foping nature reserves, between 250 and 280 giant pandas live in the region, which is estimated to represent around a fifth of the entire wild giant panda population. The mountains are also home to the golden takin, golden pheasant, golden snub-nosed monkey, Temminck's tragopan, crested ibis, golden eagle, blackthroat and clouded leopard. The Chinese giant salamander, at the largest amphibian in the world, is critically endangered as it is collected for food and for use in traditional Chinese medicine. An environmental education programme is being undertaken to encourage sustainable management of wild populations in the Qin Mountains and captive breeding programmes have been set up.
