2. The vegetation in the desertified region within Sichuan is divided into two portions: vegetation in the northwestern Sichuan plateau region and vegetation in the northwestern Sichuan gorge region. In the first region, due to its diverse relieves, accumulated water, heat energy and altitudes, the frigid plateau mire-shrub-meadow vegetation comes into being, having a vague vertical distribution feature, mainly comprising subalpine scrub or meadow, alpine scrub or meadow and meadow grassland consisting of perennial small scrub and herbs. In the second region, due to the impact of moisture and heat variance as well as rising altitude, the cold temperate forest-scrub-meadow vegetation comes into being, which is absolutely dominated by coniferous forest. The broadleaf forest takes up a small ratio; the dragon spruce takes up 55% of the total forestland area. The main constructive species include 20 species within 4 families, among which there are 9 Pinaceae, 4 Cupressaceae and 3 Betulaceae. Some rare wild medical herbs such as tendril-leaved fritillary bulb, worm grass and Chinese rhubarb grow in the scrub as well.
Section 2 Society and Economy
I. Administrative division, population and ethnic groups
Sichuan province is divided into 1 vice-province-class city, 17 prefecture-level cities and 3 ethnic autonomous prefectures, including 43 inferior city-governed districts, 14 county-level cities, 120 counties and 4 autonomous counties. By the end of 2010, Sichuan has 81.85 million permanent residents, taking up 6.1% of the national total population, ranking third in China. The population density hits 168.8 persons/km2, higher than the national average. The population is mainly concentrated in the intra-basin Min River, Tuo River, Jialing River and the Yangtze River basin, namely the east of the boundary comprising Qingchuan, Beichuan, Dujiang Weir, Tianquan, Mabian and Pingshan, taking up 1/3 of the total provincial area, accommodating more than 90% of the total provincial population, the population density exceeding 470 persons/ km2. The western part is low in population density. In Sichuan, there are 55 ethnic groups; the population of the minority groups exceeds 4 million, taking up 5% or so of the total population. Sichuan accommodates 14 permanent minority groups: Yi, Tibet, Qiang, Miao, Hui, Mongol, Tujia, Lisu, Manchu, Nakhi, Bouyei, Bai, Zhuang and Dai, being the second largest Tibetan-inhabited region, the largest Yi-inhabited region and sole Qiang-inhabited region in China.