The plant species in Sichuan take up more than 30% of the nationwide plant species. As one of the provinces with the most abundant plant resources, Sichuan accommodates such vegetation as forest, shrub, grassland, meadow, bamboo forest and swamp. The forest coverage hits 34.4%; the forests are mainly concentrated in the evergreen broad-leaved forest zone and western alpine gorge and subalpine coniferous forest zone; in Northwestern Sichuan Plateau are mainly alpine shrub and meadow.
1. The karst region in Sichuan nurtures abundant living resources and vegetation thanks to its complex landforms and diverse climate. According to incomplete statistics, there are nearly ten thousand higher plants species under over 1700 genera within more than 270 families, among which there are about 1000 arbor species. They form the subtropical deciduous broad-leaved forest, evergreen deciduous broad-leaved forest, bamboo forest, shrub and shrub-grassland. The arbor species mainly includes masson pine, Yunnan pine, cypress and oak; the shrub species includes shrubby flase indigo, Chinese sumac, Coriaria sinica and Myrsine africana; the staple economic tree species includes walnut, chestnut, tung tree, tangerine and pummelo; the bamboo species includes Omei Mountain Bamboo, Moso Bamboo and hybrid bamboo. It is worth noting that the carbonate rock distribution region is strictly picky about plants and prefers calciphilous, xeric and saxicolous plants growing slowly. Few tree species are suitable for living here. For the simple community structure and weak self-regulating ability here, the interferences caused by external factors, especially by man-made activity factors, may easily lead to retrogressive succession of communities.