West Slope of Cangshan Mountain in Yangbi County, Dali

The Western Slope of Cangshan (苍山西坡) is located in the central region of Dali Bai Autonomous Prefecture (大理白族自治州), Yunnan Province (云南省), and refers to the western side of the Cangshan Mountain Range (苍山山脉). Compared to the eastern slope, the western slope has a greater vertical climatic span, with pronounced vegetation belts. The plant diversity ranges from quasi-subtropical to desert types, making it the most botanically rich area of Cangshan (苍山).

In terms of floristic composition, the area gathers elements from the Qinghai-Tibet Plateau Plant Region (青藏高原植物区), Yunnan-Guizhou Plateau Plant Region (云贵高原植物区), Western Yunnan Valley Plant Region (滇西峡谷植物区), and the Upper Lancang and Yuanjiang River Plant Region (澜沧江元江上游植物区). There are over 6,000 plant species in Cangshan, with 2,849 species confirmed and classified into 927 genera under 182 families. Among them, nearly 40 species belong to the Rhododendron genus. A total of 26 species are listed as nationally protected endangered plants, including 4 under Category II protection, 10 under Category III, 3 species endemic to China, 4 endemic to Yunnan, and 5 unique to Cangshan.

• Chinese Name: 苍山西坡
• Location: Dali (大理), Yunnan Province (云南省)
• Climate: Subtropical alpine climate
• Protected Species: Taxus wallichiana (云南红豆杉), Magnolia delavayi (滇藏木兰), Manglietia hookeri (红花木莲)

Landscape Structure

The Western Slope of Cangshan (苍山西坡) features a more extensive vertical climate range than the eastern slope, resulting in distinct vegetation zones. It includes plant types from the quasi-subtropical to desert zones, making it the most biodiverse part of the Cangshan range. The botanical composition reflects elements from four major plant regions: the Qinghai-Tibet Plateau (青藏高原), Yunnan-Guizhou Plateau (云贵高原), Western Yunnan Valleys (滇西峡谷), and the Upper Reaches of the Lancang and Yuanjiang Rivers (澜沧江元江上游).

Cangshan harbors over 6,000 plant species, of which 2,849 have been identified and classified into 927 genera and 182 families. Nearly 40 species belong to the Rhododendron genus. There are 26 endangered species under national protection, including 4 in Category II and 10 in Category III. Additionally, there are 3 species endemic to China, 4 to Yunnan, and 5 unique to Cangshan.

Notable Flora

West Slope of Cangshan Mountain in Yangbi County, Dali

Some representative plant species include:
Rhododendron sanguineum (似血杜鹃), Rhododendron densiflorum (密枝杜鹃), Rhododendron daliense (大理杜鹃), Abies delavayi (苍山冷杉), Rhodiola (红景天), Fargesia (冷箭竹), Cupressus chengiana (曲枝柏), Rhododendron oreotrephes (火红杜鹃), Rhododendron racemosum (团花杜鹃), Tsuga dumosa (云南铁杉), Taxus wallichiana (红豆杉), Acer (槭), wild cherry (野樱), Sorbus (花楸), Illicium (野八角), Edgeworthia chrysantha (领春木), Rhododendron mucronulatum (突尖杜鹃), Rhododendron sulphureum (硫磺杜鹃), Rhododendron yunnanense (云南杜鹃), Rhododendron leptanthum (兰果杜鹃), Pinus armandii (华山松), Pinus yunnanensis (云南松), Schima superba (银木荷), Quercus serrata (石栎), Cyclobalanopsis glauca (青冈栎), Castanopsis echinocarpa (元江栲), Rhododendron charmingia (迷人杜鹃), Rhododendron dew (露珠杜鹃), Rhododendron leptophyllum (薄叶杜鹃), Cinnamomum (樟), Brugmansia suaveolens (旱冬瓜), Pterocarya stenoptera (枫杨), walnut (核桃), Keteleeria evelyniana (滇油杉), Rhododendron simsii (马缨花), camellia (山茶花), Quercus aliena (麻栎), Rhododendron decorum (大白花杜鹃), Ficus (榕), wild citrus blossom (野香橼花), Symplocos (小铁子), Bombax ceiba (木棉), Fargesia (龙竹), and wild banana (野芭蕉).

Historical Background

In 1993, the Yunnan Provincial Government designated Shimen Pass (石门关) on Cangshan as a provincial-level scenic spot under document Yunzhenfa [1993] No. 199.
In 1994, the State Council designated the Cangshan-Erhai region (苍山洱海) as a national-level nature reserve under document Guofa [1994] No. 26.

Vegetation and Glacial Heritage

The glacial relics of Cangshan are a major conservation focus within the nature reserve. In 1937, geologist H. Fissment proposed the theory of a "Dali Glacial Period." In 1972, renowned Chinese geologist Li Siguang suggested that another glacial period occurred in China after the Lushan glacial period of the Quaternary. The concept of the Dali Glacial Period is now widely accepted and considered the last glacial period of the Quaternary in China. This has great scientific, educational, exploratory, and touristic value for understanding the Earth's evolution, ecological environment, physical geography, and geological features.