A mountain range acting as a refugium where tropical and temperate species mix. DNA analysis shows it sheltered dozens of species through ice ages.
An Ice Age island in a sea of change
The Nanling Mountains are a major range in Southern China, running east-to-west for over 1,400 kilometers. This orientation is significant; the mountains form a physical barrier that separates the subtropical south from the temperate central regions of the country. They effectively block cold northern air masses, creating a distinct climatic divide. The southern side remains warm and humid year-round, while the northern slopes can experience winter freezes.
During the Quaternary period's repeated ice ages, this barrier became a haven. As glaciers advanced and climates cooled globally, the Nanling range provided stable, milder conditions. This allowed it to be a glacial refugium—an isolated area where plants and animals could survive during periods of widespread habitat loss. Environmental niche modeling confirms that the Nanling Mountains provided suitable habitat for numerous species during the Last Glacial Maximum, when much of the surrounding landscape was inhospitable. Genetic studies of local flora, such as the temperate pine Pinus kwangtungensis, show molecular evidence of glacial expansion and interglacial retreat, confirming the mountains' role as a long-term sanctuary. Because of this geological stability, the range is a "museum" of subtropical biodiversity.
A crossroads of life
The Nanling corridor is a biological meeting point. It marks the meeting point for species from the temperate Sino-Japanese region and the tropical Indo-Malayan region. The result is an exceptionally high concentration of life. Within the Nanling National Nature Reserve alone, surveys have recorded 3,892 species of higher plants and 672 species of vertebrates. The vertebrate count includes 98 mammals, 363 birds, 101 reptiles, and 45 amphibians.
Phylogeographic studies—which analyze the geographic distribution of genetic lineages—reveal the mountains' dual role. For some species, the range is a barrier that prevents gene flow between northern and southern populations. For others, particularly during climate shifts, it was an east-west dispersal corridor, allowing populations to remain connected. Studies on the plant Eomecon chionantha show that the mountains enabled population connectivity throughout the late Quaternary. This constant mixing and sheltering has led to a high degree of endemism. The vulnerable Cabot's tragopan (Tragopan caboti), a pheasant that relies on the dense forest understory, is one of many species restricted to this part of southeastern China. Other notable residents include the Chinese big-headed turtle, the Mangshan pit viper, and "living fossil" trees like the Chinese yew and the Bole tree (Bretschneidera sinensis).
💡Fun Facts
The mountains separate two of China's largest river systems: the Yangtze River basin to the north and the Pearl River basin to the south.
The region contains distinct geological formations, including karst limestone towers in the west and Danxia landforms of red sandstone in the east.
Surveys have documented over 3,195 insect species in the Nanling National Nature Reserve, including 529 species of butterflies.
The highest peak in the range, Miao'er Shan (Kitten Mountain), rises to 2,142 meters (7,028 feet).
Visitor information for Nanling National Forest Park is inconsistent, with reports of closures since 2018. It is critical to verify its operational status before planning a visit.
Admission
Previously, the entrance fee for Nanling National Forest Park was around ¥60.
Accessibility
The terrain is mountainous with steep slopes and narrow valleys. Hiking trails can be strenuous and require appropriate footwear.
The Nanling Biodiversity CorridorGuangdong / Hunan, China