Distributed in Gansu and Sichuan where the main threat is deforestation
Native to China: S Gansu, N & W Sichuan. Here the total population is declining due to past and recent exploitation for timber.
Habitat and Ecology
In small, pure stands in some valleys, but more commonly on rocky slopes or cliffs associated with Koelreuteria paniculata, Morus mongolica, Campylotropis delavayi, Bauhinia faberi, Cotoneaster multiflorus, and C. gracilis; in non-acidic brown soils over granites, quartzites and limestones. Based on verified herbarium collections, the altitudinal range is extensive, ranging from ca. 1200 to 2750 metres above sea-level. The climate is characterized by cold winters and cool to warm summers, with a distinct alternation of dry and rainy seasons; annual precipitation varies between 500–750(–1000mm), with a 50–70% moisture deficit. There is no recorded difference in ecology for the two varieties.
Timber of this species is valued for building and the species has been exploited for its larger, more or less straight trunks for many centuries. On a small scale trees have been planted as individuals or in groups in villages.
The species level assessment for Cupressus chengiana is determined by the assessment for the typical variety as it is this taxon that occupies the major part of the specie's distribution and population. Consequently the species is assessed as Vulnerable.
This species is known from about nine different locations where natural populations are now mostly restricted to more inaccessible sites such as canyons and exposed cliffs. Overcutting is the main cause of its decline. A collection from Hunan Province is most likely from an introduced tree.
This species is planted in villages within its natural range in Sichuan and possibly in Gansu as well.