Distribution

Native to China in S Gansu and N & W Sichuan. The population is thought to be decreasing due to historic and recent over-exploitation.

Habitat and Ecology

n 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.

Conservation Status

Global status

Vulnerable B2ab(v)

Global rationale

The area of occupancy (AOO) is less than 2,000km² with less than 10 severely fragmented locations.  A continuing decline in the number of mature individuals is suspected due to illegal logging. Past reductions are known to have occurred but have not been quantified. Consequently this variety (and the species as this variety accounts for the vast majority of the specie's distribution and population) is assessed as Vulnerable.

Global threats

This variety 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 [historic] decline but the habitat is now protected (see conservation actions). Illegal logging may still be a problem in certain locations. Natural regeneration is thought to be poor.

Conservation Actions

Since 1998 all old-growth forest in China has been legally protected.