Endemic to Taiwan where the population has become severely fragmented through logging and forest clearance for agriculture.
Taiwan incense-cedar and Taiwan cui bai
Taiwan (central and northern mountains). This species occurs in an area of less than 20,000km² and is limited to eight isolated locations with an area of occupancy less than 500km². Subpopulations are small and localised.
Habitat and Ecology
C. formosana occurs in mixed conifer-broad-leaved climax forest, often as an emergent, associated with Pseudotsuga sinensis, Taiwania cryptomerioides, Castanopsis spp., and Cyclobalanus spp. in deep, rich forest soil over shalestone or schist; also in secondary forest and on cliffs and rocky ridges. Its altitudinal range is (300–)800–2000 metres above sea-level.
The valuable wood of this tree is in demand for construction purposes, mainly at a local or regional level. Although known botanically since 1930, it was apparently introduced to cultivation only recently (Grimshaw & Bayton, 2009).
Calocedrus formosana has an estimated extent of occurrence of 7516km², an estimated area of occupancy of 72km² and is known from eight locations. Although there are more than five locations, the subpopulations are regarded as severely fragmented due to geographic isolation and changes in landuse in the intervening areas. There is also a continuing decline due to a variety of threats. On this basis it is assessed as Endangered under the B2 criteria.
The species is experiencing a continuing decline in its area of occupancy and quality of habitat due to illegal logging, transformation of old growth forest to managed production forest, and expansion of agriculture, especially livestock grazing.
Some stands are now protected in reserves and there is a programme of ex situ conservation to back up the remaining populations.