Pseudotsuga japonica


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Pseudotsuga japonica
Species Authority: (Shiras.) Beissn.
Common Name/s:
English Japanese Douglas-fir
Tsuga japonica Shiras.

Assessment Information [top]

Red List Category & Criteria: Endangered C2a(i) ver 3.1
Year Published: 2013
Date Assessed: 2010-12-14
Assessor/s: Katsuki, T., Luscombe, D & Farjon, A.
Reviewer/s: Thomas, P. & Yahara, T.
This is a very rare species, with only small and scattered subpopulations of very slow growing trees. The total population is not larger than 2,500 trees, there are no subpopulations exceeding 250 mature trees and there is a continuing decline. On this basis it qualifies for Endangered under the C criterion.
2000 Vulnerable

Geographic Range [top]

Range Description: Japan: W Honshu (Chugoku District), Shikoku. E H. Wilson (1916) reported it as very rare in Kyushu, but its occurrence there has not been confirmed later.
Japan (Shikoku)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The population is declining (T. Yahara pers. comm)
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Pseudotsuga japonica occurs at elevations between 500 m and 650 m a.s.l. on Shikoku; Wilson (1916) reports it from about 1,000 m on the same island. It is rare and scattered in sheltered valleys and steep ravines, growing on old volcanic rock. The climate is warm temperate, moist, with annual precipitation between 1,000 and 2,000 mm. It is locally a (major) constituent of mixed conifer-broad-leaved forests, with Tsuga sieboldii usually as the dominant species. Other conifers are Abies firma, Chamaecyparis obtusa, Torreya nucifera and Cryptomeria japonica, broad-leaved trees are e.g. Quercus salicina, Q. sessilifolia, Cleyera japonica, and Illicium religiosum (small tree), common shrubs are Eurya japonica, Pieris japonica, Rhododendron serpyllifolium, and Thea japonica. As in China, in Japan the genus, represented by a single species, is a minor constituent of mixed forests
Systems: Terrestrial

Threats [top]

Major Threat(s): The main  threat has been the conversion of habitat to plantation forestry and other uses. Regeneration is poor and older trees are declining. The total population of this species in Japan is estimated to be ca. 2,000 mature trees and is considered to be continuously declining.

Conservation Actions [top]

Conservation Actions: The species is known from at least one protected area.
Citation: Katsuki, T., Luscombe, D & Farjon, A. 2013. Pseudotsuga japonica. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 18 April 2014.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided