Thuja standishii | Threatened Conifers of the World (en-GB)

Cupressaceae

Thuja standishii (Gordon) Carrière

A medium to large tree valued for its resinous, long lasting timber. Past exploitation has led to an assessment of Near Threatened.

Distribution

Endemic to Japan occurring on Honshu, Shikoku and Kyushu. One of the main areas that it is found is in the Nagano Prefecture, around Lake Tadachi.

Habitat and Ecology

Thuja standishii occurs in mixed montane conifer or conifer-angiosperm forests, with Abies homolepis, Chamaecyparis obtusa, C. pisifera, Thujopsis dolabrata, Tsuga diversifolia, Picea jezoensis, Pinus parviflora, and Larix kaempferi. Common angiosperm trees are Betula ermanii, B. corylifolia, Fagus sieboldii, Quercus mongolica var. grosseserrata, and Zelkova serrata. Thuja standishii is a minor component in these forests, usually remaining a smaller tree than the dominants and not exceeding 15 m in height. Often it is confined to moist rocky precipices facing north, sites less suitable for larger trees. Its altitudinal range is (250-)500-2,000(-2,500) m a.s.l.

Human Uses

The wood of this species is highly prized for special building purposes, e.g. ceilings and panelling, and is also used for furniture, fanlights and clogs (wooden shoes). It was in the past regarded as one of the 'five trees of Kiso' or 'Tome-ki' (preserved trees) which meant they were the property of the Emperors of the Tokugawa dynasty in the 17th and 18th centuries and not to be used by common people. This practice helped to preserved several forests from overexploitation at least until the end of World War Two when many forests were once again subject to a period exploitation in support of reconstruction.

It is widely planted in Japan as an ornamental and is also cultivated in temperate areas of Europe and North America.

Conservation Status

Kurobe has been assessed as Near Threatened due to its history of exploitation and the uncertainty associated with quantifying resultant historical decline. It is not listed as threatened on the national Redlist.

Conservation Actions

SIgnificsant stands are preserved in forest reserves in central Honshu and in other parts of its range.

References and further reading

Carter, G. & Farjon, A. 2013. Thuja standishii. The IUCN Red List of Threatened Species 2013: e.T42264A2968225. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T42264A2968225.en. Downloaded on 18 July 2017
Kitagawa, J., T. Fujiki, K. Yamada, H. Hoshino & Y. Yasuda 2016. Human impact on the Kiso-hinoki cypress woodland in Japan: a history of exploitation and regeneration. Vegetation History and Archaeobotany 23:649-664.
Ministry of Environment 2012 Plant I (Vascular plant) Ministry of the Environment Fourth Red List (2012). https://ikilog.biodic.go.jp. Downloaded on 18 July 2017