Japanese Red-Cedar (Sugi)

Basic Information
Tree ID: 
83
Family: 
Cupressaceae
Genus and species: 
Cryptomeria japonica
Description: 
The Japanese red-cedar, otherwise called the "Japanese sugi pine" - known to the Japanese as Sugi - is a large evergreen tree which is native to Japan, can reach up to 70 m in height, and can reach trunk diameters of 4m. It serves as the national tree of Japan and is often planted around shrines and temples. Although it is an evergreen, some of the foliage has been known to bronze in cold winters. It is a pyramidal and sometimes irregular evergreen conifer with tiered horizontal branching. It is often found in moist forests that have deep, rich, well-drained soil. The bark is a red-brown color and peels in vertical strips. The needle like leaves are approximately 0.5-1 cm long while the globular seed cones are 1-2 cm in diameter and contain about 20-40 scales. The Japanese Red Cedar is often cultivated in China and planted in rows for timber production in many countries, which is why it has been deemed “economically productive”. The timber is fragrant, weather and insect resistant, soft, strong, and has a very low density, which makes it useful for furniture making and home construction. Our Japanese Red-Cedar won't reach the height of a full grown Red-Cedar since cultivation in the US is associated with much smaller (50-60 ft) versions. They are a monoecious species which reproduce via wind-based pollen and seed dispersal. The Japanese Red Cedar is susceptible to Phytophthora root disease, Armillaria root rot, and Juniper blight.
Surveyors: 
James Nicholas and Kamsi Nwangwu
Location
Area: 
Marsh and Farnam Gardens
Collected Data
Tree shape: 
Irregular
Date of tree entry: 
02/07/2018
Height: 
15.10 m
Diameter at breast height: 
0.30 m

Bark
The bark is a red-brown color and peels in vertical strips. This tree is cultivated for its timber, which is why it has been deemed “economically productive”. The timber is fragrant, weather and insect resistant, soft, strong, and has a very low density, which makes it useful for furniture making and home construction. The bark has been known to be a vital food source for some moth larvae of the genus Endoclita including E. auratus, E. punctimargo and E. undulifer.
Twigs & branches
The Japanese Red-Cedar is an irregular evergreen conifer with tiered horizontal branching. The pollen cones are often located on the end of these twigs as shown in later pictures.
Foilage
Although the Japanese Red-Cedar is an evergreen, some of the foliage has been known to bronze in cold winters. It has needle like leaves, which are approximately 0.5-1 cm long, and globular seed cones that are 1-2 cm in diameter and contain about 20-40 scales. The leaves are spirally arranged and curl inward towards the twing. The leaves are often used to make incense.
Reproductive Structures
The Japanese Red-Cedar is monoecious with the male reproductive parts appearing light yellow-brown and grow from leaf axils near the branch tips; they appear in early spring. The female cones are brown, globular, and solitary. Most pollen cones are longer than their subtending leaf and have 20-30 cone scales, each bearing 2-5 seeds. Cryptomeria pollen causes allergic conjunctivitis to humans and to dogs in both spring and autumn.
Research
Natural range of distribution: 
Habitat: 
The Japanese red-cedar prefers warmer climates with wet or moist woodlands. It varies in elevation from sealevel to over 1,000 meters.
Origin, history, and uses: 

While many believe that the Japanese Red Cedar is native to China due to the millennia for which it has been cultivated there, in reality, it is endemic to Japan, as the name suggests. The Japanese red cedar or “sugi” is the national tree of Japan. The tree has numerous economic uses - it is used throughout Eastern Asia for reforestation and gardening efforts. Furthermore, the soft but strong fragrant and beautiful wood is used to build houses, bridges, ships, and furniture; the leaves can be used to make incense. The sugi has so many uses, in fact, that its presumed economic value has led to both over-exploitation worldwide and over-planting, particularly in Japan.

On one hand, the sugi has been uprooted and chopped down for its wood worldwide, leading to its discontinuous distribution. On the other hand, however, it has been planted excessively in places like Japan and China. After World War II, the Japanese government insisted on intense artificial planting in order to take advantage of its economic productivity in place of the “commercially useless” forests previously occupying the country. This had unforeseen consequences, however, as the tree has become overly dominant and is responsible for the terrible hay fever epidemic seen in Japan today.

The heavy overabundance of this one species can threaten wildlife, cause soil erosion, reduce the water table, and can cause potential for landslides. Today, the pollen count has risen so much that people have reported actually being able to see pollen fog rising from cedar forests. Thus, while the tree is extremely successful and amazingly useful, it has had many downsides.

Phenology: 
Studies have found some latitudinal variation in the sugi's radial growth. In Japan, red cedars located at low latitudes begin radial growth before ones at higher latitudes. Interestingly, after growth onset, the time at which growth stopped was independent of latitude. Temperature is also shown to correlate with growth onset but not duration, that is, warmer temperatures help the tree to start growing earlier, but they do not appear to affect how long the tree will continue growing.
References: 

Chen, Y. (2008). Demographic Genetic Structure of Cryptomeria japonica var. sinensis in Tianmushan Nature Reserve, China.” Journal of Integrative Plant Biology. 50 (9): 1171-1177.

“Cryptomeria.” Wikipedia, Wikimedia Foundation, 23 Apr. 2018, en.wikipedia.org/wiki/Cryptomeria.

Japanese cedar, Cryptomeria japonica v. japonica.” Plant Encyclopedia. Botany Boy. N.p., n.d. Web. botanyboy.org/japanese-cedar-cryptomeria-japonica-v-japonica/

Japanese Cedar.” Encyclopaedia Britannica. 2010. Britannica Online. Web. britannica.com/EBchecked/topic/301090/Japanese-cedar

Spengler, Teo. “Japanese Cedar Tree Care And Pruning: Learn About Planting Japanese Cedar Trees.” Gardening Know How, 4 Apr. 2018, gardeningknowhow.com/ornamental/trees/japanese-cedar/japanese-cedar-trees.htm.

Tomohiro Nishizono, Kotaro Zushi, Takuya Hiroshima, Keisuke Toyama, Fumiaki Kitahara, Fumiko Terada, Masahiro Takagi, Satoshi Saito; Latitudinal variation in radial growth phenology of Cryptomeria japonica D. Don trees in Japan, Forestry: An International Journal of Forest Research, Volume 91, Issue 2, 1 April 2018, Pages 206–216.

 “Virginia Tech Dendrology.” Cryptomeria Japonica Fact Sheet, dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=458.

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