baumzaehlen - Primeval Forests & Their Trees

©2017 copyright christoph hase

Yakushima Wilderness Area, Japan

Yakushima is an island south of Kyushu, the southernmost of the four main islands of Japan. A large part of it has been nominated as a World Heritage Site. Wood has been extracted throughout most of the WH site, but in the small (12 km 2 ) Wilderness Area on the western slopes of the island, there has been no tree cutting 1 . The Wilderness Area comprises a mountain valley with very steep slopes.

On the lower slopes, forests are composed of evergreen angiosperms, most notably Castanopsis cuspidata (Japanese chinquapin). Higher, at an altitude of 1000 metres, annual precipitation is a tremendous 8000 mm, and the most important tree species are evergreens, either the conifers Opens internal link in current window Cryptomeria japonica (Japanese cedar) and Opens internal link in current window Tsuga sieboldii (southern Japanese hemlock) or the angiosperm Opens internal link in current window Trochodendron aralioides (wheel tree), though a few deciduous tree species also occur, e.g. Opens internal link in current window Kalopanax septemlobus (prickly castor-oil tree) 2 . Trochodendron most commonly regenerates on living and dead trees 3 , often called “nurse logs”. These forests can be called temperate rainforest 4 . The mentioned higher altitude species are easy to identify but generally tree identification is challenging, particularly because for most westerners, Japanese identification guides are unreadable. However they have superb photos (better than in any western book I have seen), and identification is often possible simply by comparing photos. J. Ohwi’s old “Flora of Japan” (in English) helps, too.

Precipitation is very high throughout the year. The canopy is relatively open and the shrub layer dense. Leeches abound.

References :

1 /02e609d635ef9909091ef1700c7134f7/archive/advisory_body_evaluation/662.pdf

2 Suzuki, E. & Tsukahara, J. (1987): Age structure and regeneration of old growth Cryptomeria japonica forests on Yakushima Island. Bot. Mag. Tokyo 100 : 223-241.

3 Suzuki, E. (1997): Opens external link in new window The Dynamics of Old Cryptomeria japonica Forest on Yakushima Island . Tropics 6(4) , 421–428.

4 DellaSala, D. A. (ed.). 2011: Temperate and Boreal Rainforests of the World. Island Press.

Cryptomeria japonica (Japanese cedar, straight trunks) - Trochodendron aralioides (wheel tree, broadleaf trees) forest. Elev. 1250 m.
Cryptomeria japonica (Japanese cedar) forest at 1250 m.
Kalopanax septemlobus (prickly castor-oil tree) on very steep slope.
Quercus acuta (Japanese evergreen oak), right. Elev. 900 m.
Quercus acuta (Japanese evergreen oak) trunks at 1000 m.
Stewartia monadelpha (tall stewartia) at 1160 m. Symplocos myrtacea (Japanese sapphireberry) foliage, foreground.
Elaeocarpus sylvestris at 1250 m.
Ilex integra (mochi tree, small tree on left) and Daphniphyllum macropodum (small tree, right) in Cryptomeria japonica (Japanese cedar) forest at 1250 m.
Rhododendron tashiroi (leaning small tree, centre) in Cryptomeria japonica (Japanese cedar) forest at 1150 m.
Cryptomeria japonica (Japanese cedar) at 1250 m.
Cryptomeria japonica (Japanese cedar) tops.
Chamaecyparis obtusa (Japanese cypress) at 1250 m. Symplocos myrtacea (Japanese sapphireberry) foliage, bottom.
Abies firma (momi fir).
Taiko-Dake over Koyoji River valley.
Some broadleaf trees of middle elevations (850-1250 m).
Cones of Tsuga sieboldii (southern Japanese hemlock, top), Chamaecyparis obtusa (Japanese cypress, centre) and Cryptomeria japonica (Japanese cedar, bottom right), and fruits of Trochodendron aralioides (wheel tree, bottom left).