Japanese Alpine Zone

Just above the tree line there are often extensive thickets of coniferous shrubs. These typically include Pinus pumila (Japaneae stone pine) but in the mountains adjacent to the Sea of Japan others include Juniperus communis var. nipponica and Taxus cuspidata var. nana. Broad-leaved deciduous shrubs such as Acer tschonoskii, Alnus maximowiczii and Sorbus matsumurana may also form important stands in this zone, while the ground layer can be important for lichens such as Cetraria crispa var. japonica. Alpine grasslands usually include various species of Calamagrostis including C. longiseta, C. fauriei, C. langsdorffii and C. matsumurana, but one of the most conspicuous plants of this zone is Phyllodoce aleutica.  Other flowering plants include Arnia unalaschensis, Cardamine nipponica and the endemic Parnassia alpicola (Parnassiaceae) and Boykinia lycoctonofolia (Saxifragaceae). The clubmoss, Lycopodium sitchense var. nikoense, is also likely to be featured.  In the more permanantly wet areas Moliniopsis japonica becomes the chief grass species together with Carex blepharicarpa and Fauris crista-galli.  These areas are also characterised by the presence of various tiny endemic primroses such as Primula nipponica and P. cuneifolia (Primulaceae). Other alpine grassland endemics include Minuartia hondoensis, (Caryophyllaceae), various Oxytropis species such as O. japonica (Fabaceae), Plantago hakusanensis (Plantaginaceae), Ranunculus acris var. nipponicus (Ranunculaceae, Trautvetteria japonica (Ranunculaceae), Trollius reiderianus var. japonicus (Ranunculaceae). Finally flourishing in less exposed areas are various alpine heaths. In the mountains of Japan, Empetrum nigrum var. japonicum is one of the most conspicuous elements of these heaths, while other dwarf shrubs are Arcteria nana, Loiseleuria procumbens and Diapensia lapponica var. obovata.

Hokkaido Volcanic Vegetation

Because new surfaces are constantly being created on active volcanoes, they are very important to plant ecology especially in the study of plant succession.  In this BioProvince ecological studies have been carried out on volcanoes such as Komagatake, Kousu and Ousu in Hokkaido. Some 20 years after volcanic activity on Ousu, a tall herb community including Ixeria japonica, Miscanthes sinensis, Oenotherea biennis, and the endemic Aster glehni (Asteraceae) had developed in the unstable accumulations of ash, soil and debris, whereas in the more stable areas a pioneer forest of Betula platyphylla var. japonica, B. ermanii, Populus maximowiczia and the endemic Salix sachalinensis (Salicaceae) had become established.

Hokkaido Alpine Grasslands

In the snow bed grasslands a number of communities have been described including ones co-dominated by the Phyllodoce aleutica and the endemic Salix yezoalpina (Salicaceae), while on Mount Rishiri these grasslands are occasionally dominated by the endemic Papaver fauriei (Papaveraceae). Other Rishiri endemics include Cortusa matthiola var. congesta (Primulaceae), Oxytropis rishiriensis (Fabaceae) and Trollius pulcher (Ranunculaceae). The so-called windward grasslands are mainly free of snow due to exposure to strong winds, which also have a desiccating effect. These areas are typically characterized by an abundance of leguminous species especially of the genus Oxytropis (Fabaceae), and regional speciation of this genus is a feature of the BioProvince. Some of the regional dominants include the endemic O. shokanbetsuensis on Mount Shokanbetsu, the endemic O. kodoana on Mount Hidaka and the endemic O. magalantha on Rubun Island. Other characteristic species of these grasslands include Bupleurum triradiatum, Minuartia arctica, Patrina sibirica, and the endemic Saxifraga nishidae (Saxifagaceae).

Hokkaido Alpine Deserts

At high altitudes in volcanic areas, repeated accumulation of volcanic ejecta, short growing seasons and long lasting snowdrifts have created expanses of open vegetation. Two of the most characteristic species of these barren volcanic regions are Dicentra peregrina and Viola crassa. In the serpentinitic areas, these alpine deserts are characterized by high levels of endemism. For example, on Mount Apoi (Hokkaido) endemic species such as Cirsium apoiense, Erigeron thunbergii var. angustifolius, Hypochoeris crepidioides, Saussurea reideri var. yezoensis (Asteraceae), Primula hidakana (Primulaceae), Bupleurum nipponicum var. yezoense (Apiaceae), Viola hidakana (Violaceae), Hypericum samaniense (Hypericaceae), Aruncus dioicus var. subrotundus (Rosaceae), Callianthemum miyabeanum (Ranunculaceae), Arenaria katoana var. lanceolata (Caryophyllaceae), Betula apoiensis (Betaceae), Tofieldia coccinea var. kondoi (Tofieldiaceae), Allium schoenoprasum var. yezomonticola (family) occur, while on Mount Yubari (Hokkaido) the endemics include Lagotis glauca var. takedana (Plantaginaceae), Primula yuparensis (Primulaceae) and Viola yupariana (Violaceae). The dominant species in these serpentinitic alpine deserts include the endemic Arenaria katoana var. lanceolata (Caryophyllaceae) on Mount Apoi,the endemic Viola yupariana (Violaceae) at the centre on snow patches on Mount Yubari, and the endemic Saussurea chionophyllum (Asteraceae) forms the dominant species of associations found on Mount Apoi, Mount Tottabetsu and Mount Yubari.

References

Kanai, H. 1963.  Phytogeographical observations on the Japano-Himalayan Elements. Journal of the Faculty of Science, University of Tokyo, Sect 3. Botany, 8: 305-339.

Kolbek, J., Srutek, M. & Box, E. O. 2003. Forest Vegetation in Northeast Asia. Kluwer Academic Publishers.

Numata, M. (ed). 1974. The flora and vegetation of Japan. Elsevier Scientific Publishing Company.

Numata, M., Miyawaki, A. & Itow  D. 1972. Natural and semi-natural vegetation in Japan. Blumea, 20: 435-481.

Ohwi, J. 1965. Flora of Japan. Smithsonian Institution. Washington D.C.

Satoo, T. 1983. Temperate broad-leaved evergreen forests of Japan. In: Ecosystems of the World 10 - Temperate Broad-Leaved Evergreen Forests. Elsevier.