Red List Category & Criteria: Least Concern
This species has a fairly restricted range in central Honshu, Japan. It is an extremely important timber tree and although it has been heavily exploited over time, there has been supplemental re-planting of the species essentially for commercial reasons. The provenance of the supplemental material is unknown, and it is likely that this comes from forestry sources, which is most likely improved or at least had some selection involved. It is impossible to distinguish natural trees from planted individuals, and there is also inter-breeding, so effectively the whole population is slowly being altered over time to being of mixed genetic origin. To what degree this genetic contamination results in any genetic decline is not known. As it is impossible to distinguish between the wild population and the introduced population, the species has to either be assessed as Data Deficient or Least Concern. Larix kaempferi is a species of mesic sites, occurring from the hills to high in the mountains (500 m to 2,300 m a.s.l.), on the south face of Fuji san it reaches 2,900 m. Unlike the other NE Asiatic larches it occupies better soils, often of recent volcanic origin, and is never found on peat. It is commonly found in association with other conifers, e.g. Pinus densiflora, Picea jezoensis subsp. hondoensis, Tsuga diversifolia, Abies homolepis at lower elevations, and Abies veitchii at higher elevations, but it is clearly a sub-climax species. Several broad-leaved tree genera are present at the lower elevations, e.g. Quercus, Fagus and Betula. Pure 'scrub stands' may occur at the upper limit of trees. Has been heavily exploited in the past for its timber – was used for house building, etc. But after logging, seedlings were planted back in the area again. So although the natural population has been logged, because there has been supplemental planting the exploitation can be considered not to have been that damaging as far as we can tell. The question is whether or not the seedlings were from the same subpopulation or were from a different subpopulation, or worse yet, from cultivated (improved) sources. Without further knowledge about the provenance of the seedling material one has to assume that these are introductions and thus over the long-term the population remains fairly stable. Phytopthora ramorum has been recorded to be sporulating in Larix kaempferi plants planted in Europe: if this were to spread to the native population in Japan, it could pose a problem. Japanese larch is an important timber tree in Japan and in Europe (Scotland), where it has been introduced in 1834. The wood is similar to that of European larch and is used for construction, railway sleepers, pit props and the pulp industry. It is also a frequently planted amenity tree in parks and large gardens and a limited number of cultivars are known. In Scotland, a spontaneous hybrid occurred around 1900 between Larix kaempferi and Larix decidua which was named Larix x eurolepis Henry (but is correctly named Larix x marschlinsii Coaz based on an earlier crossing event) and shows marked F1 hybrid vigour or heterosis. Its seed cones resemble those of Larix kaempferi with recurved scale apices, but are larger. This fast growing hybrid became much favoured by foresters and has been propagated and planted widely in many parts of Europe, often involving back-crosses with either parents. Despite this greater production of timber per ha/year of the hybrid, Japanese larch remains an important plantation tree for timber on poorer soils, where neither the hybrid not the other parent do so well and where much of Europe's plantation forestry is situated (the better soils being occupied by agriculture mostly for food crops). Part of the range falls inside a protected area, but much is outside. Larix kaempferi has also been planted back into the Yatsukaga-Chushin Kogen Quasi National Park.