Mitsui's Forests


Operational Flow of the Forest Industry

Explaining our work involved in forestry by showing what actually goes on in Mitsui's forests.

Here we present our operations in Sustainable Cycle Forests. This is one of Mitsui's forestry categories and refers to forests where tree saplings are planted and tended carefully for a period of 50 to 60 years before harvesting, after which new saplings are planted.

  1. Ground Clearance 1st year

    This means preparing an environment for planting tree saplings by clearing branches, shrubs, and other potential obstructions to the planting operation. In Hokkaido, this is done mainly with heavy machinery, but in Honshu, where much of the land is steeply inclined, manual clearing is the main method.

  2. New Planting 1st year

    This is the work of planting tree saplings by hand. This is done in Honshu (apart from the Tohoku region) mainly in late March to early April. In Hokkaido and the Tohoku region, the season is May after the snow melts, but in Hokkaido it is sometimes done in the fall. In Honshu, approximately 4,000 saplings of Japanese cedar or Japanese cypress are planted per 10,000 m2 (1 hectare), and in Hokkaido approximately 2,000 saplings of Japanese larch or other species.

  3. Weeding 1st year to 7th year

    This is the job of removing weeds, creepers, and other vegetation that blocks the growth of tree saplings. It is carried out from around June to August using mowing machines and sickles.

  4. Selective Clearing 8th year to around 15th year

    This is the job of clearing surrounding trees and creepers that block the growth of the planted trees. However, in Mitsui's Forests, we leave behind naturally growing trees that are productive.

  5. Low Branch Pruning 8th year to 15th year

    This is the job of lopping off low branches from approximately 1 to 1.5 meters above ground level. This spurs tree growth and facilitates later forestry operations.

  6. Branch Pruning 15th year to 25th year

    Branch pruning is the job of lopping off low branches, starting 1.5 meters above ground level, in order to produce quality lumber free of knots. Carried out from fall into winter when the trees have stopped growing.

  7. Thinning 15th year onward

    When the planted trees grow and the forest becomes too dense, daylight is blocked and growth is slowed. To remedy this, thinning is carried out by felling trees which are bent or affected by rot.

  8. Mature Tree Felling 50th to 60th year

    Trees that have reached a certain age are felled for commercial sale or other purposes.

  9. Logging and Cutting

    Carry out felled trees by thinning or clear cutting from the forest to the logging site*1 and cut them into logs using high-function forestry machines like harvesters and processors. In Hokkaido, where there is an extensive network of logging roads*2, bulldozers and high-function forestry vehicles known as forwarders are used. In Honshu, where much of the land is steeply inclined and the provision of logging roads is difficult, cables are generally used.

  10. Transportation

    Transport logs to sawmills or other wood processing sites by truck or trailer.

*1 logging site: place for temporary storage of timber
*2 logging roads: forest and mountain roads used for forestry operations and laid out in a grid pattern.