Lumber without cutting trees?

Japan is an intriguing country, never ceasing to inspire people by striving for perfection. Most of us are already familiar with the concept of bonsai – a Japanese art form dating back a thousand years, which produces small trees that mimic the appearance of full-size trees.

Daisugi has a technique similar to that of bonsai but, the result it produces is vastly different. Literally translating to ‘platform cedar’, this is a 14th century technique that offers an efficient, sustainable and visually stunning approach to forestry.

Here, planted cedars are pruned in a special way to produce “shoots” that eventually become perfect, straight, knot-free lumber.

This is an ancient method that was originally used by people living in the Kitayama region of Japan because saplings were lacking. The terrain in the region is very mountainous, and the steep slopes make planting and caring for trees very difficult.

So arborists used the technique not only to reduce the number of plantations but also to produce denser wood in a much shorter time.

The shoots are carefully and gently pruned by hand every 2 years, leaving only the top boughs, allowing them to grow straight. Harvesting takes 20 years and old ‘tree stock’ can grow up to a hundred shoots at a time.

Many advantages

The other reason the technique was developed was fashion. In the 14th century, a linear, stylised form of architecture, known as Sukiya-Zukuri, was extremely popular, and every prominent Samurai or nobleman wanted a house built in this way.

There were simply not enough raw materials available to keep up with demand, so Daisugi was developed. Not only could this lumber be produced in record time, but it was also more flexible and durable than ordinary cedar.

Wood produced in this manner is 140% more flexible than standard cedar and 200% denser and stronger.

This is particularly important for houses being built in Japan, where typhoons are common. In other words, it was absolutely perfect for rafters and roof timber, where aesthetics called for slender yet typhoon-resistant perfectly straight lumber.

The other benefit of this method is that it is durable. Instead of cutting down massive swathes of forest, only the shoots are cut. Because it takes only about 20 years for new shoots to grow, these specialised trees can keep up with the demand for lumber in a way that ordinary forestry cannot, and are much less harmful to the environment.

Unique technique

By the 16th century, demand for lumber had declined, but there was still a demand for these distinctive-looking trees. Because of their intriguing appearance, many people across the country wanted them as ornamental plants in their gardens, so this trend has kept the practice alive.

Here and there, in the forests around Kyoto, you will find abandoned giant Daisugi (they only produce lumber for 200-300 years before being worn out), still alive, some with trunk diameters of over 15 metres.

Many people marvel at the beauty and ingenuity of the technique. A similar technique is also used in other parts of the world, such as in the UK, but under the name Coppice and Pollarding.

While the technique is similar, it is not exactly the same, as Daisugi only works with seedlings from a specific mutant cedar in a specific location in Kyoto.

So while we won’t be able to use the technique in other countries, it is yet another example of the ingenuity Japan has passed on to us over the centuries.




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