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Wednesday, Dec. 7, 2005

OLD NIC'S NOTEBOOK

SYLVAN SIGNALS

Creative destruction augurs well for woodland well-being


Coming into Tokyo earlier this year, a mountain lad like me might have thought the city was hosting a great convention of bank robbers. It seemed that half the population were masked and looking grim indeed. The problem, it seemed, was an allergy to the pollen from sugi (cryptomeria, or Japanese cedar).

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This dead oak in early summer woodland (above) is one of thousands of victims in Japan of a beetle that leaves white wood dust on the trunk (bottom left) as males bore inside, to be followed by females carrying a killer fungus for their larvae (bottom right) to feed on.
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Gov. Shintaro Ishihara announced to the press in October that two-thirds of the cedar plantations in Greater Tokyo will be changed to mixed woodland. This will mean trimming out some 20,000 hectares of sugi and either replanting with broadleaf saplings, or carefully nurturing young broadleaf trees that spring up in the cleared spaces. The declared intention is to do this at a rate of 120 hectares a year.

The dynamic proposal also calls for the remaining one-third of the cedars to be replaced with ones that produce less pollen.

If it is carried out, I think this would be splendid. It could enhance the ability of wooded slopes to contain water, increase biodiversity and the range of forest products, create jobs in forestry and silviculture -- as well as (we hope) decrease the incidence of "hay fever" now afflicting one in four people in the metropolitan area and one in six nationwide.

Woodland and forest in general in Japan are in a state of crisis. All over the country you can see millions of dead standing pines, killed by disease brought into weakened trees by boring insects. Of course, the pines around the Imperial Palace are carefully tended, but nobody seems to care about those in the hills.

Another alarming development is the sudden death of thousands of Japanese oak trees, the type known as mizu nara in Japanese (Quercus crispula). This tree yields excellent lumber for furniture, wine and whiskey barrels, and its acorns are an important food for bears and other creatures. During the early Meiji years in the second half of the 19th century, mizu nara lumber, along with canned venison, was a major export from Hokkaido.

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The sudden demise of the oaks has been very prevalent along the coast of the Sea of Japan in the last few years, and from there the blight is rapidly spreading inland.

This summer I walked through some woods in Myoko, just across the Niigata border from where I live in Nagano Prefecture. Those woods are tended by my former assistant for several years, Tetsuya Fukuda, who was alarmed by the sudden death of nearly all of the mizu nara oaks -- their leaves shriveled and turned brown while those on other trees remained green and healthy.

We also saw white dust on dying trees' trunks and, looking closely, thin white tubes of wood dust coming from tiny holes in the bark. These are caused by tiny, male Platypus quercivorus beetles, which bore into the wood and make a complicated maze of tunnels. As they do so, these insects -- no more than 5 mm long as adults -- push the chewed-up wood dust backward so it emerges compacted out of the hole like so many miniature tubes of squeezed toothpaste.

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The maze of beetle-bored tunnels riddling this felled dead Japanese oak are not the reason it died. That fate befell it because of the "ambrosia" fungus introduced by females to feed the larvae after their eggs hatch.

This alone does not kill the tree. However, when females of the species enter the maze to mate and lay eggs, they carry in indentations on their thorax spores of a fungus which will feed the larvae. It is this so-called "ambrosia" fungus (which my Internet-savvy staff tell me is properly known as Raffaelea quercivorus, with the latter part of its name meaning "oak eater" in Latin) which rapidly spreads through the cambium, killing the tree. In Japanese the insect is called kikui mushi, which my dictionary tells me means "grain borer" or "gribble."

Gribble -- now that's an interesting word, but if you look it up it refers to a small marine organism that bores into submerged wood, ships, docks and so forth. I wish I could use it for woods, though I'd soon adapt it to even more uses: Don't gribble about! Silly gribbler! Quit gribbling! . . . and so on.

The problem is that nobody seems to have any idea how to counter this attack. I am submitting an experimental plan which calls for cutting down infected trees as soon as the disease is identified. Branches, bark, twigs and leaves should be incinerated on the spot. My plan calls for this to be done in a portable charcoal kiln.

The trunks should be trimmed into rough planking on site, with this lumber treated to kill both fungus and insects. I think this could be done with the steam and smoke from the charcoal-burning process, which contains a strong natural creosote. Otherwise we could gather the condensate and either paint the planking with it, or dip it in it.

This way, I believe the sickness could be halted and maybe even prevented from spreading so fast -- and at the same time valuable lumber salvaged. Some of the charcoal might also be of salable quality, suitable for barbecues and so on; the rest could be spread in the forest to improve soil quality.

Either way, whether to reduce human allergies or to try to improve the health of woodlands, we need to act. It is also sensible to derive products in the process that can support jobs and pay back some of the costs.

Recently, through friends in Canada, an excellent example of a woodland product has come into my hands. It is cutlery, made of what normally would be considered waste wood. The cutlery is made in British Columbia and is called Aspenware. It is allergen free, and biodegradable. It is also very light, and should you want to reuse it, it washes easily. The company literature claims that Americans use more than 60 billion pieces of disposable cutlery a year -- most of it plastic made from petrochemicals. This wooden cutlery is far better, and more pleasant to use.

Now I am quite aware of the great disposable-chopsticks debate in Japan. If imported tropical lumber was used to make them, I too would stand against their use. However, if trimmed-out lumber -- such as cedar, for example -- can be utilized, I will readily continue to use them. Disposable chopsticks are hygienic, easy to manipulate and, if saved, they make great kindling to light a fire. (Yes, I know, not so many of you get to light fires in Japan, but you could leave them to burn in a can when the electricity goes out after an earthquake. I've actually seen a can designed for just that.)

I've given a set of Aspenware cultery to my friends at All Nippon Airways, and another to Nagano Gov. Yasuo Tanaka, who is doing his utmost to encourage the wise recycling of trimmed-out lumber in our prefecture, using it for everything from school furniture and classroom paneling to wooden guard rails.

However we use the harvested wood, we cannot allow conifer woods to go on being sickly, nor can we have so much standing dead pine wood or oak wood. It increases the danger of forest fires, and with so much dead wood, a forest fire on steep mountain slopes could easily create intensely hot firestorms. Remember that traditional blacksmiths in Japan use pine charcoal, and that oak makes the very best firewood, burning long and hot. And also remember that only 2 percent or less of Japan's woodland is of old-growth forest, all the rest is either man-made or man-modified -- and it desperately needs to be looked after and properly managed.



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