Lessons We Can Learn from Unique Japanese Forestry
By Krunal Patel
The harvesting of timber began in the United States shortly after the arrival of settlers to Jamestown in 1609, accelerated rapidly in the 1790’s with westward expansion and, to this day, persists because of our flourishing and powerful timber industry. Due to the use of egregious methods such as clearcutting, a marked depletion of our mature, biodiverse forestlands has resulted.
Needless to say, deforestation is not unique to the United States. It is a global issue that is responsible for the removal of massive amounts of carbon from the ground, and the release of this carbon into the atmosphere has contributed greatly to climate degradation. A look at examples of how other countries have addressed the issue is instructive, as the need to develop methods to more sustainably harvest timber and limit the harmful effects of logging activities is pressing. Perhaps the best example is Japan.
The island nation contains only a few species of usable trees for construction, the most important of which is Cryptomeria japonica, or Japanese cedar, a conifer in the cypress family.
Large-scale harvesting of the cedars commenced in the 1300’s when wood was in great demand for home construction in feudal urban centers. This intense logging persisted until the mid-1500s when continued overharvesting of the trees became untenable. It was at this time that the development of a sustainable forestry technique, perhaps the first ever, occurred. This method, called daisugi, began in Kyoto. The translation of the name roughly approximates to “platform cedar”. In the daisugi process, the shoots at the base of Japanese cedars are pruned so that the main trunk remains straight. It is a sustainable method of logging because it involves pruning branches off the tree, rather than harvesting the entire tree itself. The practice also involves cutting the main branches so that the remaining shoots grow upwards from a platform, hence the name of the process. The technique results in an oddly beautiful tree that resembles an open palm with multiple trees growing out if it, perfectly vertical. To meet demand, the upper portions were logged every 20 years, leaving the base and the root system.
While centuries-old the daisugi technique remains in use in Japan today, it does so mostly only in ornamental gardens. Some argue that the practice should be revived on a wider scale since it does represent a viable source of sustainable lumber.
Afforestation is another method of forestry used in Japan that is considered sustainable by many. Prior to discussing afforestation, however, it serves to first review the nation’s contemporary logging history as it forms a foundation for understanding the use of this practice. The modern Japanese logging industry began at the end of the 19th century when timber demand skyrocketed due to industrialization and a need for more land for agriculture. Especially rapid deforestation of the temperate rainforest of the archipelago occurred between 1945–1965 This deforestation gave rise to climatic conditions that caused crop yields to fail entirely and the need to replenish trees became apparent. In 1973, a new forestry management was implemented throughout the nation that included a ban on clearcutting large swaths of forests, the adoption of selective logging as the norm for tree harvesting of existing forests as well as the implementation of afforestation to create new stands of trees.
Briefly, the process of afforestation involves planting saplings over land that has not had any trees on it for many years. In Japan, prior to planting trees, the land is plowed and soil rotated so that species such as dwarf bamboo cannot colonize the area. By rotating the soil, bamboo cannot quickly take root on the land, and planted saplings avoid any competition to hinder their growth. As the resulting plantation matures, selective logging is also used to stimulate further growth and development utilizing a method known as pit-and-mound topography. This method involves tipping selected trees over to create pits and mounds that free up nutrients within the soil, create microhabitats for new growth, and lead to an increase in sunlight for plants in the understory. A healthy understory leads to greater growth for young trees, which serve as the next generation when older trees begin to die off naturally.
Afforestation is considered by many to be sustainable because of an overall increase in the amount of forested land on the planet that is then maintained and only selectively logged. There are, however, problematic issues with afforestation as has been practiced widescale in Japan. It poses a threat to the watersheds in the afforested areas due to runoff of nitrogen and phosphorus during the plowing of the land to prepare it for saplings. Moreover, since Japanese afforestation deals primarily with the planting of monoculture cedar conifers, biodiversity is lacking and there is less resistance to fungal diseases that cause root rot in these newly created “forests”, especially as inflicted by Armilleria which moves through the soil in bootlace-like rhizomorphs.
Similar issues can also be seen in reforestation monoculture tree farms that are currently planted following clearcuts in the Western world. Another similarity is that both create industrial tree farms intended for use as commodities and they are not true biodiverse forests.
A derivative of afforestation later developed in Japan but without the negative aspects described above uses the so-called “Miyawaki Method”. The method, applicable primarily only in urban spaces, is named after Japanese botanist Akira Miyawaki and focuses on creating small, dense forests in areas inhabited by humans.
As a graduate student in the 1950s, Miyawaki studied in Germany and learned about potential natural vegetation (PNV), a vegetation cover in equilibrium with climate, that would exist at a given location if not impacted by human activities. He conducted research on PNVs in the various Shinto sites of the country and observed the sites’ chinju no mori (sacred shrine forests). By researching these forests, he determined that these miniature forests were exceptionally layered. The four categories were main tree species, sub-species, shrubs, and ground-covering herbs. He took this system and designed his own for planting artificial forests. The process is as follows:
- The soil of a future forest site is analyzed then improved, using local amendments such as rice husks which can enrich the soil.
2. The forest is planted with about 50 to 100 local plant species from the four categories as mentioned above, where the seedlings are planted densely — about 20,000 to 30,000 per hectare as compared to the standard 1,000 in commercial forestry plans.
3. For two years, the forest site is monitored, watered accordingly, and de-weeded. During this early phase, the saplings and young plants compete with one another to acquire more sunlight and water — resulting in facilitated growth.
With this method, trees grow 10 times faster as opposed to trees in conventional afforested areas and have 30 times more density and 100 times more biodiversity. They serve as a means to reforest urban and ecologically degraded settings and they provide added greenery, improved air quality, surface stormwater mitigation, counter heat island effects, provide habitat and reduce noise pollution.
The Miyawaki Method has been a great success in Japan, and has now been adopted by many other countries including India, France, Ireland and even the United States, where a Miyawaki forest can be found in western Pennsylvania.
Because the planet is experiencing rapid climatic degradation due to human activities, one of the most important being deforestation, the methods described here offer hints of the ways that our timber industry can, and should, reimagine how they can harvest trees more sustainably and minimize damage to forestlands. Key points learned from the Japanese experience are the superiority of selective logging versus clearcutting, and the importance of maintaining diversity. Learning from the flaws of conventional afforestation and reforestation, artificial forests created with newer methods mimic the qualities of their natural cousins, although, so far, only on a small scale. Perhaps one day, techniques will be developed to expand the Miyawaki Method beyond urban gardens, and perhaps daisugi will be, once again implemented on a wider scale and in more than just ornamental gardens. Perhaps these techniques will one day be applied to devastated wildlands.
Healing land that has been degraded by human development and resource extraction is a critical need, and the Japanese have demonstrated that such healing is possible. They have shown that necessity is, indeed, the mother of invention.
