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Japanese larch; how cultural differences influence utilisation of timber Dainis Dauksta

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Contents Foreword ................................................................................................................................................. 3

Executive summary ................................................................................................................................. 4

Recommendations .................................................................................................................................. 6

Introduction ............................................................................................................................................ 7

The Tōdai-ji Great Buddha Hall ............................................................................................................... 9

Geography of Japan .............................................................................................................................. 12

Sumitomo and Japanese corporate structures ..................................................................................... 13

Japanese forestry in context ................................................................................................................. 16

Plantation forests for societal needs ............................................................................................ 18

Contemporary Japanese plantation forests .................................................................................. 18

Larix kaempferi in Japan ....................................................................................................................... 20

Properties of Larix kaempferi ........................................................................................................ 21

Kajima Corporation ............................................................................................................................... 26

Yamabiko Dome ............................................................................................................................ 26

The ‘M’ Wave ................................................................................................................................ 29

Other Japanese larch structures in Japan ............................................................................................. 32

FFPRI .............................................................................................................................................. 32

Mokuzai Nakagai Kaikan ............................................................................................................... 33

Mizu-no-Machiya Nanokamachi-Gotenzeki.................................................................................. 35

Polus .............................................................................................................................................. 36

Bespoke sawmiller Taguchi Mokuzai .................................................................................................... 37

Conclusion ............................................................................................................................................. 41

Appendix ............................................................................................................................................... 42

Historical and economic context .......................................................................................................... 42

The role of the corporations ......................................................................................................... 43

Sawmilling and Log Markets ................................................................................................................. 44

Log markets ................................................................................................................................... 46

Bespoke sawmiller Maruhiro mokuzai .................................................................................................. 49

Contemporary Japanese manners ........................................................................................................ 53

Bibliography .......................................................................................................................................... 54

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Foreword This thesis sets out the background to and summarises findings from a study tour of Japan I

undertook from October to December 2014 in order to understand the place of Japanese larch in

Japanese forestry, the downstream processing industries and the built environment of Japan.

I would like to thank all of the representatives of the Winston Churchill Memorial Trust who gave me

the opportunity to carry out this research which I hope will give British engineers and architects new

confidence to work with our own larch to create inspirational, durable, low carbon buildings. I

dedicate this thesis to my oldest and closest friend the musician Bruce Duncan who passed away

while I was working in Japan.

My project objectives changed somewhat as I learnt from Japanese experts and I built up a history of

the ideas associated with Japanese larch. There are many similarities between Japan and Europe in

the way that the mining and smelting industries of the 17th century caused rapid deforestation and

consequent reforestation through plantation forestry. It was the growth of the mining industry in

both Japan and Europe which catalysed efforts to create what we now call sustainable forest

management. Japanese larch is an important detail in the larger story of the interactions between

Japan and the western world and the differences in its utilisation in Japan and Britain are a result of

historical micro-cultural differences. Readers can find more detail of historical and economic context

in the Appendix, there is also a detailed discussion of Japanese log markets.

In order to move away from building materials derived from extractive industries, governments and

designers in both Japan and the west are now driving much greater utilisation of wood in the built

environment. The Japanese have built some of the largest timber structures on the planet using their

own softwoods, confirming that we can use the same types of softwood for engineered structures in

our own built environments. We already know that larch is a high strength, durable softwood. We

can now use its potential for use in very large engineered structures but we may need to learn

lessons from Japanese business culture in order to make British construction industry supply chains

work more effectively for utilisation of homegrown softwoods.

Knowledge gained from this project will be disseminated in order to encourage more creative use of

British larch in our built environment. There are valuable lessons to be learnt from the Japanese

appreciation of the local. They value homegrown timber in the way that locally produced food is

considered to be special in Europe; we can learn from this attitude and better value our own timber.

For readers interested in greater background detail, historical context and information regarding

Japanese log markets please read the appendix.

To gain a quick understanding of this thesis please read the underlined passages in the executive

summary and recommendations, then view image 1.

Dainis Dauksta May 2015

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Executive summary 1 Japan is defined by its mountains, seismic activity and forests which make up 68% of land area;

Japanese society has responded to this environment creatively, becoming one of the most

innovative nations in the world.

2 The Japanese used timber from their forests to build some of the biggest (and oldest extant)

timber structures in the world, only surpassed in size during the 20th century.

3 The ancient, massive Tōdai-ji Great Buddha Hall at Nara demonstrates the potential for low carbon

construction of large-scale, durable structures using homegrown timber.

4 The Japanese government is implementing policies to increase sustainable use of wood in the built

environment whilst creating market pull for homegrown timber in order to revitalise domestic forest

management.

5 Edo (now Tokyo) was by 1800 the world’s largest city with a population of one million inhabitants

despite Japan’s sakoku ‘closed nation’ policy.

6 Sakoku policy denied the large coastal cities access to imported timber and so they developed at

the expense of Japanese forests causing extensive deforestation.

7 During the 17th century ruling feudal lords instituted selective cutting, tree planting, seedling

protection and forest patrols in order to counter deforestation; this was the start of modern forest

management in Japan.

8 Rapid urbanisation and industrial development in the 17th century caused the Japanese to examine

and manage the relationship between society and forests. Developing western European nations

simultaneously embarked on a similar process marked by the publication of silvicultural treatises.

9 During the Tokugawa Shogunate period of growth Japanese societal structure allowed

development of clan-based zaibatsu entrepreneurial groups which evolved into modern cross-linked

keiretsu conglomerates such as the Sumitomo Corporation.

10 The unique interlinked structure of Japanese keiretsu corporations seems to have assisted

innovation and implementation of innovative timber technology in the built environment.

11 The history of Japanese larch or Larix kaempferi as a minor species in its homeland offers some

excellent lessons on how we might optimise tree species for particular applications.

12 In Japan, larch is now mostly grown as an introduced species on large industrial plantations on

the northern island of Hokkaido, away from its native range in the Nagano region of the main island

of Honshu.

13 Plantation forests using only 7% of global forest area now supply between one third to two thirds

of global industrial roundwood demand and sequester 1.5 gigatons (1.5 x 109 tons) of carbon per

year. Plantation forests using species such as larch can help ameliorate the carbon burden in the

atmosphere whilst providing sustainably sourced timber for use in the built environment.

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14 Larch is a light demanding pioneer species and needs significant natural or man-made events to

create areas for regeneration; this is a fundamental lesson in silvicultural intervention.

15 Japanese larch is recognised as a challenging but useful timber in Japan; its genetic makeup

allows significant improvement to stem form and mechanical properties through tree breeding.

16 Several large exemplar buildings have been constructed in Japan using homegrown larch.

17 In Japan larch is considered to be an important future plantation species because of its tolerance

for cold; also for high stiffness and durability of timber.

18 Japanese larch plantations in Hokkaido provide a sustainable source of economically viable

commodity wood capable of substituting imported softwoods; a modern efficient sawmilling sector

has grown in Hokkaido alongside the larch plantations.

19 The role of plantation forests is misunderstood by the liberal western media (and some activists)

despite the World Wide Fund for Nature and the Food and Agriculture Organisation of the United

Nations clearly stating the need for more planted forests to drive sustainable development.

20 The Japanese have made best use of their softwood resources. Japanese cedar or sugi is low

density and low stiffness compared with larch nevertheless the Japanese use it for structural posts;

there is clearly potential for some fast grown low density UK softwoods to be used in structures also.

21 Japanese larch is converted into high grade, high value specialist cladding boards by small

specialist Japanese sawmillers.

22 Britain has a significant Japanese larch forest resource which has great potential to yield useful,

strong, low carbon construction components of the type that the Japanese have already integrated

into mainstream construction supply chains. Large volumes will be available because of the

pathogen Phytophthora ramorum.

23 Japanese government and institutional policies in regard to utilisation of forests for sustainable

development are as radical as any strategies posited by leading NGOs.

24 The management of Japanese forests is challenging because of Japan’s mountainous terrain.

However, it has also been seriously affected by the strength of the yen; the exchange rate has often

favoured cheaper commodity timber imported from around the globe and has disadvantaged the

Japanese domestic timber industry. Exchange rate cycles also influence the economic viability of

British timber.

25 The UK ‘Grown in Britain’ campaign could benefit from understanding how smaller Japanese

timber producers and processors have specialised in production of high grade timber from

designated areas called sanchi.

26 There are few (if any) differences in properties of Larix kaempferi between trees grown in Japan

and Britain. There are no technical or economic barriers to using British larch in massive structures

of the kind that the Japanese have built over the last two decades. Testing of UK-grown larch glulam

beams was completed in summer 2015 at Edinburgh Napier University and University of South

Wales.

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Recommendations We should take advantage of the large volume of strong, durable larch timber which will

become available over the next decade; the best of our diseased larch forests could and

should be used to catalyse creative low cost low carbon architecture.

Japanese larch is ideal for glulam (glue laminated beams) and other engineered structural

components capable of replacing steel in large structures. UK governments could use market

pull through public procurement to kick-start private investment in manufacturing plants by

specifying use of larch glulam in schools, hospitals and other public institutions.

Japanese larch is ideal for Brettstapel, an innovative structural panel for use in multi-storey

buildings, whether timber or steel framed. It can be manufactured by SMEs with little capital

investment.

The British forest and construction industries are overly conservative and dismissive of UK

grown conifers. Our neglect of Japanese larch is a negative paradigm; it has been grown in

Britain for over 150 years and we have only recently carried out enough research to enable

its use in construction. We need to invest in wood science to widen our understanding of the

potential of homegrown softwoods in construction.

We need to implement diversification of our conifer forests as soon as possible;

Phytophthora ramorum in Japanese larch is a warning to the forest industry.

UK governments or their agencies could specify larch for mass housing and because

imported larch is more expensive than UK grown material, the UK timber specification would

have a greater chance of surviving the procurement processes.

Procurement studies need to be commissioned in order to speed and optimise the passage

of homegrown softwoods such as larch into the construction supply chain; UK government

and UK forest agencies need to learn how we might make speedy and best use of our

timbers as different diseases progress across Britain.

Comparative studies of British and Japanese construction supply chains could help us to

better understand the obstacles to innovative construction using UK grown softwoods.

We should follow the advice of WWF and FAO; promote, optimise and expand UK-grown

conifer plantations.

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Introduction Japan is an excellent paradigm for both the historical and continuing relationship between societal

development and forest use. The history of forest utilisation in Japan includes all of the phases

associated with development of many modern rational societies; deforestation, reforestation,

importation and stasis. Japanese forest management has mirrored and perhaps even predated the

development of modern scientific European sustainable forest management; it also suffers the

stagnation encountered in high cost western societies, for instance as in England where 70% of

forests have little economic output and consequently are now largely unmanaged. In both Britain

and Japan, the strength of currency underpins the economic viability of homegrown timber. Japan is

the second largest net importer of timber in the world. There has been a negative perception of

Japanese wood consumption on the part of western NGOs which appears to be more of an

emotional rather than clear, rational response. Like many modern developed nations the Japanese

struggle to find a balance between sustainability and material needs of their society. Britain is the

somewhat hypocritical third largest net importer of timber in the world; there is little or no political

drive to reduce Britain’s dependence on the forest resources of other nations. Indeed, the politics

surrounding plantation forestry in Britain have stalled its expansion and any progress towards

increasing production of homegrown conifer for use in ‘low carbon’ construction.

Larch forests comprising around ten distinct species of the genus Larix grow across temperate,

boreal and tundra biomes of the northern hemisphere. Asia has the greatest larch timber standing

volume and variety of species and larches are the most common tree species in Russia at around

37% of forest area with 92% in eastern Siberia. Russia has 90% of the larch stock in the world and at

25 billion m3 standing volume it is a massive renewable resource. Larches are amongst the youngest

of conifer species and evolved under mountainous conditions and continental climates with cold

winters within what is now the territory of China. They are able to grow on a wide range of sites

even at high altitudes up to the tree line of mountains and because larches are pioneer species they

have low nutrient demands. Larch species are deciduous; their leaf litter improves soils and because

light can reach the forest floor for much of the year larch forests increase soil temperature, allowing

understorey growth and litter decomposition. Polyploidy does not occur in the larches therefore

cross pollination between all larch species is possible; this gives significant potential for tree

breeding and improvement. As pioneer species, the larches are light demanding and need significant

man made interventions such as clearfelling or natural events such as forest fire, windthrow or

pathogen attack in order to create openings of sufficient size for natural regeneration to take place.

Larch trees cannot regenerate under their own canopies therefore only more shade tolerant species

are able to colonise the forest floor. This makes the larches less suitable for dauerwald or continuous

cover silviculture; therefore clearcutting and harvesting operations actually benefit the species by

creating the conditions larch seedlings require. The prohibition of clearcutting in western Russia has

caused an increase of mean forest age and a decline in area of young larch stands (Martinsson O.

and Lesinski. J, 2007, pp. 5–15).

The combination of wood properties of larch is unique amongst the conifer species which grow in

Europe. It has twice the volume of heartwood as the more commonly used Scots pine; it is denser,

has higher strength and is more durable than any other common commercial softwood grown in

Europe. There is increasing concern over use of heavy metals and other chemicals for impregnation

of pine and spruce; therefore the naturally durable larch heartwood which is adapted into ecological

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cycles has great potential for use in sustainable construction and civil engineering as well as more

mundane applications such as fencing. Larch is attractive and its hardness makes it useful for

furniture, flooring and internal decorative wood. However, it is acknowledged that more information

is need in order to make better use of this timber (Martinsson O. and Takata K., 2000, pp. 3–14).

Since the beginnings of the 18th century early botanical descriptions of Japanese plants by Kaempfer,

Thunberg and von Siebold all served to generate interest in the potential of Japanese species

introduced to Europe. However it was only after 1858 that British plant collectors obtained access to

Japan and John Gould Veitch from the English nursery company Royal and Exotic Nurseries arrived

there in 1860. In September that year he accompanied diplomat Rutherford Alcock on a climb up

Mount Fuji where he found a conifer which the Japanese then called Fuji matsu (Fuji pine). It was

not clear whether this was a new species or Larix leptolepsis which had already been described. It

was established to be the same species and was later also named Larix kaempferi (Watkins C., 2014);

both Latin terms are now used. Veitch sent seeds back to England in 1861 thus introducing the

species to Europe (Wilson E. H., 1916, pp. 30–31). The contemporary Japanese term karamatsu is

now used for Larix kaempferi in Japan. The UK now has a large resource of Japanese larch forest;

over 140,000 hectares and currently underutilised despite its great potential. There will be large

volumes of larch timber available over the next decade as the pathogen Phytophthora ramorum

progresses through the crop. The Japanese have (like the Germans and Austrians) pioneered the

construction of massive engineered timber structures using their homegrown larch resource. There

are no technical or economic barriers to using UK larch in sustainable, inspirational architecture.

Image 1: The massive interior of Yamabiko Dome in Matsumoto showing larch glulam structure

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The Tōdai-ji Great Buddha Hall

The Japanese have built some of the largest timber structures on the planet including the Tōdai-ji

Great Buddha Hall within the temple complex at Nara; it is incorrectly described as the largest

wooden building in the world amongst others by Encyclopædia Britannica (Encyclopædia Britannica,

2015). Although Tōdai-ji was one of the largest timber structures historically it has been exceeded in

size by Tillamook Hangar built in America during WW2 (Dauksta D., 2011, p. 13) and in Japan by

Yamabiko Dome (image 1 above) built in 1993 using Japanese larch glulam (Takata K., 2004, pp. 3–1).

Nevertheless Tōdai-ji is an imposing, unique, inspirational work of architecture that reminds the

world of what can be achieved with our most sustainable construction material, wood. The Tōdai-ji

Great Buddha Hall is a massive post and beam construction 57m wide, 50m deep and 47m high,

which is approximately the equivalent of a 16 storey building. Wood is one of the oldest building

materials used by mankind. However tall timber structures are nowadays considered to be unusual

and innovative, steel and concrete became the materials of choice for large structures during the

20th century and they remain default choices. Wood is anisotropic (showing directionally different

mechanical properties) and is therefore a more complex engineering problem for structural

engineers. Despite this fundamental challenge, by the 12th century the Japanese had evolved a

system of timber construction suitable for large scale timber structures which could survive the

seismic events for which Japan is renowned. The Great Buddha Hall at Nara uses simple massive logs

around 30m long for the principal columns which support the bracketed roof structure (Pryce W.,

2005, pp. 42–43). The shaped logs have staves fixed (with massive iron nails) onto their outer

surface to a diameter of around 1.2m, increasing load bearing capacity; see image 3 below.

Image 2: The Tōdai-ji Great Buddha Hall at Nara

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Image 3: The massive timber columns of the Great Buddha Hall at Nara

A slot has been cut in one of the massive columns and it is possible to estimate its age (probably

around 140 years old); see image 4 below. The most common species used in Japanese temple

construction is Japanese cypress (Chamaecyparis obtusa), although as many as ten timber species

have been identified (Itoh T., 2004). The ancient Tōdai-ji Great Buddha Hall at Nara demonstrates

the modern potential for simple, massive, low carbon, durable structures using sustainably managed

homegrown timber.

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Image 4: Slot cut into one of the columns allows tree age estimation

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Geography of Japan

The Japanese archipelago comprises four main islands, from south to north; Shikoku, Kyushu,

Honshu (the biggest and most populated) and Hokkaido. Mountains dominate the terrain of Japan

occupying 80% of land area. There are 186 volcanoes including iconic Mount Fuji and Japan is

defined by seismic disturbance and disaster; many cities including Tokyo have been destroyed and

rebuilt following earthquakes (Petry A. K., 2003). Some buildings brutally reveal seismic dampers on

their exteriors reminding visitors of Japan’s precarious position, sitting directly on the western arc of

the Pacific ‘Ring of Fire’ (National Geographic, 2015), see image 5 below.

Image 5: Seismic dampers revealed on the exterior of Yamagata City Office

The Japanese environment and society are defined by their relationship with seismic activity in more

subtle ways; for instance hot springs or onsen are common. Communal bathing, often in beautiful

natural settings, is an important social and cultural pastime which is similar to sauna culture of

northern and eastern Europe. Much of the mountain landscape is forested with narrow steep sided

valleys along which roads and railways wind. Some of the mountain routes are largely tunnel with

short open stretches spanning river valleys between mountains. Japan is in the northern hemisphere

and has seasons similar to Europe. Climate varies from semi tropical in the south where cherry trees

blossom in late March, to cool temperate in the north (Petry A. K., 2003) where some of the deepest

snow in the world can fall (Erdman J. and Martinez E., 2015). The native range of Japanese larch or

Larix kaempferi is limited to the central mountains of Honshu but was introduced to the

northernmost island Hokkaido in the early 1900s and now 80% of Japan’s larch production occurs in

these plantations (Nagamitsu T. et al, 2014a).

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Sumitomo and Japanese corporate structures The culture within Japanese corporations reflects core cultural characteristics found across Japanese

society; loyalty, conformity, respect and social hierarchy define their structures. Sumitomo, one of

Japan’s oldest and iconic corporations, traces its history back to the establishment of Besshi copper

mine in 1691 when the Tokugawa Shogunate granted permission for the company to use timber

from the local forests (Sumitomo Forestry, 2014, p. 1). Adapting German smelting techniques,

Sumitomo created their own process called nanban-buki and by the late 17th century the firm was

one of the principal enterprises helping to make Japan the largest copper producer in the world (Eiji

I., 2013, p. 18). The mass production of metals was gained through deforestation, just as in Europe.

Income from copper production allowed Sumitomo to extend their interests to textiles, clothing,

sugar and medicines. One of the Sumitomo clans founded a money exchange firm. Sumitomo

Corporation during the Meiji era became a typical zaibatsu; a family clan controlling a pyramidal

structure with financial institutions near the top and different industrial enterprises lower down in

the network.

Zaibatsu organisations became holding companies controlling diversified enterprises. The Sumitomo

network included bank, insurance, trust, chemical, metal and trading (sogo shosha) companies and

before WW2 were one of the ‘Big Four’ zaibatsu companies. The owning families adapted to

changing times and regulations by owning enough shares throughout the zaibatsu structure to

maintain their control (Grabowiecki J., 2006, pp. 6–14). However under WW2 mobilisation the

situation changed significantly, banks were nationalised and control of the zaibatsu conglomerates

was taken by the military administration. Post-war American occupation authorities, suspicious of

the old zaibatsu corporations, attempted to rebuild their structures and open them up. When Japan

gained its sovereignty again in the 1950s new corporations called keiretsu were formed out of the

old zaibatsu, sometimes taking their names. Today’s Sumitomo conglomerate is a horizontal group

of companies with shares in one another’s stock formed around a bank (Grabowiecki J., 2006, pp.

19–23). Sumitomo has been described as virtually integrated, where individual companies bid for

one another’s services or products (Iizuka Y., 2015) with a degree of security offered by their

reciprocal share ownership.

The keiretsu structure undoubtedly plays an important part in the creation of stable supply chains

capable of delivering the innovative timber structures which the Japanese have been building since

the early 1990s. Under the aegis of the keiretsu horizontally integrated structure the cross-

ownership of stock gives little incentive for the individual companies to adopt adversarial stances in

order to increase their own profits; rather the whole supply chain shares risk and then benefits from

successful outcomes. The complex cultural and environmental strands out of which modern

Japanese society is woven have created one of the top five most innovative nations in the world

(WIPO, 2014).

The construction industry in Britain is significantly different where supply chains made up of

separate companies attempt to negotiate and also pass liability back down through each node in the

chain. Therefore when main contractors win contracts to construct innovative timber buildings it is

the specialist timber engineering subcontractor who takes most of the risk whilst being at the mercy

of the main contractor. Arguably this is one of the biggest challenges facing clients with aspirations

to build large innovative timber structures in Britain. A number of commentators have seen the

keiretsu groups as drivers of economic growth and ideal for delivery of innovative processes or

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products; keiretsu groups served as an effective mechanism to reduce coordination failures in large

scale investment projects, in which businesses individually are not willing or able to take risks.

Furthermore; keiretsu groups are still the engines of innovation and new business formation

(Grabowiecki J., 2006, p. 1).

The Sumitomo Forestry Company developed out of an early industrial extractive industry into a

modern ‘green’ company with the strapline Happiness grows from Trees. Image 6 below promotes

the company’s approach to biodiversity using an image of the regenerated forest now growing on

their original Besshi site. Old photographs show this view almost completely devoid of trees and

with smoke rising from the industrial buildings on the valley floor. Their latest annual report states:

The Sumitomo Forestry Group will continue to pursue the potential of wood in order to assist the

realization of a prosperous and sustainable society by continuing to pursue the potential of wood

(“Happiness Grows from Trees 2014” p. 11). This axiom reflects the 2012 WWF Living Forests Report

which sets out the role of plantation forests as wealth creating renewable resources for sustainable

societies (WWF, 2012). The company owns nearly 46,000ha of forests in Japan; this includes nearly

18,000ha in Hokkaido, the main larch growing area of Japan. The group owns or manages around

200,000ha of plantations in Indonesia, Papua New Guinea and New Zealand and is Japan’s leading

timber and building materials supplier. They also renovate traditional post and beam houses,

construct domestic custom built housing, overseas housing and are expanding their interests in care

homes for the elderly, biomass energy production and wooden public buildings.

Leading contemporary architects such as Michael Green in Canada (MGA, 2015) and Craig White in

Britain (white design, 2015) express the view that using timber within the built environment is a

major step towards implementing a low carbon economy. Timber from sustainably managed forests

can replace high energy embodied materials such as steel and concrete in construction. However,

Japanese keiretsu conglomerates such as Sumitomo have in the past received a great deal of critical

attention by NGOs such as ‘Global Witness’. In 2011 Japan was the world’s second largest importer

by value of roundwood and the third largest importer of sawnwood (UNECE/FAO, 2014); from being

95% self-sufficient in 1955 Japan was 26% self-sufficient in 2010 (Aga Y., 2013, p. 6). A document

with the title Timber Takeaway…Japanese Over-consumption- the Forgotten Campaign published in

1999 was highly critical of the sogo shosha trading companies responsible for importing and

distribution of timber into Japan (Global Witness, 1999). However, 25 years after its release this

document, although coherent now appears somewhat naïve and judgemental in its approach to the

use of wood in construction. The document posited no realistic alternative, more sustainable

approach for Japanese construction and demonstrates the gulf of misunderstanding which exists

between neo-romantic and rational world views. Furthermore a long standing debate continues in

regard to the role of plantation forests despite their increasing importance for wood supply and

carbon sequestration. Plantation forests using only 7% of global forest area now supply between one

third to two thirds of global industrial roundwood demand and sequester 1.5 gigatons (1.5 x 109

tons) of carbon per year (Mendes A. et al, 2013). If developed societies are to move towards greater

resource self-sufficiency then planted forests will be needed to supply increasing industrial

roundwood demands; a recent World Wide Fund for Nature (WWF) report is predicting that under

their ‘Living Forests Model’ global demand for industrial wood could triple by 2050 (WWF, 2012, p.

8). The Japanese government has implemented measures which attempt to move towards

consumption of more domestic timber from plantations and the Sumitomo group is following

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government policy. Both Japanese government and Sumitomo Forestry Company have formed

radical strategies that predate the WWF report of 2012.

A comparison between the situation in Britain and Japan is not flattering for the former because

although the word ‘sustainable’ is liberally sprinkled throughout British government and NGO policy

documents, the UK lacks the type of sustainable horizontally-linked supply chains which have

survived in Japan since early industrialisation. Civil servants in both England and Wales do not fully

understand the role of conifer plantation forestry in modern societies as drivers for sustainability.

Although Welsh government ministers now aspire to use homegrown softwoods from local Welsh

plantation forests in mass housing and public buildings, public procurement policy actually tends to

work against this aspiration. Exemplar timber buildings such as Burry Port Infants School near Llanelli

are dogged by supply chain issues which point to contradictory government policies. Indeed larger

homegrown softwood processors and membership organisations such as CONFOR within Wales have

for several years been suggesting that policymakers are failing to take steps to ensure sustainable

future supplies of homegrown softwood. As the third largest net importer of timber globally Britain

is certainly not in a position to preach sustainability to other nations. Could UK governments benefit

from commissioning further research of implementation of Japanese government policy regarding

forestry and the built environment?

Image 6: Company literature showing the regenerated forest at Sumitomo’s original Besshi site

Sumitomo Forestry established a new division called MOCCA in 2011 to promote the use of timber in

public buildings and non-housing sector. This action followed various Japanese government

strategies for revitalisation of Japanese forest management and to increase the national timber self-

sufficiency rate to 50% by 2020. In 2010 the government passed the Act for Promotion of Use of

Wood in Public Buildings in order to create a market pull for homegrown timber. MOCCA is now

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involved in construction of elderly and child care facilities using timber both in the structures and as

an ameliorative interior material which increases comfort for users. In 2012 MOCCA signed a

Community Reconstruction Cooperative Agreement with Higashimatsushima City in the tsumani-

devastated Tohoku region with the agreed ambition to rebuild the city using homegrown timber.

(“Happiness Grows from Trees 2014”).

Sumitomo recognise the importance of micro-cultural factors which influence Japanese customers

for instance, shopping centres constructed in timber can draw in more clients and make higher

profits. The firm actively markets branded homegrown structural timbers; in northern Japan where

larch is grown, the company promotes its use in local housing (Iizuka Y., 2015). Sumitomo have their

own research facility in Tsukuba Science City about 70km from Tokyo where research is carried out

in plantation forestry and wood science including testing of material properties of timber and testing

of timber structures especially in the context of seismic events. The positive influence of wooden

internal environments on occupants is also studied. The company has recently patented a simple,

novel panel product composed of two glued criss-crossed layers of separated lamellae which look

very much like trellis-work. When used with the lamellae crossing diagonally within post and beam

structures, these kizure panels can create strong shearwalls, see image 7 below (SUMITOMO

FORESTRY CO. LTD., 2015). There may be potential to use a similar panel product in the UK to

replace oriented strand board (OSB) as the racking panel fixed to timber frames in order to create

shearwalls. Larch falling boards would be ideal high stiffness lamellae for this type of product made

in Britain. There may be potential for using this type of latticed panels within rendered, breathable

hygroscopic walls.

Image 7: A timber wall cassette with applied kizure racking panel under test

Japanese forestry in context

Although John Evelyn and Hans Carl von Carlowitz had published treatises on afforestation in 1664

and 1713 respectively, during the last decades of the 19th century there was a growing awareness in

developed countries worldwide that ad hoc management of forests threatened future supplies of

timber. In America Gifford Pinchot, concerned about deforestation and influenced by German

forester Dietrich Brandis (who worked for the British Imperial Forestry Service in India) became the

first head of the US forest service in 1898 (USDA, 2015). Professor Wilhelm Schlich, assistant of

Brandis and also Pinchot’s friend started writing his five volume Manual of Forestry in 1889 and in

1905 founded the school of forestry at Oxford University (Steen H. K., 2000, p. 42).

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Within this wider context of concern for better forest management across the world the Tokyo

School of Agriculture and Forestry was formed in 1886 (Sowa J. M., 2012, p. 145). Then in 1905 the

first Government Forest Experiment Station was formed and this became the largest forest and

forest products governmental research agency in Japan. It is now an Incorporated Administrative

Agency charged with policy implementation and is called the Forestry and Forest Products Research

Institute (FFPRI) with the following stated mission: To contribute to sustainable development of a

world blessed with richness and diversity of forest, through research on forest, forestry and forest

products (FFPRI, 2014, p. 2).

There is active debate about the status of Japanese silviculture and whether an optimal system has

been implemented or formulated as yet even though plantation forestry has been practiced since

the late 16th century (Iwai Y., 2002, p. 10). Academics regard modern Japanese forest science as a

derivation of German and French practice adjusted to suit local conditions (Takata K., 2014),

however as in western Europe a backlash against even-aged scientific silviculture is evident.

Environmentalist and author C. W. Nicol, originally from Wales, is well known in Japan through

writing a best-selling book in the 1970s called Moving Zen. Nicol is nowadays a concerned

environmentalist and a leading critic of modern Japanese forestry. He is chairman of the Afan

Woodland Trust which manages a conservation forest project near Kurohime intended for ecological

research and promotion of a natural forest management system harnessing nature’s processes

(Ricoh, 2015). Nicol is an advisor in conservation to Sumitomo Forestry and has been involved in

setting up the ‘Woodlands School Project’ near to Higashi-Matsushima, one of the cities destroyed

by the tsumani which followed the Great East Japan Earthquake of 2011 (Iizuka Y., 2015). Now in his

mid-70s Nicol considers this to be his last lifework (NHK, 2013).

Nicol’s neo-romantic aspirations although expressed in emotional terms actually are not dissimilar to

the mission statement of the FFPRI which is of course driven by a rational scientific approach to the

same perceived environmental problems facing the world. A similar apparent dichotomy exists in

Wales, Nicol’s homeland, where environmentalists such as George Monbiot have also been

fomenting debate around the role of conifer plantation forestry in contemporary society. Although

well intentioned, this debate does not offer pragmatic solutions to the resource-hungry developed

nations across the world that increasingly depend on high yield plantation forests to provide the

industrial roundwood necessary for societal demands. Furthermore if developed nations are to drive

their economies towards sustainable development by using renewable resources such as timber

then world demand for industrial roundwood will increase dramatically, perhaps threefold by 2050

under scenarios proposed by WWF (WWF, 2012, p. 8).

Researchers are already aware that high yield plantation forests are under pressure (for instance by

NGOs) to be redesigned in order to gain wider acceptance and suggest that closer to nature

principles could be adopted: Large-scale single species plantations with strong environmental

impacts should be replaced by more ecological and integrated approaches at stand and landscape

levels, including mixed species plantations, and greater use of silvicultural systems based on close-to-

nature principles. However: Planted forests are exposed to socio-economic risks due to governance

failures. These risks comprise a weak or inadequate forest policy framework including insecure

investment conditions (Mendes A. et al, 2013). Furthermore, few economic or pragmatic strategies

have been developed or implemented in order to establish more biodiverse plantations apart from

those aspirational exemplar projects with charitable or other external funding. These projects may

18

demonstrate alternative silvicultural methodologies but they do not necessarily demonstrate

economic viability or any potential for tripling industrial sawlog production in line with WWF

predictions.

Plantation forests for societal needs A plethora of verbiage spouts from the liberal media about

biodiversity and sustainability and yet little is heard about plantation forests, the concept of which

gave us the context for Nachhaltigkeit,or sustainability. The term was first used by Hans Carl von

Carlowitz in the world’s first treatise on sustainable forest management (see Appendix). Global area

of plantation forests increased from 178 million ha in 1990 to 264 million ha in 2010, making up 7%

of total forest area. Although only covering this small proportion of the planet’s forest area,

estimates show that plantation forests now supply between one third to two thirds of global

industrial roundwood demand and sequester 1.5 gigatons (1.5 x 109 tons) of carbon per year

(Mendes A. et al, 2013, p. 6). In other words, at worst current global industrial roundwood needs

could be met from plantation forests grown on only 20% of the world’s forest area; however at best

this could be as little as 10%. Societies and governments across the developed world need to

understand not only how to protect and manage their native forests, they also need to better

understand the potential for plantation forests to supply all their industrial roundwood needs thus

relieving pressure on natural forests.

Contemporary Japanese plantation forests With over 25 million ha (MAFF, 2015) of forest

covering 68.6% of land area Japan is one of the most heavily forested developed nations on the

planet alongside Sweden (69.2%) and Finland (72.9%) (World Bank, 2015). Planted forests have

existed in Japan since at least the end of the 16th century. Various indigenous silvicultural techniques

evolved historically in response to societal needs and the development of specialist industries such

as shipbuilding, construction, window and door manufacture and cooperage. Planting densities for

afforestation varied greatly from 1000 to 10,000 seedlings per hectare. Most of the ancient national

forests were almost pure natural conifer stands preserved by feudal rulers of the Tokugawa

Shogunate during the Edo era (1608-1868). Plantations now make up 41% of Japanese forests and

90% of these forest plantations were planted after the Second World War in response to forest

overexploitation for the war effort. The post war drive to increase national income and the need to

meet increasing timber demand because of rapid economic growth influenced silvicultural decision-

making. Therefore tree selection and breeding programmes were undertaken as well as introduction

of some exotic species such as Pinus taeda. Japanese larch from its native range of Honshu was

introduced to the northern island of Hokkaido.

The growth of the post-war economy and increasing urbanisation drove a housing construction

boom, raising the demand for softwoods with a concomitant increase in conifer planting. This has

caused a bias in forest age structure, with one age class dominating so that Japan now has too much

mature or over-mature conifer plantation area. Furthermore liberalisation of wood imports in 1960

which then flooded the Japanese market with cheaper commodity timbers (Iwai Y., 2002, pp. 10–15)

coupled with a strengthening yen (Ito T., 1996, pp. 205–210) caused a rapid decline in

competitiveness of and consumption of homegrown conifer logs. The immature conifer plantations

and downstream processing industry were largely unable to supply large volumes of softwood as

cheaply as imported wood (Aga Y., 2013, p. 8). See table 1 below. However this downward trend of

homegrown log utilisation was contradicted by a slowly increasing use of Japanese larch from the

end of the 1970s. Large scale plantations of Japanese larch in Hokkaido gave sawmillers easy access

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to sawlogs (Iwai Y., 2002, p. 170) allowing them to remain competitive. Hokkaido larch sawmillers

now produce 36% of Japan’s packaging timber (Shimase T., 2014) in a competitive market sector.

Whilst plantings from the 1950s grew, economic incentives to thin and manage the new plantations

decreased and since the 1970s annual area of reforestation has declined so that age distribution of

plantation forests is uneven; 70% of planted forests are between 31-60 years old. Planted conifers in

the age group 45-55 years now make up 4,660,000ha or more than twice the area of Wales

representing a massive resource which needs intervention. The age group 95+ years comprises

170,000ha (Karube M., 2014, p. 3), more than all of the conifer forests of all ages in Wales combined.

The area of Japanese larch (mostly plantation forests) alone in Japan is half the area of Wales.

The noticeable steep decline in hardwood utilisation shown below followed societal changes,

especially the ‘fuel revolution’ whereby increasingly affluent households moved from burning

firewood to the more convenient fossil fuels (Iwai Y., 2002, p. 14). Developed societies in the west

also use very little domestic hardwood; in 2013 the UK produced 529,000 green tonnes, 76% of

which was used for firewood. Softwood production in 2013 was over 10.5 million green tonnes (FC,

2014). This dramatic contrast between utilisation of softwoods and hardwoods is clear in both

Japanese and UK societies. However in Britain charities and NGOs are biased towards the planting of

broadleaved forests of native species despite the protestations of professional foresters who view

this strategy as creating yet more unmanaged woodland, especially in England (Bishop M., 2014)

where native broadleaved species already make up 75% of forest cover (FC, 2014). A recent report

published by the Food and Agriculture Organisation of the United Nations (FAO) states; Current

trends in European forest management could result in an over-supply of wood from broadleaved

species, as well as a shortfall of coniferous timber from European forests, in particular as an increase

in harvest is difficult to achieve due to restrictive environmental policies (Mendes A. et al, 2013).

Table 1: Decreasing homegrown log consumption in Japan (Aga Y., 2013, p. 9)

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Larix kaempferi in Japan Japanese larch has a very limited native distribution, mostly restricted to mountainous or sub-alpine

zones in the Nagano prefecture of central Honshu growing between a lower limit of 900m and upper

altitudinal limit of 2800m. Perhaps its most famous provenance is Fujisan, Mount Fuji, where John

Gould Veitch collected the first seeds to be sent to England. Historical logging has diminished the

area of mature natural stands although remnants exist in national parks or other reserved forests

(Takata K., 2004, p. 4–1) and 80% of all Japanese larch production in Japan is now grown as an

introduced exotic species in plantations on the northern island of Hokkaido (Nagamitsu T. et al,

2014b, p. 99). Although Japanese larch has become the second most planted tree in Japan (Karube

M., 2014, p. 2), the species still only comprises 10% of conifer forest area (Nakada R., 2012, p. 2). It

normally grows in colder parts of Japan nevertheless of all the Eurasian larches Larix kaempferi has

the lowest latitudinal distribution. It is also the most diverged in nuclear and organellar genomes

furthermore maternally inherited mitochondrial DNA displays geographical variation despite its

limited native geographical distribution. It is suggested by Japanese researchers that the species’

diverse, fragmented habitats with their microclimates varying greatly between opposite coasts of

the Honshu mainland have caused significant trait variations among provenances. Studies of growth

characteristics (for instance stem volume, diameter, height and wood density) from 25 provenances

in the species’ natural range showed large variance. This gives considerable scope for tree breeding

and improvement. Trees of Fuji provenance are amongst the best performers for stem height and

diameter (Nagamitsu T. et al, 2014b, pp. 87–99).

Luc Paques of INRA reported rapid juvenile growth and courser branching of Japanese larch when

compared with European larch and American tamarack (Nagamitsu T. et al, 2014b, p. 87). Proportion

of juvenile corewood zones to their surrounding mature heartwood zones has been debated since

American researcher B. H. Paul wrote Juvenile Wood in Conifers (Paul B. H., 1957). Juvenile wood is

the first-formed wood near to the centre of the tree. It is perhaps one of the main causes of wood

variation in conifers as well as of one the main causes of concern when considering the management

and utilisation of conifers. It is also one of the main causes of confusion in regard to the perceived

quality of fast grown, wide ringed wood; because juvenile wood is a different wood type with

distinct anatomical and mechanical properties it is erroneous to assume that fast grown mature

heartwood with wide growth rings is similar to juvenile wood with wide growth rings. However,

researchers have done exactly that (Zobel B. J. and van Buijtenen J.P., 1989, pp. 82–87).

Older British studies such as those of G. M. Lavers showed that stiffness (modulus of elasticity or

MOE) of homegrown European larch at 9900N/mm2 was significantly higher than stiffness of

homegrown Japanese larch at 8300N/mm2 (Lavers G. M., 1969, p. 17). However this is now

considered to be the result of testing younger Japanese larch samples (with higher proportions of

juvenile wood) alongside older European larch samples (with lower juvenile wood proportions).

Tests conducted on samples from trees of similar age revealed no differences in stiffness (Bravery A.

F., 1999, p. 7). The latest bending tests carried out by Edinburgh Napier University confirm that

Japanese larch stiffness is close to that of European larch (Ridley-Ellis D., 2015). Conflicting data in

regard to stiffness of larch also exists in Japan. One researcher from Sumitomo stated an MOE of

around 9900N/mm2 (Ishigaki H., 2014), but older data shows a mean MOE of 8360/mm2 (Karube M.,

2014, p. 8). Japanese and British data and the spread of values appear to be very similar.

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The transition from juvenile wood typically occurs over several years and depending on species and

site conditions can take up to twenty years; Isebrands and Hunt reported a juvenile wood zone of

around ten years from the pith for Japanese larch (Zobel B. J. and van Buijtenen J.P., 1989, p. 105).

Initial close spacing at the time of planting in order to restrict the size of juvenile core has been

suggested by researchers and foresters including Paul. Site class and stand density play significant

roles in determining the width of juvenile wood zones in Japanese larch (Zobel B. J. and van

Buijtenen J.P., 1989, p. 83). However Zobel throws doubt on the economic viability of close spacing

(Zobel B. J. and van Buijtenen J.P., 1989, p. 94). Close initial spacing does have currency with

enthusiasts of continuous cover forestry; however because larch species cannot regenerate within

uneven aged forests (Martinsson O. and Lesinski. J, 2007, p. 15) this silvicultural method is not an

option. Foresters need evidence of increased returns for extra investment in techniques such as

close initial spacing especially in view of the need for concomitant added early thinning

interventions which incur extra costs. Furthermore there is a need to study the differences in

economic potential for mature heartwood grown over small diameter juvenile cores compared with

mature heartwood grown over large diameter juvenile zones. Without this evidence the debates

surrounding juvenile corewood are being conducted with insufficient data.

Growing of Japanese larch as a plantation timber started around 130 years ago but tree breeding did

not start until 1957 when a total of 530 plus trees were selected from across the larch growing zones

of Japan and planted in clonal seed orchards and test sites in order to select the superior trees. Stem

straightness is an important factor in processing logs, this was scored and some improvement was

demonstrated; percentage above second graded logs was 30% for the commercial controls and 45%

for plus tree progeny. Highly significant clonal variations in wood density and stiffness (MOE) have

been reported and these differences are regarded as being independent of growth rate, annual ring

width or stem diameter. Furthermore clonal ranking of MOE was fairly stable between different

locations and wood density was shown to be heritable; therefore because density and MOE

correlate well in Japanese larch all of these results suggest that superior growth can be achieved

alongside improvement of the most important wood properties. A hybrid between Larix kaempferi

and Larix gmelinii has proved particularly successful, being tolerant of vole damage and showing

better stem straightness; up to 70% above second graded logs (Kurinobu S., 2005, pp. 127–129). For

full-sib progenies of Japanese larch, stem crookedness has shown comparatively large heritability

values of 0.33 and 0.59 using two different analyses (Oshima T. et al, 1997).

Properties of Larix kaempferi Larch species are notorious for developing spiral grain; it occurs

when wood fibres follow helical paths around the longitudinal axis of a tree and it is considered to

be one of the most serious of defects encountered in sawn timber. It tends to be most severe

towards the centre of the tree, within the juvenile corewood (Zobel B. J. and van Buijtenen J.P.,

1989, p. 23). Spiral grain tends to cause boards containing juvenile corewood to ‘wind’ or twist

during drying (Fonwenban J. et al, 2013, p. 1). Image 8 below shows a Japanese larch centreboard

twisted through 20o during kiln drying, the juvenile corewood is marked approximately with a green

circle. In some softwoods spiral grain tends to increasingly wind to the left, this is called S-spiral,

reaching a maximum after 10 to 20 years. Then in the mature heartwood the grain straightens up

and the spiral increasingly winds to the right, this is called Z-spiral (Wilson K. and White D. J. B.,

1986, p. 178). Sumitomo Forestry have studied the use of twisted larch boards for glulam production

using lamellae dimensioned to 27mm*117mm*3000mm. A three year-long project demonstrated

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that by distributing a proportion of boards twisted (up to 10mm out of true) within different glulam

lay-ups twist in the final glulam components varied between 1-3.5mm (Ishigaki H., 2014).

Traditional carpenters in Japan say of larch that it spirals to the left for fifty years and then spirals to

the right for fifty years and so it should not be cut until it is over a century old (Eiji U., 2014).

Japanese researchers have found that larch mature wood grain generally tends to spiral only a little

and in the opposite direction to that of the juvenile corewood and that degree of twist in mature

wood is highly correlated with growth ring number from the pith (Koga S. et al, 2004).

Image 8: Spiral grain has twisted this Japanese centreboard through 20o

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Spiral grain is under considerable genetic control but its expression may be dependent on the local

environment. Spiral grain angle of plantation grown Japanese larch ranges from 2o to 10o and shows

a heritability of 0.5 at 15 years old. Furthermore there is no significant correlation with diameter

suggesting that faster growth does not necessarily induce spiral grain. Since 1980 additional plus

trees have been selected for spiral grain improvement and some progress has been made including

use of tissue culture for mass propagation of clones with less spiral grain. Despite the drawbacks

with spiral grain in larch, the Japanese regard the species as unique and especially useful for growing

in colder zones (Kurinobu S., 2005, p. 128). Furthermore, amongst conifer species Japanese larch has

amongst the lowest trunk diameter to sapwood ratio; heartwood can make up over 80% of stem

area and trees from the Fuji provenance have around 81% heartwood (Nakada R., 2012, pp. 12–14).

Japanese larch has significant potential for improvement in all of its most important properties;

growth rate, stem straightness, stem volume, wood density and MOE. Reduction of spiral grain is

also possible; therefore along with improvement of those other properties this species could be

particularly useful for volume production of a naturally durable strength graded construction timber.

The significant improvement in stem form through tree breeding in Japan can be seen below in

image 9. The left hand image shows normal larch, the centre image shows improved larch and the

image to the right shows a ‘super’ F1 hybrid of Larix gmelinii var. japonica x Larix kaempferi. This

hybrid shows some resistance to pests in Japan and Professor Katsuhiko Takata of Akita Prefectural

University Institute of Wood Technology suggested that experiments with this type of hybrid in

Britain might be worthwhile. However, the larch expert Luc Paques of INRA in France has no

information to suggest that the Larix gmelinii var. japonica x Larix kaempferi has increased

resistance to Phytophthora ramorum (Paques, 2015). Perhaps this could be confirmed through tests

here in Britain.

Image 9: From left to right, normal Japanese larch, improved larch and hybrid larch

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The wood properties of Japanese larch have been studied in great depth by Japanese researchers.

The consensus suggests that long term retention of this species will allow higher yields of more

stable, higher grade yakumono timber that could be suitable for use in furniture or high value

bespoke projects. Larger diameter older logs yield larger volumes of stable mature heartwood which

can be sold into high value added markets; it is also possible to completely separate juvenile

corewood from mature wood. This can then be sold for applications where stability is not so critical.

Despite its rapid growth, ready availability, stiffness and durability Japanese larch has remained an

under-utilised construction timber in Japan. Its tendency to distort, resin leakage and the low

strength of the large juvenile corewood zone reduces yields of the useful mature heartwood needed

for critical applications such as sophisticated engineered structures (Takata K., 2004, p. 3).

Nevertheless several exemplar structures using homegrown larch have been constructed in Japan

including the Yamabiko Dome, The Nagano ‘M Wave’ arena, and several schools such as Wada

Elementary School (image 10 below) near Nagawa in Nagano prefecture. Sumitomo Forestry

routinely use Shinsu Japanese larch structural components manufactured by Saito Wood Industry

Co. Ltd. in houses built near to larch production areas(Sumitomo Forestry, 2010). Using more

domestic timber not only contributes to local employment it is also a selling point for customers who

are increasingly demanding locally grown timber (Iizuka Y., 2015).

Image 10: Interior of Wada Elementary School showing larch timber frame and furniture

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The relatively high stiffness of larch makes it very useful for critical structural applications where

strength is essential. Experiments at the Forestry and Forest Products Research Institute (FFPRI) in

Tsukuba have confirmed the usefulness of 28mm thick larch plywood panels for manufacture of high

racking strength floor diaphragms, see image 11 below. This plywood significantly stiffens structures

allowing improved performance during seismic disturbance and reduces the number of supporting

joists necessary, see image x below. The FFPRI have also tested glulam made using larch for the high

stiffness outer lamellae with a low stiffness spruce core, see image 12 below.

Image 11: High stiffness thick larch plywood floor diaphragms

Image 12: High stiffness outer lamellae with lower stiffness wood used in the core of this glulam

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Miyamori, a company in Akita prefecture are a leading producer of glulam components for the

house construction sector (Miyamori, 2015); they routinely produce glulam using mixed timber

species in order to optimise performance by positioning high stiffness larch as outer lamellae. This

pragmatic technique derives from a Japanese tradition of using the right material in the right place.

Kajima Corporation Iwakichi Kajima started his carpentry business in 1840 in Edo (now Tokyo). Taking advantage of the

Treaty of Amity with America and the establishment of Yokohama as an international trading port

after 1858, he moved there and built the first western style building in Japan, Ei-Ichiban Kan (British

house no.1) in Yokohama for the trading firm Jardine, Matheson & Co (Kajima, 2015). A construction

boom followed the opening of Yokohama port as foreign companies established their first Japanese

trading bases. Yokohama grew from 1000 to 100,000 inhabitants in thirty years (Atsumi T. and

Bernhofen D. M., 2011, p. 12). The Kajima construction business adopted western building

techniques and grew by taking a role in the modernisation of Japan’s infrastructure building

railways, harbours, dams and airports and other civil engineering structures (Kajima, 2015). Kajima

Corporation built two massive structures using laminated homegrown larch in the early 1990s;

Yamabiko Dome and the ‘M’ Wave arena. Both structures are in Nagano prefecture, the latter on the

outskirts of Nagano city.

Yamabiko Dome Yamabiko Dome was built in 1993, its construction being made possible by the

advances made in timber engineering techniques and regulatory changes made within the Buildings

Standards Act in 1987. This act accelerated development of large scale exemplar timber buildings

using homegrown Japanese timbers. From the late 1980s research into kiln drying and laminating

larch was conducted by Nagano Forestry Research Centre, Shinsu University and Saito Wood

Industry Co. Ltd. (the main building at Nagano Forestry Research Centre is itself constructed using

larch glulam). This research established the material characteristics of homegrown larch allowing

engineers to design a new generation of Japanese wooden structures. Yamabiko Dome was the first

of the modern wide span buildings in Japan to use local timber; it is 110 metres in diameter and 40

metres high (Takata K., 2004, p. 3).

The main curved larch glulam beams have a cross section of 900mm*300mm and were

manufactured by Saito Wood Industry Co. Ltd. Sections of the ridged elements were prefabricated

and craned in place, see: www.kajima.co.jp/tech/mokuzou/ex/dome/index.html#anc_yamabiko

The bolts which fix the simple steel connector plates between glulam elements are clearly visible

within the green circle in image 15 below. Principal glulam elements are around 12 metres long and

therefore could be manufactured on a conventional glulam line. The designers used simple tried and

tested technology, joining short sections of ridged modules together with steel connector plates to

create the first larch wide span dome in Japan. This approach needed no special technology but

rather depended on detailed knowledge of the material characteristics of the materials used gained

through basic wood science such as four point bending tests.

It is a pleated structure using folds in order to stiffen the fabric of the roof in the way that the art of

origami uses folds to stiffen small paper structures (Meyer J. et al, 2014). The pleated form of the

roof can be clearly seen in image 13 below.

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Image 13: The pleated form of the Yamabiko Dome roof

Approximate estimates of material costs for the manufacture of an equivalent timber frame using

homegrown larch in Britain have been extrapolated in table 2 below from the volumes of glulam and

solid wood used at Yamabiko. Using estimates for cost of manufacture of homegrown larch glulam

discussed with Buckland Timber Ltd (Buckland Timber, 2015), cost of a similar frame made in the UK

could be under £500/m2.

Detail Dimension UK cost now

Yamabiko glulam frame Japanese larch 4,000m3 volume £4 million

Yamabiko ribs/joists Japanese cedar 1,200m3 volume £360,000 (use spruce?)

Yamabiko span diameter 110m

Total area/frame cost 9500m2 area £4.36 million

Frame cost/m2 in UK 1m2 £459

Table 2: Yamabiko frame details with projected costs for a similar UK structure

There are no technical barriers to utilising UK grown larch in a massive glulam structure such as

Yamabiko dome. The cost per square metre is extremely competitive.

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Image 14: Curved larch glulam for Yamabiko dome being clamped up at the Saito factory

Image 15: The main curved larch glulam elements with cedar ribs, a connection is circled green

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The ‘M’ Wave The Nagano Olympic Memorial Arena (also called the ‘M-Wave’) built by the Kajima

Corporation is an example of utilisation of local Japanese larch in construction which predates the

political drive to use more home-grown softwoods. Started in 1994, this innovative structure utilised

what was then the world’s largest suspended timber roof at 80 metres span, shown in image 16,

below. It was made using local Shinsu larch laminated into 300mm deep hybrid glulam elements

each incorporating a 12mm thick steel plate which extends out from the sandwich to form

connections at either end of the glulam components, see image 17 below. Wood was chosen to

reduce condensation above the massive expanse of the ice rink below and the suspended roof helps

energy conservation by reducing the interior volume in comparison with the dome structures often

used for arenas of this type (Kajima Corporation, 1997). Image 18 below shows ends of larch

lamellae demonstrating that Larix kaempferi from Japan can grow relatively fast. The glulam

incorporates some juvenile corewood lamellae.

Image 16: The massive larch suspended roof in the ‘M’ Wave arena

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Image 17: A sample of the connecting end of the glulam/steel sandwich roof elements

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Image 18: Lamellae ends showing relatively fast grown larch including juvenile corewood

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Other Japanese larch structures in Japan FFPRI Image 19 below shows a massive glulam frame on one wall of the testing hall at the Forestry

and Forest Products Research Institute (FFPRI) in Tsukuba. The uprights are over one metre deep.

Image 19: Massive larch glulam frame of the FFPRI testing hall at Tsukuba

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Mokuzai Nakagai Kaikan Images 20 & 21 below shows the Mokuzai Nakagai Kaikan office building

in Osaka using larch structural elements and finishes in the two upper storeys and constructed by

the Takenaka Corporation.

More information is available here:

https://www.google.co.jp/maps/place/34.672543,135.484182

http://www.takenaka.co.jp/recruit/fresh/project/osakamokuzai/index.html

Image 20: Osaka Mokuzai Nakagai Kaikan

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Image 21: Osaka Mokuzai Nakagai Kaikan, the side view shows curved front

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Image 22: Mizu-no-Machiya Nanokamachi-Gotenzeki

Mizu-no-Machiya Nanokamachi-Gotenzeki in Yamagata city is a 753m2 commercial

development which used 179m3 of larch glulam up to 200mm*650mm*10.92m in dimensions

(Zenmoku, 2015), see image 22 above.

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Polus Post war economic growth caused expansion of urban areas and created a market pull for a

new commercialised house building service which did not depend on family connections with local

traditional carpenters. With a new approach to house construction, a new way of selling houses was

necessary and home exhibition centres which show construction details, interior and exterior

finishes and furniture became the vehicle for selling houses (Iwai Y., 2002, p. 211). ‘Wood Square’ in

Minamikoshigaya about 30 km north of Tokyo is the exhibition centre for Polus-Tec.

Image 23: ‘Wood Square’, the exhibition centre for Polus-Tec

Image 24: A structural wall panel on show in Wood Square

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Image 25: A wall panel demonstrating different techniques to achieve racking strength

Image 25 above shows different techniques for adding racking strength to shearwalls; on the left

simple diagonal ties are demonstrated, then thick plywood and structural fibre racking board and on

the right is an interesting criss-cross diagonal system of ties. This recalls the smaller scale cross-tie

kizure panels made by Sumitomo.

Wood Square is a simple massive post and beam construction of 6,600m2 floor space using 633m3 of

larch glulam. Its scale and finish are impressive and clearly demonstrate that larch can be used in

simple, large, engineered structures. Polus-Tec is part of the Polus Group; http://www.polus.co.jp/

Bespoke sawmiller Taguchi Mokuzai This firm is situated on a site of around 4ha next to Tazawako station, Akita prefecture and

specialises in sawmilling Japanese cedar, sugi and Japanese larch or karamatsu. The mill appears

quite old-fashioned to a western observer, with primary headrig and secondary resaws all using

spoked bandwheels of a type rarely encountered in European sawmills nowadays. Nevertheless

Taguchi Mokuzai use this aging infrastructure to produce a diverse range of value added products

including kiln dried, profiled cladding from local logs and timber wall cassettes using imported

Canadian softwoods. The sawline is shown in image 26 below, the primary headrig out of sight to the

right, two resaws in the middle and edger by the operator on the left.

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Image 26: The sawline at Taguchi Mokuzai

Separate buildings house the sawline, kilns, wall cassette production and cladding board profiling

facilities. The aging, masonry-built kilns are shown below in image 27.

Image 27: Timber drying kilns at Taguchi Mokuzai

After crosscutting of imported timber to length, wall cassettes are assembled on large benches, a

simple method of production that can also be seen in Britain, Europe and America. This method of

prefabricating building panels off-site is increasingly important in the developed world as a modern

method of construction which allows better quality control and faster erection times on-site, a very

important factor in busy urban settings; see image 28 below. In Japan the aging demographic and

diminishing number of skilled carpenters available for on-site work has led to an increase of this

method of production (Iwai Y., 2002, pp. 207–210).

39

Image 28: Prefabricating wall cassettes using Canadian softwood

Taguchi Mokuzai convert and kiln dry local Japanese larch for processing into high grade cladding

boards. A stack of sawn, kiln dried larch boards can be seen to the left of image 29 which also shows

the planer/moulder which is used for machining profiled cladding boards in one pass. The operator is

checking samples of finished profiles. This planer/moulder is an older generation machine with no

acoustic enclosure or electronic braking and would not pass European health and safety regulations.

However it is capable of producing high quality profiled larch boards which can be seen stacked in

image 30 below.

This sawmill and production facility typifies the problems facing rural timber processing SMEs in

Japan. Considerable investment is needed to replace its aging infrastructure but with continuing

economic uncertainty there can only be limited incentive to borrow the necessary funding.

Nevertheless, by specialising in production of high quality cladding boards this sawmill successfully

converts Japanese larch logs into high value added products.

40

Image 29: Operator checking samples from the planer/moulder which produces profiled boards

Image 30: Stacks of finished high grade machine-profiled larch cladding boards

41

Conclusion Japanese larch is a minor species in its own native range but the Japanese have increased its growing

area and economic viability by creating large scale plantations in Hokkaido where it is an introduced

species as it is in Britain. The Japanese have carried out significant research in order to understand

the characteristics of Japanese larch and their studies confirm that there are few (if any) differences

in material properties of Larix kaempferi between trees grown in Japan and Britain. There is

considerable genetic variance despite the species’ small native range in Honshu and this gives

significant scope for tree breeding and improvement. Trees of Fuji provenance are amongst the best

performers for stem height and diameter. ‘Super’ F1 hybrid trees of Larix gmelinii var. japonica x

Larix kaempferi have significantly improved stem form and are more pest resistant than pure Larix

kaempferi but there is no research to establish its sensitivity to Phytophthora ramorum. Perhaps this

research could be carried out in Britain because P. ramorum resistant larches could still have great

potential in UK plantations where future climate change may restrict use of spruce.

90% of the world’s larch forest resource is in Russia, mostly Siberia. There is great potential for larch

species to contribute to the supply of durable, sustainably grown timber for the built environment

replacing high fossil fuel energy embodied materials such as concrete and steel. Furthermore larch is

amongst the stiffest and strongest of the world’s softwoods as well as being integrated into

ecological cycles unlike timber treated with creosote, synthetic chemicals or heavy metals. The

Japanese have built several large exemplar structures using Japanese larch, Yamabiko Dome being

one of the largest engineered timber domes of its type in the world. In order to supply increased

uptake of larch in construction, new larch plantations in Europe could offer opportunities for

increased biodiversity within the light, airy forest structures created by the species.

New strength grading settings have been generated by recent research carried out in Britain and so

there are no technical barriers to the use of homegrown larch in engineered structures of the kind

seen in Japan. Furthermore the cost of larch glulam (laminated larch structural elements) can now

be quantified because of a recently completed study using Welsh grown larch carried out by Napier

University and Woodknowledge Wales. Therefore the most important barriers to increased use of

Japanese larch in British construction are perception and the structure or management of supply

chains. The new Burry Port infants’ school near Llanelli is an example of how architectural

aspirations tend to be restricted by UK public procurement policy and UK construction industry

practices. Although homegrown larch is eminently suitable for a wide range of structural

applications its use has been restricted to the outer cladding of Burry Port school. The case study of

this project will be available in late 2015. Japanese keiretsu conglomerates, although viewed

suspiciously by post WW2 American occupation forces and then later by western NGOs such as

‘Global Witness’, have delivered large modern exemplar structures using larch of the same type that

we in Britain use for fencing. It is sobering to compare policy implementation and the progress of

timber construction in Japan with that of Britain, especially when bearing in mind the criticism

levelled at Japanese corporations by British commentators or NGOs based in Britain. Indeed,

regarding sustainability critics would be justified in pointing to an entrenched British attitude of do

as we say, not as we do.

Only cultural barriers in public procurement processes and business structures appear to be

stopping the British from utilising their own considerable larch resource for a new generation of

engineered structures using the world’s only sustainable construction material; timber.

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Appendix

Historical and economic context

Prior to 1639 westerners traded with Japan and Christian missionaries including Francis Xavier

travelled there. However the nation’s feudal rulers, the shoguns, closed off Japan in 1639 following

the Sakoku edict and foreigners were expelled apart from a small Dutch trading mission at Dejima in

Nagasaki who remained there as intermediaries for the outside world (Dower J. D., 2008, p. 1.4).

Despite its seclusion and unknown to the outer world by 1800 Japan had developed the world’s

largest city, Edo (later Tokyo) then with a population of one million. Growth of large cities such as

Edo and Osaka increased demand for timber and pressure on natural forests; however no imported

timber was available because of sakoku policy. Therefore the isolationist Tokugawa Shogunate

needed to start auditing and managing Japanese forest resources. During the 17th century the feudal

lords instituted selective cutting, tree planting, seedling protection and forest patrols in order to

counter deforestation; this was the start of forest management in Japan. Increasing demand drove

the establishment of new planted forests near to the growing cities. Mainly sugi or Japanese cedar

(Cryptomeria japonica) and hinoki or Japanese cypress, (Chamaecyparis obtusa) were planted (Iwai

Y., 2002, pp. 3–7); and these two species still make up 68% of Japan’s conifer plantation area now

(Karube M., 2014, p. 2).

With increased urbanisation and the first phases of industrialisation, Japanese forests became

essential resources for the expansion of mining and smelting, just as was happening in Europe at the

start of the Industrial Revolution. In Britain the Royal Society commissioned their first report and in

1664 John Evelyn published it; Sylva, Or, a Discourse of Forest Trees was written in order to

encourage tree planting to ensure future timber supplies for the Royal Navy (Cambridge University

Press, 2015). Perhaps the best known exhortation in Sylva is Let us arise and plant! Sylva was the

first European treatise to describe the planting of trees as a renewable resource for future

generations.

In Saxony the Chief Inspector of Mining in Freiberg, Hans Carl von Carlowitz was concerned about

deforestation and the potential decline of mining and smelting industries for lack of mining timber

and charcoal. Half a century after Evelyn’s Sylva von Carlowitz published Sylvicultura oeconomica,

the first treatise on forestry to formulate the word sustainability or Nachhaltigkeit (Grober U., 2015).

Simultaneously on opposite sides of the planet, European and Japanese societies were beginning to

describe, formalise and regulate tree planting and forest management in order to ensure future

supplies of timber for societal needs from planned anthropogenic forest plantations.

In 1853 American coal-fired warships under the command of Commodore Matthew Perry entered

the harbour near Edo, this incursion marking the end of isolationism and the emergence of modern

Japan. Black smoke from the steamships’ funnels reinforcing the power expressed by these alien

black-hulled vessels traumatised the nation and iconic images of the ‘Black Ships’ were burnt into

the national psyche; see image 36 below. The phrase ‘Black Ships’ is still widely used in Japan in

symbolising threats emanating from outside, especially the west (Wilson G., 2011).

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Image 36: A Japanese image of ‘Black Ship’ steam frigate USS Susquehanna

Perry’s gunboat policy forced the Japanese to abandon sakoku policy and sign the Treaty of

Kanagawa which although it was not a commercial agreement unfairly named the United States a

most favoured nation. The Treaty of Amity and Commerce was then signed with the US in 1858

which forced Japan to accept rights for westerners and the opening up of a number of trading ports.

The decline of the Tokugawa era began and the Shogunate ended with the Meiji restoration in 1868

followed by introduction of western ideas such as land ownership. The aggregation of businesses

started and acceleration of industrialisation ensued.

The role of the corporations The sharing out of common forestland allowed private ownership of

forest holdings by families. The newly expanding economy increased demand for wood resulting in

destructive overcutting; in order to manage this situation the Japanese government passed the First

Forest Law in 1897 and the Second Forest Law in 1907 (Iwai Y., 2002, pp. 7–8). In order to encourage

modern industries the government raised capital for infrastructure development by selling some

large tracts of forest to mining and papermaking companies; this was the origin of corporate

ownership of forests (Iwai Y., 2002, p. 25). The 1897 law was intended to regulate forest practices.

These had been formalised earlier in limited areas by formation of forest associations who

attempted to prevent burning, quarrying and other destructive interventions. The 1907 law provided

structures for establishment of associations for creation of management plans, afforestation, forest

road construction and prevention of fires or pests. By 1939 there were 2,654 associations

established (Iwai Y., 2002, pp. 42–43).

Economics during the Tokugawa era had been driven by Confucian ethics and the notion of a

harmonious society. The caste system worked from top to bottom in the order of imperial family,

44

samurai, craftsmen and peasants, and lowest of all the merchant classes who because of their

financial dealings were treated with contempt by the samurai. Despite the ambiguity of the

relationship between rulers and the merchant traders who worked with far less freedom and

security than their European counterparts, cooperation between these castes developed with

granting of licenses and creation of guilds. Specialist merchant families with control over particular

commodities became increasingly powerful through supplying their rulers with necessary goods and

services including financial services. These families developed into merchant houses some of whose

names survive today amongst the modern corporations for instance Mitsui and Sumitomo

(Grabowiecki J., 2006, pp. 4–7).

Sawmilling and Log Markets In 1997 there were 13,400 sawmills in Japan (Iwai Y., 2002, p. 170), 7,905 in 2007 and by 2011 the

number had declined to 6,242. Of those remaining 65% have power capacities 75kw or less, implying

rather low annual productive capacity (MAFF, 2013); average log consumption of sawmills using only

homegrown timber is 1,800m3 and when speaking of large-scale Japanese sawmills Iwai’s book

quotes average log consumption of 30-40,000 m3 (Iwai Y., 2002, p. 170). With a total softwood log

production of 16.4 million m3 in 2011 and 6,242 sawmills the average annual log consumption in

Japan across all mills is only 2,631m3 per mill.

This contrasts strongly with the situation in Britain where the number of sawmills now stands at 177

and where there has also been a decline in the number small sawmills; however the number of large

sawmills is increasing. 6.53 million m3 of softwood logs were processed in 2013 and sawmills with

total annual sawnwood production of over 10,000 m3 accounted for 94% of the total output.

Altogether there were 166 sawmills processing softwoods in 2013 (FC, 2014), therefore the average

annual log consumption across all of those mills was nearly 40,000 m3. The BSW sawmill at

Newbridge on Wye in Powys, Mid Wales alone produces 150,000 m3 of sawnwood from over

250,000 m3 of logs annually (BSW, 2015).

Despite the availability of high-performance forestry machines, labour productivity is low and

logging costs are high in Japan. Private forests are small, averaging 3ha (Okano T., 2014) and

dispersed making log collection inefficient and expensive. Japan’s mountainous terrain offers a

mostly unsuitable road system (Iwai Y., 2002, p. 162); often winding along narrow precipitous valleys

with little potential for road widening. Articulated lorries of the type that are ubiquitous in Britain

and Europe are rare on Japan’s narrow roads, therefore both road transport and log extraction add

significantly to unit cost of Japanese softwoods. A creative approach is needed; Professor Takeshi

Okano, the director of the Wood and Plywood Museum in Shinkiba near Tokyo suggests that

payments to small forest owners should be based on annual increment of timber grown rather than

product output (Okano T., 2014).

In 2011 the mean value of domestic Japanese cedar 4m long 14-22cm diameter sawlogs was 12,300

yen/m3 (MAFF, 2013). The exchange rate was around 135 yen/1GBP in 2011, so Japanese cedar logs

were costing Japanese mills the equivalent of £91/m3, the same price as the very best, largest

Douglas fir grown in Britain, or around 50% more than UK-grown western red cedar logs, the nearest

equivalent timber to Japanese cedar. Douglas fir is the dominant imported log species in Japan (Aga

Y., 2013, p. 10). 1.2 million m3 was landed from Canada in 2013 (Japan Lumber Journal, 2014, p. 11),

45

with an average price of around 25,000 yen for logs of 30cm and over diameter (Japan Lumber

Journal, 2013, p. 6). Japanese sawmillers were paying the equivalent of £172/m3 for Douglas fir logs

of a size for which UK sawmillers pay around half that price (XE.com, 2015).

Many subsidies, tax advantages and other financial incentives have been used by the Japanese

government in order to increase domestic harvesting and processing but production costs have

remained high and imported softwoods offer more competitive pricing. The Japanese domestic

softwood harvesting and processing industries are severely challenged; both sectors suffer a lack of

scale because of dispersed, remote forest holdings. Restricted road infrastructure in the mountain

zones where the forests are situated hamper delivery of increased roundwood volumes to sawmills.

Achieving economies of scale and reduction of unit costs appear to be extremely challenging

although several funding programs, for instance the New Production System, have been

implemented in order to encourage larger scale sawmilling infrastructure. These schemes have not

necessarily increased market pull on demand for homegrown wood (Aga Y., 2013, p. 14). This

situation becomes especially ironical when observing the forested landscape of Japan from high

speed shinkansen trains where the Japanese have used advanced engineering technology so

effectively. It is clear that without continuing heavy government subsidies or extreme price rises of

industrial roundwood globally, the outlook for the more remote conifer plantation forests in Japan is

at best challenging. Table 3 below shows the continuing decline of Japanese sawlog prices to 2012.

Although relatively low compared to other species the price of Japanese larch has remained stable

since 2000, in 2012 and at around 11,000 yen this was equivalent to £81 (XE.com, 2015). This is the

price of best grade homegrown Douglas fir in Britain. In other words homegrown larch in Japan is

not strictly speaking cheap but rather it is the other homegrown species which are expensive relative

to softwoods available on global commodity markets.

Table 3: Japanese sawlog prices 1985-2012, source MAFF (Aga Y., 2013, p. 26)

46

Although the continuing competitiveness of Japanese larch contrasts with the difficulties faced by

other conifer plantation species, it also highlights what is needed of modern plantation forests in

order to keep them competitive in global commodity timber markets. Accessibility and scale of

production are the keys to success in volume markets. Tree breeding adds competitive edge by

engineering wood qualities and productivity, there is also potential to increase resistance to pests.

Although Hokkaido-grown larch is a minor species relative to the more common Japanese cedar and

Japanese cypress, Hokkaido processors continue to survive by processing modest commodity

products such as packaging. Hokkaido plantation forests are large scale and direct selling to sawmills

is easy (Iwai Y., 2002, p. 170). Hokkaido sawmillers also have the largest capacity mills and therefore

the highest average annual log consumption (Shimase T., 2014, pp. 23–27), giving them economic

scale and competitive advantage.

Log markets The Japanese have a unique log market system which is intended to act as a buffer

between log production in the many thousands of small conifer plantation forests scattered around

Japan’s mountainous interior and the several thousands of small domestic sawmills. The markets are

able to gather and sort logs by species and size into suitable lots for sawmillers. The small scale of

the individual links in the supply chain of this mechanism, fixed costs associated with large areas of

hard yard space and the added handling costs do not allow sufficient economies of scale for

economic production of construction timber for mass markets. Nevertheless it does allow specialist

sawmills to select and bid for small batches of logs suitable for bespoke sawmilling. Bespoke

sawmills are able to process many sizes of component and use different styles of cutting needed to

construct new vernacular houses or refurbish old houses in local styles. However this flexibility adds

on-costs; the log market collects commissions amounting to 12%, adding extra cost to the already

expensive harvesting and transport stages of log distribution from small forests. Keiretsu businesses

such as Sumitomo aggregate the numerous stages of the construction supply chain within their own

groups; they use efficient quality control and distribution systems allowing scale of economy and

more uniform quality (Iwai Y., 2002, pp. 172–173). Image 37 below shows a small lot of Japanese

larch sawlogs for sale at Takayama in Nagano prefecture. Around seven sawmills survive in

Takayama and several are located on the same industrial estate as the log market allowing easier

collection of logs. One local sawmiller priced the batch of sawlogs in image 8 as being worth 12,500

yen/m3 or £69/m3 (Nakahata A., 2014).

47

Image 37: Japanese larch at Takayama log market

Some bespoke sawmillers appear willing to be to pay high premium prices for high grade large logs.

The Japanese cedar sawlog no. 227 shown in image 38 below was considered to be worth 70,000

yen/m3 or £389/m3 (Nakahata A., 2014). This roundwood input price is almost as much as the output

sawnwood price charged for western red cedar by small bespoke sawmillers in Britain and around

the same price as good quality large oak in the UK.

48

Image 38: A large Japanese cedar valued at £389/m3 in Takayama log market

49

Bespoke sawmiller Maruhiro mokuzai Akahito Nakahata-san is the present owner of this bespoke sawmill located on the same industrial

estate as Takayama log market. The original mill was situated in the town but as with many sawmills

formerly based in urban commercial areas of Japanese towns, the owner was encouraged to move

into modern premises on the outskirts to reduce fire risk within the town. Before the move,

Nakahata-san travelled to America to study the sawmilling business there; on his return he

constructed the new sawmill building using laminated timber portal frames in a similar manner to

the timber industrial buildings he had seen in America. The glulam frames can be seen in image 10

below. Nakahata-san is the son of the firm’s founder and now his son is the sawyer who can be seen

breaking down the 60+ year old Japanese cedar (sugi) log in image 39 below.

The firm Maruhiro mokuzai (Maruhiro wood) as well as cutting to special order, cuts, kiln-dries and

profiles high quality sugi interior cladding boards. Squared posts for construction are cut from the

corewood of larger logs; they are machined with a narrow slot on one side to the centre of the

square in order to reduce instability and splitting, see image 40 below. Interior cladding boards are

machined from higher grade sugi logs which can cost as much as 50,000 yen/m3 or the equivalent of

£278/m3 (Nakahata A., 2014). This price is around the same as beam-grade oak sawlogs bought in

the UK. Therefore although Japanese cedar is a low density softwood very similar in character to the

western red cedar (WRC) grown in Britain, these high grade logs need to be converted into high

value-added, quality niche products such as interior cladding in order to justify the initial cost of the

logs. By way of contrast, UK grown WRC logs rarely make more than £70/m3, a quarter of the cost of

high grade sugi, and few bespoke sawmillers kiln dry and profile WRC.

The front-end of this sawmill’s processing line is a primary mill of at least 40-50 years old technology

which is of low productivity by today’s standards, also the kiln can only dry limited volumes of

timber. Nevertheless the specialist niche markets into which Maruhiro mokuzai sell their standard

products allows a small volume turnover to create enough profit for this small family business to

survive. Furthermore the range of standard products makes optimal use of sawlogs; for instance the

construction posts are cut from the corewood heart and cladding boards are cut from tangential

‘falling boards’ which are taken from around the heartwood. Image 41 below shows Nakahata-san

standing next to stacks of finished cladding boards, their cross sections show how the coloured

heartwood is retained on the revealed side of cladding boards whilst the lighter sapwood zone is on

the reverse side of boards. This production system is normal in sawmills across the world but it

demonstrates how tradition within the timber trade can be at odds with wood science; because tree

stems generally increase in stiffness radially from pith to bark, corewood is the weakest and falling

boards are the stiffest (highest modulus of elasticity). Therefore in theory it is better to take

structural material from the outer zones of logs and corewood should be used for applications

where stiffness is not essential. However Japanese post and beam construction allows relatively

large, low stiffness posts, therefore use of corewood or boxed-heart small logs is common.

Traditional houses anyway are mostly built by small local firms (Iwai Y., 2002, p. 207) often known to

the customer and extra cost of using timber from small sawmills is considered to be worthwhile

(Iizuka Y., 2015).

50

Image 39: Nakahata-san junior is the sawyer, shown breaking down a 60+ years old sugi log

51

Image 40: Air dried slotted sugi corewood posts for typical Japanese post and beam construction

Liberalisation of wood importing regulations in 1961 severely affected the economic viability of the

domestic forestry sector (Aga Y., 2013, p. 5), forcing small scale Japanese sawmills to adapt or close.

Many timber producing areas began to specialise in production of high grade homegrown timber

called yakumono. These areas developed a system derived from Japanese agriculture where produce

is marketed for its quality and uniqueness; specialist high grade timber producing areas are called

sanchi. A similar culture for specialist agricultural products exists in Europe, for instance Protected

Designation of Origin where specialist food names are protected under EU legislation (UK

Government, 2015). This concept has yet to be used in Britain for creation of new markets for

homegrown timber although the ‘Grown in Britain’ campaign is exploring options for raising the

profile and value of British domestic timber (Forestry Commission, 2015). Furthermore there are

opportunities for growing large conifers in western Britain under long term retention to produce

very high grade softwoods such as Douglas fir. A sanchi type of protected designation could add to

the perception of value of specialist UK homegrown softwoods in the way that brand-names have

added value to ‘handmade’ potato crisps and UK produced wines.

52

Image 41: Akahito Nakahata-san standing next to the sawmill’s premium grade cladding

53

Contemporary Japanese manners Visitors from the western cultures which have become more relaxed and informal in everyday

lifestyle and manners may be surprised by the formality of Japanese culture, for instance the

ubiquity of bowing and variety of expressions of gratitude which proliferate throughout daily

transactions. At thresholds, for instance shop doorways or at the top of escalators in airports

professional greeters stand formally to welcome their ‘honourable’ guests and clients. Department

stores may have elaborate opening rituals lasting for several minutes undertaken by immaculately

dressed staff. Cleaners of shinkansen or bullet trains line up at the platform’s edge bowing formally

and thanking passengers as they board the train. Japanese business culture demands neat formal

dress codes including uniforms and business suits; dressing inappropriately is seen as a mark of

disrespect. Although the Japanese can appear very welcoming (even to strangers) they do not share

the touching culture which is so common in the west (Alston J. P., 2005). Conformity, tradition,

respect and service underpin Japanese culture although superficially it may appear to be driven by

modernity, manga imagery and iconic technology such as electronics, cameras and shinkansen.

54

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