|Many Japanese hills and mountains were bare during the Edo Period|
Throughout the Jomon Period (14,000 - 400 BC), Japan was bountifully endowed with forests. This wealth of forest was maintained from the Yayoi Period (400 BC - 300 AD) - when rice cultivation began - until the postwar years of spectacular growth in the 1960s. At least, that is what I had been led to believe. In fact, however, Japan's forests and mountains have been subjected to devastation ever since the Yayoi Period.
Wood has been employed not only to construct houses and to manufacture tools and boats, but also as fuel to meet the needs of industry and of everyday life. Early in the 7th century, large-diameter timbers were logged from the deep forests for use in building the capital of the time, and for constructing huge Buddhist temples. These trees were replaced by pine trees, which can flourish on barren land.
By the middle of the 17th century, increases in population and the development of society made it difficult to sustain managed forests and this resulted in the appearance of tracts of treeless forest land throughout the country. During the Edo PeriodĀ@(1603 - 1867), Japan's population peaked at 30 million. Two of the reasons for this were limited food production and the depletion of forest resources.
Barren land illustrated by pine trees
Some pictures in Hiroshige's "The 53 Stages of the Tokaido” depict matured forest in the near distance, whereas there is no evidence of dense forest in the distant landscape. Pine trees growing on barren forest areas can be seen in many pictures dating from the Edo Period. Because pine trees can grow even on barren and sandy land with poor quality soil, their numbers increased throughout the country. Today, however, because enriched forest soil weakens pine trees, they can be seriously damaged by insects. Nutrients need to be removed from such soil in order to ensure the survival of pine trees.
Even during the Meiji Period (1868 - 1912), forests were left barren, due to the absence of a forestry policy as well as to the increasing demand for wood fuels created by the development of modern industries. The problem of deforestation reached its most serious level during this period. The Meiji Government then formulated three flood-control laws, the River, Forest and Erosion Laws, and strove to reduce the area of barren forest land by introducing a forest conservation system, as well as by implementing soil-conservation and anti-erosion projects. However, these modern land-conservation and flood-control projects failed, due partly to the dependence of energy resources upon the forests and to the advent of war.
Large scale deforestation deep within mountainous areas began during the Showa period (1926 - 1987) and grew rapidly worse after the Second World War. The huge scale of this deforestation, mainly of broadleaf trees, and the implementation of afforestation projects employing mainly coniferous trees have together completely changed the appearance of our forests.
Fossil fuels contributed to verdant forests
By 1955, much barren land had been transformed into verdant forest. This transformation owed much to the success of long-term land-conservation and flood-control projects, but also to revolutionary changes in the use of fuels and fertilizers. The principal fuels and fertilizers changed from forest biomass to fossil fuels and to chemical fertilizers respectively, rendering agricultural forest unnecessary. The liberalization of timber imports also reduced the demand for domestically-grown timber and the logging of timber in the Japanese mountains was diminished. However, although the forests have become smaller, more trees are being grown on streets and in parks.
The verdancy of Japanese forests has increased dramatically during the past 50 years. The overall area of forest has grown for the first time in the history of afforestation in Japan. Two thirds of Japan's land is still covered by forest, despite the dramatic inroads made by agricultural land and urban areas during the years of rapid economic growth. This might be explained by the fact that large areas of formerly barren land have been transformed into forest.
The benefits bestowed by verdant mountains
The greatest benefits that have been derived from the restoration of forests are the reductions in mountain surface erosion and in the incidence of the landslide disasters that were at one time a nationwide problem. Landslide disasters still occur in up to 2000 places a year, causing the deaths of some 10 people. Fifty years ago, however, torrential rain could easily cause landslides in over 30,000 places, killing hundreds of people every year. The landslides that occur today are not attributable to deforestation.
Reduced erosion of mountain surfaces diminishes the amount of sediment entering the rivers and, consequently, the number of rivers whose beds have been raised by sedimentation, a phenomenon that often caused flooding during the Edo Period. River beds have become deeper, with bedrock exposed in more and more watercourses. All of this has been achieved by the development of verdant forests, rather than by building dams.
Afforestation is even more important in some overseas countries
Because of Japan's mountainous backbone, running from North to South, two thirds of the country's land is mountainous and there is now no barren land requiring afforestation. However, the latter is far more important in some developing countries.
The Japanese are aware of the importance of the role played by trees in mountain areas, and make conscious efforts to plant them. However, people in some tropical countries are less aware of the kinds of dreadful disaster that can be caused by the absence of trees. Coconut oil is environmentally friendly. Thanks to our experience, we Japanese can help to protect the environment by making people living in tropical climates more aware of the risks to coconut plantation development that can be posed by deforestation.
Japanese forests also face problems of qualitative deterioration. However, they are not on a scale that would be likely to endanger the Japanese countryside. Japanese forests enjoy adequate water resource facilities, such as "green dams". Landslides, floods that cannot be prevented - even by green dams - and increasing demands for water for a population of 130 millions, should be dealt with by means of flood-control systems and basins, water utilization measures, sediment-control dams and dykes.
Thinning has a negative influence in terms of carbon dioxide emissions trading
The serious issue of global warming has emerged. Japan's mountains have been covered by green plants and trees since the evolution of a society which depends on underground resources. But now we need to reduce, control and absorb "greenhouse-effect" gases.
Japan's greenhouse gas reduction target, established by the Kyoto Protocol, is 6% below its 1990 baseline, and Japan plans to achieve a reduction of 3.9% through the absorption of carbon dioxide by her forests. From 1990, afforestation, which increases CO2 absorptions, counts as a factor in the reduction of CO2 emissions, whereas deforestation attributable to urbanization and to the use of forest as agricultural land is counted as a factor in the increase of CO2 emissions. Existing forest, if managed properly, counts as a factor in the reduction of emissions. Scientifically speaking, it is an over-simplification to state that afforestation counts as a plus and deforestation as a minus.
The growing of trees increases our capacity to store carbon, which is absorbed as carbon dioxide. In general terms, however, when trees have grown sufficiently or, to be more precise, when climax community has been attained as a result of ecological succession, the quantities of carbon dioxide absorbed and emitted by forest become equal.
Apart from a few natural ones, Japanese forests, whether well managed or not, are increasing their carbon stocks. This is thanks to the vigorously growing trees planted in forests that had been left unmanaged until 50 years ago. However, Japanese forests are effectively absorbing CO2 only for a short time, until they attain full growth. We must prepare to plant more young trees now, so as to ensure that the forests will continue to absorb carbon dioxide.
In the context of CO2 trading, deforestation is a minus factor, but the growth of young trees in thinned forest is a plus factor. "Under the terms of the Kyoto Protocol, the effects of afforestation and thinning sometimes cancel each other out. However, while young, growing trees absorb carbon emissions effectively, large, mature trees offer many other benefits, This means that forests should be composed of a variety of trees at different stages of growth.