Roger A. Sedjo is Director of the Forest
Economics and Policy Program, Resources for
the Future, Washington, DC, United States.
By 2050 most industrial wood could come from a small area of plantation forests, much of it in subtropical and tropical developing countries, while natural forests could remain for environmental and other non-wood services.
The latter part of the twentieth century saw the beginning of a powerful transition in forestry and in the production of wood for industry: humans are now meeting an increasing (although still small) portion of their industrial wood needs from planted forests, many of them high-yielding. The majority of the natural forests are being left available for other purposes. This transition has yet to run its course. This article develops the concept of an ongoing transition to plantation forestry and examines its implications for timber supply and demand, in particular, and for conservation, the environment and the future of forestry, in general. These issues are examined in light of the dynamic global context, characterized by changes in population, economies and technology.
A pine forest in Zimbabwe - by the middle of the twenty-first century, most of the world's industrial wood will be produced from planted forests
- FAO/20274/G. DIANA
The article predicts that by the middle of the twenty-first century most of the world's industrial wood will be produced from planted forests covering a remarkably small land area, perhaps only 5 to 10 percent of the extent of today's global forest. While some of this area will be in the temperate world, much of it will be in subtropical and tropical developing countries. Most of the current global forest will be retained, to be devoted to non-forest outputs such as the maintenance of wilderness, wildlife and watershed protection and recreation.
More than 4 000 years ago humans began to change the way in which they met their food needs by moving from foraging and hunting to crude cropping and herding and, finally, to modern agricultural cropping and livestock raising. Today this transition in agriculture is largely completed, except in a few parts of the world.
It was only in the latter half of the twentieth century that humans began to make similar changes in forestry: a transition from a primitive mode of gathering forest bounty, which is created solely by nature (old-growth harvesting) to the development of the science of wood production (silviculture) (see Figure). By the middle of the twenty-first century, the transition to tree cropping will be largely completed, and the greatest part of human wood consumption will come from planted forests, most of them intensively managed.
Much of future plantation development will be in subtropical and tropical developing countries; here, nurseries in the Niger, Pakistan and Cambodia
Through tree growing, commercial wood can become a crop, as in agriculture, to be planted, tended and harvested. Tree growing allows for a choice of location and species, as well as providing the opportunity to provide intensive management. It is only with tree planting that investments in tree improvement are justified. Improvements that result in higher yields or desired traits only make sense if those gains can be captured physically and in the market. Under an intensively managed regime, trees can be grown much faster with the desired traits. Climatic conditions for this are particularly favourable in parts of the subtropical and tropical world.
Transitions in forest management and harvests
- Source: Sedjo, 1999b.
The trend towards tree planting will undoubtedly continue. It is driven by two powerful forces: economics and environmental concerns. Promising economic returns on tree planting have been realized in some locations for several decades, especially in advantageous areas of subtropical and tropical South America, Asia and Africa, where biological growth rates are high. In recent decades, large areas of previously unforested land have been converted to planted forests across the globe from the Nordic countries to New Zealand and from South Africa to South America. Although much of the activity has been in the industrial world, many of the most promising opportunities are in developing regions. Many planted forests are on land that was previously in low-productivity agricultural uses. The economic returns on planted forests, especially high-yielding intensively managed forests, are sufficient to continue to induce substantial investments in plantation forestry (Sedjo, 1999a).
The general trend to high-yielding planted forests is receiving additional momentum from environmental concerns which have resulted in prohibitions on harvesting from some old-growth and secondary forests and regulations that make such harvesting more expensive. As the environmental movement continues to exert pressure for the protection and setting aside of more native and natural forest areas, less of this type of forest is available for logging and the costs of obtaining wood from these sources are rising.
New forest practice acts and codes are increasing harvesting costs in natural forests in many countries. For example, Kajanus and Karjalainen (1996) calculate that new forest policies in the Nordic countries, which emphasize the preservation of biodiversity, have increased harvesting costs. Similarly, it is estimated that the recently revised forest practices code in British Columbia, Canada, which deals with roading standards, riparian zones and harvesting practices, has increased the costs of timber harvests in the province by at least 15 percent (Haley, 1996). As harvesting costs have increased, harvests have declined in the coastal mountains of British Columbia.
A dramatic example of the reduction in harvests from national forests is the drop in the United States, from roughly 60 million cubic metres annually in the late 1980s to about 15 million cubic metres today.
Pressures resulting from environmental concerns are likely to be amplified through the impacts of various efforts, such as those of the Forest Stewardship Council (FSC), to audit forest management practices or certify forest products. Although auditing applies to plantation forestry as well as natural forest management, it tends to raise the cost of natural forest management relative to plantation forestry. This is especially true where the planted forests are established on lands that were previously in other uses, e.g. agriculture.
The forces discouraging logging in natural forests are unlikely to go away in the foreseeable future. The pressures to reduce harvesting in old-growth and some second-growth natural forests will add to the attractiveness of the movement to invest in planted forests.
Over the next several decades, the demand for industrial wood will undoubtedly increase, but not dramatically. Since the mid-1980s industrial wood demand has stagnated, with consumption of industrial wood remaining at roughly 1 500 million to 1 600 million cubic metres annually (FAO, 1984-2000). This levelling out can probably be attributed in part to the decline in production within the countries of the former Soviet Union as markets have replaced the earlier command and control economy. Increased recycling is probably another contributing factor.
Since the decades immediately following the Second World War, the increase in wood consumption has been following a downwards trend. This trend towards stabilization has occurred in the face of substantial growth in the world's population and at a time when the global economy as a whole has been experiencing rapid economic growth, particularly in highly populated Asia.
Furthermore, if the latest United Nations (UN) population projections are to be believed, there is a good chance that by the middle of the twenty-first century the population of the planet will stabilize or even begin to decline (UN, 1998). In this context, it is difficult to see the basis for any dramatic acceleration in the rate of growth of industrial wood demand. By 2050, total world industrial wood demand will be higher than it is today, but not very much - perhaps 50 to 75 percent over 50 years (Sohngen, Mendelsohn and Sedjo, 1999).
The predicted transition to planted forests would make the sources of wood supply dramatically different from what they are today. The author estimates that, at present, 22 percent of the world's timber harvest comes from what are essentially old-growth forests, while 34 percent originates in planted forests, and only 10 percent in fast-growing forests, which in 2000 consist of fast-growing exotics (Sedjo, 1999b) (Table 1).
TABLE 1. Current and forecast global harvests, by forest management situation
Forest management situation
% of global industrial wood harvest
Second-growth, minimal management
Indigenous second-growth, managed
Industrial plantations, indigenous
Industrial plantations, fast-growing
Source: for 2000, Sedjo, 1999b (revised to reflect the dramatic demise of Russian timber production); for 2050, author's forecasts.
By contrast, Table 1 forecasts that by 2050 up to 75 percent of industrial wood will come from planted forests, and about 50 percent from fast-growing forests. The fast-growing forests may no longer consist largely of exotics; rapid improvement is being made with certain temperate species, e.g. poplar, so that a large fraction of future fast-growing forests may be made up of improved domestic species. However, in much of the subtropical developing world, exotics are likely to dominate.
Sources of wood supply will be dramatically different from what they are today; in the photo, logs in Brazil
- FAO/15899/G. BIZZARRI
Much of the planted industrial wood would come from high-yielding intensively managed forest operations. In some parts of the world, as is already the case in certain areas of the United States and Canada today, these operations may be called "fibre farms" and may operate on rotations as short as five to six years. However, most of the increased plantation output is likely to come from the newly created planted forests of the subtropics. Globally, fast-growing planted forests will encompass an area of perhaps 200 million hectares, or only about 6 to 7 percent of the world's currently forested area. Extensively managed natural forests that meet the auditing standards are likely to continue to provide a portion of the world's industrial wood, but largely for speciality products.
Such changes have profound environmental implications. The far more rapid growth associated with intensive management implies that huge volumes of wood will be produced from relatively small areas of land. Thus a trend towards planted forests and tree breeding does not imply, as some erroneously maintain, that vast areas of natural forests are to be replaced with planted forests. Accordingly most of the world's natural forests would remain for other purposes.
Indeed, it has been seen (for example, in the National Forest System of the United States) that increased demands are placed on natural forests for other purposes as the production of industrial wood from these lands declines. Often this change is driven by policy and regulations, but such policies would not be feasible in a world where demand for industrial wood is far outstripping supply.
TABLE 2. Gains from various traditional breeding approaches: loblolly pine
Increase in yield
Orchard mix, open pollination, first-generation
Family block, best mothers
Mass pollination (control for both male and female)
Source: D. Canavera, personal communication.
One of the challenges to industrial forestry is the contention that the world's fibre needs could best be met by substituting wood with annual fibrous plants, such as hemp and bagasse. However, the following factors suggest that the prospects for other plant fibres as alternatives to wood are likely to be small over the next 50 years.
First, using these types of fibre sources involves a number of economic and ecological problems. A major economic problem is that they have a specific peak harvesting period: the crop must then be stored and preserved until it is to be processed, and both of these functions incur cost. By contrast, timber can generally be harvested throughout the year, or at least throughout a larger portion of the year than an annual crop can, so the labour and capital equipment can be used year-round. In addition, wood tends to resist deterioration better than non-woody plants do.
From an environmental perspective, it is difficult to see how an annual crop, planted and harvested every year, can be more benign to the environment than a tree crop harvested only 20 years after planting. An annual crop generates 40 disturbances of the land over a 20-year period, compared with two disturbances for a tree crop. Furthermore, the energy required for annual planting and harvesting, and the greater amounts of other inputs such as fertilizer almost surely make such an approach environmentally inferior to tree plantation (Sedjo and Botkin, 1997).
While the costs of harvesting natural forests are rising because of the effects of both availability and restrictions on current practices, the costs of intensively managed plantations tend to be falling because of new techniques, improved plants and the like. Costs can be lowered in forestry, as they have been in agriculture, through the introduction of appropriate technology.
New technology can reduce unit costs by increasing the yield or the output per unit cost. Similarly, innovation can make possible the same production at reduced costs, again reducing the unit cost.
Lower costs are likely to have two effects. In the short term, return or profitability per unit will rise. Over a longer period, rising profitability is likely to increase production, thereby lowering prices to consumers and eroding some of the increased profitability. The short-term effect increases profitability, while the longer-term effect leads to lower prices for the consumer.
In the context of forestry, where there is a high degree of substitutability between plantation and natural forest wood for most purposes, lowering the costs of plantation forestry also has the effect of providing a financial incentive for the industry to continue its shift away from higher-cost natural forestry.
As already noted, tree improvement has few applications in the absence of planted forests. As planted forests become more common, the actual and potential applications of tree improvement using traditional techniques or biotechnology increase. Table 2 shows the extent to which various breeding approaches have been able to generate increased productivity.
Biotechnology is expected to serve as a useful tool in breeding. Genetic modification will probably usually be applied to superior trees obtained through traditional techniques.
Traits that are of interest to forestry and that are likely to be enhanceable through genetic engineering include herbicide tolerance, flowering control, fibre and lignin content, insect tolerance, disease tolerance, wood density, growth, stem straightness, nutrient uptake, and cold, wet and drought tolerance. Genetic modification of some of these traits, e.g. herbicide tolerance, has already been well developed in agriculture.
The introduction of genetically modified organisms (GMOs) into agriculture, and now forestry, is very controversial because of a host of real or perceived risks to health, safety and the environment. It is difficult to predict the extent to which this issue will ultimately be resolved. However, it should be recognized that, globally, biotechnology need not be an "all or nothing" proposition. As with nuclear power, it may well be that some nations will utilize the technology while others will not. Thus, industrial wood from genetically altered trees could become common in parts of the world while remaining largely absent elsewhere.
The financial incentives for the utilization of biotechnology in forestry appear to be strong. Short rotation periods, which are emphasized in high-yielding plantation forestry (where rotations are typically from six to 30 years), provide an inherent financial advantage. Furthermore, the use of biotechnology, which is currently under development, to improve fibre characteristics and/or reduce lignin extraction costs would reduce processing costs, thereby improving financial returns. To the extent that costs of establishment and/or processing can be reduced or yields can be increased without increasing costs, net benefits can be achieved.
Perhaps the greatest unknown for the future of forestry is the phenomenon of global warming and its possible effects (IPCC, forthcoming). Warming could not only change the global distribution of forests (although probably not greatly by 2050), but could also have an influence on the extent of forest plantations. Should forests be used as major global carbon sinks to mitigate the build-up of carbon in the atmosphere, afforestation of large areas could be undertaken as part of the mitigation process. This activity could receive further impetus should bioenergy be used on a large scale to replace fossil fuels.
Finally, wood materials sequester carbon even as they are utilized, and they have a lower energy (fossil fuel) input in their production than most other materials, e.g. steel, brick or concrete. These advantages could provide additional incentives for the expansion of planted industrial forests.
Over the past 50 years forestry has experienced a notable transition from being a foraging operation to becoming what is increasingly a cropping operation. Although there are no really reliable estimates, a rough conjecture is that almost one-third of the world's timber is harvested from planted forests (Table 1). Much of this timber has been produced through the use of improved seedlings and intensive management.
This trend will undoubtedly continue. Whatever the future of biotechnology, tree improvement through breeding will continue.
A river in Peru that has flooded as a result of heavy rainfall believed to be caused by cyclic warming of coastal waters (El Niño) - global warming is perhaps the greatest unknown for the future of forestry
- FAO/20780/J. SPAULL
While the demand for industrial wood will certainly increase over the next several decades, its growth will be modest, perhaps increasing by 50 percent over the 50-year period. By 2050, about 75 percent of the world's industrial wood could come from intensively managed forest operations, many of them in the subtropical developing world. These operations will involve an area of about 200 million hectares, or about 6 percent of the area currently under forests. The high productivity achieved from the lands dedicated to high-yielding forests will allow large areas of forest land to be dedicated to other purposes, including biodiversity and ecosystem preservation, watershed protection and recreation. A large part of the total forested area of the world will remain much as it is today.
A much larger fraction of the world's forests will be used for non-timber purposes. The issue of tropical deforestation will be largely, but not entirely, a problem of the past. The area of global forest will have stabilized at a level only slightly below the current one. Much of the world's forests will continue to be essentially wild. Large areas of wild forests in Canada, the Russian Federation and parts of the United States will be retained or will have regained their essential wildness.
While much of the developing world is expected to achieve substantial economic growth over the next several decades, some regions may continue to experience only modest economic growth. In these regions pressures to convert forests to other uses will continue. In general, pressures on forests will be greatest where the basic problems of economic development have not been successfully addressed.
The wild card in the forecast is climate change. Globally, warming is likely to expand the area of forest in the long term, but the problems of the transition could be significant. The next 50 years will be the transition phase. Nevertheless, warming could bode both badly and well for forestry and global forests. It would cause a redistribution of natural forests, but the fact that forests sequester carbon, the leading cause of warming, suggests the possibility of future forest programmes to maintain existing forests and to promote the establishment of new forests. Furthermore, the use of wood materials and biofuels to replace fossil fuels could have a prominent role in policy directed to the warming problem.
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