The extent to which wood from forest plantations is accepted in the market is determined by both quantitative and qualitative dimensions. At a very broad level it is feasible to estimate approximate aggregate yields from a given plantation resource base and thus, develop simple wood production forecasts (as was done above and is done regularly in the UK and New Zealand, for example). An equally important but far more difficult proposition however, is to determine the degree to which future plantation production will be substituted for wood from other sources. This is particularly important in countries that have large areas of natural forest, but can also be important in countries where plantations are the major domestic forest resource. For example, Japan has a large domestic plantation resource but still chooses to import a large proportion of its domestic industrial roundwood requirements each year as naturally-grown industrial roundwood from other countries.
This point is exemplified by noting that a predominant strategy in evaluating plantation establishment uses financial criteria as the key decision variable. Under current log price structures, plantation investment models based on internal rate of return (IRR) analysis, have encouraged a weighting in establishment towards short rotation lengths and high-yield, fast-growing, industrial-grade species. For example, around 50% of identified tropical plantations are either eucalyptus or fast-growing pine species. The likely trend, therefore, is that plantation-grown wood will increasingly substitute for small-sized naturally grown wood, in the markets for wood pulp and for the production of composite wood panels. The products least likely to be supplied to great extent by plantations in the future are consequently likely to be slow-growing, high-value "luxury" timbers and large peeler logs used in producing veneer and plywood.
Another issue affecting the role plantations might play in future wood supply concerns their acceptability from an environmental viewpoint. Despite the apparently key role plantations may play in meeting future wood demands, plantation programmes have been increasingly surrounded by controversy. A number of criticisms have been levelled at plantations, the prominently that they: promote the loss of biodiversity; degrade soils and reduce soil fertility; deplete groundwater reserves; are susceptible to catastrophic loss through pests or disease; and destabilise the often fragile social fabric of rural communities, by reducing the amount of land available to the poorest sections of society.
Examples can be found of all these faults. Equally, in almost every instance the major difficulties can be overcome or countered through careful planning. Biodiversity (if it is lost) can be promoted through mixed species planting and silviculture that promotes the development of understorey species; soil degradation can be avoided by better land preparation techniques; pest risks can be reduced by targeted research and development; social problems can be ameliorated by careful consideration of community-based issues in project planning. The key to ensuring the future acceptability of forest plantation establishment, is to ensure that they are established within the broad context of sustainability.
The future potential supply of industrial roundwood from forest plantations will depend upon a number of factors. The most crucial factor will be the rate at which new planting is sustained, although improvements in fields such as plant breeding, silvicultural techniques, plant survival and harvesting techniques, are all likely to contribute to greater productivity. This analysis has assumed that the latter variables will all remain unchanged and has concentrated on producing three future scenarios for new planting, in order to forecast potential industrial roundwood supply from forest plantations through to the year 2050.
Scenario 1 provides a baseline forecast, by assuming that forest plantations are not expanded beyond their current area and that all areas are replanted after harvesting.
Scenario 2 assumes that new planting will increase the forest plantation area at a constant rate of 1.2 million ha per annum in total (equal to 1% of the current area of forest plantations).
Scenario 3 assumes that the annual rate of new planting estimated in 1995 (4.71 million ha in total) is maintained until the year 2010, after which it is reduced by 940,000 ha at the start of each of the following decades (i.e. until it declines to zero in 2050).
All three of these scenarios assume that the geographical distribution of the global forest plantation estate will not change (in other words, that any new planting will take place in proportion to the current share of forest plantations located in each country). However, the age-class structure (and hence the annual volume harvested) in each country will change over time, in response to harvesting, replanting and new planting. The implications of these scenarios, in terms of plantation establishment by region and for the countries with most forest plantations, are shown in Table 21.
Table 21: Industrial forest plantation areas in 2050 under three new planting scenarios
Country or region |
Scenario 1 (million ha) |
Scenario 2 (million ha) |
Scenario 3 (million ha) |
Africa |
3.6 |
5.6 |
8.9 |
Asia |
41.8 |
64.8 |
119.5 |
China |
17.5 |
27.1 |
68.3 |
India |
4.1 |
6.4 |
11.7 |
Japan |
10.7 |
16.6 |
12.4 |
Oceania |
2.7 |
4.2 |
5.7 |
Europe |
8.7 |
13.5 |
15.3 |
Former-USSR |
22.2 |
34.4 |
28.0 |
Russian Federation |
17.1 |
26.5 |
21.1 |
North and Central America |
18.9 |
29.3 |
43.2 |
United States |
18.4 |
28.5 |
41.2 |
South America |
5.4 |
8.4 |
13.6 |
World |
103.3 |
160.2 |
234.2 |
Source: Brown (1999).
Scenario 2 is notable for requiring only relatively modest, and seemingly plausible, increases in plantation areas (+55%). For example, the 27.1 million ha proposed for China in 2050 under Scenario 2 is markedly less than the 40.4 million ha currently planned in China to 2050. Plantation development is, however, unlikely to be uniform across countries. Countries such as Chile and New Zealand have, for example, achieved isolated increases in plantation areas of 5% to 10% in a single year. Other countries have gone for extended periods with little or no plantation establishment. South Africa, for example, is not encouraging further afforestation because of water scarcity. Conversely, Australia has targeted the development of a 3 million-hectare plantation estate (a trebling of the current estate) by 2020.
The areas implicit in Scenario 3 also seem to be generally achievable in physical terms. Institutional and policy constraints may, however, play a highly significant role in limiting planting below the indicated levels. Two notable cases are China and the United States, both of which would be required to maintain rates of plantation establishment higher (or for longer) than seems likely at present. Some of this "excess" planting could, however, be spread across other countries without markedly affecting the results of Scenario 3. It is believed that these three scenarios cover the most pessimistic and optimistic likely futures for global rates of forest plantation establishment and their impacts on future potential wood supply from plantations will be discussed at the end of this section.
Increases in the demand for wood products are often simplistically portrayed as leading directly to increases in forest harvesting. While this may be true in a number of countries, it overlooks the wide mixture of land-based and non-land-based resources which are currently used to meet wood and fibre demands. One such non-forest resource is trees outside of forests. As more information is collected about this resource, the important role that trees outside of forests play in current wood supply and the potential they have for increasing supplies in the future is gaining increasing recognition.
Trees outside of forests play important economic, social and environmental roles and nowhere are these roles more critical than in developing countries. They act as the primary source of industrial roundwood, wood fuel and non-wood forest products in many countries, they often perform vital environmental function such as soil and water conservation and they can provide multiple social benefits to both rural and urban populations.
This section describes what the resource encompasses, presents information about the extent of the resource in some countries and discusses some of the key issues related to the potential wood supply from the resource.
By definition, trees outside of forests include all areas of trees and woody crops not identified as forests. However, although there is a commonly accepted international definition of forests, there is not yet a definition of what should be counted as trees outside of forests. Therefore, definitions vary widely between countries, which makes it difficult to estimate and analyse the extent of this resource at the global scale20.
Trees outside of forests undoubtedly encompasses a wide variety of situations, from individual trees to areas of woodland considered too small to count as forest under the agreed international definition. This analysis has not attempted to clarify exactly what trees outside of forests should include. Rather, the analysis has accepted that definitions vary and has included the wide range of resource types identified as trees outside of forests in various countries, including: agricultural tree crops; agro-forestry plantations; individual trees on agricultural and other land trees; home gardens; roadside trees; wood-lots; and other wooded land.
Information about the area of trees outside of forests is not collected globally, so it is difficult to get an idea of the total global extent of the resource. Furthermore, because of the diversity of the resource, any statistics which are available are only likely to be partial. However, there are some statistics on certain types of trees outside forests and a few countries (particularly where the resource is significant) have detailed statistics which give an idea of the diversity and importance of the resource in particular circumstances.
Table 22: Forest, other wooded land and agricultural tree crop area
Region |
Forest area (1,000 ha) |
Other wooded land (1,000 ha) |
Area of agricultural tree crops harvested in 1998 (1,000 ha) |
Africa |
545,085 |
591,591 |
5,150 |
Asia |
497,359 |
162,911 |
19,813 |
Oceania |
71,467 |
106,336 |
616 |
Europe |
904,253 |
212,220 |
0 |
North America |
456,737 |
292,552 |
0 |
Latin America & Caribbean |
967,469 |
292,249 |
1,282 |
World |
3,443,370 |
1,658,859 |
26,861 |
Note: Agricultural tree crops defined as including: oil palm; rubber; and coconuts. Other significant agricultural tree crops include fruit and nut trees, but these are not included here.
Two components of the trees outside of forests resource about which global statistics are available are other wooded land and agricultural tree crops. Table 22 summarises the areas of these two resources. As the table indicates, the area of these two resources is, in some cases, significant. For example, Africa has a greater area of other wooded land than it does of forest. Overall, the global area of other wooded land is about half the area of forest.
The area of agricultural tree crops shown in the table is less significant. In total, the area of agricultural tree crops is only equal to about 1% of the area of forests, but in some regions they are relatively more important (e.g. Asia, where the area equals roughly 4% of the area of forests in the region). However, it should be noted that the area of agricultural tree crops shown in the table does not include the area of fruit trees in each region. These are known to total several million hectares in Asia and may equal several hundred thousand hectares in each of the other regions. Furthermore, the table shows the area harvested and does not include the area of immature crops not yet ready for harvesting in each region. Recent work in the APFSOS showed that if fruit trees and immature crops were also to be counted, the area of agricultural tree crops in Asia could equal the area of forest plantations.
Table 23: Area of forest and trees from homesteads contributing to wood supply in Bangladesh
Year |
Forest area (1,000 ha) |
Area of trees outside of forests from homesteads (1,000 ha) |
Total area used for wood supply (1,000 ha) |
Share of productive area from homesteads (%) |
1966 |
719 |
360 |
1,079 |
33 |
1970 |
532 |
360 |
892 |
40 |
1975 |
214 |
400 |
614 |
65 |
1976 |
217 |
360 |
577 |
62 |
1977 |
290 |
360 |
650 |
55 |
Since 1980 |
60 |
Sources: FAO (1981)
Most of the countries where statistics about trees outside of forests are readily available are in South Asia, where the resource contributes significantly to wood supply. For example, Table 23 shows the contribution of homesteads (i.e. small farm woodlots) to wood supply in Bangladesh. With the gradual loss of forest cover experienced in Bangladesh since the 1960's, homesteads have increased in prominence in the country's wood supply and now provide approximately 60% of the total wood supply. Other examples of the contribution of this resource to wood supplies are given at the end of this section.
In order to estimate the potential for wood supplies from trees outside of forests, it is necessary to have information about both the area of the resource and the level of stocking or growth of utilisable wood. As noted above, only partial information is available about area and, unfortunately, even less is known about stocking and the growth potential of trees outside of forests. Furthermore, as with forest plantations, the social and economic conditions which lead owners of the resource to turn potential yields into actual timber supply have to be better understood before forecasts can be made. However, from experiences gained in the APFSOS, it is possible to make some general statements about the nature of wood supplies from the resource and these are summarised below.
Ownership. In contrast to much of the worlds forest resources, trees outside forests are largely in the hands of private owners and, to some extent, outside the control and regulation of forestry authorities. Therefore, the supply of wood from trees outside of forests is likely to be more strongly influenced by social and economic factors and less influenced by forestry policy decisions than is, say, supply from natural forests and plantations.
Motivation to use for commercial wood supply. Following on from the above, experience suggests that in many countries at the moment, trees outside of forests are seen by large commercial wood producers as a resource to be used as a last resort, when forests have been depleted or placed under harvesting restrictions. This is largely as a result of pricing policies, where it is often cheaper to access forest resources (particularly if they are controlled by the government) rather than purchase wood from smallholders, farmers and others, at something closer to a competitive market price.
Motivation to plant. Similarly to the point raised above, trees outside of forests are often initially planted by individuals to provide a wide range of goods and services, when natural forests have been depleted in the areas in which they live. However, systems of land tenure can complicate the picture (for example, in some countries, areas of natural forest are cleared and planted with crops and trees to establish a right to use the area). There are also now some schemes (e.g. outgrower schemes in India) whereby commercial forestry interests are paying farmers and other landowners to plant trees to secure future wood supplies. Planting for multi-purpose benefits is a prominent feature of trees outside of forests in both developed and developing countries.
Potential yields. Although areas containing trees outside of forests often have low stocking (a few trees per hectare), the lack of competition and the fact that these areas of land are often more fertile (and may be improved with additional nutrient inputs) can lead to very high yields. Thus, for example, one hectare of agricultural land containing 5% tree cover growing at 20 m3/ha/year, can sustainably supply the same amount of wood as a natural forest with 100% stocking but only growing at 1 m3/ha/year. High yields are often also common because, due to the fact that much of the resource is privately owned, the resource is often well managed and maintained.
Management for multiple-use benefits. Given that trees outside of forests are often managed as part of an agricultural enterprise and for a range of expected benefits, decisions to cut them for timber supply can be influenced by a range of factors other than wood prices. For example, in many developed and developing countries around the world, farm woodlots are managed as a store of value and are only cut to cover large irregular expenses. Woodlot owners in Asia appear to have started to take greater interest in the commercial timber value of their timber resources and manage them for timber production. However, it may be more difficult to persuade such owners to supply timber in Africa, where the non-timber benefits of trees (e.g. food security) generally vastly outweigh their potential commercial value.
Many of the points raised above have interesting implications both for the future for wood supplies and the achievement of other policy objectives, such as the development of small and medium-sized enterprises, alleviation of rural poverty and sustainable development. These will be discussed in the concluding chapter of this report.
The concept of Sustainable Forest Management (SFM) has increased in prominence in the public policy debate about forest management over the last decade. Policymakers are slowly reaching a consensus as to what the concept means exactly and how it can be implemented and the implementation of SFM could have a significant impact on future wood supplies.
SFM is primarily a systematic approach to sustaining each component of the forest ecosystem and sustaining interactions between the components. In natural forests, this usually means combining wood production with other management objectives and, above all, maintaining ecological capacity through the conservation of plant and animal biological diversity and soil and water conservation.
Similar intentions are not specified as clearly in the classic management concept of sustained yield. It is now, however, generally agreed that forest management must systematically address a fuller range of environmental, social and economic issues. Box 5 presents a summary of major differences in management approaches between the two concepts of SFM and traditional sustained yield forestry.
Measures to encourage the implementation of SFM have started to be introduced at the international and national level. At the international level, several groupings of countries are working on mechanisms to measure and report criteria and indicators for SFM. At the national level, countries are revising legislation and introducing policies such as new codes of forest practice to incorporate wider objectives, such as those outlined in Box 5, into forest management. The extent to which SFM is implemented will primarily depend upon the cost of such measures and the extent to which forestry administrations monitor and enforce compliance with the policies to encourage SFM they are currently introducing.
Box 5: Typical contrasts between Sustainable Forest Management and sustained yield
Sustainable Forest Management |
Sustained yield forestry |
Maintain the productivity of the forest, by avoiding erosion, soil degradation, and impoverishment of the soil ecosystem. |
Emphasises productivity but tends to use intensive techniques to replant or to use the least cost regeneration technique. |
Use practices that mimic natural disturbances to the extent that is feasible. |
No emphasis on the mimicking of natural disturbances. Aesthetic impacts are considered, as well as the silvicultural characteristics of species and economic considerations. Where feasible, stands of low value species tend to be converted to high valued species. |
Seek harvesting methods that reduce the level of disturbance in the forest. This has primarily meant that the size of clear-cut areas is being reduced and partial harvesting systems are being used more widely. |
Increasing utilisation and reducing costs are the primary motivations to change harvesting practices. Such motivations often have to be constrained by regulation (e.g. on clear-cut size). |
Maintain wildlife populations and maintain species. |
Maintaining wildlife and non-timber species was generally considered outside the purview of forest managers and applied biologists were primarily concerned about maintaining populations of game species. |
Maintain structural and biological diversity in managed forests. |
The agro-industrial ideal was to have uniform rows of same sized, single species trees. Aesthetic considerations and economic costs were primary constraints. |
Source: Bull, Williams, and Duinker (1996)
20 The exception to this is "other wooded land", for which there is an internationally agreed definition. Other wooded land is not included as forest in international forestry statistics and is, thus, a component of trees outside of forests.
