The majority of forest plantations in Africa have been established in South Africa (1.4 million hectares) and in the Mediterranean countries of North Africa. In North Africa the countries with the largest area of forest plantations are: Algeria (0.6 million hectares); Morocco (0.6 million hectares); Tunisia (0.3 million hectares); and Libya (0.2 million hectares). Collectively these countries account for 55 percent of all forest plantations in Africa. Forest plantations are, nonetheless, widely distributed amongst other countries in Africa, with another 16 countries having more than 0.1 million hectares of plantations.
South Africa's plantations largely comprise Pinus, Eucalyptus and Acacia species (particularly: Pinus patula; Pinus elliottii; Pinus radiata; Eucalyptus grandis; and Acacia mearnsii). Other countries in Southern Africa (including: Swaziland; Zimbabwe; and Malawi) have also established significant areas of forest plantations with similar species compositions as South Africa.
The plantations of North Africa tend to be of very slow growing species suited to arid and semi-arid conditions. A considerable amount of planting has been carried out in dune stabilisation projects in an attempt to halt desertification. The Algerian "green dam" project is particularly notable in this regard. Indeed, although very little information is available about this resource, the second largest industrial forest plantation resource in Africa is in Algeria. The predominant species grown in Algeria are, however, very slow growing. The most common species used are Cork oak (Quercus suber) and Aleppo pine (Pinus halepensis). Other common forest plantation species used in North African countries include: Pinus halepensis; Pinus brutia; Eucalyptus camaldulensis; Eucalyptus globulus; Eucalyptus gomphocephala; and many species of Acacia.
Africa has the highest proportion (36 percent) of non-industrial plantations to total plantations of all the geographical regions and probably the highest proportion of forest plantations used for wood fuel production. In particular, Sudan, Ethiopia and Rwanda, are countries with relatively large areas of forest plantations used for wood fuel, which are mostly planted with Eucalyptus or Acacia species.
Several special purpose species are also grown extensively in African plantations. Cork oak (Quercus suber) is widely planted in Algeria; Acacia senegal (a source of gum arabic) is grown in plantations in Sudan, Senegal and several other Sahelian countries; and Acacia mearnsii (wattle) is grown for its bark in South Africa, Zimbabwe and Swaziland.
The estimated industrial forest plantation age-class structure in Africa in 1995 is shown in Figure 8. As this figure shows, the structure of age-classes in industrial forest plantations in Africa contains slightly larger areas in younger age classes, reflecting increases in planting rates in recent years. However, the proportion of younger industrial forest plantations is not as great as in Asia. In the older age classes, South Africa accounts for the largest share of industrial forest plantations. In fact, 79 percent of all industrial forest plantations over 30 years old are in South Africa.
The most comprehensive information about forest plantations at a regional level can be found in Oceania. Australia and New Zealand account for 95 percent of forest plantations in the region, having areas of 1 million hectares and 1.5 million hectares respectively. Both of these countries have recently produced comprehensive inventories of their forest plantations, giving numerous details of their plantation forest resources. The other country in the region with a significant area of forest plantations is Fiji, with 0.1 million hectares of forest plantations.
The main species used in forest plantations in Oceania is Pinus radiata, which accounts for 91 percent of the forest plantation area in New Zealand and 62 percent in Australia. Other pine species, most notably Pinus caribaea in Fiji and Pinus caribaea and Pinus oocarpa in Northern Australia, account for most of the rest of the forest plantation area that is planted with softwoods. Eucalyptus is the most common hardwood planted in forest plantations in the region and is found mostly in Australia. However, Fiji also has significant areas of forest plantations containing Mahogany (Swietenia macrophylla) and Teak (Tectona grandis).
Sources: New Zealand Ministry of Forestry; Australian National Forest Inventory; and Author.
The estimated industrial forest plantation age-class structure in Oceania in 1995 is shown in Figure 9. The age-class structure is more balanced than in most of the other regions, due to an early recognition of the role that forest plantations could make in meeting the region's demand for wood. Both New Zealand and Australia began establishing forest plantations before 1930 and significant areas are currently reaching maturity or are already into second or third rotations. The predominance of areas under 35 years old in the region reflect the rotation ages typically used in forest plantations in the region (i.e. a significant proportion of these areas are replanted areas rather than areas of new planting). New Zealand, Australia and Fiji all anticipate significant increases in wood production from their industrial forest plantations during the next decade.
The United States of America accounts for nearly all of the forest plantation area in North and Central America, with a total area of 18.4 million hectares.17 Among the other countries in the region, only Cuba (with 0.4 million hectares), Mexico (0.2 million hectares) and Costa Rica (0.1 million hectares) have significant areas of forest plantations.
The bulk of forest plantations in the United States of America (90 percent) are located in the Southeast and South-central regions and around 85 percent of forest plantations in the United States of America are planted with pine species. Loblolly pine (Pinus taeda), Shortleaf pine (Pinus echinata), Longleaf pine (Pinus palustris) and Slash pine (Pinus elliottii) are the most common species found in these forest plantations.
Cuba, Costa Rica and Mexico have all planted a variety of species in their forest plantations. In Cuba, fast-growing pine species (notably Pinus caribaea, Pinus tropicalis and Pinus cubensis) account for 48 percent of the forest plantation area. The main species planted in Costa Rica is Gmelina arborea (accounting for 34 percent of the forest plantation area), although significant areas have also been planted with Teak (Tectona grandis) and alder (Alnus acuminata). In Mexico, pines (including: Pinus patula; Pinus ayacahuite; and Pinus strobus var. chiapensis) account for most of the area of forest plantations planted with softwood species. A wide range of species (including: Eucalyptus; Acacia; and Casuarina species) can be found in the forest plantations planted with hardwoods.
The vast majority of forest plantations in the United States of America and Costa Rica are classified as industrial forest plantations. In contrast, more than 40 percent of forest plantations in Cuba and more than 60 percent in Mexico are classified as non-industrial forest plantations (Pandey 1997).
The estimated industrial forest plantation age-class structure in North and Central America in 1995 is shown in Figure 10. This figure shows that forest plantations in the United States of America dominate the age-class distribution in North and Central America, where about 77 percent of forest plantations are less than 20 years old.
Again, the distribution of areas amongst different age-classes is relatively balanced. In total, nearly all of the forest plantation area in the region is less than 30 years old (reflecting rotation ages used in most of the region) and some of these areas are second or third rotation forest plantations. For example, much of the forest plantation area in Cuba and Mexico was first planted in the mid to late 1950s, although the majority of these areas are now less than 20 years old (i.e. most areas are now into their second rotations). The exception to this is Costa Rica, which reported only 2,700 hectares of forest plantations in 1980 in the 1980 Tropical Forest Resource Assessment (FAO, 1981b). This suggests that the majority of forest plantations in Costa Rica have been established in the past 15 years.
The total estimated area of forest plantations in South America in 1995 is 8.2 million hectares. The following three countries account for 82 percent of this resource: Brazil (with 4.2 million hectares); Chile (1.7 million hectares); and Argentina (0.8 million hectares). However, despite the dominance of these three countries, large areas of forest plantations can also be found across most of the rest of the region, with 8 of the other 13 countries in South America having more than 0.1 million hectares of forest plantations each.
The most common species used in forest plantations in South America are fast-growing Pinus and Eucalyptus species. The total area of forest plantations planted with Eucalyptus is about 3.9 million hectares, closely followed by forest plantations of Pinus species, which account for a further 3.5 million hectares.
Although, for convenience, the whole region has been classified as tropical and subtropical for this study, large areas in the southern part of the region are in the temperate forest zone. The forest plantations in these areas are dominated by pines (most notably Pinus radiata, Pinus elliottii, and Pinus taeda), which account for 49 percent of the forest plantation area in Argentina and 78 percent in Chile. Pines also account for 80 percent of the tropical forest plantation area in Venezuela, where the most common species used is Pinus caribaea.
Eucalyptus species are the most commonly used species in the remainder of the tropical and subtropical zone in South America, accounting for 65 percent of the forest plantation area in Brazil, 90 percent in Peru and 80 percent in Uruguay. Particularly common species include: Eucalyptus globulus; Eucalyptus grandis; Eucalyptus saligna; Eucalyptus urophylla; Eucalyptus deglupta; and the F-1 hybrids of the latter two species, which are used in the tropical parts of Brazil.
It is estimated that industrial forest plantations account for 74 percent of the total forest plantation area in South America, while Brazil, Peru, and Uruguay have the largest non-industrial forest plantation resources.
The estimated industrial forest plantation age-class structure in South America in 1995 is shown in Figure 11. The region is similar to the other tropical and subtropical regions, in that the age-class distribution is dominated by areas in the younger age-classes, reflecting increases in new planting in recent years. The area of forest plantations under 10 years old accounts for 45 percent of the total industrial forest plantation area. An interesting feature of the industrial forest plantation age-class distribution shown in Figure 11 is a small but significant decline in planting rates since 1990, particularly in the four countries with the largest forest plantation resources. It is most likely that this is a result of recent reductions in various plantation incentive schemes in these and other countries in the region.
As noted earlier, many countries in Europe have not previously made the distinction in their national forest inventories between forest plantations and other types of forest. For example, countries have reported forest plantation areas as part of the temperate and boreal component of FRA 2000. However, in many cases, this is the first time that this has been attempted. Consequently, it has been very difficult to collect and collate historical statistics on forest plantation areas.
The main difficulty encountered in this analysis has been to match historical information about areas planted and replanted (from a search of the literature on each country), with the areas of forest plantations reported in the temperate and boreal component of FRA 2000. This is partly because it is suspected that many areas reported as forest plantations in the historical data are now classified as semi-natural under the terms and definitions agreed for FRA 2000. Therefore, it has been necessary to make a number of assumptions in order to resolve discrepancies between the historical planting data and the data reported in FRA 2000. In doing this, it has been assumed that areas recently reported as forest plantations are still reported as forest plantations in FRA 2000, while areas planted some time ago may now be classified as semi-natural forests.
Sweden can be taken as an example of how this has been done. Widespread planting of Pinus contorta in Sweden began in the early-1970s and Sweden now reports around 550,00 hectares of forest containing this species. This number is very close to the 572,000 hectares of forest plantations reported by Sweden in the FRA 2000. Consequently, it has been assumed that most forest plantations in Sweden have been planted with Pinus contorta since 1970 and that earlier recorded areas of forest plantations are now classified as semi-natural forests.
Several countries in Europe do however, classify a high percentage of their forests as forest plantations in FRA 2000. For example, Ireland and Malta classify 100 percent of their forest area as forest plantations. Other countries reporting a high proportion of forest plantations include: Denmark (92 percent of the total forest area); United Kingdom (57 percent); and Belgium (46 percent). In contrast, several European countries with significant forest resources report no forest plantations at all. These countries include: Austria; Finland; Germany; and the Czech Republic.18 These countries are not included in this analysis.
Five countries in Europe account for two-thirds of the area of forest plantations in Europe. Spain has the largest forest plantation area with 1.9 million hectares, followed by the United Kingdom (with 1.4 million hectares), Bulgaria and France (with 1.0 million hectares each) and Portugal (0.8 million hectares).
Spruce, pine and fir species account for the largest share of the forest plantation area in Europe. Forest plantations in Spain and Portugal are dominated by pines (especially Pinus pinaster, Pinus halepensis, Pinus pinea and Pinus radiata) and Eucalyptus species. The United Kingdom has a high proportion of forest plantations planted with Sitka spruce (Picea sitchensis) and Douglas fir (Pseudotsuga menziesii). In France, the most common species used in forest plantations are Populus species, Norway spruce (Picea abies) and Douglas fir (Pseudotsuga menziesii).
The estimated industrial forest plantation age-class structure in Europe in 1995 is shown in Figure 12. As the figure shows, the distribution of forest plantation area across age-classes is quite balanced in Europe, with significant proportions of the forest plantation area between 30 and 50 years old and over 50 years old. Of the five countries with the largest forest plantation areas, France has the greatest proportion in older age-classes. Age classes in the United Kingdom are fairly evenly distributed, while forest plantations in Spain, Portugal and Bulgaria tend to have a relatively high proportion of younger aged forest plantations.
The 15 countries of the former USSR have also been included in the temperate and boreal component of FRA 2000 and all have reported that they have some areas of forest plantations. The Russian Federation accounts for the largest share of forest plantations in this region (with 17.3 million hectares), but only 2 percent of forests in the Russian Federation are classified as forest plantations. The Ukraine accounts for the next largest share in the region, with 47 percent of the total forest area classified as forest plantation. Belarus, Estonia, Latvia and Lithuania have much smaller, though still significant, areas of forest plantations. Although the other countries of the former USSR all report having small areas of forest plantations, very little information is available about forest plantations in these countries, so they have been excluded from the analysis.
Very little information is also available about the species composition of forest plantations in this region. Pandey (1995) reported the following species composition for forest plantations in the USSR in 1988: pines - about 52%; spruce - 24%; oak - 6%; and cedar - 1%. It is unlikely that this species distribution has changed significantly since 1988.
Information about the age structure of forest plantations in the Russian Federation is available in the State Forest Account and much of this information has been made accessible through forestry research projects carried-out at the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria. For example, a time-series showing the accumulated area of forest plantations is given in Shvidenko and Nilsson (1997) and, from this, an approximate age-class structure for forest plantations in the Russian Federation can be derived. Shvidenko and Nilsson note that, between 1961 and 1993, significant efforts were made to establish forest plantations in the Russian Federation, but also that survival rates were typically only 55 to 60 percent.
Figure 13 shows the estimated industrial forest plantation age-class structure in countries of the former USSR in 1995. A significant proportion (56 percent) of the area of forest plantations in the Russian Federation was planted before 1973 and is consequently now over 25 years old. Afforestation efforts slowed markedly after 1988 and, given the dramatic fall in roundwood production in the Russian Federation that has occurred since 1992, it seems reasonable to assume that the rate of forest plantation establishment during the period 1990 to 1995 has been negligible. A similar pattern in forest plantation establishment can be seen in the Ukraine, where large-scale afforestation and forest regeneration efforts took place throughout the 1960s, but have subsequently been reduced, particularly after 1980.
In many countries, forestry policy has encouraged the development of forest plantations for roundwood supply. In some cases, this has been done to meet rising demand where existing supplies from the natural forest are very low (e.g., forest plantations for wood fuel production in India). In others, forest plantations have been seen as an important supplement to supplies from natural forests (e.g. Indonesia) or even as a complete substitute to them (e.g. New Zealand). Given this trend, the following questions are becoming increasingly important for the analysis of such policies:
· what role are forest plantations currently playing in regional and global roundwood supply;
· what is the future potential supply of roundwood from forest plantations;
· what are the ecological impacts of forest plantations and how sustainable is this model of forestry development in the long run; and
· what are the effects of forest plantations on forest values as a whole?
In attempting to shed some light on the former two questions, four variables are of fundamental importance: the current and future likely area of forest plantations; the species used in forest plantations; the age-class distribution in forest plantations; and the growth or mean annual increment that can be expected in forest plantations. A number of additional factors are also important, such as: the rotation lengths and silvicultural regimes used in forest plantations; tree mortality; the potential for genetic improvements to increase yields; and the overall quality of management in forest plantations, but these factors are largely subsidiary to the main variables of forest plantation area and yield.
Previous sections have discussed the species composition, areas and age-class distributions currently found in forest plantations around the world. This section examines the last of the important variables identified above, namely the yields (and, associated with this, the rotation lengths) typically achieved in forest plantations.
In order to model future potential roundwood production from forest plantations, it is necessary to have information about average forest plantation yields that might typically be achieved under normal operational conditions. Unfortunately, such information is both scarce and often imprecise.
A vast amount of literature is available about the yields of different species achieved in forest plantation research trials and experiments. However, it is likely that the yields obtained in forest plantations managed on a commercial scale will vary considerably from these results, due to variations in land quality and the quality of establishment and silviculture. It is also likely that, overall, commercial operations will achieve generally lower yields than those reported in the research literature, because the quality of establishment and silviculture is likely to be lower in commercial operations.
Assessing the yields that might be obtained under normal operating conditions is crucial, because a small variation in yield can have a major impact on final harvest volumes. For example, if research results suggest that a species will grow at 7 m3/ha/ year, but only 5 m3/ha/ year is achieved in commercial operations, using the former figure would overestimate final harvesting volume by 40 percent. Thus, at an aggregate level, it is important to avoid overestimating likely potential roundwood yields (on the basis of research results), which could result in biased forecasts of total future potential roundwood production.
A database of forest plantation yields by species and country is currently being constructed by FAO. The database mainly focuses on tropical countries and is being developed in a stepwise process, utilising data collected from literature searches, field visits, expert opinion and review and, finally, refinement and validation of the yield estimates by national experts. Because of the lack of statistical surveys of plantation yields at the national level, this process relies heavily on expert opinion and judgement. However, it is believed that this approach will result in estimates that are reasonably accurate, robust and reliable even if they are not particularly precise.
The projections of future potential roundwood production from forest plantations (given in Section 3 below) are based on the ranges of estimated average yield shown in Table 6 and Table 7 below. In general, these tables contain estimates that are believed to be at the lower end of the range of yields that might be achieved in the future. For example, in the projections of future potential roundwood production from forest plantations in Brazil, yields of between 16 m3/ha/year and 25 m3/ha/year have been used for Eucalyptus species. However, the Associação Brasileira de Celulose e Papel (1999) estimates that the average yield of Eucalyptus species in forest plantations in Brazil is already 45 m3/ha/year. This difference reveals a number of problems that arise when estimating average yields, such as: changes in yields between earlier and later surveys; the breadth of surveys on which yield estimates are based; and the question of whether data are derived from research plots or field surveys of commercial operations. By taking the lower end of the range of future potential roundwood production from forest plantations, it is believed that the results of the modelling exercise reported in Section 3 below are unlikely to overestimate future potential roundwood production from forest plantations.
17 In the information provided for the temperate and boreal component of the FRA2000, none of the forest area in Canada is classified as forest plantations. Consequently, Canada is not included in this analysis. However, under alternative definitions of forest plantations, up to 6.8 million hectares in Canada has been classified as forest plantation. For example, the Canadian Forest Service (1998) reports that 5.86 million hectares of forest was directly planted or seeded between 1981 and 1995.
18 In the temperate and boreal component of FRA 2000, the following clause has been added to the general terms and definitions of forest plantations used for all other countries:
"excludes: stands which were established as plantations but which have been without intensive management for a significant period of time. These should be considered semi-natural."
Presumably, significant areas of forest in these countries are considered to fall into this category and are, thus, not considered to be forest plantations.