Forest plantations, which are expanding rapidly in the tropics and sub-tropics will clearly play a very important role in the future world wood supply (see Working Paper FP/paper 13). Currently, eucalypts and pines are the most commonly used species in tropical timber plantations (Evans 1992); together, they account for 43 percent of all tropical plantation area (FAO 1999). Pines dominate temperate and boreal plantations; 54 percent by area (FAO 1999).
Productivity of tropical plantation forests grown on short to medium-term rotation lengths varies greatly from 1-2 m³ ha-¹ yr-¹ to 25-30 m³ ha-¹ yr-¹ (Table 1 and Appendix 1). A similar range is found in temperate countries (Evans 1992, FAO 2000). Higher yields have been reported for some species and situations. However, while the potential for achieving high productivity is clearly evident, there are many constraints on yield (see Working Papers FP/3 and 15) and perhaps sustainability (see Working Paper FP/2) or environmental concerns.
Table 1. Productivity and rotation lengths for main forest plantation trees in selected tropical countries
| Species |
Region | Country |
Rotation length |
MAI |
| Eucalypts |
S. America | Brazil |
8-10 | 18-20 |
| Africa |
Burundi | 8 |
1-2 | |
|
Congo | 7 |
30 | ||
|
Rwanda | 8 |
8.5 | ||
|
South Africa | 8-10 |
18-20 | ||
|
Pines |
S. America | Brazil |
16-25 | 15-25 |
| Venezuela |
10-20 | 10 | ||
| Chile |
20-30 | 24 | ||
| Africa |
Malawi | 20-25 |
17 | |
|
Madagascar | 15-18 |
6-10 | ||
|
Mozambique | 18-25 |
11 | ||
|
Teak | Asia |
Bangladesh | 60 |
2.6-3 |
|
India | 70 |
2.5 | ||
|
Indonesia | 50-70 |
1.3-2 |
Source: Brown et al 1997.This paper focuses on the main tropical and subtropical forest plantation species. The key measurements discussed are mean annual increment and rotation length. Mean annual increment (MAI) is defined here as the merchantable stand volume at harvesting divided by the stand age (rotation length), although in some instances MAI for pre-harvesting stands are also discussed. Unless otherwise stated these are over-bark log volumes. It should be noted these do not take into account losses during conversion to sawn timber, plywood, pulp etc.
