3.1. Pinus caribaea var. caribaea
3.2. Pinus caribaea var. hondurensis
3.3. Pinus oocarpa
3.4. Pinus patula
3.5. Pinus radiata
Tropical pine species play an especially important role in modern plantation forestry. Several species, mostly originating from the American or Asian tropics and subtropics are now widely cultivated (Appendix 1). Pines enjoy such great popularity because:
In the Southern Hemisphere the Central and North American pines predominate; Pinus patula, P. taeda, P. elliottii, P. caribaea and P. radiata. For example, the first three species are planted in South Africa in summer rainfall zone and their average productivity is 15 m³ ha-¹yr-¹ (Du Toit et al. 1998). P. radiata is widely used in summer-dry climates. Brazil, with its humid summers, largely uses P. caribaea, P. taeda and P. elliottii. Pines in Brazil produce 8-30 m³ ha-¹ yr-¹ on rotations of 20-25 years.
P. caribaea plantations are found throughout the tropics and in some parts of the subtropics: in Africa from Nigeria to South Africa; Latin America from Puerto Rico to Brazil; Asia from Malaysia to India; and in Oceania from New Guinea to Australia (Lamprecht 1990). A MAI of 21-40 m³ ha-¹ yr-¹ can be achieved on suitable sites for up to 13 years of age (National Academy of Sciences 1983), but average growth rates are often lower than the upper figure (Appendix 1, Evans 1992).
Within its native habitat, this variety of P. caribaea has low standing volumes and growth increments. An inventory performed on nearly 7,000 ha in Guatemala found the standing volume was 46.3 m³ ha-¹ (± 26%), with a MAI of 2.6 m³ ha-1 yr-1 (Lamb 1973). Annual increments between 3 and 37 m³ ha-¹ have been measured on plantations in Queensland, Australia. The lower figure indicates that P. caribaea plantations were not justified on all sites. However, on suitable sites between 30° N/S latitude a MAI of between 17.5 and 21 m³ ha-1 yr-1 (under bark) can be expected until the trees are 15 years old (Lamb 1973). In 15 to 20-year-old trees the bark accounts for 20-30% of total stem volume (Lamprecht 1990).
Growth increment and quality yields vary considerably between the two varieties of P. caribaea. In general var hondurensis is faster growing but of poorer quality (Lamprecht 1990, Martin 1971, Lamb 1973, Rollet 1980). Thus the average MAI for Pinus caribaea var hondurensis is between 20 and 50 m³ ha-1 yr-1 compared to 10-20 m³ ha-1 yr-1 for P. caribaea var caribaea (Appendix 1).
In South Africa, this species has average MAIs of 22 m³ ha-1 yr-1 (v. Meyenfeldt et al. 1978); on the best sites it has attained an annual increment of 35-42 m³ ha-1 yr-1 at age 14 years (Lamprecht 1999). In Panama growth rates tend to be slower. Here the MAI fluctuates between 5 and 22 m³ ha-¹ yr-¹ (outside bark) with an average of 11 m³ ha-¹ yr-¹ at age 7-11 years (Gewald 1986).
Table 7 illustrates how the MAI in P. caribaea var hondurensis continues to rise up to 24-25 years of age (Wadsworth 1997).
Table 7: Mean annual volume increment of Pinus caribaea var hondurensis in Trinidad as related to age and site quality
|
Age |
MAI |
| Site
I | |
| 0 |
- |
|
10 | 14 |
| 15 |
17 |
|
20 | 19 |
| 25 |
20 |
|
Site II | |
|
0 | - |
| 12 |
12 |
|
18 | 14 |
| 24 |
16 |
Source: Wadsworth 1997.
The natural range of P. oocarpa extends from 12° N in Nicaragua to 28° N in northwestern Mexico (Lamprecht 1990). In Costa Rica, the mean annual volume increment for a 12 year-old trial stand is 22 m³ ha-¹ yr-¹ (unthinned trial stand); this value can be considered representative of the average yield obtained on P. oocarpa plantations (Lamprecht 1990). Plantation-grown trees have MAIs ranging from 10-40 m³ ha-1 yr-1 (Appendix 1).
Pinus patula is native to Mexico where its range is limited and disjointed. P. patula plantations are concentrated in eastern, central and southern Africa, which together account for over 95% of the total area planted with this species (Lamprecht 1990). Depending on site factors and intermediate treatment, the mean annual volume increments with 30-40 year rotations vary between 8 and 40 m³ ha-¹ yr-¹ (Appendix 1). Examples from a range of countries are given in Table 8.
The possibility of a decline of productivity with successive rotations of this species has been studied in Swaziland and no evidence has been found (see Working Paper FP/2).
Table 8. Examples of the MAI for Pinus patula growing in different countries.
| Country |
Age |
MAI |
Reference |
|
Brazil | |
21-36 | Wormald
(1975) |
| Columbia |
10 | 20
(thinned plots) | Ladrach (1986) |
| South Africa |
| 15-20 |
Lamprecht (1990) |
|
Swaziland | 14 |
20 | Wadsworth
(1997) |
| Tanzania |
25 | 18.2
(heavy thinning) |
Sommer and Dow (1978) |
|
West Bengal, India |
19 | 25.0 |
Sommer and Dow (1978) |
|
33 | 22.2 |
| |
| 38 |
37.1 | |
Pinus radiata naturally occurs only on the Californian coast (35-37°N) and 800 km further south on Guadeloupe Island. For over 80 years it has been grown as large plantations in the temperate Southern Hemisphere countries of Australia, New Zealand, South Africa and Chile (Lamprecht 1990). The MAI over 25 years is often 25-30 m³ ha-1 yr-1 (Lamprecht 1990). However in New Zealand growth rates of up to 50 m³ ha-1 yr-1 having been recorded on the best sites and as low as 11 m³ ha-1 yr-1 on very dry sites (Burdon and Miller 1992). On average New Zealand has higher growth rates than the other major growers of this species, despite the heavier thinning schedules.
