The management and prospects of teak in Vietnam - Ministry of Forestry

Forest Science Sub-Institute of Southern Vietnam

Ministry of Forestry

One of the oldest teak plantation in the country. Dong Nai Province, southern Vietnam.

ABSTRACT

Teak was introduced in Vietnam by the French at the turn of the century - largely in parks and along road sides. Southern regions were more suitable and small-scale plantings were made from 1952; these suffered losses (50%) from war and land trespass. Post-war efforts have established some 2,000 ha of teak plantations, of which 5% is now over 30 years age. Establishment is by the taungya system with food crops: rice, maize, green bean, and soya bean. Growth is variable on different soils (MAI 4.0-11.5 m³/ha). Thinning occurs in the 10th year with removal of diseased and poorly formed trees; a rotation of 40-50 years is planned for high value products. Teak improvement is in operation; 100 ha of the best teak has been converted to a seed stand and 10 ha of grafted seed orchard have been established. Marketing is not well developed due to the small size of the planting area and of the trees; small end diameter thinnings are sold locally (US$150-180/m³). Investment funds are limited; teak planting is not attractive to private investment due to the lengthy return period. Government policy aims to establish 15,000 ha of teak plantation, financed by national funds, by the year 2000.

Key words: Tectona grandis, Vietnam, plantations, taungya, improvement.

HISTORY

Teak (Tectona grandis) was introduced into Vietnam by French foresters in both the northern and southern regions in the first years of the twentieth century. It was planted along roads and in public parks around French buildings. In the 1960s, some forestry enterprises in northern Vietnam collected seed from the first introductions for planting in some tens of hectares. However, because of the lack of teak silvicultural knowledge, and as the growth rate and quality of the plantings were evidently lower than different indigenous species, teak plantations have not increased in the north to date.

As the climatic and edaphic conditions in the south (based on the first trials) are more suitable for teak, it was planted on a small scale from 1952. By the 1960s there were nearly 300 ha of plantations, concentrated in Dong Nai and Songbe Provinces. However, more than half of the teak areas were destroyed by warfare and land encroachment for food crops by local people. Along with the post-war afforestation policy established in 1976, the Vietnamese Government has achieved more than 2,000 ha of teak plantations, concentrated in the eastern, southern, and highland regions.

CONDITION AND MANAGEMENT OF TEAK RESOURCES

Vietnam does not have any natural teak forests; thus, all teak resources originate from man-made forests. The current area of teak plantations is shown in Table 1 by age class.

Growth rate and quality of teak plantations

The growth rate and quality of teak trees greatly differs according to the soil types and other associated characteristics. The main soil types in teak plantations are: 1) basaltic soil originating from volcanic rocks, which is very fertile and moist with good drainage; 2) ancient alluvial soil, which is deep and has sandy loam structure, usually being covered by shrubby trees and grasses; and 3) ferralitic soil, which is thin, of low fertility, has poor drainage, and is severely affected by drought in the dry season. Using these characteristics, the soils are classified as good, medium and poor sites for teak planting respectively. The growth rate on these three types of sites are shown in Table 2.

Table 1. Teak plantation areas by age classes in Vietnam

Table 2. Average annual growth rate over 20 years in above soil types

Note: MAI = mean annual increment; DBH = diameter breast height; * = over bark.

On good and medium soil, the average ratio of healthy and well formed trees comprises 60-65% in plantations. On poor soil, the average ratio of badly formed and crooked trees rises to over 60%.

MANAGEMENT OF TEAK PLANTATIONS

Until recently, little attention was paid to teak plantings due to the following:

• Teak plantations were only successful in limited areas of some provinces in the eastern, southern and highland regions.

• Wood of indigenous species of the natural forest was preferred to teak.

• Local forestry enterprises preferred planting pulp wood species with short rotations to achieve early cash returns.

• Lack of knowledge about the processing and utilisation of teak wood and of its price on the international market.

Teak plantations on good and medium soil categories are established by the agro-forestry method.

As a consequence, they are well looked after for many years after planting, and forest fires rarely happen. On good soils teak is raised with crops such as green bean, soya bean, maize, dry land rice, etc., until the seventh year; on medium soils teak is planted more closely so that intercropping is possible only up to the third year. Due to the lack of funds, and as there is no market for small, thin logs, thinning operations tend to be delayed in both sites until the tenth year. In thinning operations, poor growing, badly formed and diseased trees are felled. It is considered that 2-3 thinnings would be needed until the final cut after 40-50 years. Produce is expected to be utilised in high value end products, quality furniture, and housing decorations.

Teak plantations on poor soil are treated in two different ways. First, plantations that have less risks of forest fires and less conflicts with local people can get more funds for protection and tending. Though the cutting rotations will become longer, the plantations are expected to supply high value produce. Second, plantations that are under a high human population pressure and are subjected to frequent bush fires and land trespass, as well as poor growth, are to be replaced with other tree species.

Thinning schedules

Thinning schedules have been prepared for large-scale plantations. Their operational guidelines are shown in Table 3.

Table 3. Trees remaining after thinnings on three site categories

* Site soil category

Difficulties in the management of teak resource development

After the First Regional Seminar on teak, held in China in 1991, the Ministry of Forestry became interested in developing teak. It planned that 10-15,000 ha of teak plantations would be established by the year 2000. These plantations would be established on suitable sites, mainly in the eastern, southern, and highland provinces, in larger blocks for producing industrial materials. Important preparations that have been already carried out in this programme include:

• The setting-up of seed orchards by selecting 100 ha of the best teak plantations established in 1962.

• The setting-up of 10 ha, plus tree seed orchards, by grafting the genetically superior stocks found in local plantations.

• Some silvicultural techniques have been developed for site determination, stump planting, and tending and thinning skills.

The major difficulty, however, still remains in the current deficiency of investment capital. This restricts the raising, tending and protection of teak plantations, especially under the new large-scale planting programme.

Established plantations require two tending treatments a year until the end of the third year. After that, on good and some medium sites, depending on the agricultural crops planted under the teak, some additional tending may be needed for a few more years until its canopy closes. As farmers are more concerned with the food crops, a part of teak trees is destroyed - on an average 20%. Teak plantations on poor and medium soil quality sites, which are too far for villagers to cultivate food crops, face another problem. Tending is carried out only for the first three years. Natural grasses develop vigorously in the rainy season, but die off in the dry season. This causes forest fires which can destroy the teak plantation, or cause seriously malforming stems and slow growth.

TRADE AND MARKETING

The teak plantations in Vietnam are still small in area and young in age. None of them have reached their rotation age yet. Therefore, trading information on teak is not an urgent requirement. However, as the valuable wood resources in the country’s natural forests have been nearly exhausted, and also as the Ministry of Forestry restricts its harvest, small diameter teak logs produced from thinnings sell in the local market at an acceptable price of US$150-180/m³. These logs are used for housing, decorative goods, and high grade furniture in major cities.

IMPORTANT SUBJECTS FOR THE DEVELOPMENT OF TEAK RESOURCES

Improvement of national forestry policies

Plantation teak wood is of lower value compared with some prized indigenous species. However, as its growth rate is much higher than that of these high quality indigenous species, the Ministry of Forestry is promoting its development in large-scale plantations. Since its rotation period is longer than that of fast-growing species such as eucalypts and acacias (mainly used for paper-making), this makes private investors prefer planting these species to teak. Under these circumstances, teak is only planted by the Government sector, financed by national funds. In order to motivate the active participation of the private sector in teak plantations, the Government will further improve land, tax, and relevant funding policies, besides technical development. At the same time, the Government has to address how to minimize problems of forest fires, pests and diseases, and declining soil fertility in forest plantations through appropriate policy measures.

Policy measures cannot produce a maximum result unless they are well combined with research and technology development efforts. The following address some research and technological aspects to lead the current re-afforestation plan to the year 2000 to a great success.

Research of teak processing

The felling volumes from thinnings and final cuts in teak plantations will steadily increase in Vietnam as teak plantation resources grow bigger in the re-afforestation plan to the year 2000, at the annual rate of 3,500 ha. Teak processing technologies, especially for the effective use of small diameter teak wood, are needed

Improvement of silvicultural techniques

Current considerations on silvicultural and utilisation techniques include: 1) genetic improvement of teak seed sources; 2) mapping of suitable teak planting sites; and 3) complete development of technical packages of raising, tending and thinning of teak plantations.

In Vietnam now, the genetic improvement of teak seed sources relies on the existing plantations. However, it is most likely that the genetic basis is quite narrow and maybe very poor. If this is true, it would not only be difficult, but impossible to improve growth rates and tree quality from such poor genetic resources. Thus, genetic improvement work on Vietnamese teak becomes one of the top priority subjects. Important components of this programme will be: provenance trials from the best exotic sources and their comparison with local seed sources under different environments in southern Vietnam; and the establishment of seed orchards and development of micro-propagation techniques (cuttings, tissue culture) to supply improved planting materials as soon as possible.

The second subject is related to land use, soil nutrients, climate, infrastructure, processing and marketing facilities, etc. This covers a wide range of natural sciences as well as socio-economic subjects. More integrated information should be collected and analysed for this purpose. The third subject can be achieved when all these information are well consolidated in an integrated body.