Part II
COUNTRY BRIEFS (continued)

BURMA (continued)

1.1.2 Present areas

The forest covered area of Burma was determined in 1968 by using serial photographs taken between 1953 and 1962. It was estimated that about 57% of the land area of the country was covered by forest.

The interpretation of the Landsat satellite imagery taken between 1973 and 1979 was carried out to correct and supplement the forest statistics being collected separately. The detail of the Landsat satellite images used is shown in annex 1.

The satellite images cover the whole area of Burma except for small area in the Chin hills near the Indian border.

Interpretation of Landsat images was carried out visually with the help of a light table. The finer details were interpreted using magnifying lens on single images. The combined interpretation of band 5 and of colour composite was used to identify the non-forested areas and to classify the forested areas. With the help of band 7 water bodies could be identified when it was not conspicuous on the other images.

The following six classes were delineated on Landsat images: (1) “closed forest”, (2) “closed forest affected by shifting cultivation”, (3) “degraded forest”, (4) “degraded forest affected by cultivation”, (5) “non-forest” and (6) “water bodies”.

The definition of these terms is given in appendix 1.

The interpreted information was transferred to the base map at 1/1 000 000 scale. The area of each class for each state and division was computed by dot grid counting.

Because of the limitations of visual interpretation of small scale satellite images, only these few forest classes could be directly delineated. Bamboo forests, coniferous and broadleaved forests could not be clearly differentiated and other available information had to be used. Mangrove forests could also be identified with some accurady on the satellite images.

The following table summarizes the results of the interpretation of Landsat imagery. The average date of the images is considered to correspond to end 1976.

Area estimates for whole Burma (end 1976)
(in thousand ha)

The area of classes 1 and 3, amounting to 32 289 000 ha (about 47.7% of the total area of Burma) can be considered as representing the total forest cover of the country including shrub formations. Classes 2 and 4 (17 755 000 ha) are regarded as forest fallow since these forests are mixed with shifting agriculture.

Taking into account present deforestation figures for the whole of Burma (see paragraph 2.1.1) the area figures have been updated to end 1980 and are shown in the following table.

Areas of natural woody vegetation estimated at end 1980
(in thousand ha)

The following remarks are necessary:

• the Landsat class 1 forests (“closed forest”) of bamboo, mangrove and conifer are put under N.f1uv category;

• the Landsat class 3 forests (“degraded forest”) of bamboo, mangrove and conifer are put under N.f1uo category;

• in other broadleaved forest, NHCf1uv includes areas under teak selection working circle only, which have never been girdled. NHCf1uc includes closed forests of mixed species where teak alone is extracted which forms only 10% of the crop. NHCf1m includes forests of mixed species where teak and other commercial species are extracted and are artificially regenerated;

• the areas of closed broadleaved forests unproductive for legal reasons (NHCf2r) is about 299 000 ha. The areas under rules 19,27 and 28 are productive as extraction from these forests is possible with the permission of the Forest Department;

• in certain localities and under certain conditions closed broadleaved forests develop in open formations with a grass layer (NHc/NHO). However the area covered by this category is assumed to be small (ε);

• total area of natural shrub formations has been estimated tentatively at 2.6 million ha;

• N.a are those areas of forests mixed with permanent and shifting agriculture.

The rest of the country is occupied mostly by agriculture, water bodies and villages and towns. Their total extent is estimated approximately at 17 614 000 ha (about 26% of the total area of Burma).

If the area of land covered by forest as interpreted from aerial photographs in the 1950's is compared to the area covered by forests as interpreted from satellite images (Landsat classes 1 and 3) the forest cover percentage appears to have decreased from 57% to 47.7%. However, due to the unavoidable difference in the definition of the concept “forest”, the estimated forest reduction mentioned above cannot be very precise (see section 2.1.1).

Ownership

All forest land in Burma is state owned. Forest administration is shared by the Forest Department and the State Timber Corporation, both of which come under the Ministry of Agriculture and Forests. The Forest Department is directly responsible for the management of all forests. The Forest Department carries out forest conservation works and determines the annual allowable cuts for teak and other hardwoods in consultation with the State Timber Corporation. The State Timber Corporation, which is responsible for the extraction, milling and marketing of timber for both internal consumption and export, plans its operations on information supplied by the Forest Department.

Legal status and management

The forests of Burma are classified as either reserved or unclassed (public) forests. The reserved forests are well defined, legally constituted forests under the complete control of the Forest Department. The proportion of these reserved forests amounts to over 14 percent of the total land area of Burma. Within the reserved forests, no unauthorized felling, grazing or trespassing is permitted by law, except to qualified inhabitants of villages adjacent to the reserves.

The forested land not under reservation is referred to as unclassed forests. Although such forests are state owned, villagers are permitted to cut unreserved species for the purpose of clearing land for cultivation and providing building materials and firewood for domestic use, provided such cutting is within 20 miles of the villager's home.

Charcoal manufacture and firewood cutting for commercial users and practice of shifting cultivation in some areas are regulated under the Burma Forest Act. Within reserved and unclassed forests, a number of species have been classified as reserved trees, and their cutting prohibited except with the permission of the Forest Department. Game Sanctuaries were also established to conserve certain fauna in both unclassed and reserved forests. There are so far 15 game sanctuaries distributed throughout the country extending over 472 800 ha.

The forests in a forest division are managed under a working plan which generally covers three working circles, namely: teak selection working circle (TSWC), commercial supply working circle (CSWC) and local supply working circle (LSWC).

The TSWC includes all teak bearing forests. Teak logs from any part of the forest can be floated downstream. All teak extraction is organised under the working circle. Forests included in the CSWC are those situated close to the main transportation routes such as railway lines, main roads and main rivers. The extraction of all marketable hardwoods other than teak is organised under this working circle. Forests readily accessible to the local population are usually included in the LSWC, the purpose of which is to supply firewood and small timber for local consumption.

In both the TSWC and CSWC, silvicultural practice involves selected harvesting of the marketable trees and undertaking improvement felling and other cultural operations. These operations constitute the Burma Selection System. The cultural operations include cutting climbers, thinning young overstocked stands of teak and cutting back undesirable teak stems with the object of producing straight coppice shoots.

Burma has had a long history of artificial regeneration by taungya system. The great bulk of the artificial regeneration was teak. After reaching the age of 40, the artificially regenerated areas were not treated any further but left as natural forest and treated as such under the selection system. Since 1962, there has been a major increase in artificial regeneration. The artificially regenerated species next to teak is Xylia dolabriformis. Up to 1980, the area of artificial regeneration is 99 590 ha.

Forest utilization

Log harvesting

Timber harvesting is based on the selection system. All marketable teak trees which have attained the prescribed girth limit are measured and selected for extraction. The girth limit varies with the type of forest. In good teak forest the limit is 230 cm and in poor teak forest, it is 200 cm. Evergreen, moist upper mixed deciduous and lower mixed deciduous forests are considered to be good teak forest while dry upper mixed deciduous forest is considered to be poor.

Teak is generally girdled three years ahead of felling and extraction. Girdling kills the tree and by the time of felling and extraction the wood is partly dry. This has two advantages:

• less damage is caused at felling;

• the logs float easily; this permits transport to the mill by water which reduces cost. Teak logs are skidded to streams by elephants and floated down the streams in the rainy season.

Marketable species other than teak are selected on the basis of a girth limit which varies with species from 150 and 240 cm. Selected trees are marked with a blaze and are felled and extracted the same year. The logs are trucked to nearby sawmills, railway lines or main rivers. In some areas, logs are made buoyant using bamboo and other materials and floated down streams to the mills.

The production of teak and other hardwoods is shown in the following table
(extracted from the “Report to the Pyithu Hluttaw 1980–81”):

(in million m³

1 The production of other hardwoods includes production both for trade and domestic uses by local villagers.
2 The production in 1973–74 is only for six months.
3 The figures for 1979–80 are estimates.

Other forest products

The forests of Burma are capable of yielding a very wide range of useful wood and vegetal products. Roughly, there are about 27 different kinds and the most important ones are:

• fuelwood: it is still in great demand for domestic use, the railways and the brick kilns. The annual production is about 18 million m³;

• charcoal: it is also in great demand, mainly for domestic purposes and its yearly production is about 561 000 m³;

• bamboo: it is by far the most important among the minor forest products. Annual production for trade and domestic uses by the local villagers is estimated at about 669 million pieces;

• canes: they belong to the palm family and are found throughout Burma in the moist forests of the plains and lower hills. They are used mainly in the rafting of timber, wicker work and the furniture industry. There are about 30 different species of canes of which only a few are of economic importance. Annually about 56 million pieces are taken out from various parts of the country;

• cutch: it is a water extract of the wood of Acacia catechu. It is a tan as well as a dye. The production of cutch forms an important local industry in central Burma. The annual production is around 360 metric tons.

1.1.3 Present situation of the growing stock

Several small-scale forest inventories applying modern sampling methods have been carried out in Burma. These inventories aimed mainly at collecting numbers of trees by girth classes, except in some forest areas where volumes were also estimated. Overbark volumes per hectare with the corresponding minimum diameter at breast height are presented in the following table (a factor of 1.05 has been applied to underbark volume to estimate the corresponding overbark volume).

The stocking in the poor deciduous dipterocarp type is low and trees are not big. Although the type of evergreen forest found in the Henzada/Bassein Forest Division has generally a high stocking the volume per hectare is also low because the inventoried forests had been damaged and much disturbed by a cyclone in 1975. The volume per hectare for the dry upper mixed deciduous forest is 83 m³ with a minimum of 39 cm. The volume per hectare will be 166 m³ overbark of the boles of all trees more than 10 cm DBH (VOB) assuming that the volume overbark of all trees more than 10 cm DBH is equivalent to twice the same volume of all trees more than 39 cm DBH. This figure cannot be used as an average for all closed broadleaved forests since the dry upper mixed deciduous forest type, which contains a generally lower growing stock than other important broadleaved types, forms only a small proportion of the closed broadleaved forests. Therefore a little higher figure (180 m³/ha) will be used as the average volume for the closed broadleaved forests (except mangroves).

The growing stock of the mangrove forest of the Tenasserim and Arakan coasts was estimated by the Forest Department (4). The volumes per hectare of all trees more than 10 cm DBH were found equal to 55 m³ and 26 m³ respectively in these two areas. An intermediate value of 40 m³/ha has been used as the average growing stock (VOB) of Burmese mangroves.

The volume of merchantable logs extracted per hectare of closed broadleaved forests (“volume actually commercialized” or VAC) is estimated at 15 m³ (1). Difference in stocking between virgin and logged-over forests can be taken as twice this figure, i.e. 30 m³ to account for logging losses and breakage.

The volumes per hectare in the pine forests in Southern Shan State (Kalaw reserve) and Chin Hills Forest Divisions of all trees more than 20 cm DBH were found equal to 115 and 168 m³ respectively (2) (6). The volume per hectare overbark of the boles of all trees more than 10 cm DBH (VOB) are 126 and 185 m³ in Southern Shan State and Chin Hills respectively (assuming that the volume overbark of all trees more than 10 cm DBH is 10% higher than the corresponding volume of all trees more than 20 cm DBH). The average VOB estimated for Burma has been taken at 155 m³/ha.

The total growing stock (VOB) and volumes actually commercialized (VAC) for the closed forests of Burma are estimated as follows:

Growing stock estimated at end 1980 ¹
(totals in million m³)

¹ Figures between brackets are tentative estimates not based on forest inventory figures.

Total annual allowable cut for teak is estimated at 174 000 trees of exploitable size or at 628 000 m³ (underbark net volume) for the whole country (10). The exploitable size prescribed varies from forest to forest, in the range of girth at breast height from 200 cm to 230 cm. Total annual allowable cut for non-teak commercial species is calculated at 2 460 000 m³ (underbark net volume) (10). These species include Xylia dolabriformis, Pterocarpus macrocarpus, Hopea odorata, Shorea oblongifolia, Pentacme siamensis, Albizia lebbek, A. odoratissima, A. procera, Michelia champaca, Dipterocarpus tuberculatus, evergreen dipterocarps, Lagerstroemia speciosa, Gmelina arborea, Adina cordifolia, and some other marketable species. The exploitable sizes of the species vary from 150 cm to 240 cm in girth at breast height. The felling cycle for both teak and other hardwoods areas is generally fixed at 30 years.

For three main logging zones, where operations are carried out with international financial assistance, covering a total area of nearly 3.6 million ha, annual allowable cut was calculated at 504 000 m³ of teak and 1 556 000 m³, or a mean AAC per ha of 0.57 m³/ha/year.

The average green weight per hectare of bamboo in the Arakan Yoma is about 25 tons (9). It is assumed that air-dry weight is about 60% of green weight or 15 tons/ha. The growing stock of bamboo in terms of air-dry weight for the class NHBf1uv at end 1980 will be 9.3 million tons.

1.2 Plantations

Introduction

In this report, the term “plantation” applies to establishment of an essentially new tree species (on land previously forested or not), and does not include artificial regeneration of intensively managed forests.

In Burma, eucalypts have been introduced since the 1950's on an experimental scale in the dry zone where fuelwood and small timber are very scarce in order to satisfy the needs of the local population in these products. They were planted on a somewhat larger scale from 1970. Later on, they were introduced in areas outside the dry zone, where fuelwood is scarce and population density high. From 1975 eucalypts were also planted with the object of supplying raw material for the two paper mills. In the fiscal year 1979–80 3 554 ha of Eucalyptus plantation were established.

The main species is Eucalyptus camaldulensis which shows good growth rates over a variety of edaphic and climatic conditions in the lowlands. Eucalyptus tereticornis has been planted on a limited scale in the lowlands of middle and upper Burma and its growth and form are comparable or better than E. camaldulensis, E. grandis shows the best growth in the higher region above 900 m elevation.

Leucaena leucocephala has also been introduced on an experimental scale quite recently. It is a fast growing species which can be used for improving soils, for producing fuelwood and as a fodder crop. From observations made so far, it has been found that Leucaena needs good soil and moisture for good growth and that it does not thrive well in the arid regions.

The survival rate of the plantation is counted usually in December and generally the success rate is over 70%. Patching is usually done up to the third year of establishment. During drought year, the survival per cent may be below 70%.

1.2.2 Area of established plantations

Industrial plantations

Areas of established industrial plantations estimated at end 1980
(in thousand ha)

The main purpose of industrial Eucalyptus plantations is to provide raw material for the two paper mills.

Other plantations

The following table gives the areas of established plantations for fuelwood, poles and posts for the local population.

Areas of established plantations for firewood, poles and posts at end 1980
(in thousand ha)

All plantations

Area of established plantations estimated at end 1980
(in thousand ha)

1.2.3 Plantation characteristics

Estimated figures regarding plantation characteristics used in drawing up the Local Fuelwood Supply Plantation Project are given in the following table.

2. Present trends

2.1 Natural woody vegetation

2.1.1 Deforestation

Large numbers of people living in the hilly zones, which cover about nearly half of the total land area of Burma, are still practising shifting cultivation, on a greater scale than before due to population pressure. Because of the population growth, the number of cultivators in the lowlands has risen considerably resulting in the encroachment of forest lands adjoining the paddy fields. In each and every division of the forest in the country there are many cases of encroachment on forest lands and when these are added up together, it amounts to a quite substantial area. However, there are no definite records and surveys regarding these encroachments.

Two methods have been used to assess the rate of deforestation. The first one is based on the comparison of aerial photographs taken in the 1950's at a scale of 1:20 000 and 1:50 000 and the Landsat imagery taken between 1973 and 1979 at a scale of 1:1 000 000.841 centre points on the photo indices were identified on both imageries using the classification key adopted for the interpretation of Landsat images (see paragraph 1.1.2).

In the above table, the “closed forest” and “degraded forest” are treated as forest covered area and the “closed forest with shifting agriculture” and “degraded forest with agriculture” are classed as forest fallow. Out of 415 points of forest covered area in 1955. 6 points have turned into forest fallow or non-forest area in 1975. This would mean that deforestation rate has been 1.45% in twenty years and 0.073% annually or that 23 320 ha would be deforested annually, a figure apparently very low. Some doubts may be expressed on such a method due to the differences in scales and nature of the images.

Another method used for the determination of the rate of deforestation is based on the numbers of people practising shifting cultivation who represent the principal factor of deforestation. These numbers are determined by projecting the 1973 census data at an annual increase of 2.2%. Only figures from the hilly areas, where shifting cultivation is most practised, are projected. The numbers of households in the rural areas of the hilly states in 1980 are estimated below.

Population estimates in 1980
(in thousand)

It is estimated that each household in the rural areas cultivates on the average one hectare of land per year. Assuming the cultivator practises the shifting cultivation on a six year rotation for three rotations, the 6 hectares of forested land have been abandoned on the 18th year of cultivation. So the natural consequence will be that after 18 years, the 6 ha of forested land will be deforested.

According to this assumption, the total area deforested annually by shifting cultivation will be approximately 788000 × 6/18 = 262 000 ha. Here it is assumed that all the households practise shifting cultivation which in reality may not be true. However, there are other states and divisions in which some of the rural population practise shifting cultivation to some extent as well as encroachment of forest land for permanent agriculture. This may compensate for those who do not practise shifting cultivation in our projection. It is also assumed that about two thirds of the deforested area are from the forest fallow (NHCa). So the annual rate of depletion for closed forests (Landsat class 1 and 3) is estimated at 262 000 :3–87 000 ha. To that figure must be added deforestation caused by other factors. Between 1976 and 1980, the following approximative deforested areas were recorded: 8 000 ha for river valley and other projects, 12 000 ha for roads and communications, 3 500 ha for other uses such as urbanization and industrialization. In total some 5 000 ha of forests have been cleared annually for non-agricultural uses. The total annual deforestation rate could therefore amount to 92 000 ha rounded off to 95 000 ha.

Different rates of deforestation have been arrived at by the two methods employed above. The first method, though straightforward, is liable to large biases for the reasons already mentioned. The order of magnitude of the second estimate appears more realistic although its calculation is much imprecise. An increase of 10% of deforestation rates has been assumed for the next 5 year period to account mostly for the increase of population practising shifting cultivation.

Annual average deforestation
(in thousand ha)

1976–80

Annual average deforestation (follow-up)
(in thousand ha)

1981–85
(projections)

2.1.2 Degradation

Degradation of forests is mostly due to population pressure. Accessible closed forests are subject to degradation by man in many parts of the country. Cutting of wood for fuel and small timber for domestic purpose is the main cause of degradation of the forests. The major source of fuel used by people in Burma is firewood and charcoal. Increasing demand for a growing population results in the overexploitation of forested lands, especially of those accessibles areas adjacent to heavily populated tracts.

2.1.3 Trends in forest utilization

Teak can be extracted more or less according to the annual allowable cut. It is not the case of other hardwoods. But there is a tendency to extract more hardwoods other than teak with the help of foreign loans. It is estimated that the production of teak and other hardwoods will be 0.6 and 3.4 million m³ respectively in the year 1985. Production of fuelwood and small timber for domestic purposes should also increase with increasing population.

The forests of Burma will be managed under the Burma Selection System with the attended cultural operations carried out regularly. However, there is a trend for increasing the growing stock of teak and other hardwoods by artificial regeneration. This latter system will also be used with some other suitable species for fuelwood and watershed management. In 1985, the area of artificially regenerated forest will reach about 221 000 ha.

2.1.4 Areas of natural woody vegetation estimated at end 1985 (in thousand ha)

The corresponding volume for growing stock (VOB) and commercialized volume (VAC) are given in the following table:

Growing stock estimated at end 1985
(in million m³)

The air-dry weight of bamboo for the class NHCf1uv at end 1985 is estimated 9.1 million tons.

2.2 Plantations

Planting of eucalypts has been stopped in 1980 except for industrial purposes. Lowland tropical pines have been introduced in 1980–81 on an experimental scale. The object of introduction is to produce softwood pulp on short rotations. However it is not expected that there will be significant areas planted before 1985.

Industrial plantations

Areas of established industrial plantations estimated at end 1985
(in thousand ha)

Other plantations

The areas of established plantations for firewood, poles and posts at end 1985 are the same as the area at end 1980.

All plantations

Area of established plantations estimated at end 1980
(in thousand ha)

Bibliography

(1) Kermode, D.W.D. 1964 “Some Aspects of Silviculture in Burma Forest” - Forest Department - Rangoon

(2) Forest Department 1971 “Preliminary Survey of Areas of Pine Forests in the Shan and Kayah States With Estimates of Their Potential for Wood Chips and Saw Production” - Rangoon

(3) Forest Department 1971 “Survey of Indaing Forest (Shwebo Forest Division)” - Rangoon

(4) Forest Department 1972 “A Preliminary Evaluation of Wood Chip Potential of the Tidal Forests Along the Fringes of the Coastline of Burma” - Rangoon

(5) Forest Department 1973 “A Brief Note on Bamboo Potential in Burma for Industrial Utilization” - Rangoon

(6) Forest Department 1973 “Preliminary Survey of Areas of Pine Forests in the Chin Hills of Burma” - Rangoon

(7) Forest Department 1973 “Forest Feasibility Study” - Document X4040/3 - Rangoon

(8) Forest Department 1973 “Forest Feasibility Study” - Document X4040/11 - Rangoon

(9) Forest Department 1978 “A Preliminary Estimate of Forest Resource for Pulp and Paper in a Forest Area Situated in Parts of the Arakan and Henzada/Bassein Forest Divisions” - Rangoon

(10) Forest Department 1979 “Annual Allowable Cut of Teak and Other Non-teak Hardwoods in Burma” - Rangoon