Part II
COUNTRY BRIEFS (continued)

BHUTAN (continued)

1.1.3 Present situation of the growing stock

Growing stock per hectare by species in the different forest types has been estimated by P.I.S for almost the entire country (5) (6). The gross volume of wood has been estimated down to 5 cm top diameter under bark. These figures have been used for unmanaged virgin forests (N.f1uv) and projected to the forest areas tabulated earlier to give the present situation of the growing stock. For unmanaged logged-over forests (N.f1uc) and unproductive forests (N.f2i) figures have been reduced by 60% and 50% respectively.

Growing stock estimated at end 1980
(in thousand m³)

1.2 Plantations

1.2.1 Introduction

Plantations started in the country in the early sixties and progress has been slow. The total area planted during the past 18 years amounts to 7 000 ha approximately. Accessible areas suitable for forest plantations are not readily available due mainly to prevailing rights of pasture. Another constraint is the shortage of labour. It has not been possible so far to achieve the annual planting target of 1 000 ha.

1.2.2 Areas of established plantations

Almost all the plantations have been raised for production of wood for industry and can therefore be regarded as industrial plantations. The species planted are: blue pine (Pinus wallichiana), chir pine (Pinus roxburghii), Robinia pseudoacacia, deodar (Cedrus deodara), poplars, willows and blue gum in the northern part of Bhutan and Michelia champaca, Chukrasia tabularis, teak etc. in the southern part. No data are available on survival/success rates. Based on the Indian experience a survival rate of 70% has been assumed and the planted areas are tabulated as under:

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

2. Present trends

2.1 Natural woody vegetation

2.1.1 Deforestation

Shifting cultivation is the main cause of deforestation. However the government has prohibited clearing of new land for agriculture with the declaration of National Forest Policy and people are encouraged to adopt settled agriculture on terraced fields. So far 2000 families have been settled (7). As a result new clearing of forests for agriculture is declining. However shifting cultivation being a traditional practice it will take some time before it can be completely stopped, particularly in remote areas without a communication system and beyond control. The other cause of deforestation is the gradual extension of permanent agricultural through illegal encroachment on forest lands. The process is very slow and does not have appreciable effect on the extent of total forests. For plantations only such lands are selected which are either without vegetation cover or have scrub or secondary growth of forest fallow. Forest plantation is not carried out therefore at the expense of natural forests. Estimates of the annual rates of deforestation are given below.

Average annual deforestation
(in thousand ha)

2.1.2 Degradation

The degradation of present woody vegetation is a continuing process but is limited mostly to the vicinity of scattered villages. The completely unregulated grazing practices prevent natural regeneration, deteriorate soil by trampling and are the main cause of forest degradation. Another factor of degradation consists of the frequent forest fires resulting from either natural causes or careless handling of open fires by farmers and road labourers, or intentional burning of forest land by cattlemen to achieve better grass growth. The important requirements for firewood and construction timber result in overexploitation of the woody vegetation near the villages. It is likely that these degradation processes will continue due to increasing population pressure on the forest cover.

2.1.3 Trends in forest utilisation

No significant changes in forest utilisation are expected in the near future except that mechanised logging will be extended to open some forests for commercial exploitation. For development of wood based industries several studies have been carried out such as those for a plywood factory near Chukha, a veneer manufacturing unit in Samchi, and a veneer manufacturing unit near Gedu. However, in view of the present situation of power supply and other constraints, no immediate development of new forest industrial units is foresen.

With the fast degradation of forest around villages fuelwood supply will become more and more difficult due to the increase of population (12% over the next five years) and improvement in standard of living, particularly in valleys having high population density.

The Forest Department envisages to bring large areas of forest under management plans (7). In the following table it has been assumed that by 1985 there will be some 100 000 ha under intensive management in the meaning used in this study.

2.1.4 Areas and growing stock at end 1985

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

Growing stock estimated at end 1985
(in million m³)

2.2 Plantations

During the fifth five-year plan (1981–86), the Forest Department envisages afforestation of an additional area of 5 000 hectares, which has been reduced in the following table to 4 000 ha to take into account success/survival rates.

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

Bibliography

(1) Champion, H.D. and Seth, S.K. 1968 “A Revised Survey of the Forest Types of India” - Publication Division, Government of India - Delhi

(2) Preinvestment Survey of Forest Resources 1973 “Report of the Preparatory Mission to Bhutan” - Ministry of Agriculture, Government of India - Delhi

(3) FAO 1975 “Management Plan for the Chimakothi Management Unit” - Forestry Development in Bhutan, Forestry Department, Royal Government of Bhutan and FAO/UNDP Office - Thimphu

(4) FAO 1975 “Preliminary Assessment of a Forest Industries Complex in Western Bhutan - Project Findings and Recommendations” - Rome

(5) Lerche, C. 1976 “Forestry Development in Bhutan” - Summary Report - Rome

(6) Preinvestment Survey of Forest Resources 1976 “Report on Survey of North Western Bhutan” - Ministry of Agriculture, Government of India - Dehradun

(7) Chandrasekharan, C. 1979 “General Information about Forests and Forestry in Bhutan” - FAO Regional office for Asia and the Far East - Bangkok

(8) Preinvestment Survey of Forest Resources 1979 “Draft Report on Survey of Central and Eastern Bhutan” - Ministry of Agriculture, Government of India - Dehradun

BRUNEI

Brunei is situated on the north-west of the island of Borneo, between longitudes 114°23' and 115°23'E and latitudes 4° and 5°5' N covering a total area of 5 765 km². It has a common border with Sarawak, one of the two eastern states of Malaysia, which also divides Brunei into two parts. The western part of Brunei state, comprising Brunei/Muara, Tutong and Belait districts, consists predominantly of hilly lowland below 100 m but rising to over 300 m in places on the Sarawak border. The eastern part of the state, comprising Temburong district, consists predominantly of rugged mountain terrain, rising up to 1 850 m on Bukit Pagon. Near the coast, it has a wide, tidal and swampy plain. Narrow alluvial valleys extend up the main rivers (4).

The land surface is developed on bedrock of tertiary age, comprising sandstones, shales and clays. Several factors have influenced the moulding of this surface into its present form, namely the comparatively youthful state of the present cycle of geological erosion, the nature and angle of dip of the strata, the climate factors of high rainfall and the temperatures that maintain a dense forest cover on all landforms and induce deep chemical weathering and rapid erosion. These have contributed to produce a strong undulating ridge and valley terrain with universally steep slopes. Erosion occurs even under a forest canopy, but the rate is considerably accelerated when the forest is cleared. The sediments washed off the hill are redistributed by the rivers and floods to form the extensive alluvial plain near the coast (4).

Generally in common with its surrounding neighbours, Brunei has a tropical climate. This is characterised by constant temperature and humidity and high rainfall. Rainfall in Brunei normally ranges from about 2 800 mm annually in the lowland areas to over 3 800 mm in many parts of the interior. Temperatures are high throughout the year and annual extreme range of temperature is 23°C to 32°C. Relative humidity is high, and average fluctuation between 67% to 91% throughout the year (4).

In 1971, the population of the state was estimated (5) as 136 000 with an annual increase of 4.5% of which 1.2 was due to immigration. The population density was 23.5 persons/km². About 65% of the population was urban. The contribution of agriculture, forestry and fisheries sectors to total employment fell to 11.7% in 1971 as compared to 32.9% in 1960. In this respect the structure of employment in Brunei differs radically from its two neighbours, viz. Sabah and Sarawak. It may be added that Brunei has the second highest per capita income in Asia next only to Japan.

Keeping in view the composition of the population of the state (4) and by comparison with Sarawak, the number of families practising shifting cultivation in 1966 is tentatively estimated by this study to be of the order of 2 000 (or 12 400 persons at the rate of 6.2 persons per family). Assuming an annual growth rate of 3% the population of shifting cultivators in 1971 comes to around 14 400 (or 10.6% of the total population).

1. Present situation

1.1 Natural woody vegetation

1.1.1 Description of the vegetation types

The state may be ecologically classified under the following five types (4):

• mangrove forests found at sea level and characteristically inundated at high tides by brackish water;

• heath forests found on sandy alluvial soils usually below 30 m above sea level, but occasionally also on high altitude sandstone ridges in Ulu-Temburong;

• peat swamp forests found adjacent to the main rivers. These forests merge irregularly into the following type;

• mixed dipterocarp forests lying immediately above peat swamp forests and extending up to above 1 300 m where they give place to montane types;

• montane forests which are found only in Ulu-Temburong adjacent to the state border up to 1 800 m.

Species composition and physiognomic characteristics of the forest types closely resemble those of Sarawak and Sabah, country briefs of which may be referred to for a detailed description.

1.1.2 Present situation of the woody vegetation

Present areas

Based on the report of the Forest Department (6) the following data are considered as reasonably good tentative estimates of forest type areas by end 1980:

The above figures and others derived from documents (1), (4) and (5) lead to the following table:

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

The following remarks explain the estimation procedure:

• the area of the mixed dipterocarp forests includes 4 000 ha (4 107 exactly) of national park, 3 000 ha of inoperable forests (in montane type), 229 000 ha of virgin forests and 12 000 ha of logged over forests. The logging is still very limited in this forest type due to steep terrain and lack of infrastructure. Shifting cultivation is mainly responsible for the reduction of closed forest areas estimated since 1965 as 111 000 ha;

• 80% of the logging activities are reported to be concentrated in the western part of Brunei (5), where peat swamps are predominant. The same percentage of the log outturn has been assumed to originate from the peat swamps. The area of logged over forest is estimated on the basis of past log production data, assuming an average yield of 65 m³/ha before 1975 and 75 m³/ha after 1975.

Ownership and legal status

All the forest land in Brunei belongs to the state. The forest land is further distinguished into “forest reserves” and “state land”. Forest reserves are generally created to serve as permanent source of timber production or protection. The state lands have from a landuse point of view a somewhat less settled status because they can be alienated to other uses than forest production more easily. The areas of forest reserve and state land were reported to be 212 000 ha and 222 000 ha respectively in 1976 (4).

Forest management

Forestry operations in Brunei are not so far controlled by a long term or medium term plan (or working plan). No attempt appears to have been made to work out an annual allowable cut. Extraction is reported to be generally light, mainly for meeting the local requirements except for the export of a small quantity of ramin (Gonystylus bancanus) (5).

No statistically designed inventory appears to have been carried out in Brunei. There are, however, a number of survey reports of several companies in the context of feasibility studies for the establishment of new wood-based industries in the country (e.g. Settsu Paper and Board Manufacturing Co. in 1974, the National Lumber Co. of the Philippines, Heilborn Engineering Pte Ltd. for Worldwide Timber Corporation, and Tropical Forestry Association of Japan (5)). It is understood that new aerial photography for the whole of the state is available now which, combined with ground survey, could be used for reliable estimations of forest area and growing stock (4).

Forest utilization

Log harvesting

The FAO Yearbook of Forest Products indicates an average annual production of sawlogs and veneer logs of 37 000 m³ during the period 1961–65, 81 000 m³ from 1966 to 1970 and 92 000 m³ from 1971 to 1975. It should amount to 140 000 m³ approximately in the period 1976–80. As mentioned earlier, most of logging in Brunei is concentrated in the western part where 90% of the land is not higher than 60 m from the mean sea level. On the eastern part 75% of the area is rugged with moderate to steep slopes. Such physiography makes commercial exploitation very expensive. In 1975 about 25 000 ha (61 594 acres exactly) were reported under licence for timber production. In this year about 47% of the timber production originated from the forest reserves and about 53% from the state lands.

Other forest products

The annual amount of other forest products is reported as follows:

1.1.3 Present situation of the growing stock

For estimating the growing stock figures per ha data from Sarawak and Sabah forests have been taken as a basis. The figures for 1980 arrived at are given in the following table.

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

1.2 Plantations

Experimental trials on Pinus caribaea were started in 1971. The total area by end 1980 is very small, and does not exceed 200–300 ha.

2. Present trends

2.1 Natural woody vegetation

2.1.1 Deforestation

Shifting cultivation appears to be the main source of deforestation. The area under shifting cultivation around 1966 is estimated by this study as 126 000 ha, which is rather close to the figure of 119 000 given by the Forest Department (4). The former figure has been obtained assuming

• that proportions of Ibans and Dayaks (8.6%) and other indigenous races (5.6%) with respect to total population were the same in the sixties as those given in document (4);

• that the relationship between man and land with reference to shifting cultivation is the same in Brunei as in Sarawak.

The shifting cultivation areas in 1980 is based on a report of the Forest Department (6).

In 1971, as compared to 1961, the size of labour force employed by the agriculture sector dropped down from 32.9% to 11.7%. On the contrary, the average annual rate of deforestation, mainly due to shifting cultivation, is expected to slow down from 7 000 ha per year to 5 000 ha per year. Keeping this view no expansion of the land under permanent agriculture has been assumed. An area of about 1 000 ha is supposed to be cleared annually for settlement and other development purposes.

On the basis of the above data, the rates of deforestation are estimated as follows:

Average annual deforestation
(in thousand ha)

2.1.2 Degradation

There is no significant form of degradation reported.

2.1.3 Forest utilization

An annual increase of 5 to 10% in the level of log production has been assumed during 1981–85. This is based on extrapolation of the trends observed during 1971–76.

2.1.4 Areas and growing stock estimated at end 1985

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

Growing stock estimated at end 1985
(in million m³)

2.2 Plantations

During 1981–85 it is estimated that the state would start programmes of industrial plantations and raise about 2 000 ha of plantations of Pinus caribaea (PS.1)

Bibliography

(1) State of Brunei 1966 Report of the 1964 Census of Agriculture

(2) State of Brunei 1969 “National Progress Report on Forestry - Period: 1965/1968” - by C.G. Merton - Asia Pacific Forestry Commission - 8th Session (Seoul, 1–8 May 1969) - Brunei

(3) Agriculture Department 1972 Reply to the FAO Annual Questionnaire for the Production Yearbook - Brunei

(4) State of Brunei 1975 “Annual Report - 1975” - Brunei

(5) FAO 1976 “Brunei: The Challenge of Agriculture Development” - Report of the Agriculture Mission to Brunei by R.N. Poduval and C. Chandrasekharan - Regional Office for Asia and the Far East - Bangkok

(6) Forest Department, Brunei: 1981 Comments on the draft country brief of the FAO/UNEP Tropical Forest Resources Assessment - Brunei

BURMA ¹

Burma has an area of 676 580 km² and is situated between latitudes 10°N and 29°N and longitudes 92°E and 101°E. It is bordered in the south by the Bay of Bengal and the Andaman Sea and has land borders with Bangladesh, India, China, Lao and Thailand. It is roughly diamond shaped and is about 2 092 km from north to south and about 933 km broad from east to west.

The country is drained by a number of rivers, mostly flowing from north to south. The most important of them is the Irrawaddy which runs through the middle of the country to the sea in the south. It is navigable for about 1 500 km northward from Rangoon. The elevation of the land surface of Burma varies from sea level along the coastal section to about 6 000 m on the mountains bordering China. On the Arakan Yoma, which forms a divide between the Irrawaddy basin on the Bay of Bengal, altitudes in places run to over 3 000 m. The hills of the Pegu Yoma, which lie between the Irrawaddy and Sittang plains and which contain some of the most extensive and finest teak forests in Burma do not exceed 900 m.

Over most parts of Burma, there are three well defined seasons, the rainy season, the cold season and the hot season. The rainy season starts about mid-May and ends in October. It is followed by cold weather from November to January. The hot season is from February to mid-May with the hottest period occurring before the rains. The annual rainfall varies according to locality. The heaviest rainfalls occur in the coastal regions and range from 3 000 mm to over 5 000 mm a year. Rainfalls of up to about 3 000 mm occur in the hill tracts. The rainfall gradually decreases down to about 760 mm a year in the middle of the country.

The average range of temperature in most parts of the country is from 21° to 32°C in the rainy season, 10° to 30°C in the cold season and 32° to 38°C in the hot season. In central Burma, the temperature can reach 43°C in the hottest months.

For the purpose of administration the country is divided into seven states and seven divisions. The total population for the whole country is estimated at about 33 million in 1980. The population is most dense in the deltaic areas and along the Irrawaddy river valley amounting to about 137 per km². In the hilly states and divisions, population density is quite low varying from 9 to 25 per km².

¹ The country brief is based on the work of Mr. Shwe Kyaw, Assistant Director, Forest Department of Burma and his colleagues, within the framework of an agreement between this institution and FAO. Advice on interpretation of Landsat satellite imagery was provided by Mr. J.P. Aggarwal consultant in remote sensing, who had been responsible previously for similar work in India for this global projet.

1. Present situation

1.1 Natural woody vegetation

1.1.1 Description of vegetation types

As a result of the great variation in rainfall, temperature, soil and topography, there are many different forest types in Burma. Tropical evergreen forests occur in many places of the highest rainfall zone in the south of the country. Hill and temperate evergreen forests are found in the eastern, northern and western regions where elevation exceeds 900 m. The forest type changes to deciduous, then to dry forests along the transect towards the middle of the country as a result of decreasing rainfall. The types described below are known as the Burma Standard Types (1) which are currently used by the Forest Department. They are presented below within the broad categories used in this study.

Closed broadleaved forests (NHC)

Broadleaved forests with fairly dense conopy are grouped together in this class.

a) Tidal forests

This class corresponds to the following types of Champions's classification: “low mangrove forest”, “tree mangrove forest”, “salt water Heritieraforest” and “fresh water Heritiera forest”.

These forests are situated within the tidal limits on alluvial flats in the delta and on sheltered muddy coastal areas. They are subdivided depending mainly on how much the area is affected by the daily rise and fall of the tides. The most abundant species are Rhizophora apiculata and R. mucronata, Heritiera fomes, Carapa moluccensis, Sonneratia apetala and Excoecaria agallocha.

b) Beach and dune forests

This class corresponds to the “beach forest” of Champion's classification. These forests form narrow strips along the coasts on sandy beaches and dunes. They are of little importance commercially and they are very often characterised by an abundance of Casuarina equisetifolia.

c) Swamp forests

This type corresponds to the following forest types of Champion's classification: “delta fresh water swamp forest”, “tropical valley fresh water swamp forest” and “moist riparian forest”.

These are found in inland fresh water swamps on low-lying alluvial land, usually near rivers and lakes. The land is inundated for periods during the rains. These forests are relatively open with small and scattered trees. Their total area is negligible.

d) Evergreen forests

The evergreen forests are subdivided into three subtypes namely riverine evergreen, giant evergreen, typical evergreen. The corresponding Champion's types are respectively. “south Burma tropical semi-evergreen forest”, “evergreen dipterocarp forest” and for typical evergreen, the following ones: “eastern tropical evergreen forest”, “southern low tropical evergreen forest”, “north Burma tropical evergreen forest”, “Chittagong semi-evergreen”, and “north Burma tropical semi-evergreen forest”. Other evergreen forests of Champion's classification, occurring in Burma are: “cane brake”, “southern tropical wet bamboo brake”, “northern tropical moist bamboo brake”, “northern tropical semi-evergreen riverine forest”, “southern secondary tropical semi-evergreen forest” and “Chittagong Gurgan forest”.

Riverine evergreen forests are situated along the banks of streams and in low-lying areas and consist mainly of Hopea odorata and Lagerstroemia speciosa. They occur mainly in southern Burma.

Giant evergreen forests, which are characterised by the presence of giant evergreen trees over a lower storey of smaller evergreen trees, occur mainly in south Tenasserim. A great number of species are present. The most important ones include: kanyin (Dipterocarpus alatus, D. turbinatus and D. griffithii), Parashorea stellata, Anisopetera scaphula, Swintonia floribunda and Eugenia grandis in the upper storey, and Pentacme burmanica, P. griffithii, Hopea minutiflora and Michelia champaca in the lower storey. This subtype is typical of tropical rain forest.

Typical evergreen forests are characterised by a dense understorey of evergreen trees of numerous species or by a dense growth of bamboo, such as tin-wa (Cephalostachyum pergracile), Oxytenanthera nigrooiliata and Dendrocalamus hamiltonii. The subtype, requiring more than 2000 to 2500 mm of annual rainfall, occurs throughout Burma. Its species composition varies to some degree with location. Various species of kanyin are present, together with Anisoptera scaphula, Parashorea stellata, Hopea odorata, Pentacme burmanica, Swintonia floribunda, Eugenia grandis, Xylia dolabriformis, Gmelina arborea, Salmalia insignis, S. malabarica, Albizia procera and Castanopsis spp.

e) Mixed deciduous forests

These are economically the most important forests of Burma, as they produce teak and other commercial hardwoods. They are subdivided into three types, namely moist upper mixed deciduous forests (MUMD), dry upper mixed deciduous forest (DUMD) and lower mixed deciduous forests (LMD). The class corresponds to the following forest types of Champion's classification:

• moist upper mixed deciduous forests: “south Burma tropical semi-evergreen forest”, “north Burma tropical semi-evergreen forest”, “Burma tropical upper moist deciduous forest”, “southern tropical moist bamboo brake”, “northern tropical moist bamboo brake” and “secondary tropical moist bamboo brake”;

• dry upper mixed deciduous forest: “dry teak forest” and “tropical dry bamboo brake”;

• lower mixed deciduous forest: “southern tropical moist deciduous riverine forest”, “moist riparian forest”, “eastern laterite tropical semi-evergreen forest”, “Burma tropical moist clay-soil forest” and “Burma tropical lower moist deciduous forest”.

Moist upper mixed deciduous forest is characterised in lower Burma by the presence of the bamboos Bambusa polymorpha and Cephalostachyum pergracile. In upper Burma, Bambusa polymorpha is replaced by B. hamiltoni or B. membranaceus with Cephalostachyum pergracile. This latter is the most typical bamboo of the subtype. MUMD contains the finest teak with Xylia dolabriformis usually associated. Other important species are Dipterocarpus spp., Gmelina arborea, Eugenia, spp., Terminalia tomentosa, Salmalia insignis, Lannea grandis, Pterocarpus macrocarpus and Milletia pendula. The subtype occurs on well-drained slopes and usually indicates a good quality of soil. On ridge tops and dry aspects, it is often replaced by the dry upper mixed deciduous subtype. A peculiar type of forest which may best be included under the MUMD is found in Arakan over wide stretches of the Arakan Yoma. A bamboo, Meloccanna bambusoides, invades several forest types, including evergreen forest. As the dense growth of this bamboo precludes natural regeneration of most species, the tendency is to reduce the vegetation over these areas to pure stands of Meloocanna bambusoides.

Dry upper mixed deciduous forests are usually characterised by the presence of the bamboo Dendrocalamus strictus. In many places Thyrsotachys oliveri is also a characteristic bamboo and in upper Burma may predominate over large areas. Cephalostachyum pergacile and even Bambusa polymorpha may also occur in this subtype but there are usually less frequent than in moist forest and cannot be considered characteristic. In lower Burma, B. tulda is found in this subtype and is usually an indicator of stiff soil. Characteristic tree species are teak, Xylia dolabriformis, Terminalia tomentoca, T. chebula, T. pyrifolia, Pterocarpus macrocarpus, Adina cordifolia, Pentaome siamensis, Shorea oblongifolia and occasionally Dipterocarpus tuberculatus.

Lower mixed deciduous forests occur on lower ground, usually with clayey soils, and are characterized by a scarcity of bamboos. The most caracteristic form of the subtype is found on alluvial flats near streams. Here teak occurs in quantity, often in pure stands and with trees of large diameters but of a shape not as good as is found on the slopes. Other caracteristic species of this subtype are Lagerstroemia speciosa, Dillenia pentagyna, Homalium tomentosum, Albizia procera and Anogeissus acuminata.

f) Deciduous dipterocarp forests

This class corresponds to the following types of Champion's classification: “Indaing high forest”, “semi Indaing forest”, and "Indaing scrub forest (classed in the shrub vegetation category (nH) of this study).

These forests are characterized by the prevalence of in Dipterocarpus tuberculatus which may form almost a pure crop. In some places Pentacme siamensis and Shorea oblongifolia may replace in, the forest becoming known as semi-Indaing. The type occurs mainly on laterite, but also on sandy or gravelly soil. The forests are usually relatively open with a ground cover of grasses and shrubs.

g) Hill forests

These forests mainly serve as protective cover for slopes between 900 m and 1 800 m. They may be somewhat roughly divided into hill evergreen forests and dry hill forests. This class corresponds to the following types of Champion's classification: “Burma sub-tropical wet hill forest”, “Burma sub-tropical moist hill forests” and “Burma sub-tropical hill savanna forest”.

Hill evergreen forests are characteristic of high rainfall areas and resemble evergreen forests in many ways, with high trees and luxuriant growth. The species are, however, usually distinct. Quercus spp., Castanopsis spp., Schima wallichii and species of the families Magnoliaceae and Lauraceae are characteristic of this subtype. The forest usually contains a large number of climbers and dense undergrowth.

Dry hill forests occurring on drier localities, have shorter or even stunted trees and the vegetation is less luxuriant. Characteristic species are Quercus serrata with several other species of Querous and Castanopsis, Schima wallichii, Alnus nepalensis and occasionally, ingyin.

Closed coniferous forest (NS)

Pine forest is found in the Shan and Chin states. In the Shan state, Pinus merkusii occurs in the hills of the Salween and Thsungyin drainages. It extends to lower altitudes and may be found associated with Indaing forest, between 150 m and 750 m. It occurs in the hills of upper Burma, the Shan state, the hills between Sittang and Salween and in the Arakan Yoma and Chin hills, at heights between about 1 500 m and 2 500 m. It may occur as almost pure pine forest or may be associated with such species as Alnus nepalensis, Querous spp., Rhododendron arboreum and bracken fern (Pteris aquilina).

Bamboo forests (NHB)

Bamboo grows profusely in Burma. There are about 90 different species of bamboo, of which about half a dosen (mainly Cephalostachyum pergracile, Bambusa polymorpha, Dendrocalamus membranaceus, D. strictus, Melocanna bambusoides and Oxytenanthera nigrociliata) can be considered to be of major economic importance because of their high occurrence. It is estimated that there are about 9 million ha of bamboo in pure stands and as undergrowth in Burma (1). Arakan, Tenasserim and Pegu Yoma area are considered for their bamboo potential as these contain large reserves of bamboos in continuous blooks and as yet unutilized for domestic consumption.

The predominant species to be found in the Arakan area is Melocanna bambusoides which grows almost in pure stands, and is not associated with other tropical hardwood species. This species is somewhat different from other bamboo in that the growth is in single culms as opposed to clumps for most other species. There are extensive areas of bamboo growth mixed with other hardwood species in the Tenasserim and Pegu Yoma regions.

Scrub formations (nH)

a) The group of “dry forests” corresponds more to shrub vegetation as defined in this study. They are usually found where the rainfall is under 1000 mm. It is often difficult to decide where dry forest ends and dry upper mixed deciduous forest begins, as the two merge gradually into each other. There are three subtypes: than-dahat forest, thorn forest and aukchinsa-thinwin forest. The corresponding Champion's types are: “Burma dry mixed deciduous forest”, “tropical dry bamboo brake”, “southern tropical dry riverine forest”, “dry savannah forest”, “Burma than-dahat forest”, “southern cutch-thorn forest”, “southern Euphorbia semi-desert scrub forest”, “Burma dry Diospyros forest” and “tropical dry evergreen forest”.

Than-dahat forests are characterized by the predominance of the two species than (Terminalia oliveri) and dahat (Tectona hamiltoniana). In areas with rainfall of less than 1 000 mm, this subtype is replaced by thorn forest.

Thorn forests, constitute an open type of low growth, characterized by the presence of a number of thorny species such as Acacia catechu, A. leucophloea and Zizyphus jujuba.

Aukchinsa - thinwin forests are fairly-rare. They consist of A. catechu and Millettia trees scattered in an undergrowth of grass or stunted D. strictus.

b) “Indaing scrub forest” can also be classed among the shrub formations of Burma.