South Myanmar Irrawaddy Dry Forest

These forests are found in the dry zones of central Myanmar where what little rain that does fall usually occurs in torrential downpours. The soils substrates are largely soft sandstones and clays with very little subsurface moisture retention. This together with high levels of surface runoff can cause extreme dryness. The most common trees are Tectonia hamiltoniana and Terminalia oliveri, while associate trees include Acacia catechu and Bauhinia racemosa. There are also stands of dipterocarps and, in fact, Dipteocarpus tuberculatus can form pure stands. Others include Shorea oblongifolia and Pentacme siamensis.

 

South Myanmar Irrawaddy Moist Deciduous Forest

These typically occur on well-drained hilly terrain up to an altitude of about 1000 m. They are not confined to the Irrawaddy Basin but also occur along the Chindwin, Salween and Sittang rivers. In the Irrawaddy Basin they extend over large areas in the Pegu Yoma region. Canopies are usually closed and can reach heights of up to 30 m. The dominant canopy species are Tectonia grandis (teak) and Xylia kerri (ironwood), but composition varies and often includes bamboo groves. Other tree include Berrya ammonilla, Ginelina arborea, Homalium tomentosum, Lannea grandis, Millettia pendula, Mitravgyna rotundifolia, Odina wodia, Pterocarpus macrocarpus, Salmalia insigni, Terminalia belerica, T. pyrifolia and T. tormentosa.  Among the bamboos Bambusa polymorpha and Cephalostachyum pergracile are the most common, but in the north Dendrocalamus hamiltonii and D. membranaceus become conspicuous. The undergrowth typically includes Barleria strigosa and species of Leea.

 

South Myanmar Irrawaddy Swamp Forest

These highly fertile forests are largely composed of deciduous trees such as Andina cordifolia, Anogeissus accuminata, Dalbergia kurzii, Lannea grandis, Manglietia insignis, Milletia pendula, Schleichera oleosa, Terminalia balerica, T. chebula, T. tomentosa, Salmalia malabrica, S. insigni, Spondias pinnata and Vitex pubescens. Bamboo breaks are a feature with Melocanna bambusoides being one of the main species. Other typical bamboos include Bambusa polymorpha, B. tulida, Cephalostachyum pergracile, Dendrocalamus longispathus, Dinochloa m’clellandi, Melocanna bambusoides and Oxytenanthera albo-ciliata.

 

South Myanmar Montane Forest

Montane forests in this BioProvince can be found on the Arakan Yomas Mountains and the Chin Hills on the west coast of Myanmar. The area is described as having a tropical wet climate. Up to an elevation of about 1000 m the canopy dominants include Bauhinia variegata, Derris robusta, Lagerstroemia speciosa and species of Ficus. These typically support a variety of lianas with Congea tomentosa and Mucuna pruriens being two of the main species. At elevations ranging from about 1000-21000 m these forests give way to mixed evergreen forest of oak (Quercus) with species of Castanopsis, Eriobotrya, Eugenia, Saurauia and Schima. Above 2000 m, Himalayan elements become conspicuous including Alnus nepalensis, Betula alnoides and species of Carpinus, Prunus, Pyrus and Torreya. Oak (mainly Quercus xylocarpus) become dominant again at altitudes ranging from 2400-2750 m, but higher than this Rhododendron arboreum and Quercus semecarpifolia become the main species. Many of these high altitude forests are shrouded in clouds and could be described as cloud forests. They support a wealth of epiphytic species; common among these are orchid taxa such as Dendrobium and Pleione, species of Aeschynanthes and Agapetes and more surprisingly Rhododendron cuffeanum. Above 3000 m shrubby vegetation predominates comprising species such as Hypericum patulum and Rhododendron burmanicum, while herbaceous elements include species of Aconitum, Lactuca, Pedicularis and Veronica.

 

South Myanmar Myanmar Coastal Rain Forest

These evergreen and semi-evergreen forests are found on the western side of the Arakan Yoma and Tenasserim mountains ranges on the west coast. They also extend into southeast Bangladesh. These lush forests are largely dominated by dipterocarps mainly Anisoptera glabra, Dipterocarpus alatus, D. obtusifolius, D. pilosa, D. turbinatus, Hopea odorata, Lagerstroemia calyculata, L. floribunda, L. speciosa, Parashorea stellata, Pentace birmanica and Swintonia floridunda. The undergrowth includes Calamus palms and the creeping bamboo Temostachyon helferi. There are also stands of mixed delta scrub and low forest characterized by Calophyllum amoenum, Diospyros burmanica, Elaeocarpus hygrophilus, Litsea nitida and species of Eugenia. Here the undergrowth is mainly Calamus erectus and Pinanga gracilis.

Further information required.

 

References

Blasco, F. 1983. Southeast Asian Savannas.  In: Ecosystems of the World 13 - Tropical Savannas. Ed. F. Bourliere. Elsevier Scientific Publishing Company.

Chatterjee, D. 1939. Studies on the endemic flora of India and Burma. Journal of the Royal Asiatic Society of Bengol, 5: 19-67.

Gopal, B. & Krishnamurthy, K. 1993. Wetlands of South Asia. In: Wetlands of the World: Inventory, ecology and management. Vol. 1. Eds. D. Whigham, D. Dykyjova and S. Hejny. Kluwer Academic Press.

Kurz, S. 1877. Forest Flora of British Burma. Government of India.

Rao, A. S.  Vegetation and Phytogeography of Assam - Burma. In: Ecology and Biogeography in India. Ed. M. S. Mani. Dr W. Junk Publishers. The Hague.

Stamp, L. D. 1924. The Vegetation of Burma from an Ecological Standpoint. University of Rangoon.