Vegetation of Southeast Asia Studies of Forest Types 1963-1965

found also in western Cambodia in the Cardamom and Elephant mountain
ranges. There are some isolated stand3 of Rain forest, also, in
the Annan Mountains of contra! Vietnam, "in Puerto Rico Rain forest
is confined mostly to the upper sloped of the Luquillo mountain, in
the northeast. Dominant trees in this forest are Dacryodes, 'tabar.uco 1 ,
associated with Sloanca. On the summit of these ranges in Puerto
Rico dwarf trees form wnat some call k fcllfin woodland' Ln the Montane
forest. The same type of forest is found on the summit of mountains
Irithanon, Gutep, Angka, Puy, and Chien^iao in northern Thailand.
Mossy forest occurs at the upper limit of the Montane forest
in Thailand as well as in northeastern Puerto Rico. In this forest
the tree trunks and branches are covered with mosses and lichens, and
the ground is a moist, sphagnum bog.
Evergreen Moist forest is wideJy distributed along the lower and
Middle windward slopes of hills and mountains both in Thailand and .
.Puerto Rico. Stands of Dry Kvergreen forest are scattered in eastern
and western Thailand, and along the north coast of Puerto Rico.
Mixed Deciduous forests are also a common occurrence in Thailand,
Puerto Rico, as well as in Texas.
The mountain cabbage or 'sierra' palm (Eu terpe 'glubosa) is a distinctive
and characteristic feature of the vegetation in upland areas
of Puerto Rico, often forming extensive stands. In Thailand palms are
also well represented by several species, but nowhere do they fonr.
large, dense stands, comparable to the IMerto Rican Euterpe globosa.
Trees of the wood-oil family (Dipterocarpaceae), represented oy
several genera, are a dominant and characteristic feature in Southeast
Asia. In Thailand they constitute about 4^ percent of the total
forestea area. These trees do not grow naturally, and no attempts
have been made to propagate them eitner in Puerto Rico or Texas.
Bamboos, of which there are about 19 species in Thailand, are
widely distributed throughout Southeast Asia, develop rapjdly and
form extensive brakes in forest clearings and play a very important
part in supplying the daily needs of the people. Bamboos are not
native to Puerto Rico or Texas, but several species have been introduced
and propagated successfully in Puerto Rico.
A distinctive topographical character, with a characteristic
plant cover, are the limestone bluffs, "haystacks' or 'mogotes',
frequent in northern Puerto Rico. Similar liit.estone buttes, often
with steep slopes covered with distinctive vegetation are found in
widely scattered areas of Thailand, especially in the southern
Peninsula where they form a prominent feature of the landscape
(Fig. 111).
Thorn forests are common in cleared land in Thailand, especially
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