Vegetation of Southeast Asia Studies of Forest Types 1963-1965

on the south by the Gulf of Thailand; and on the east by a mountain
range, Khao Banthat, - extending along the border of VJestern Cambodia.
The region includes a well-dissected upland In the northern and
central ports, and by a coastal plain in the south and west. It is
drained by numerous streams, till flowing in a southerly direction.
Moist Evergreen forests, on the mountain slopes (Fig. 2), and
Mangrove forests along the coast (Pigs. 58, 59) are the characteristic
vegetation in this area. The principal rivers are the Mae Warn Char.-
taburi, Prasae, Wen, and Trat. The principal mountain peaks are Khao
Khieo in the weat, with an altitude of about 2,C3 ft. (SCO n.); Khao
Soi Dao, altitude 5,200 ft. {l,&;0 m.); and Khao Sa Bap, altitude
3,030 ft, (933 m.), northeast of Chantaburi.
Climate: In some sections the climate of the southeast is
somewhat of the tropical rain forest type, and, is similar to that along
the west coast of the Peninsula. The wettest period lasts for 6 months
extending from May to October. Precipitation at Chantaburi is greatest
in July and least in February, with an annual average of 97-2 inches
(2,1*91+ mm.). Temperatures are generally high and uniform. The highest
recorded temperature is 10l°F. (38.8°C.) and the lowest 5^.5° F.
(12.5°C.). Seasonal variations are similar to those in central Thailand,
with the main difference that the rainfall is more abundant
and well distributed. The period between November and April is best
for ground surveys.
(5) Peninsula
General features: The physiographic features of the Peninsula
include both plains and highlands. Plains flank the coastal areas
and highlands form the backbone of the region. The total length of
this region is about h6f) miles (750 'cm.), and the width ranges from
about 10 to 125 miles (15 to 200 km.). The mountain range trends from
north to south and is formed of short ridges arranged in echelon.
Between these ridges there are small plains and valleys which are
considerably dissected.
Along the western side of the Peninsula the Tenasserim range extends
southward until it separates into two ranges in the trough of
the- Kra Isthmus or Pak Chan river. The western range lies in Burmese
territory, and the eastern in Thailand. The eastern range extends
couth of the Kra Isthmus to Ranong and skirts the Indian Ocean
to the bay of Phuket. The main range of the Peninsula again starts
anew to the north of Nakhon Srithamarat, extending in a southerly
direction to the province of Satun. In the area between this main
range and the island of Phuket there are isolulc^ button and peaks
rising sheer from the surrounding lowland. One such peak, Khao
Phanom Bencha, attains an altitude of about ^,500 ft. ^1,370 m,),
but for the most part the buttes are only a few hundred feet high
(Fig. 111). i;
I!
South of Songkhla there are three other ranges running north and !
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