Vegetation of Southeast Asia Studies of Forest Types 1963-1965

This is a report on the economic conditions in the two northeastern
circles of Nakon Rajas ima and Udon.
Up to about 1932 the northeast of Thailand, owing to its remote
position and difficulties of communication, was still little known
to the general public. This part of the Kingdom covers about 63,
sq. miles, or 31.7 percent of the total area of the country. It had
a population in 1932 of nearly 4 millions, or more than one-third
of the entire population.
Various, resources, chiefly agricultural and forest, products, are
found in the area, and large tracts of land are suitable for rice
cultivation, plantations and cattle raising. It is only within recent
years that this region has begun to develop, with the advent of
railroads and the construction of highways, providing quicker and
cheaper transportation, with the result that the general economic
conditions are showing some improvement.
There is a discussion of the principal industries, namely rice
growing and cattle raising; and the trade and production of each of
the 15 provinces within the two circles. A series of tables indicate
population density; monthly aud annual rainfall; crops under cultivation;
live stock; trade; etc.
Lew, G. T. Observations on citrus culture in Thailand. Kasikorn 27
CO: 381-395.
Loetsch, F. The effects of shifting cultivation on the Composition of
Tropical Forest, and the Regime of Rivers - A study of Northern
Thailand (Title in German). Erdkund 12 (3). Sept. 1958.
This report treats with factors relating to the long established
system of shifting agriculture, known as rai in Thailand and Vietnan
and chan car in Cambodia, and which is widely practiced in Southeast
Asia and other tropical regions. These include observations on:
(1) Areas covered by two types of forest: Mixed Deciduous Monsoon
forest; and Semi-evergreen Broadleaf forest. Of this forested area
55 percent is considered unproductive.
(2) In some areas Teak slowly colonizes cutover arena; elaevhere
it does not colonize cleared sites. Secondary growth is usually
without Teak. This tree occurs in island- like stands. Under shifting
cultivation valuable timber land is destroyed. The present area
of Monscon forest, with Teak, is cbout U5 percent of the original
stand.
(3) Of areas above 1,000'm. in altitude, only one- third are unimpaired
Brcadleaf or Coniferous forests; two- fifths are clearings
(nomadic); and one- fourth are savannas, resulting from earlier shifting
cultivation. The practice of shifting cultivation has been on
the increase during the Irst 25 years.
Shifting cultivation is of two types: (a) 1-year cultivation;
and (b) no established cycle, which is destructive to the noil. This
primitive system also causes extensive damage to valuable timber.
The author recommends the ela'jnination of shifting cultivation
from teak forest areas; and that teak planting should be increased.
232