Vegetation of Southeast Asia Studies of Forest Types 1963-1965

These wooded savannas are Influenced by the T.ionroon climate, The
soil is usually improverished. Consequently, ^he trees are of small
dimensions, usually not exceeding 30 ft. (10 ni.) in height, and
thc-ir crowns seldom touch. They are dominated by members of the woodoil
family (Dipterocarpaceae), especially Shore a obtusa, Pent aone
siar.er.rrio, and Dlpterocarpiis obtusifolius. 'LTfe""^eneraT landscape
often has a park-like appearance.
These savannas are burned over annually, but several of the trees,
as wel] as Gone grasses, particularly Impcrata cylint'.rira, and cer- •
tain herbaceous plants, Including Hupatorium odoratu:n, are capable
of surviving jround fires. If recurrent fires were eliminated, resulting
in t.he gradual restoration of the soil to its original condition
of fertility, it is possible that the open rprassland savanna,
a's well as wooded savanna, would be replaced by a Deciduous type of
forest, especially the Dry Dipterocarp forest widespread in northeastern
Thailand. Where the savanna woodland extenas to streams or
rivers, the hij.'.h soil moisture content close to or alonn the banks
is sufficient to support a Krin^inf, or Gallery forest, of the Dry
'Sver^reon type, already discussed. Because of the open nature of s.
savanna, whether grassland or wooded, ground-to-ground anri ai r- t,op.round
visibility is usually most favorable. Ground mobility also
is satisfactory, since the soil usually forms a hard pan during the
dry season.
GROUND STUDIES OF GTRUCTLTHE O. ;1
THAI FOixb'STS
About the middle of 19^3 the Bangkok of'jce of AHPA's Research
and Development ield Unit arranged, on contract basis, with Mr. Tern
orut.inand, forest botanist of the Hoyal Forest Department of Thailand,
to organize a field team, with the objective of making profiles and to
assemble, data on the principal types of forests in Thailand. The team
recruited is composed of p our or more forest rangers, mostly graduates
of the Forestry School at Kasetsart University, accompanied by technicans
to gather soil samples, and others to serve as assistants and
drivers (i iG. 121).
Under the direction of I,t. Col. V.'.R. Scheible (U3AF) of ARPA, this
project commenced in Auf^ust 1 C XX3 w i"th the study of selected sites in
the Kliao Khieo forest, in the Korat area of central Thailand. Since
that time a lar^e series of profiles has been made, covering almost
the entire country. Two weeks are usually spent in a selected area,
to prepare profiles and to gather data -and plant materials. These
are evaluated later during a period of one or two weeks at the Forest
Department in Bangkok, immediately following each field trip.
briefly, the procedure followed is to select a representative plot
of about two acres in a particular type of forest. A rectangular
strip is staked in the sample plot. The width of the transect is
kh