Vegetation of Southeast Asia Studies of Forest Types 1963-1965

CLASSIFICATION OF TROPICAL FOREST TYPES
With Special Reference to
SOUTHEAST
ASIA
The classification of vegetation has long been a fertile ground
for discussion and speculation. This is because plant-cover, even
in its simplest manifestation, is a complex variable owing to the
many interrelated factors that control its distribution.
The flora and vegetation of much of the world, especially of
temperate regions, are well known. Considerable information is
available on the operation and effect of the environment on the
vegetation of many of those areas, and which makes classification
possible. But in many tropical forest regions the technical problems
of descriptions and identification are great. Usually thera
is little information available on the influence of the climate, soil
and. other factors on the vegetation. So that rnuch data still remain
to be assembled before a standard system of classification of tropical
forest types can be established, which would be applicable tc
widely separated area, such as Southeast Asia, Tropical America or
Central Africa.
.Several systems have been suggested or adapted for the classification
of vegetation. Such plant geographers as Drude (1890),
Gauscen (1933), Cain (lyuU), and Good (19^7) are concerned mainly
with the distribution of individual species and the relative coincidence
of members of the same flora in certain areas.
The need for a physiognomic an opposed to taxonomic description
of vegetation was recognized by Schimper (1903), the renowned plant
physiologist and geographer, and later by Warming (1909), who desscribed
equivalent formations based on similarity in appearance and
function of..botanicolly unrelated dominant or characteristic species.
These criteria represent an appreciation of the vegetation in general
and not of flora. The system advanced by Riibel (1930) covers the
most important types of plant associations, and makes possible their
subdivision into many fades, but it does not depend upon botanical
classification of dynamic status. The main criteria he considers
are woodiness, leaf-uhape, type and deciduousness.
A radical departure from toxonomic thinking in descriptive ecology
was also made by Raunkiaer (193M> to whom the concept of life-forms
must be credited. Several authors have modified somwhat the system
proposed by Rauiikiaer, but on the whole the original framework hes
been retained. Its object is to provide a small number of categories
into vhich all plants can be fitted according to their apparent
morphological-physiological response to the unfavorable season,