Vegetation of Southeast Asia Studies of Forest Types 1963-1965

A postscript treats with the future of the Tropical Rain forest.
Included also are a long list cf references; an index of plant
names; and a general index.
. The types of vegetation of the humid tropics in relation to the
soil. Proc. of the Abidjan Symposium U.N.E.S.C.O. pp. 15-23. 1961.
This is a discussion of: 1) the principal types of vegetation in
the plains and lower mountain regions of equatorial and subequatorial
zones and in adjoining tropical axeas, and the soils in which they
are to be found; 2) characteristics of soils in this climatic zone
which influence the occurrence of vegetation, and the possible influence
of the various types of vegetation on the soil; and 3) evaluation
of the soil in bringing the land under c-xltivation.
. Plant Life and Tropical Climate. Biometeordlogy. pp. 67-75.
1962
Ṫhe absence of a cold season results in plant activities in the
tropics being limited by lack of water rather than by low temperatures.
The distribution of natural vegetation types in the tropics
is thus mainly determined by the seasonal distribution of rainfall.
Th< effects of excessively high temperatures on plants growing in
some tropical habitats has been little studied, but the survival of
some plant species in the same areas seems to be dependent on the
coo.ling effect due to transpiration. Information on the growth
rates of plants, apart from a few cultivated species, is surprisingly
incomplete. Available data indicate that the very high rates
among some species depend on the rapid development of new leaf area
rather than on net assimilation rates being higher than those of
temperate plants. Scanty evidence suggest that the rate of organic
production by tropical forests is not much higher than in temperate
hardwood forests.
In tropical countries, with little seasonal change, plants often
show regular rhythms of flowering, leaf change, etc., but these may
be out of phase with the climate. I^en where there are marked wet •
and dry seasons, plants do not always behave in the way expected.
For example, seme trees lose their leaves in the wet season, hut not
in the dry period. Seasonal rhythm in plants seems to be partly
dependent on internal physiological rhythm and not entirely on the
external environment. Kven in latitudes where differences in daylength
are very small, day-length may be an important factor in
controlling flowering and other seasonal phenomena in plants.
Literature cited contains twelve titles.
., A=.G. Tanslqy and A.S. Watt. The recording of structure, liveform
and flora of tropical forest communities as a basis for their
classification. Imperial Forestry Institute, University of Oxford,
Institute Paper No. 19. pp. 3-19. 1939.
This paper f trims a valuable supplement to Burtt Davy's Institute
Paper No. 13, published in 1938. It embodies the opinion of a
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