Wood, is a hygroscopic substance. It has the ability to
adsorb and desorb moisture. When wood is exposed to atmospheric
condition its moisture content adjusts itself until it is in
equilibrium with the moisture content of the surrounding
atmospheric humidity. The equilibrium moisture content of wood
is dependant on the atmospheric temperature and relative humidity
and consequently a change in temperature and relative humidity
will bring about a change in the moisture content of wood. This
fluctuation of moisture content is generally accompanied by a
corresponding change in the dimension of the wood. The situation
becomes complicated by the fact that the dimensional change is
not same for all the species. Some timbers are comparatively
stable in respect of shrinkage and swelling while others are more
susceptible to such changes causing trouble during wood in service,
particularly in joinery work, such as, drawers, doors and windows,
etc. Thus knowledge on the seasonal variation of moisture content
of different species of wood and their concomitant dimensional
changes is of considerable practical importance in determining
their suitability for good quality furniture and cabinet manufacture.
A study was, therefore, undertaken to evaluate the relative
dimensional stability properties of some of the indigenous wood
species of Bangladesh where temperature and relative humidity
conditions of the atmosphere between the winter and monsoon
months vary widely.

In Bangladesh bamboos are the most important forest
produce and have become an integral part of the life of most
people. Five species of bamboos occur in the forests of Bangladesh.
The most important is Melocanna bambusoides. Other species such
as Bambusa tulda, Dendrocalamus longispathus, Neohauzeaua dullooa
and Oxytenanthera nigrociliata occur sporadically in gregarious
areas of Melocanna bambusoides. The stocking varies from extensive
areas of pure bamboo to scattered undergrowth in predominantly
timber producing areas. In order to meet the increasing demand of
bamboo, for both commercial and industrial purposes, all accessible
areas have been overfelled and the obvious result has been their
disappearence. Felling has now started in the less accessible
areas and it appears that these will meet the same fate. Replenishment
of stock has, therefore, attained a new dimension. All
cultivated species respond well to vegetative propagation but
the species found in forests are not amenable to any of the known
methods. Seed, therefore, remains the only method by which large
scale plantations of forest species can be undertaken.

Earlier investigations on kraft pulping studies of Albizzia•
moluccana Miq. wood (1) reveals that pulp of good physical strength
properties could be obtained from this exotic wood species. After
the successful completion of the kraft pulping, attention has been
diverted to observe the response to the Semi—chemical pulping of
the wood. If the response is positive, it may be possible to
suplement the existing short supply of pulp-wood in Bangladesh
by introducing large scale plantation of Albizzia moluccana.
Several logs of Albizzia moluccana were collected from the
tea-gardens of Khadimnagar, District Sylhet, Bangladesh. After
debarking, these logs were sawn to 6* x 4″ x 4” sizes and left
for air-drying by stacking. Chipping was subsequently done in a
laboratory model Murrey chipper to 1″ x 72″ x 78″ sizes. The
chips were hand sorted to remove the over and undersized ones.
Moisture content of the chips were then determined.

Albizzia moluccana is a fast growing tree of Leguminosae
family and Mimoseae sub—family, with light foliage and straight
clean bole. The wood is soft and light. It grows rapidly in the
wet zone (in the rainfall, range of 75 inches to 200 inches) and
reaches 32 ft. in height in about four years. The chief use in
Bangladesh appears to be for shade purpose in, tea garden:.., o -her
probable uses include making of tea-chests and planks. This
species is a native of Moluccas and Java (2).

When, one speaks of self-sufficiency in any commodity, one
means balancing the supply with the demand or the consumption
requirement over a period of time. For achieving such balance or
eVen to plan for achieving such balance, it is necessary to have
reliable data about the current consumption requirement, the
current supply position and the trend of change in both upto a
certain point of time in the future. Unfortunately, there are no
adequate and reliable data on the pattern of consumption
requirement of various forest produces nor is there any data about
the supply position.except about those which are obtained from
the reserved forests. As a result it is extremely difficult even
to assess the situation correctly. There are no literature which
can be drawn upon to prepare any paper on the subject. There are
a number of feasibility studies on the aspect of utilisation of
forest produce but they do not reflect the total position. Three
publications which have been found to be useful and relevant to
the subject arc: (1) “Timber Trends studies in East Pakistan”
prepared in 1957 by Kr. S.I-I. Ishaque, Forest Utilisation Officer
of the then Government of Pakistan, (2) “The Forest Products
Market Survey” prepared in the year 1963 by Messrs Forestal
International, and (3) ”An estimate of long-term timber trends
and prospects in East Pakistan” prepared in the year 1968 by the
Chief Economist and the Assistant Chief of the Planning Department
of the then Government of East Pakistan. These publications have
been used freely in preparing this paper. In those works attempts
have been made to assess the consumption requirement of ‘various
forest produces and, in the absence of reliable data, it has been
done, obviously, on certain assumptions made by the authors
themselves and it is interesting to note that they have produced
results which do not agree with each other. This disagreement
amply clarifies as to how difficult it is to arrive at any
reasonably correct conclusion. As there is no better information
available, the figures mentioned in the estimates prepared by the
Planning Department, being the most recent one, has been taken as
guide and the discussion is being based on these figures.

The’ mangroves are tidal vegetation peculiarly adopted to
tidal saline water. This is a complex plant community primarily
controlled by cdaphic factors. Due to their, peculiar morphological,
anatomical and physiological features, they are most suitably
adopted to the saline muddy habitat. Their occurrence 1 is
dependent on the tide level and are not found beyond the high
tide mark. These communities are the product of the constantly
changing conditions of its habitat.

Summary of data for the month of January to June, 1973-
Station: Forest Research Institute, Chittagong.