Introduction
In East Pakistan due to various pressure on the sal
forests, the original crop lias deteriorated further in its
genetic composition, bo vigorous attempts have to be made to
Shorea robusta’, a member of the genus Shorea, belongs
to the family Dipte.rocarpaceae0 Sal (local name) occupies
two main regions of the subcontinent (separated by gangetAc
plain) the Northern and the Central region of Indo-Pakistan,
In East Pakistan it occurs in three areas Dacca, Mymensingh
and Dinajpur-Kangpure Dacca-Mymensingh sal is the tail end
of the Eastern range following Garo Hills of Assam (India)
where_as the Dinajpur-Kangpur sal is the continum of Bengal
Duars.

During the months of June and July, 1970, severe defoliations of
young teak plantations were observed in several localities of Chittagong,
Chittagong Hill Tracts North and Cox’s Bazar Divisions ( see Table I ) •
Especially leaves in the upper part of the crowns were eaten causing the
teak look rather naked as during winter time. The leaves were eaten up
except the major veins, as showns in Figure 1 •

INTRODUCTION;
Dhaincha (Sesbania cannabina ), an annual plant, is cultivated in the riverine deltas, charlands and alluvial banks of rivers in the districts of Dacca, Faridpur and Mymensingh. It also grows in other areas of North, Central and Eastern part of East Pakistan .
Locally it is known as Kath-Dhaincha and botanically falls in the Leguminosae family. There are three plants akin to each other under the names Sesbania Aculeata, Sesbania Cannabania and Sesbania paludosa Sesbania paludosa, commonly known as Shola or Kath-sola, grows in the marshy lands and is lighter in weight than Dhaincha. Sesbania aculeata is a virgate and prickly shrub, whereas Dhaincha, a slender, straight, unarmed plant, grows to a maximum height of 20 feet. Dhaincha plants, flexible when green, become stiff after cutting and drying and are used as fencing material, creeper support and fuel wood. Even by most conser- vative estimates the annual production of the plant is enough for running a large paper mill on perpetual basis.

Gamari or Gamar is a well known furniture wood in
East Pakistan, particularly in Chittagong. The botanical
name for Gamar is Gmelina arborea, Roxb. , and it belongs to
the family Verbenacr.c to which teak belongs. The generic
; Melina) is named after S.Gottlieb
The la’<in rceanirg of ’’arborea” is Local names : Gamari; Gamar (Chittagong, Chittagong Hill Tracts, bylhet), Joginichakra (Mymensingh), Ramani (I'lagh) Gambar, Bol-gippok (Garo), Kumhar, Gumhar, Gumliar (W.Pak.) In Burma} the plant is known as Yemani, Name used in the exotic plantations, e.g, Nigeria, is Gmelina or Yemani. In English it is known as Kashmir tree or white teak.

Like the starving man of legend many developing countries are
sleeping, unaware, on a heap of gold.Most of the largest and richest
tropical rain forests are located in the “Third World”, but for the
mosy part they are unexploted, ignored, unattended or poorly managed.
And it is in these regions that hunger and poverty are most acute.
There would seem little- if any- connction between developing
forest land and solving the hunger problem. But it has become increasingly clear to economic planners and developing experts that the two
are so closely linked that in the years ahead forestry would be a key
factor in the fight against hunger.

Summary of data for the month of November 1970 to March,1971°
Station: Forest Research Institute,Chittagong:
Time of observation: 0800 hours

Introduction
1 All the figures are for conifers and on dry wieght basis.
Major constituents of wood are cellulose, lignin and hemicelluloses. Small amounts of pectic material, starch and other extraneous substances are also present. The ash content of wood seldom
exceeds 0,5%..) (2) o Normal hardwoods and softwoods usually contain
42?2 percent of cellulose. The lignin content of hardwoods varies
from IS to 25%, while in softwoods the range is 25 to 35%. A partly
acetylated5 acidic xylan accounts for 20 to 35% of the wood of hardwoods, with a second hemicellulose, a glucomannan occuring in small
amounts. A partly acetylated galacto-gluco-mannan makes up almost
20% of coniferous wood, but the xylan, .in this case, comprises only
10% of the total wood substance(2).
S3
In a typical wood cell, the primary wall forms an envelope
for the secondary wall, which in turn, encloses the lumen. The primary wall, as well as the intercellular substance, are highly lignified (71 per cent lignin and 14 per cent pentosan in Douglas Fir) ,
whereas the secondary wall is largely cellulose ( over 50% in 8^
and slightly less in layer) , though lignified ( 13 to 25% in
$2 and 11 to 13/j in layer). The hemicellulose content is about
20% in the primary wall, 25 to 30% in the So, and 30 to 35% in the
layer ( 37)—. Regions of. approximately parallel change alternate
with less ordered regions in the secondary wall cellulose. The
molecules in the crystalline regions and to a certain extent, in
the amorphous regions, are held primarily together by a large
number of hydrogen bonds while Van der Waal’s forces probably make
some contribution to the cohesion.