The effect of wax emulsion varying in concentration from 0 to 1.5% at 0.5% increments on the strength and dimensional stability of urea formaldehyde bonded particleboard at three glue levels, 8%, 10% and 12% has been observed. Results show that the addition of wax emulsion is useful to manufacture particleboard at low glue level, viz., 8% and 10%. But it does notshow any appreciable effect on the board made with 12% glue.

The properties of particleboards improve with increasing addition of wax emulsion for 8% glue and for 10% glue, the addition of 1% wax has beneficial effect on all the properties under investigation. Beyond this, further improvement is not marked. A combination of 10% glue and 1% wax is found advantageous to manufacture strong particleboard having good dimensional stability.

The growth and yield models/tables for Gmelina arborea Roxb. (gamar) in the plantations of Bangladesh have been prepared based on site indices. Models were derived by the data collected from permanent sample plots and also from temporary sample plots. Step-wise and all probable combinations of the independent variables methods were used to select the best suited models subject to the satisfaction of the statistical and biological requirements. Models were selected to estimate the stand dbh,stand mean height,stand basal area per hectare, total overbark volume yield per hectare and underbark volume yield per hectare upto top-end diameter of 10.0 cm. The yield prediction models derived in the study could satisfactorily be used for gamar plantations within the limitations ofstands of ages 3-12 years and site indices of 7.5 to 20.0 meters based on a base age of 12 years.

Acacia mangium seeds were subjected to six one-day pre-sowing treatments and their effects
on germination and seed deterioration in germination medium were studied under laboratory
conditions. The pretreatments were imparted by soaking the seeds, with and without funicle,
(a) in tap water (25^C) for three hours, (b) in boiled water (immediately after removing from heat
source) for one hour, (c) in boiling water for 30 seconds, and (d) treating with 95% sulphuric acid
for two minutes. Hot and boiling water treatments produced maximum germination, and at the
same time maximum damage to seeds. Other treatments had little effect on germination. A dry- •
weight analysis ofseed parts recorded 21% funicle, 30% seed coat, 47% cotyledon and 2% embryo
of the total weight.

The variation of strength properties of mangium (Acacia mangium) wood treated with the CCA preservative has been studied. It is found that compression parallel to grain, tension perpendicular in radial face and shear parallel to grain in tangential face have been significantly affected by the treatment. The treatment causes reduction in modulus of rupture, stress at proportional limit in static bending and shear parallel to grain. All other strength properties are observed to increase from 3 to 81 percent by treatment.

Seven different bamboo species have been growing naturally in the forests of Sylhet, Chittagong Hill Tracts, Chittagong and Cox’s Bazar of Bangladesh. Bamboo does not grow naturally in the mangrove and sal (Shorea robusta) forests. The distribution and ecological conditions of species have been described. The overexploitation, fire and other biotic interferences are reducing the area of natural bamboo forests on an average by two per cent annually. Lack of scientific management, especially large scale death after gregarious flowering is also considered to be an important factor for shrinking the bamboo area in the forests. Among the naturally grown forest bamboos the occurrence of Dendrocalamus hamiltonii, Melocalamus compactiflorus and Neohouzeaua dullooa is reducing alarmingly due to the destruction of their habitat. Therefore, these three species have been considered as threatened bamboo species of Bangladesh.

The nature and status of the non-wood forest products (NWFP) of Bangladesh have been discussed. The present institutional arrangements for collection and processing of NWFP have been analysed and major problems identified. Some policy and functional/managerial suggestions have been made to improve and augment the production and management of the NWFP.

Seed germination of golla-bet (Daemonorops jenkensiana) after pre-sowing treatment was studied. The seeds treated with HCL and H2SO4 separately showed 64-68% and 50-68% germination respectively irrespective of different concentration of acid. On removing only scally epicarp, germination of golla-bet increased to 51% without any acid treatment. The results indicate that acid scarification turn the hard seed coat into thin and papery resulting easy infiltration of water to accelerate possible enzyme activities in endosperm.

The physical characteristics, physical and mechanical properties of Calamus ereclus have been studied at three height positions. The variation of physical properties due to node and internode have also been investigated. The moisture content and shrinkage increase, whereas the specific gravity decreases with the height of the stem. The specific gravity is higher at the node than that at the internode. The bottom portion is stronger in respect of compressive strength, bending strength, nail withdrawal and side hardness.

The effectiveness of the preparation with borax, boric acid and copper sulphate salt (BBC) as a water borne wood preservative was studied in the laboratory soil-block test. Blocks of civit (Swintonia floribunda) and chapalish (Artocarpus chaplasha) wood were dip-treated with the preservative solution and exposed to a common white rot fungus (Polyporous versicolor) and a brown rot fungus (Poria nionticola). The loss in weight of the wood blocks due to the fungal decay was recorded to be in the range 0-1.4%. This showed that the preservative was very effective. The field test of the preservative is being carried out with chapalish and garjan (Dipterocarpus spp.) wood stakes along with untreated ones. All the untreated stakes deteriorated due to fungi or other wood destroying agents within two years, but the treated stakes remained uneffected even after five years of exposure.

The growth and distribution of root systems of an annual crop (French dwarf bean) and a young tree species (poplar) in large soil columns at three different soil water supply regimes were studied in a simulated agroforestry under a greenhouse condition at the University of Edinburgh, UK. The root biomass production of bean plants was found unaffected under the limited soil water supply whether grown in a monoculture or in mixed stands in contrast to that of poplar plants. The root system of bean explored only top 36 cm of soil column whereas poplar root system explored beyond the depth of 36 cm . These differential responses of an annual crop and a young tree species may be used as a basis for selecting complementary agroforestry components in a dry area.