BANGLADESH JOURNAL OF FOREST SCIENCE
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
Air drying is an important mode of seasoning timber in Bangladesh where sawnjill owners and lumber dealers can hardly afford to possess modern dry kilns. Due to lack of adequate knowledge and absence of proper drying schedule, the method is not being practised effectively to get the best result. It is, therefore, considered ‘partinent to study the air drying characteristics of some of the important wood species of Bangladesh.
The establishment of efficient drying schedules for various species is dependent upon the rate at which a given species loses moisture. This is, also, affected by the drying condition existing in a particular region at any given time of the year. The present paper deals with the rate of moisture loss and air drying time of 10 indigenous wood species of Bangladesh under two conditions of exposure.
The paper examines the profitability of teak ( tectona grandis, Lin. f) plantations under the existing system of management in Bangladesh. The Forest Department has fixed 69 years as the rotation length for teak on all sites. Land expectation values have been calculated on the basis of the Faustmann formula and preliminary yield tables for three site qualities. They have been calculated on the assumption that the sites would be used for teak plantations for an infinite number of 60 year rotations. The sensitivity of results to changes in the planting and overhead costs and in yields was also calculated. The result indicates positive net returns for sites of qualities I to III under all cost conditions at an eight percent rate of interest. At thirteen percent, sites of qualities I and II show a positive result but those of quality III indicate a net loss Land expectation values are not found to be a convenient index of profita
The lack of knowledge of treatability of timber species with pressure method may result in poor treatment in respect of penetration and retention of the preservative chemical Inwood. This knowledge for our indigenous timber species was not ascertained before. The relative penetrability of nineteen timber species was, therefore, determined with Lowry empty cell process using 40:60 creosote and light diesel oil mixture.
Specific gravity of species did not seem to have any bearing on the penetration cf preservative. Grain structure and presence of tyloses appeared to be correlated with penetrability of the wood. The species were classified into four treatability groups according to the degree of heartwood penetrability.
Green Garjan, Dipterocarpus spp. sleepers, which are very difficult to treat, were treated successfully with an oil-borne preservative. Bethel full cell process was followed. Before treatment the sleepers were conditioned by alternate steaming and vacuum to facilitate impregnation. Sleepers thus treated had an average penetration of 4.9 cm (1.95 in) which is higher than that required for outdoor use in Bangladesh.
The necessity of adjusting the temperature as well as the duration of pretreatment in relation to residual moisture content of green Garjan sleepers has been discussed.
In this paper efforts have been made to put together scattered information available on various species belonging to the family Dipterocarpaceae found within the geographical boundaries of Bangladesh. Importance has been given to the genus Dipterocarpus. Their taxonomy, distribution and past and present management practices have been particularly discussed.
Dendrocalamus Strictus Nees-was introduced to Hazarikhil during the year 1939 (Hasan 1978). Eight offsets of this species were collected from that area and planted in the Forest Research Institute campus (FRI), Chittagong in 1974. Later on, during 1981-1982, five clumps were also
raised in Keochia Research Station through offsets collected from the same mother clump of Hazarikhil.
Micrococca mercurialis ( Linn. ) Benth (Euphorbiaceae) cited as CaloxyIon mercurialis Thwaites by Hooker ( 1887) was reported by the same author as occurring at Mongir of Behar, the Deccan Peninsula, Burma and Ceylon. It is distributed in Arabia and tropical Africa. Prain ( 1903) reported it from Behar. This species has recently been collected from Chittagong district. In the various floristic works by Heining ( 1925 ), Raizada ( 1941 ), Datta and Mitra ( 1953), Sinclair ( 1955) and Khan and Banu ( 1972) the species has not been recorded from the region now under Bangladesh.
Based on availability and strength properties, eight indigenous species were selected as alternatives to Garjan for use as railway sleepers.
The sleepers were put to service test in the main track of the Bangladesh Railway. The performance of seven of them has been found satisfactory
and, therefore, are recommended for use as railway sleepers.
The paper includes a field key of 12 species of Bangladesh Loranthaceae based on their leaves and indumentum characters. Brief taxonomic notes on vegetative characters of the species, their flowering time and distribution in Bangladesh have been presented.
Local substitutes for expensively imported malt extract and dextrose in agar media in the form of sugarcane gur and glaxose respectively were investigated. Colony diameter of 14 fungi and mycelial dry weights of 9 fungi were compared on 2 % malt extract agar (MA) and 2,3, 4 and 5% sugarcane gur agar (GA) ; potato dextrose agar (PDA) and potato glaxose agar (PGA). Diameter giowth on 4 % GA and PGA was comparable to 2 % MA and PDA respectively. Four per cent gur is recommended for GA medium. Glaxose is incorporated in PGA at the same rate as dextrose in PDA. Gur frem 4 different localities in Bangladesh incorporating 4% GA resulted in
insignificantly different colony growth of the two fungi tested.
Welcome to the Bangladesh Journal of Forest Science (BJFS) – a leading platform for advancing the knowledge and understanding of forest science in Bangladesh and beyond. Established with a commitment to excellence, BJFS serves as a cornerstone for researchers, practitioners, and enthusiasts dedicated to the sustainable management and conservation of forest ecosystems.
