94 research outputs found
DEVELOPMENT OF DRYING SCHEDULES FOR RUBBER AND PINE TIMBER FOR THE DEHUMIDIFICATION KILN DRYING
Most of the limber in Sri Lanka is used in unseasoned state or seasoned using conventionalkilns which use fuel wood boilers or open fires as a heating source. A study has beenconducted to introduce dehumidification drying kiln. which is easy to fabricate andconsumes less energy hence ideal for small scale timber industries.Experiments were conducted to investigate drying behaviour. to develop kiln schedules andto evaluate the developed kiln schedules for Pine (Pinus caribaea ; and Rubber (11('\'('(/brasiliensis) timber. The dehumidification kiln used in the present study is locallyfabricated and it has 25 cuhic feet capacity. The temperature of the kiln can be increasedto 50flC and relative humidity can he reduced to 16%.Drying rate. percentage shrinkage and drying defects were observed for these two speciesby drying 21.'ix75x300 mm stakes in temperature. humidity and air circulation controlledmini chamber. It was found that Pinus caribaea was relatively fast drying timbercompared with l lcvea brasiliensis. However. II. brasiliensis showed higher percentageshrinkage and defects over P. caribaea during the early stages of drying. This indicatesthat 1/. brasiliensis should be dried slowly at the initial stages of drying.Three k iln schedules with slow. medium and fast drying rates were developed forseasoning 25 nun planks based on the results of drying behaviour. Drying rate. dryingefficiency. drying defects. drying cost and thermal efficiency of these kiln schedules wereevaluated by drying 25x 150x 1O00 mm sample hoards in the dehumidification kiln.Compared with conventional kiln seasoning. dehumidification kiln seasoning gave higherquality dried timber with more than <JO%drying efficiency and faster drying rate. whilemaintaining higher thermal and economical efficiency,It is concluded that higher quality II. brasiliensis and P. caribaca dried timber can beobtained at a faster rate by drying them using these schedules ill the dehumidificationdrying kiln compared with conventional drying,
Product Carbon Footprint of Wooden Products in Sri Lanka Special Reference to a Life Cycle of an Arm Chair
Forest and forest products have a vital role in mitigation of the global climate change. Themain objective of this study was to assess the carbon emissions in the manufacturing of woodproducts taking an example of the production of an arm chair using life cycle assessmentapproach (LCA) which provides a methodological framework for evaluating environmentalperformance over the life cycle of a product, process, or an activity.The product Carbon Footprint was assessed for a typical wooden arm chair manufactured inan average sawmill. Assessment boundary was cradle to grave. The system boundaryencompasses each product manufacturing process including material (logs, wood, resin,fuels) transport to each production facility. Transportation distances were reported in surveysand used to calculate product transported per kilogram–kilometers (kg-km). The embedded Cflux in harvested timber, GHG emissions and the flow of embedded CO2 stock during theprocessing were analysed. The cumulative system boundary includes all upstream flows ofenergy, fuel, and raw material for production. Energy consumed during transportationbetween the harvesting life-cycle stage and manufacturing accounts for actual distancesreported from each production region.The functional unit for the product was referenced to 1 m3 of the product. All input andoutput data within the cumulative system boundary were allocated to the functional unit ofproduct and co-products in accordance with International Organisation for Standardisation.The data represent average regional data from sample studies. Umberto for Carbon Softwarewas used for the analysis. The total life cycle consists of 08 stages, raw material and timberharvesting, timber depot operations, log conversions, wood preservation, timber seasoning,manufacturing, use phase, end of use/ final disposal.Based on the calculations, percentages of GHG emissions in each stage of life cycle were54% for raw material and timber harvesting, 4% for timber depot operations, 11% for logconversions, 5% wood preservation, 1% for timber seasoning, 12% for manufacturing and13% for use phase and end of use/final disposal. From the above results it is apparent that ascarbon emissions are greatest at the timber harvesting stage, measures should be taken tointroduce more efficient and effective machinery and methodologies to reduce the emissions.Keywords: Product carbon footprint, Wood products, Life cycle analysis, Climate chang
DISTRIBUTION OF INVASIVE PLANT Ulex europeus IN HORTON PLAINS NATIONAL PARK
One of the most sensitive problems facing the conservation and management of HortonPlains National Park is the spreading of Ule.r europeus (gorse), an invasive plant species.To effectively manage and control this species it is necessary to have a sound knowledge ofits distribution within this park.This study was carried out to find the extent and distribution of Ulex CUUiPl'llS in the parkand finally to prepare a map showing the extent and distribution. The percent coveragewas assessed using 2m x 2m quadrats. In each quadrat percentage cover of reproductivesand non-reproductivcs were measured.According to the results of this study, about 6ha of the area is covered by Ule .r curopeus.Total amount of the area which covers more than 80% of Ulex europeus is 2.4ha. The areawhich consists of less than 8OCYr, of Ulex europeus is 3.3Iha. The extent of reproductivcsand non rcproduciivcs are also presented in the paper. Findings on the distrihution patternor the species show that the area around the main gate and Farr Inn guest house is themost densely and continuously distributed area with more than 80% coverage of Ulexcuropcus. Except this there arc a few isolated patches on either side of the road and trailwith more than 80% coverage of Ulex europeus. The distribution of the Ulex europeusplants arc mainly restricted along the stream from Black bridge to Gem pit pool. Thedensity of the species gradually decreased from up stream to down stream hut it was higherin the areas where water is stagnated along the stream. It is interesting to note that therearc no plants of Utes europcus found inside the natural forest except at the margins of theforest.
Investigation of timber utilization properties of Khaya senegalensis and Switenia macrophylla
As the need for wood and wood products is steadily rising, both the private and government sectors have increasingly become interested in introducing new, commercially valuable, fast growing timber species. A major drawback for the efficient utilization and promotion of new species is the lack of information regarding their wood properties when grown under local conditions. The present work was designed to investigate some wood properties of Khaya senegalensis , which has been established by the Forestry Department and much familiar Swetenia macrophylla.Three trees each from three crown classes (suppressed, co dominant, dominant) from 62 years old K. senegalensis were studied. Three trees from 88 years old S. macrophylla were also studied which belong to co-dominant class. Log end splits were measured from the extracted boles. Sample disks were extracted at breast height from each tree and pith eccentricity, heartwood percentage and colour were measured. Radial variations of density and shrinkage were studied at percentage distances from pith to bark. To investigate the effect of growth rate on specific gravity, ring width and specific gravity were measured from the extracted disks from breast height.Colour of the heartwood of K. senegalensis was reddish brown and sap wood was pinkish white. In S. macrophylla heartwood was reddish yellow and sap wood was yellow. Log end splits were higher in K.senegalensis. Pith eccentricity and heartwood percentage values were higher in S. macrophylla. According to the results, the general pattern of radial variation of specific gravity in both K. senegalensis and S. macrophylla was similar: remaining more or less uniform from pith to bark. It was observed that the two species show a gradual increase of volumetric shrinkage from pith to barkThe mean ring width values of K. senegalensis for suppressed (3.92 mm), co-dominant (6.09 mm) dominant (7.02 mm) crown classes were significantly different. The mean specific gravity for these classes (0.654, 0.602 and 0.686) was also significantly different. But no significant relationship between ring width (growth rate) and specific gravity was found among each crown class. The mean ring width and specific gravity values of K. senegalensis were compared with the initial 33 years of co-dominant trees of the S.macrophylla. The mean ring width value obtained for the K. senegalensis (5.67 mm) was significantly higher than the mean ring width of S. macrophylla (4.32 mm).Also specific gravity of K. senegalensis (0.647) was significantly higher than S. macrophylla (0.577). Therefore, it can be concluded that growth rate and specific gravity are higher in K. senegalensis compared with S. macrophylla. Hence this initial study suggests that recently introduced K. sengalenis will produce better quality timber in term of specific gravity at a faster rate compared with presently popular species S. macrophylla. However other factors such as colour and appearance and market acceptability should also be explored
ISOLATION OF SOME WOOD DECAYING FUNGI AND STREPTOMYCES AND THEIR EFFECTS ON SOME COMMERCIAL TIMBER SPECIES IN SRI LANKA
Wood is subject to .utack by wood inhahiting fungi in a variety of environmental situationslrnm the standing tree to the wood product in service. An investigation was carried out tostudy the resistance or five conuncrcial timhcr species namely Rubber (111'1'('11 brasiliensis),Luuumidcll.r (Mcli« rlllhlll) Pine (PiIlIlS raribca). Mahogony (.)11'/1'11'11/0 I)I{/(.,.o/,llylla)andTeak (1""("/(11111 ,~nlllrlls) to lung.il attack.Four wood decaying fungal species were isolated from naturally infected wood samples,Three species namely Trirodcrma Sfl., Mycrlia stcrilia and Streptomvccs sfI. belonging toDcutcromycot ina subdivision and AspergillI'S sp. belonging to Ascomycotiua subdivisionwere identified. These species were used to assess the initial decay of wood. Out of thelour SI1l'l'ics tested SIU'f)/OIlIH'C.I .III. was the most destructive fungal species.The wl'i)!ht loss or timber was taken as parameter or decay. Wood species and the fungalxpccicx had a significant effect on the weight loss. The highest weight loss due to fungalattack was caused hy Strcptomvrcs species in all the timber species except in Lunumidcllawhere Trirodcrnia Sf' recorded the highest weight loss.In Rubber, Lunumidclla and Pinus moisture gain was observed with fungal attack whilemoisture loss was observed in controls. In Mahogany and Teak moisture gain due toIUllgal auack was negligihle. Since these fungi caused a considerable damage at the initialstage or decay they can he grouped as primary decaying fungi in wood.
A STUDY ON THE STATUS OF FURNITURE MANUFACTURING INDUSTRIES IN MORATUWA AREA
Moratuwa area has a long history of furniture industry in Sri Lanka. In the present study,furniture manufacturing industry (FMI) in Moratuwa was studied using twoquestionnaire surveys. The main raw materials. manufacturing process, technologicallevel, furniture designing methods, seasoning methods. waste disposal methods,educational and sociological aspects of workers of the FMI were studied. In addition, datawere collected on furniture marketing from the Ratmalana furniture permit-issuing centerof the Forest Department. Raw material supplies (timber logs) into the Moratuwa areawere also studied at five different locations including timber-checking stationsThe study revealed that the Moratuwa area consists of considerable amount ofmechanized carpentry sheds and some associate with furniture shops or saw mills. 83%of furniture is manufactured using heavy wood species and 17% using light wood species.Teak is the most popular timber species followed by Satin and Nadun. Most of thetimbers used in the industry are air dried, while others are kiln-dried. Three commonmethods are observed for designing of furniture: based on consumer preference,traditional designs by carpenters and use of designs from foreign catalogues. Furniturecan be categorized into six broad categories, based on their quality and finishing level.Semi- finished Furniture are mostly sold in bulk to furniture dealers in out side areas, andafter transportation, they are finished and sold based on regional requirements.The total number of furniture production per month is estimated as 63,612 units, when41 furniture items are considered. Teak Cabinets, Teak Elmira, and Teak Chairs are themain manufactured items. The overall monthly income from all the FMI of Moratuwaarea is estimated to be Rs. 54.05 million.Wooden wastes mainly consist of sawdust! slabs (2854 cum) and fuel wood (1850 cu.rn),which arc estimated to value approximately Rs. 569,270.00. 13 % of this wooden waste isused for cooking purposes in the FMI of Moratuwa area. 34% is used for other purposessuch as agricultural and poultry industries and as fuel for kilns of the brick industry.However 44% of wooden wastes is not utilized and is disposed by burning.The total number of workers is estimated as 3515 workers which comprises, skilledcarpenters (68%), semi skilled carpenters (11%), laborers (7%), other category workers(5%Y," managerS (4%) and supervisors (4%). The dominant age class-ilrthe"FMJ is"4F55 years, which represents 44 percent of the total workers. 192 children (out of 378) ofthe workers are employed in FMI; which accounts 51 percent children of the workers jointheFMI. The educational levels of the workers are low and they have gained their skills fromtheir fathers and forefathers
RESIN YIELD AND TIMBER QUALITY OF Pinus caribaea TREES TAPPED USING RILL METHOD
Experiments to study the oleo-resin yield in different diameter trees, tapping depths andtapping heights were under taken in the wet zone in the Kalutara District. Oleo-resin yieldwas measured in Pinus caribaea trees belonging to two diameter classes (10 em - 20 cmDBH, >20 cm DBH classes), two tapping heights above ground (0.5 m and 1.3 m) andthree tapping depths (I mm, 2 mm and 5 mm).Results showed that oleo-resin yield was higher in larger diameter classes compared withlower diameter classes. Resin yield was also higher at 1.3m tapping height compared with0.5m height. Resin yield also increased as the tapping depth increased from I mm to 5mm. Based on these data it is recommended that the lowest tappable limit may be above20 ern DBH and it can expected to increase the yield of oleo-resin as well as health andvigour of the tree. It is suggested the height of tapping should be increased to yield moreoleo-resin. However the cost of tapping would increase when higher heights are to be used.A 5 mm depth starting from the live bark can be recommended as suitable depth in resintapping. This depth can increase the yield of oleo-resin while maintaining the health andvigour of the tree.Experiments to study the growth rate and timber quality of tapped and untapped P.caribaea trees were also done by measuring density and width of the rings. Log samplesfor this experiment were obtained from plantation at Guruthalawa in the Badulla district.At the time of sampling these trees had been tapped for 5 years.There were three tapped and three untapped trees which belonged to 3 diameter classes(20cm, 28cm, 36.5 ern). Each couple of tapped and untapped tree had the same diameter.For each tree, discs were extracted at 0.5 m height and 1.3 m height. The width of growthrings which is a measure of growth rate, were measured on untapped tree, tapped radiusand untapped radius in tapped tree. The data showed that wood production has not beenaffected considerably by resin tapping.The density which is an indicator for wood quality showed an increasing trend from pithoutwards. Density in the tapped trees was higher due to infiltration of oleo-resin into thewood after resin tapping. Except this variation, no other considerable difference wasobserved in density between tapped and untapped trees.
TREATABILITY OF PLANTATION TIMBER SPECIES WITH CCA (COPPER·CHROME·ARSENATE) PRESERVATIVES AND THEIR EFFECTIVENESS AGAINST INSECT AND FUNGAL ArrACK
This study was conducted to asscss the treatability of four plantation timber species (PiIlIlScariboca, 1/('\'('(/ brasiliensis, EII(,I1/I,/)IIIS gran.lis and EII('(/{y{)IIIS microcorvs) withCoppcr-Chromc-Arscn.uc (CC A) by using pressure impregnation full-cell process. Thetreatability of core wood and outer wood of the species were also investigated. Treatabilitywas evaluated by measuring the preservative retention (Net Dry Salt Rctcnt ion or NDSR)and dcpt h of pellet rat ion.According to the results. Pinus I'IIl'ih(/(,1I showed the highest treatability while treatabilityof //C'I'I'(/ hrasilicnsis, Em (/{YfiIIlS grandis and EII('(/II'f'IIIS microcorvs were respectivelylower. A significant negative corrckuion was observed between density of the timber andtill' treatability. Rased on depth of penetration of preservatives. Pinus (,(/I'i/)II(,(/ and 1/('\'('(/brasiliensis were classified as permeable to preservative treatment. E. grandis was resistantwhile E. microtorvs was extremely resistant to preservative treatment.Trc.unbilitv of outer wood of all the species were higher than that of core wood indicatingthe higher pcnncabiiity of outer S;IPWOOt! area compared with the inner core wood.Trc;lting schedule with initial vacuum of -O.X bar. pressure of 6.5 bar maintained for IXOminutes ami final vacuum of -(),X bar was effective treatment of l l evcu hrasilicnsis. Evenwith this pressure. it was unable to achieve depth of penetration levels as specified in theSri Lankan Standards for E. grandis and E, IIIicro 1'01'\'.1'.When wood samples were exposed to exterior ground contact in the grave yard test for fivemonths. none of the treated samples were infected, hut untreated control samples wereattacked hv fungi and termites. This indicates the effectiveness of the CCA treatment incontrolling fungal and insect attack.
FUNGAL SUCCESSION AND BIODEGRADTION OF RUBBER SAW DUST
Sri Lanka has a long tradition of saw milling, But the waste product (saw dust) from thesemills is not adequately utili sed for beneficial purposes. In a functioning sawmill about twohundred kilograms of organic matter is dispelled as saw dust everyday. Saw dust samples were kept in the garden exposed to normal climatic conditions, a greenhouse or on a laboratory bench for this study. Fungal species that appeared on sawdustwere isolated, identified and number of fungal colonies were counted by dilution platecount technique. During this study seven prominent fungal genera were observed. Fourspecies (Fusarium sp, Penicillium sp, Stemphy/ium sp, Trichodema sp) out of seven wereDeuteromycetes and these were observed in all the three conditions; Two species (Lentinussp and Coprines sp) were Basidiomycetes; one (Aspergillus sp) was Ascomycetes, Thefungal succession appeared in the saw dust showed that first fungal colonizers cause brownrot decay followed by white rot. Saw dust exposed to the fungal growth in laboratoryconditions showed the highest weight loss (42,86%) at the end of the study periodcompared with the weight loss observed in green house conditions and in laboratoryconditions,It is clear that these fungal species have the ability to degrade complex cellulose and ligninmolecules to simple compounds. Due to the fungal activity, weight and strength of the sawdust were reduced, and the texture changed. This showed that there is a possibility ofusing saw dust as a growing medium, after its deterioration by suitable fungi,
Distribution, ecology and morphology of a newly discovered Poecilotheria species of Sri Lanka (Araneae - Theraphosidae)
Scientific studies on Poecilotheria in the wild are limited. In a broad perspective, their distribution, identification and their speciation are poorly studied. Therefore, their life requirements and any conservation issues are less well known. Only 16 Poecilotheria have been discovered in the Indian continent (with only 5 identified Poecilotheria form Sri Lanka), but there may be more species in the wild. The objective of this research was to clear the doubts of a possible new Poecilotheria species found in northern parts of Sri Lanka, and to find its distribution, taxonomic description and ecological requirements.To assist understanding of the subject, a comprehensive literature search was conducted on reported Sri Lankan Poecilotheria and the one Indian species that show similar characteristics. This also assisted in finding out whether existing data support any evidence of a new species.The field data collection was carried out in the northern part of Sri Lanka, in the North and North Central Provinces (around Vavniya District). An average 40 km radius was surveyed, with 30 individual sampling sites. Out of the samples, 5 sites showed the presence of the unknown Poecilotheria species, with healthy populations. This comprised 42 individuals: 11 adults (8 females and 3 males) and 31 juveniles. Field data on fauna and flora were also collected to show vegetation richness and diversity in the studied areas. These results proved that the areas contained rich vegetation cover with a high diversity of fauna and flora.An identification key that consists of leg patterns and prominent features was then established with the aid of samples, drawings and images taken during the research. By comparing ventral leg patterns, none of the known Sri Lankan Poecilotheria resembled similar characteristics to the newly discovered species. Also, the closest match, to the Indian species P. regalis, shows differences in the ventral leg markings (on the 1st and 4th legs) to the new species. Additional morphological features of the new Poecilotheria was also collected and compared with known data to show correlations and differences between species. The geographical differences (between P. regalisand the newly discovered), also confirmed that the species is a new form. The species is proposed to be named as Poecilotheria amarasekerai, Perera (2012), with a supporting species descriptio
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