Journal of Tropical Forestry最新文献

{"title":"An overview of heavy metal contamination in coastal sediments of Sri Lanka","authors":"A. Adikaram, H. Pitawala","doi":"10.31357/JTFE.V7I2.3301","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3301","url":null,"abstract":"Coastal sediments are often subjected to heavy metal contamination as they reside at the marginal environments of anthropological water releases. These sediments provide the habitat for marine aquatic life of seafood. Therefore, heavy metal contamination in coastal sediments is one of the major environmental concerns. The coastal belt of Sri Lanka is highly urbanized with high population (59% of Sri Lankan population) and is mostly depend on the sea. Therefore, anthropogenic inputs of pollutants in to the marine environments have been increased during last decades.  Heavy metal contamination of the coastal sediments of Sri Lanka has been discussed by several studies, focusing on selected coastal regions. In this article, previous studies have been reviewed in order to understand the contamination status and ecological risks due to heavy metal accumulations. Despite the sampling location, the elemental distribution of coastal lagoonal sediments shows similar trend indicating the dominance of natural elemental sources rather the anthropogenic influences. The concentrations of As and Cr in sediments are high compared to the upper continental crust values which is a characteristic feature in possible source rocks, soils and sediments of Sri Lanka. The results of the previous studies indicate that coastal sediments are low to moderately contaminated but not at ecological risk. However, anthropogenic activities are highly variable across the coastal regions. Since limited results of the previous studies is not enough to get an overview of the heavy metal concentrations around the island, urgent need for a spatial and temporal geochemical database for coastal sediments of Sri Lanka is emphasized. Keywords: Contamination, coastal, metals and sediments","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85784070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation of Microcystin LR, Oxytetracycline and Amphicillin by Four Native Bacteria Species","authors":"P. Dharmadasa, G. Liyanage, P. Manage","doi":"10.31357/JTFE.V7I2.3305","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3305","url":null,"abstract":"Pollution reaches its most serious proportion in past few decades and adversely effect on animals and human health. Reduction of pollutant in the environment take place with microbial metabolism and remediation studies by microbes have proved their feasibility on clean up the contaminated environment. Thus, the present study reports the biodegradation of Micocystins (MC-LR) and antibiotics [Oxytetracycline (OTC) and Ampicillin (AMP)] by Bacillus cereus , Enterobacter ulcerans, Enterobacter sp. and Micrococcus sp. strains which were previously reported as potential crude oil degraders.  A 0.5 ml of overnight starved bacterial suspensions was introduced into medium containing antibiotic (OTC, AMP) at 60 µg/ml and Microcystin-LR at 10 µg/ml respectively. Triplicate samples were incubated at 28 0 C while shaking at 100 rpm. A 0.5 ml of aliquots was removed at 2 days interval for a period of 14 days and analysis was done by High Performance Liquid Chromatography (HPLC). The highest degradation of MC- LR was shown by Micrococcus sp. (97%) where as other stains; E. ulcerans (96 %), Enterobactor sp. (95 %) and B. cereus (88%) also showed comparative high degradation after 14 days of incubation. B. cereus , Enterobacter sp. and Micrococcus sp. were identified as AMP resistance bacteria and degraded AMP at 81%, 22% and 39% respectively. It was found that B. cereus was resistance to OTC and showed 56% reduction at 14 days of incubation. The results of the present study revealed that the bioremediation potential of harnessing microbes can cleanup of pollutant in the environment and use as eco friendly tool for removal of environmental pollutants. Keywords: Bacillus cereus, Enterobacter sp., Enterobacter ulcerans, Micrococcus sp., Antibiotics and Microcystin","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91270194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro screening of, antibacterial antifungal and cytotoxicity activities in crude extract of freshwater cyanobacterium Oscillatoria sp.","authors":"W. Wijesekara, P. Manage","doi":"10.31357/JTFE.V7I2.3310","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3310","url":null,"abstract":"Cyanobacteria, highly diverse group of prokaryotes are recognized as a potent source of biologically active compounds with antiviral, antibacterial, antifungal, and anticancer properties.The aim of the present study was to screen antibacterial, antifungal and cytotoxic activities of intracellular secondary metabolites of freshwater cyanobacterium Oscillataria sp. Cyanobacterium Oscillatoria sp. was isolated from Senanayaka Samudraya reservoir (7 0 11’ 37.37 0 N 810 31’ 47.13 0 E), Sri Lanka.In vitro antibacterial and antifungal activity of Oscillatoria sp. was screened against Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 25923, Bacillus anthracis and Gram-negative Pseudomonas aeruginosa (ATCC 25853), Salmonella typhi and Escherichia coli (ATCC 25922) and fungi, unicellular Candida albicans (ATCC 60192) and Candida tropicalis using agar disc diffusion method.The Minimum Inhibitory Concentrations (MIC), Minimum Bacteriocidal Concentration (MBC), Minimum Fungicidal Concentrations (MFC) and cytotoxic effects (brine shrimp bioassay) of Oscillatoria crude extract were determined. 10% and 60% of biomass was extracted with hexane and methanol respectively.Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify compounds in the crude extract.  The highest antibacterial and antifungal activity of crude extract were detectedin methanol extract against S.aureus (19 ± 2 mm)and C.albicans (10 ± 1 mm) within 24 hours wherein the hexane extract, antibacterial activity was detected only for S. aureus and mean diameter of inhibition zone was 11 ± 1mm within 24 hours.The lowest MIC of methanol extract against S. aureus wasfound as 156.25 µg/ml. The lowest MBC and MFC of methanol extract against S. aureus and C.albicans were 0.63 mg/ml and 1.25mg/ml respectively. Lethal concentration, 50% of the crude extract against brine shrimp was recorded at 2.50  g/l, 1.25 g/l and 0.625 g/l for 6, 12, 24 hrs intervals respectively. GC-MS analysis revealed that the methanol crude extract of Oscillatoria sp. contains important fatty acid namely hexadecanoic acid methyl ester, methyl tetradecane and 13-tetradecanoic acid and n-hexane extract contains Bis (2-ethylhexyl hydroxypyridine oxide, 1 2-benzenedicarboxylic acid mono (2-ethylhexyl) ester, Phthalic acid 6-ethyl-3-Octyl heptyl ester and  Phthalic acid  dodecyl nonyl ester which may possess antibacterial  and antifungal properties. Keywords: Oscillatoria sp., MFC, MIC, MBC, Cytotoxicity","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87206635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Land Use Changes on Soil Properties and Organic Carbon Distribution Using Tracer Techniques in Selangor State of Malaysia","authors":"M. Hossain, K. Jusoh, S. Fatimah","doi":"10.31357/JTFE.V7I2.3309","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3309","url":null,"abstract":"Root and litter biomass on carbon dynamics and its effect on other soil properties information are needed to explore in Malaysia due to rapid change of land use. Objective of this study was to determine the effect of root and litter biomass of forest and oil palm under different soil depths on soil organic carbon and its stock, soil available water, bulk density, pH, electrical conductivity. In this regard, two land use systems (forest and oil palm) were selected for the study. In each land use we collected litter biomass, root and soil samples from four different locations. For the characterization of soil and root three core samples were taken (0–5, 5-15, 15-30, 30-60 and 60-90 cm)from each location, and then combined and air-dried. Soil samples were air-dried for 2 weeks at room temperature, grounded and sieved (<2 mm). Soil available water content, soil organic carbon, pH and EC were determined by standard methods. Results revealed that maximum organic matter (6.75%) was found in forest soil at 0-5 cm depth of soil. SOC content was decreased with the increase of soil depth in forest. On average soil organic carbon stock was significantly higher under oil palm (3.09 t ha -1 ) than forest (2.28 t ha -1 ) up to 90 cm depth of soil. Available water content was higher in surface soil (0-15 cm) than subsurface soil due to mechanization of oil palm plantation area. Soil reaction (pH) was higher in forest soil than oil palm plantation soil. Litter biomass or droppings performed δ 13 C dilution in surface soil but root system enriched δ 13 C in subsurface soil. 13 C isotope tracer technique confirmed that root and litter biomass of forest and oil palm plantation can greatly influence on vertical distribution of organic carbon when soils show gradual increase of δ 13 C values with depth. Keywords: Land use, forest and oil palm, soil depth, carbon and tracer techniques","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89185322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Vegetation Change of Lower U Minh National Park of Vietnam from 1975 to 2015","authors":"P. T. Khanh, S. Subasinghe","doi":"10.31357/JTFE.V7I2.3304","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3304","url":null,"abstract":"The vegetation of the Lower U Minh is an important ecosystem as it contributes to preserrve the nature while providing many bebefits. It is also used as an excellent indicator for identifying early signs of ecosystem change in the entire area. In order for that, however, an effective method should be used to re-evaluate the change occurred during the past years. Use of remote sensing is the most effective method that serves for this purpose which was also used in the present study. In order to identify the vegetation change over a 40 years of time since 1975, three Landsat (TM) satellite images (1975, 1995 and 2015) were taken to develop the base maps which were then compared to identify the vegetation change of the national park. Using the base maps, six different vegetation types were identified using unsupervised and supervised classifications to build vegetation classification map with an overall accuracy of 86.33% and a kappa coefficient of 0.81. The results showed that multi-temporal Landsat images with the average resolution bear the ability to assess the vegetation coverage changes. Though the total extent of the National Park has not been changed during the study period, the extents of its vegetation types changed in different manners. The grass cover changed from 155.57 ha in 1975 to 643.24 in 2015 while extent of water changed from 315.24 ha to 194.92 ha during the same period. The extents of the grass cover and water were 884.95 and 697.60 ha respectively in 1995. The Melaleuca forest cover of different ages was also changed in significant manner during the study period. Keywords: Landsat, Remote sensing, the Lower U Minh National Park, Ca Mau.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78705733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forest Carbon Stock Assessment of the Musk Deer National Park, Azad Jammu and Kashmir (AJK)","authors":"M. Qasim","doi":"10.31357/JTFE.V7I2.3315","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3315","url":null,"abstract":"To tackle with the increasing challenges of climate change, forests are considered as a viable option. Schemes such as Reduced Emissions from Deforestation and Forest Degradation Plus (REDD+) are regarded as financial ventures for not only tackling climate change but also conserving forestry resources and for alleviating poverty. Such schemes however require the exercise of forest carbon stock assessments. It is therefore essential to understand the dynamics of carbon stocks in various forest ecosystems. The study therefore was conducted to assess the carbon stocks of the forests of Musk Deer National Park, AJK. Standard methods were used to calculate the carbon stocks of the Musk Deer National Park. The results revealed that the sampled area of the park contained mean carbon stocks per hectare (ha) of 44.64 ± 12.44 Mg ha -1 . The Picea smithiana with 25.40 ± 14.53 Mg ha -1 had the highest of the mean carbon stocks per ha followed by Abies pindrow which had the mean carbon stocks per ha of 17.77 ± 11.80 Mg ha -1 . The study was the first attempt, to the extent of my knowledge, for forest carbon stock assessment of the Musk Deer National Park. The results can be helpful in developing REDD+ projects in future, which can assist in forest resource conservation and poverty alleviation.   Keywords: Carbon Stock, forest and climate","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84527418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aboveground biomass and carbon stock assessment in forest stands of Gmelinaarborea Roxb. in Mizoram, North-East India","authors":"R. Hauchhum","doi":"10.31357/JTFE.V7I2.3306","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3306","url":null,"abstract":"Aboveground biomass and carbon stock in tropical forest play an important role in global carbon cycle. Assessment of biomass and carbon pool in different forest stands may provide information in making decisions about the carbon management within the forest. Gmelina arborea , a fast growing species that is widely distributed and an important timber species of Mizoram has been chosen to assess its biomass and carbon stock. The present study was carried out to estimate the aboveground biomass and carbon stock in G. arborea in different forest stands of Mamit District, Mizoram, north-east India. The result shows that the total aboveground biomass ranged between 66-108 Mg ha -1 and carbon stock (30.00-53.20 mg C ha -1 ). The aboveground biomass and carbon stock was maximum in forest stands (site-III) with highest tree density and diameter class of 30-40cm and 40-50cm indicating the forest site was mature and undisturbed. The result demonstrates that G. arborea contribute in carbon sequestration and helps in mitigating global warming. Further, the aboveground biomass and carbon sequestration potential was greatly affected by the tree composition, population pressure and anthropogenic activities. Keywords: Aboveground biomass, carbon stock, diameter class,Gmelina arborea, tropical forest.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85447003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation for Estimating Stem Volume for Agar tree (Aquilaria malaccensis Lamk) Grown in the Plantations in Bangladesh","authors":"S. Islam, M. Chowdhury","doi":"10.31357/JTFE.V7I2.3311","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3311","url":null,"abstract":"Agar tree ( Aquilaria malaccensis Lamk, Family- Thymeleaceae) has drawn unique position due to the production of world’s most expensive essential oil used in fragrances and also medicine. It is one of the most valuable and economically important commercial tree species planted in some potential forest areas of Bangladesh. The main aim of this study is to develop mathematical models for total volume estimation of Agar tree. In order to meet the requirements we have selected 21 models of volume equation which are tested by regression technique. Among them for one way volume equation  and for two way volume equation appeared to the best model for estimating the Agar tree volume. From these models conversion factors equation ( r =11, 13, 15) has been determined to estimate under bark volume and under bark volume of different top end diameters of 11, 13, and 15 centimeters. Keywords: Aquilaria malaccensis, model, stem volume and validation","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87899597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Modeling of above Ground Biomass in Ranges of Corbett Tiger Reserve using Dual-Polarization ALOS PALSAR Data","authors":"Y. Kumar, Sarnam Singh, R. Chatterjee","doi":"10.31357/JTFE.V7I2.3314","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3314","url":null,"abstract":"The study has been carried out in the Pauri Garhwal district of Uttarakhand keeping the focus on Corbett Tiger Reserve (CTR). The total area of CTR covered in the scene is 889 sq. km. The main aim of the paper is to develop a model by establishing a relationship between backscatter coefficients generated from dual polarization L-band ALOS PALSAR data acquired in July 2008 and the field inventory data collected by Forest Survey of India team in 2010. A total of 120 sample plots data were collected in the area out of which 60 plots were used for the training of the model and the remaining 60 plots were left for the validation of the most significant model. The Simple regression analysis was computed between HH & HV backscatter as independent variable and per plot biomass as dependent variable. The Linear, Logarithmic and Polynomial best fit regression models were analyzed. It was found that the coefficient of determination is more with HV backscatter (R 2 =0.75) using logarithmic model as compared among HV in linear and polynomial on one hand and HH in linear, logarithmic and polynomial on the other hand. To improve the accuracy and to know the combined effects of both the polarizations, multiple linear regression analysis (MLR) was applied. There was a significant improvement in correlation coefficients (R 2 =0.86).The in-situ field inventory data shows that the biomass in the CTR ranges from 9.6 t/ha to 322.6 t/ha. The simple regression modelled biomass ranges from 26.2 t/ha to 401.43 t/ha, whereas the MLR modelled biomass ranges from 10.96 t/ha to 312.64 t/ha. The majority of the area was found to be in the range of 100 t/ha to 150 t/ha biomass. The coefficient of determination (R 2 ) between observed and predicted biomass was found to be 0.734 with simple regression, whereas it was found to be 0.83 with MLR. Key words: biomass, modeling and remote sensing","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88919984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of tropical vertical subsurface flow constructed wetlands for leachate treatment at different hydraulic loading rates","authors":"T.A.O.K. Meetiyagoda, N. Bandara, K. Jinadasa, C. S. Kalpage, C. Pathirana","doi":"10.31357/JTFE.V7I2.3308","DOIUrl":"https://doi.org/10.31357/JTFE.V7I2.3308","url":null,"abstract":"This study is focused on the investigation of three different types of plant species namely; Narrow leaf Cattail (Typha angustifolia), Green Bulrush (Scirpus atrovirens) and Umbrella Palm (Cyperus alternifolius) for treatment of leachate. Twelve laboratory scale subsurface flow constructed wetland models were operated in batch mode. Four models, each containing similar plant species were fed with synthetic leachate having four different concentrations (25%, 50%, 75% and 100%) and 7 days HRT was given. The duration of a batch run was 12 weeks. Removal efficiencies of BOD5, COD, PO43-, TC, and TN were measured. Evapotranspiration (ET) loss of each test run was also assessed. According to the results, the constructed wetland planted with Umbrella palm and fed with 25% leachate showed the best pollutant removal efficiencies of 99.26% for BOD5, 99.61% for COD, 98.78% for TN and 97.34%for TC. Highest ET potential of 93.57% was also observed from the constructed wetland with umbrella palm fed with 25% leachate. Two way ANOVA analysis was carried out for each plant species and leachate concentration and the Umbrella Palm species was identified as the best for leachate treatment. Key words: Constructed wetlands, landfill leachate, plant species and pollutant removal","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74108544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}