Journal of Tropical Forestry最新文献

{"title":"Soil Properties under Various Stages of Secondary Forests at Sarawak, East Malaysia","authors":"K. Karyati, I. Ipor, I. Jusoh, Mohd Effendi bin Wasli","doi":"10.31357/JTFE.V4I1.1827","DOIUrl":"https://doi.org/10.31357/JTFE.V4I1.1827","url":null,"abstract":"Changes in the forest community during secondary succession are influencing in various soil properties. However, there is limited information available on the soil properties under different stages of secondary forests in Sarawak. The aims of this study are to clarify \u0000the soil morphological and physicochemical properties at secondary forests under different age stands after similar land change (slash and burn). Field surveys were conducted at 3, 5, 10, and 20 years old of secondary forests in Sabal, Sarawak. Different fallow time influence changing soil properties in various stage secondary forests. A number of soil properties \u0000affected soil development process and land use change. Soil morphological and physicochemical properties differed under different stages of fallow periods. The results showed that the soils under different stages of fallow lands after shifting cultivation in the study sites was categorized in acidic soil as indicated by pH (H2O) values of below than 5 and the low content of T-C and T-N as well as exchangeable bases. The close relationship can be assumed between soil development process and vegetation succession. The knowledge of \u0000forest soil properties is essential to understand the change and development process under various stages secondary forests. The comprehensive understanding about soil properties and development process is important in order to conserve and manage secondary forests.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88280708","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":"Prediction of stem biomass of Pinus caribaea growing in the low country wet zone of Sri Lanka","authors":"S. Subasinghe","doi":"10.31357/JTFE.V4I1.1056","DOIUrl":"https://doi.org/10.31357/JTFE.V4I1.1056","url":null,"abstract":"Forests are important ecosystems as they reduce the atmospheric CO2 amounts and thereby control the global warming. Estimation of biomass values are vital to determine the carbon contents stored in trees. However, biomass estimation is not an easy task as the trees should be felled or uprooted which are time consuming and expensive procedures. As a solution to this problem, construction of mathematical relationships to predict biomass from easily measurable variables can be used. The present study attempted to construct a mathematical model to predict the stem biomass of Pinus caribaea using the data collected from a 26 year old plantation located in Yagirala Forest Reserve in the low country wet zone of Sri Lanka. Due to the geographical undulations of this forest, two 0.05 ha sample plots were randomly established in each of valley, slope and ridge-top areas. In order to construct the model, stem wood density values were calculated by using stem core samples extracted at the breast height point. Stem volume was estimated for each tree using Newton’s formula and the stem biomass was then estimated by converting the weight of the known volume of core samples to the weight of the stem volume. Prior to pool the data for model construction, the density variations along the stem and between geographical locations were also tested. It was attempted to predict the biomass using both dbh and tree height. Apart from the untransformed variables, four biologically acceptable transformations were also used for model construction to obtain the best model. All possible combinations of model structures were fitted to the data. The preliminary model selection for further analysis was done based on higher R 2 values and compatibility with the biological reality. Out of those preliminary selected models, the final selection was done using the average model bias and modeling efficiency quantitatively and using standard residual distribution qualitatively. After the final evaluation the following model was selected as the best model to use in the field.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79822426","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 Association of Environmental Changes and the Replacement of Mosquito Fauna in the Colombo District, Sri Lanka","authors":"Bas Priyangika, B. D. Silva, D.P.W. Jayatunga-Katuwawalage, M. Wickramasinghe","doi":"10.31357/JTFE.V4I1.1057","DOIUrl":"https://doi.org/10.31357/JTFE.V4I1.1057","url":null,"abstract":"The mosquito survey was carried out for 8 months between October 2009 and May 2010. Investigations included 12 randomly selected urban (6) and semi-urban (6) areas in the Colombo District of Sri Lanka. Thirty eight mosquito species were found and Anopheles interruptus, An. pseudojamesii, Aedes stenovensoni, Ae. edwardsi, Ae. vittatus, Culex  barraudi, Cx. fatigans, Cx. univittatus, Cx. aculeatus, Cx. purplexus, Cx. spiculosus, Cx. quadripalpis, Cx. halifaxi, Uranotaenia atra, Ur. unguiculata were new findings that were not recorded  previously in the period 1981-1982 from the same locations although 11 different breeding habitats were examined. Rainfall had a direct relation (P=0.000) with the distribution and the density of mosquitoes. Unplanned urbanization, human activities and irregular or non-disposal of domestic waste products have led to a population replacement of the mosquito fauna in these locations.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82970501","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":"Environmental impact assessment of transport infrastructure projects in Sri Lanka: Way forward","authors":"I. Gamalath, L. Perera, S. Bandara","doi":"10.31357/JTFE.V4I1.1833","DOIUrl":"https://doi.org/10.31357/JTFE.V4I1.1833","url":null,"abstract":"Environmental impact assessment (EIA) was established to manage impacts on environment due to development projects and to enhance its quality where possible. However recent incidents concerning several projects have aroused the question, “Are we utilising EIA effectively?” Therefore this study was conducted to find possible methods of improving the quality and effectiveness of EIA. Literature regarding EIA process in both Sri Lankan context and international context was reviewed together with several past EIA reports related to Civil Engineering infrastructure projects to identify possible improvements. Identified problems can be categorised in to two; problems in established EIA framework, methodologies adopted in impact assessment. Main problems identified in the framework are the lack of, broad frameworks of environmental, social protection; accountability of EIA process; public participation and proper post monitoring system. The problems identified in the assessment process are the lack of incorporating cumulative effects and sustainability concepts. To address these issues, legislature should be improved and they should focus on allocating proper weight to the EIA findings in the decision process. Analysing impacts should focus more on concepts of environmental resources and limitations rather than narrow impacts of the project. Further in impact assessment the product of magnitude of the impact and the duration of impact should be taken into account rather than just focusing on the magnitude. In addition to the project based EIA process, Strategic Environmental Assessment (SEA) can be practised to overcome the weaknesses of the reactive nature of EIA and to direct development in the right direction. Keywords: Environmental impact assessment, Effectiveness, Assessment methodology","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85998308","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":"Occurrence of polycyclic aromatic hydrocarbons (PAHs) in beached plastic pellets from Mumbai coast, India","authors":"Sri Jayewardenepura, S. Lanka, Jayasiri H.B, Purushothaman C.S","doi":"10.31357/JTFE.V4I1.1819","DOIUrl":"https://doi.org/10.31357/JTFE.V4I1.1819","url":null,"abstract":"PAHs are a class of ubiquitous pollutants which consist of two or more fused benzene rings in various arrangements. A number of PAH compounds are known carcinogens and bioaccumulate and biomagnify. These compounds originate naturally as well as anthropogenically through oil spills, incineration of waste and combustion of fossil fuels and wood. The environmental consequence of plastic pellets is the sorption of organic pollutants on their surface from the sea surface microlayer (SML) where the hydrophobic contaminants are known to be enriched. The plastic pellets were collected along the recent high tide line from four beaches of Mumbai coast bimonthly during May 2011 and March 2012. A total of 72 pools of plastic pellets were extracted, fractionated and analysed by gas chromatograph coupled to a mass spectrometer to evaluate the extent and sources of 16 PAHs. The mean ΣPAH concentration in pellets was 9,202.30±114.89 ng g -1 with a wide range (35.4-46,191.58 ng g -1 ). The concentration of fluorene was found to be the highest (1,606.30±251.54 ng g -1 ) followed by anthracene, chrysene and phenanthrene. The ΣPAH concentration was significantly varied among months and there was no significant difference among sites at p=0.05. The 2-3 aromatic ring compounds accounted for 60% of the total PAHs in pellets of Mumbai coast while 4 rings and 5-6 rings compounds accounted for 26 and 14%, respectively. The ratio of low and high molecular weight PAHs indicated that the contamination by petrogenic sources was predominant over the pyrogenic ones in plastic pellets suggesting oil pollution in coastal area of Mumbai.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74586265","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":"Allelopathic potential of rice residues of selected rice varieties (Oryza sativa L.) against Echinochloa crus-galli","authors":"A. Ranagalage, T.S.D. Jayakody, D. L. Wathugala","doi":"10.31357/JTFE.V4I2.1848","DOIUrl":"https://doi.org/10.31357/JTFE.V4I2.1848","url":null,"abstract":"Allelopathic potential of rice residues of selected rice varieties ( Oryza sativa L .) against Echinochloa crus-galli Abstract Allelopathic compounds will play a vital role in sustainable weed control in paddy cultivation in future. Exploitation and implementation of this technology in weed management has been considered as ecologically sound, resource conserving and economically viable method.  The objective of this study was to assess the allelopathic traits of rice residues of selected (Bg359, Ld365, Bg407, At401, Bg358, At362, At402, Bg450, Bg300, Herathbanda and Handiran) rice cultivars to control of barnyard grass ( Echinochloa crus-galli ) one of the most destructive weed in Sri  Lankan paddy ecosystem. Completely Randomize Design was used with three replicates for each cultivar. According to the research findings, significant differences (p≤0.05) were observed among cultivars and amount of residue mixed with sand (2.0, 4.0, 6.0g of ground residue per 500.0g of sand) in terms of barnyard grass plant height, number of leaves, germination and total dry weight. Among those measured variables germination and dry matter of barnyard grass showed significant reduction when increasing amount of rice residue. Among different cultivars used Ld365 showed the highest inhibition % for all above measured variables and the lowest was the Herathbanda. As an example the inhibition percentages of plant height, seed germination and shoot dry weight of Ld365 were 60%, 56% and 65% respectively. In contrast, rice cultivar Herathbanda caused 27%, 26% and 26% inhibition respectively for above mentioned parameters. When comparing  three levels of rice residue mixture   63% dry weight reduction was observed  in 6.0g rice residue  and (51%)  4.0g and 27% with  2.0g  mixture. Furthermore percentage germination also reduced with increased amount of rice residue mixture. It indicated that highest in 6.0g, which is 49% closely followed by 4.0g (41%) and the lowest is 2.0g by 12%. Therefore, it could be suggested that the allelopathic potential of rice residue significantly changes with cultivar and amount of residue mix with soil. Knowledge of rice allelophathic properties of rice residue will offer several possibilities for ecological management of weeds in paddy fields of Sri Lanka. Keywords: -      Allelopathy, Echinocloa crus-galli ,  Inhibition, Oryza sativa","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86870556","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":"Wild ungulate distribution in the Naban River Watershed National Nature Reserve, southwest China.","authors":"A. Treydte, P. Trumpf, G. Langenberger, Y. Yang, F. Liu","doi":"10.31357/JTFE.V3I2.1843","DOIUrl":"https://doi.org/10.31357/JTFE.V3I2.1843","url":null,"abstract":"Southeast Asia´s tropical forests harbour a unique diversity of wildlife but species and numbers are rapidly declining under current land use. To improve conservation strategies in these biodiversity hotspots, knowledge of animal species present and their distribution is crucial. We wanted to identify the ungulate community composition and distribution of a ‘Man and Biosphere’ reserve, the Naban River Watershed National Nature Reserve (NRWNNR), Yunnan, Southwest China. Using camera traps, transects, and spoor-plots we identified wild ungulate species and corresponding habitat properties. We compared two study sites of different protection status – the buffer and experimental zones – on an overall transect length of 32 km and analysed relationships between wildlife activity, forest vegetation structure, and human disturbance. We documented six ungulate species, all of which occurred in the buffer zone while only three species were found in the experimental zone. Wild boar sign density was about 10 times higher in the buffer than in the experimental zone. Overall wildlife sign density increased with distance away from human settlements and closer to the core zone. Hence, human disturbance strongly influenced wild ungulate abundance but the NRWNNR was found to host a diverse ungulate community, considering its small size and compared to other conservation areas in the region. The combination of various methods proved to be successful in identifying and locating forest wildlife. The NRWNNR, particularly the more strongly protected zones, could greatly contribute to future ecotourism activities in Yunnan if a strict preservation of buffer and core zones can be maintained.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76758572","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 Current Status of the Tiger Beetle Species of the Coastal Habitats of Sri Lanka","authors":"C. Dangalle","doi":"10.31357/JTFE.V3I2.1841","DOIUrl":"https://doi.org/10.31357/JTFE.V3I2.1841","url":null,"abstract":"The species of tiger beetles inhabiting coastal habitats of Sri Lanka have not been studied for nearly three decades. We report the tiger beetle species currently occupying the coastal habitats of the island, their distribution, microhabitats and habitat preferences. Species and distributions reported nearly three decades from similar previous studies are also recorded. Southern, North-Western and Western coastal belts (n=22) of Sri Lanka were investigated for the presence of tiger beetles. Three species, Hypaetha biramosa , Lophyra ( Lophyra ) catena , Myriochila ( Monelica ) fastidiosa , were recorded from eleven locations. M. ( Monelica ) fastidiosa was reported for the first time, in a single location of the Southern coastal belt. Habitat parameters of the locations and the length of the body and mandible between H. biramosa and L. ( Lophyra ) catena , were statistically compared to determine specific habitat preferences of the two species. Analysis of Variance using Minitab 16.0 revealed that H. biramosa occupy habitats with high solar radiation (438-1023 w/m 2 ) and soil salinity (0.0-0.1ppt) while L. ( Lophyra ) catena occupy habitats with low solar radiation (132-402) and non-saline soils (0.0 ppt). Similar length of mandibles of these two species indicated that habitat selection of the species was not based on prey utilization, but may depend on the intensity of solar radiation and the level of soil salinity of the locations.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76472555","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":"Impacts of Woody Invader Dillenia suffruticosa (Griff.) Martelli on Physio-chemical Properties of Soil and, Below and Above Ground Flora","authors":"B. A. K. Wickramathilake, T. Weerasinghe, S. Ranwala","doi":"10.31357/JTFE.V3I2.1844","DOIUrl":"https://doi.org/10.31357/JTFE.V3I2.1844","url":null,"abstract":"D illenia suffruticosa (Griffith) Martelli, that spreads fast in low-lying areas in wet zone of Sri Lanka is currently listed as a nationally important Invasive Alien Species that deserves attention in ecological studies. Thus, impact of this woody invader on physical, chemical properties of soil and below and above ground flora was investigated. Five sampling sites were identified along a distance of 46km from Avissawella to Ratnapura. At each site, two adjacent plots [1m x10m each for D . suffruticosa present (D +) and absent (D - )] were outlined. Physical and chemical soil parameters, microbial biomass and number of bacterial colonies in soil were determined using standard procedures and compared between D + and D - by ANOVA using SPSS. Rate of decomposition of D. suffruticosa leaves was also determined using the litter bag technique at 35% and 50% moisture levels. Above ground plant species richness in sample stands was compared using Jaccard and Sorenson diversity indices.  Decomposition of D. suffruticosa leaves was slow, but occurred at a more or less similar rate irrespective of moisture content of soil. Particle size distribution in D + soil showed a much higher percentage of large soil particles.  Higher % porosity in D + sites was a clear indication that the soil was aerated.  The pH was significantly lower for D + than D - thus developing acidic soils whereas conductivity has been significantly high making soil further stressed. The significant drop in Cation Exchange Capacity (CEC) in D + soil was a remarkable finding to be concerned with as it correlated with fertility of soil. Significantly higher values of phosphates reported in D + soil support the idea that plant invaders are capable to increase phosphates in soil. Higher biomass values recorded for D + sites together with higher number of bacterial colonies could be related to the unexpectedly recorded higher Organic Carbon. Both  the  Jaccard  and  Sorenson   indices indicated  that  D + and  D - sites  were dissimilar with respect to  above ground  plant  species  richness.  Thus, changes in above ground vegetation and soil properties due to the invasion were identified and further studies are needed for determining the degree of soil deterioration due to the invasive behavior of D. suffruticosa .","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90473207","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":"Wildlife Viewing Preferences of Visitors to Sri Lanka’s National Parks: Implications for Visitor Management and Sustainable Tourism Planning","authors":"H. Senevirathna, Priyan Perera","doi":"10.31357/JTFE.V3I2.1838","DOIUrl":"https://doi.org/10.31357/JTFE.V3I2.1838","url":null,"abstract":"Wildlife Viewing Preferences of Visitors to Sri Lanka’s National Parks: Implications for Visitor Management and Sustainable Tourism Planning","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74700981","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}