The environmental concern and global demand for organically produced products provide an impetus to search for new, effective, safe and economical pesticidal formulations. Plants provide enormous scope for development into pesticides. Though more than 2000 plants are known to possess insecticidal properties, neem is the only established botanical pesticide. Hence in this study, we tested the insecticidal activities of the organic solvent extracts from the leaves of L. nicotianaefolia against the larval and egg stages of a serious defoliator pest, Hyblaea puera as the test insect . The organic solvent extracts of the leaf of L. nicotianaefolia were evaluated for their contact and feeding toxicity. The larvicidal action by contact toxicity on 3 rd instar larvae of H. puera showed 100% mortality at 25% concentration. The ovicidal activity varied among the different extracts. All the treatments did not show any activity and were on par with control except ethyl acetate and water extracts and exhibited highest egg hatch inhibition (80%) and (64%) respectively at highest concentration (2%). The LC 50 value for ethyl acetate extract and water extract was 0.55 and 1.014 respectively was not significant (P>0.05) for ovicidal action. The feeding toxicity tests performed on 4 th instar larvae of H. puera showed that among all the extracts of L. nicotianaefolia , methanol extract showed highly significant insecticidal activity with mortality of 92%, followed by ethyl alcohol extract (90%) and water extract (86%). The study reveals that L. nicotianafolia has immense potential to be explored as botanical pesticide.
{"title":"Leaf Extracts of Lobelia nicotianaefolia as a Potential Biopesticide Against Defoliator Pests","authors":"B. Deepa, O. Remadevi","doi":"10.31357/JTFE.V5I2.2663","DOIUrl":"https://doi.org/10.31357/JTFE.V5I2.2663","url":null,"abstract":"The environmental concern and global demand for organically produced products provide an impetus to search for new, effective, safe and economical pesticidal formulations. Plants provide enormous scope for development into pesticides. Though more than 2000 plants are known to possess insecticidal properties, neem is the only established botanical pesticide. Hence in this study, we tested the insecticidal activities of the organic solvent extracts from the leaves of L. nicotianaefolia against the larval and egg stages of a serious defoliator pest, Hyblaea puera as the test insect . The organic solvent extracts of the leaf of L. nicotianaefolia were evaluated for their contact and feeding toxicity. The larvicidal action by contact toxicity on 3 rd instar larvae of H. puera showed 100% mortality at 25% concentration. The ovicidal activity varied among the different extracts. All the treatments did not show any activity and were on par with control except ethyl acetate and water extracts and exhibited highest egg hatch inhibition (80%) and (64%) respectively at highest concentration (2%). The LC 50 value for ethyl acetate extract and water extract was 0.55 and 1.014 respectively was not significant (P>0.05) for ovicidal action. The feeding toxicity tests performed on 4 th instar larvae of H. puera showed that among all the extracts of L. nicotianaefolia , methanol extract showed highly significant insecticidal activity with mortality of 92%, followed by ethyl alcohol extract (90%) and water extract (86%). The study reveals that L. nicotianafolia has immense potential to be explored as botanical pesticide.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"183 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90548277","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}
The demand for sawn timber and wood-based products is rising steadily with new developments and the growing domestic consumption in Sri Lanka. Therefore, it is important to strike a balance between the increasing demand and consumption of forest resources. Thus, the key objective of this study was to investigate the effects of sawmill management and technological parameters on loss in conversion from logs to sawn timber and to compare the sawmill efficiency in private sawmills with the state timber corporation sawmill. Sawmill management and technological parameters were studied in 21 private sawmills and State Timber Corporation sawmill in Kaldemulla to evaluate the effects on loss in conversion. The selected sawmills represent all types available in Sri Lanka, i.e., frame saw, circular saw and band saw mills. Based on the results, mean percentage loss in conversion of teak and mahogany timber for all sawmills (private and State Timber Corporation) in Moratuwa found to be 53.10%. Significant differences were observed in loss in conversion values between the three categories of private sawmills as well as within sawmills of the same category. It was shown that loss in conversion values also varied with sawmill management and technological parameters such as type of machinery employed, sharpening frequency and sawyer’s experience, saw setting, availability of log alignment equipment and saw guards, oversizing and sawn timber sizes.
{"title":"Investigation of Sawmill Management and Technology on Waste Reduction at Selected Sawmills in Moratuwa, Sri Lanka","authors":"H. Caldera, H. Amarasekera","doi":"10.31357/JTFE.V5I1.2499","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2499","url":null,"abstract":"The demand for sawn timber and wood-based products is rising steadily with new developments and the growing domestic consumption in Sri Lanka. Therefore, it is important to strike a balance between the increasing demand and consumption of forest resources. Thus, the key objective of this study was to investigate the effects of sawmill management and technological parameters on loss in conversion from logs to sawn timber and to compare the sawmill efficiency in private sawmills with the state timber corporation sawmill. Sawmill management and technological parameters were studied in 21 private sawmills and State Timber Corporation sawmill in Kaldemulla to evaluate the effects on loss in conversion. The selected sawmills represent all types available in Sri Lanka, i.e., frame saw, circular saw and band saw mills. Based on the results, mean percentage loss in conversion of teak and mahogany timber for all sawmills (private and State Timber Corporation) in Moratuwa found to be 53.10%. Significant differences were observed in loss in conversion values between the three categories of private sawmills as well as within sawmills of the same category. It was shown that loss in conversion values also varied with sawmill management and technological parameters such as type of machinery employed, sharpening frequency and sawyer’s experience, saw setting, availability of log alignment equipment and saw guards, oversizing and sawn timber sizes.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"19 1","pages":"71-82"},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77243927","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}
This study investigated the effect of pre-treatment and particle geometry/stratification on the physical and mechanical properties of cement-bonded particle boards (CBPBs). 6 mm thick homogeneous cement-bonded particle boards were made from Gmelina arborea roxb. sawdust and bambusa vulgaris shard. fibres with type 1 Portland cement. The CBPBs were manufactured at four particle geometry/stratification levels and three pre-treatment levels. The CBPB was manufactured with a cement wood ratio of 3:1, board density of 1500 kg/m3, board size of 350×350×6 mm and a pressing pressure of 1.23 N/mm2. The CBPBs were tested for modulus of rupture (MOR), modulus of elasticity (MOE), thickness swelling (TS) and water absorption (WA). The MOR obtained for each of the 12 factor combinations in this experiment ranged from 2.02 to 11.27 N/mm2 while MOE value ranged from 253.88 to 4942.60 N/mm2. The mean percentage for water absorption (WA) values ranged from 8.78% to 35.66% while mean TS values ranged from 0.16% to 15.71%. Stronger and stiffer boards were produced using the sawdust/fibre/sawdust geometry stratification. Calcium chloride pre-treatment increased the mechanical properties of the boards, while Al2(SO4)3 improved their physical properties. There were significant differences between particle geometry and pre-treatment on both physical and mechanical properties of cement-bonded particle board (p<0.05).
{"title":"Physico-Mechanical Properties of Cement-Bonded Particle Boards of Bambusa vulgaris and Gmelina arborea Fibres","authors":"D. Izekor, A. Erakhrumen","doi":"10.31357/JTFE.V5I1.2495","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2495","url":null,"abstract":"This study investigated the effect of pre-treatment and particle geometry/stratification on the physical and mechanical properties of cement-bonded particle boards (CBPBs). 6 mm thick homogeneous cement-bonded particle boards were made from Gmelina arborea roxb. sawdust and bambusa vulgaris shard. fibres with type 1 Portland cement. The CBPBs were manufactured at four particle geometry/stratification levels and three pre-treatment levels. The CBPB was manufactured with a cement wood ratio of 3:1, board density of 1500 kg/m3, board size of 350×350×6 mm and a pressing pressure of 1.23 N/mm2. The CBPBs were tested for modulus of rupture (MOR), modulus of elasticity (MOE), thickness swelling (TS) and water absorption (WA). The MOR obtained for each of the 12 factor combinations in this experiment ranged from 2.02 to 11.27 N/mm2 while MOE value ranged from 253.88 to 4942.60 N/mm2. The mean percentage for water absorption (WA) values ranged from 8.78% to 35.66% while mean TS values ranged from 0.16% to 15.71%. Stronger and stiffer boards were produced using the sawdust/fibre/sawdust geometry stratification. Calcium chloride pre-treatment increased the mechanical properties of the boards, while Al2(SO4)3 improved their physical properties. There were significant differences between particle geometry and pre-treatment on both physical and mechanical properties of cement-bonded particle board (p<0.05).","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78441264","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}
Deforestation has been a complex phenomenon to study in sub-Saharan Africa. The average annual deforestation rate in the region is by far higher than the world average. What causes and drives deforestation in the region are debated to date. The present paper is motivated by this debate. It attempts to test whether the maintained hypotheses on the causes of deforestation can give answer to the problem in sub-Saharan Africa. It used average cross-national data of forty eight countries in the region. The data are retrieved from international sources. The Spearman’s rank correlation coefficients between two deforestation indicators and five often-cited causes of deforestation were computed. The role of public forest ownership, share of forest and agricultural products in total exports, and the year of forest laws enacted are also discussed. However, it finds no clear, strong, and systematic pattern to argue that population density, rural population, rural poverty, industrial logging for exports, economic growth, late enactment of forest laws, and public ownership of forests are underlying causes of deforestation in the region. The trends of forestland in Rwanda and Zimbabwe vividly present the finding. Therefore, future studies related to the topic in the region shall focus on sub-national panel data.
{"title":"The Perplex of Deforestation in sub-Saharan Africa","authors":"A. Yalew","doi":"10.31357/JTFE.V5I1.2494","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2494","url":null,"abstract":"Deforestation has been a complex phenomenon to study in sub-Saharan Africa. The average annual deforestation rate in the region is by far higher than the world average. What causes and drives deforestation in the region are debated to date. The present paper is motivated by this debate. It attempts to test whether the maintained hypotheses on the causes of deforestation can give answer to the problem in sub-Saharan Africa. It used average cross-national data of forty eight countries in the region. The data are retrieved from international sources. The Spearman’s rank correlation coefficients between two deforestation indicators and five often-cited causes of deforestation were computed. The role of public forest ownership, share of forest and agricultural products in total exports, and the year of forest laws enacted are also discussed. However, it finds no clear, strong, and systematic pattern to argue that population density, rural population, rural poverty, industrial logging for exports, economic growth, late enactment of forest laws, and public ownership of forests are underlying causes of deforestation in the region. The trends of forestland in Rwanda and Zimbabwe vividly present the finding. Therefore, future studies related to the topic in the region shall focus on sub-national panel data.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"115 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73414274","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}
M. Sirirwardane, M.A.D. Samanmali, Rangajeewa Rathnayake
Geographic Information Systems (GIS) can be used as a powerful tool in many aspects of handling geospatial data. By considering the modern geospatial approaches, this research is focused on monitoring environmental pollution in the coastal zone of Kalutara area, with the objective of identification of existing natural resources. Green vegetation patches, water bodies and beech areas were detected using remote sensing techniques. A detailed GPS field survey was conducted and identified minor environmental resources with various pollution incidents. This information was used to improve the available data sets. The types of pollution incidents were categorised according to the severity level by considering the relationship to each natural resource. Maps were created and data was uploaded to the ArcGIS online cloud platform. Web services were hosted using this cloud infrastructure. Pollution incidents data layer has been given web based editing capabilities for field monitoring using GPS enabled mobiles. Field observations were conducted and locations of the pollution effects were uploaded into web maps from the field with related attributes. The hot spots were used to get better understanding and awareness of the environmental pollution. As the results, pollution incidents were identified and there was a significant effect to the minor environmental elements. The cloud infrastructure, helped to bring down the barriers of data sharing and the incident reporting mechanism became more convenient during the field observations.
{"title":"Cloud Based GIS Approach for Monitoring Environmental Pollution in the Coastal Zone of Kalutara, Sri Lanka","authors":"M. Sirirwardane, M.A.D. Samanmali, Rangajeewa Rathnayake","doi":"10.31357/JTFE.V5I1.2493","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2493","url":null,"abstract":"Geographic Information Systems (GIS) can be used as a powerful tool in many aspects of handling geospatial data. By considering the modern geospatial approaches, this research is focused on monitoring environmental pollution in the coastal zone of Kalutara area, with the objective of identification of existing natural resources. Green vegetation patches, water bodies and beech areas were detected using remote sensing techniques. A detailed GPS field survey was conducted and identified minor environmental resources with various pollution incidents. This information was used to improve the available data sets. The types of pollution incidents were categorised according to the severity level by considering the relationship to each natural resource. Maps were created and data was uploaded to the ArcGIS online cloud platform. Web services were hosted using this cloud infrastructure. Pollution incidents data layer has been given web based editing capabilities for field monitoring using GPS enabled mobiles. Field observations were conducted and locations of the pollution effects were uploaded into web maps from the field with related attributes. The hot spots were used to get better understanding and awareness of the environmental pollution. As the results, pollution incidents were identified and there was a significant effect to the minor environmental elements. The cloud infrastructure, helped to bring down the barriers of data sharing and the incident reporting mechanism became more convenient during the field observations.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78947401","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}
M. Abdullah-Al-Mamun, M. Billah, M. Hossain, M. Alamgir
Solid waste disposal and management became one of the major environmental concerns in Bangladesh. Realising the problem, the present study has been undertaken with a view to find a sound and effective way of bio-degradable solid waste management. The study was carried out in the nursery of Institute of Forestry and Environmental Sciences at University of Chittagong to determine the effects of solid waste and waste inoculated with mycorrhizal soil on initial growth performance of Acacia auriculiformis and Cedrela toona. Before planting the seedlings, decomposable waste and mycorrhiza inoculated decomposable waste were placed on the planting holes. Physical growth parameters of seedlings (shoot and root length, leaf and branch number, fresh and dry weight of shoot and root and nodulation status) and the macro nutrients (N, P and K) were recorded after six months of planting. The highest performance of physical parameters was recorded in the soil treated by mycorrhiza inoculated waste. Cedrela toona was represented by maximum nutrients uptake (N-2.60%, P-0.21% and K-2.34% respectively) in the soil treated with mycorrhiza. In case of Acacia auriculiformis, N uptake was maximum (3.02%) in control while K uptake was highest (1.27%) in soil with waste and P (0.18%) uptake was highest in the soil treated with mycorrhiza inoculated waste. Highest initial growth performance was revealed by seedlings treated with mycorrhiza inoculated waste. This study suggested to use mycorrhiza and waste for plantation purposes for hygienic disposal of solid waste and to reduce cost of cultivation.
{"title":"Effect of Household Solid Waste on Initial Growth Performance of Acacia auriculiformis and Cedrela toona in Mycorrhiza Inoculated Soil","authors":"M. Abdullah-Al-Mamun, M. Billah, M. Hossain, M. Alamgir","doi":"10.31357/JTFE.V5I1.2500","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2500","url":null,"abstract":"Solid waste disposal and management became one of the major environmental concerns in Bangladesh. Realising the problem, the present study has been undertaken with a view to find a sound and effective way of bio-degradable solid waste management. The study was carried out in the nursery of Institute of Forestry and Environmental Sciences at University of Chittagong to determine the effects of solid waste and waste inoculated with mycorrhizal soil on initial growth performance of Acacia auriculiformis and Cedrela toona. Before planting the seedlings, decomposable waste and mycorrhiza inoculated decomposable waste were placed on the planting holes. Physical growth parameters of seedlings (shoot and root length, leaf and branch number, fresh and dry weight of shoot and root and nodulation status) and the macro nutrients (N, P and K) were recorded after six months of planting. The highest performance of physical parameters was recorded in the soil treated by mycorrhiza inoculated waste. Cedrela toona was represented by maximum nutrients uptake (N-2.60%, P-0.21% and K-2.34% respectively) in the soil treated with mycorrhiza. In case of Acacia auriculiformis, N uptake was maximum (3.02%) in control while K uptake was highest (1.27%) in soil with waste and P (0.18%) uptake was highest in the soil treated with mycorrhiza inoculated waste. Highest initial growth performance was revealed by seedlings treated with mycorrhiza inoculated waste. This study suggested to use mycorrhiza and waste for plantation purposes for hygienic disposal of solid waste and to reduce cost of cultivation.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81192238","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}
The use of suitable tree biomass allometric equations is crucial for making precise and non- destructive estimation of carbon storage and biomass energy values. The aim of this research was to evaluate the accuracy of the most commonly used pantropical allometric models and site-specific models to estimate the above-ground biomass (AGB) in different aged teak plantations of Southern Western Ghats of India. For this purpose, the AGB data measured for 70 trees with diameter > 10 cm from different aged teak plantations in Kerala part of Southern Western Ghats following destructive procedure was used. The results show that site specific models based on a single predictor variable diameter at breast height (dbh), though simple, may grossly increase the uncertainty across sites. Hence, a generic model encompassing dbh, height and wood specific gravity with sufficient calibration taking into account different forest types is advised for the tropical forest systems. The study also suggests that the commonly used pantropical models should be evaluated for different ecosystems prior to their application at national or regional scales.
{"title":"Evaluating Generic Pantropical Allometric Models for the Estimation of Above-Ground Biomass in the Teak Plantations of Southern Western Ghats, India","authors":"S. Sandeep, M. Siveram, K. Sreejesh, T. P. Thomas","doi":"10.31357/JTFE.V5I1.2492","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2492","url":null,"abstract":"The use of suitable tree biomass allometric equations is crucial for making precise and non- destructive estimation of carbon storage and biomass energy values. The aim of this research was to evaluate the accuracy of the most commonly used pantropical allometric models and site-specific models to estimate the above-ground biomass (AGB) in different aged teak plantations of Southern Western Ghats of India. For this purpose, the AGB data measured for 70 trees with diameter > 10 cm from different aged teak plantations in Kerala part of Southern Western Ghats following destructive procedure was used. The results show that site specific models based on a single predictor variable diameter at breast height (dbh), though simple, may grossly increase the uncertainty across sites. Hence, a generic model encompassing dbh, height and wood specific gravity with sufficient calibration taking into account different forest types is advised for the tropical forest systems. The study also suggests that the commonly used pantropical models should be evaluated for different ecosystems prior to their application at national or regional scales.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"13 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73496527","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}
This study was designed to identify the influence of canopy cover on butterfly abundance in young secondary forest and regenerating forest at Maragamuwa area of Kumaragala forest reserve in Naula, Matale district of Sri Lanka. Line transect method was used to collect data. Hundred meter long five transects were established in each forest area. Butterfly abundance data were collected weekly for eight months from January to August 2014. Regenerating forest had low canopy cover (<50%) than young secondary forest (20-90%). Total of 2,696 butterflies belonging to 87 species in six families were recorded. Some butterfly species were restricted to shady areas, but most butterflies were abundant in sunny areas. Butterflies in some families (Family Lycanidae, Nymphalidae, Pieridae) were abundant in sunny conditions and some families (Family Hesperiidae, Papilionidae) abundant in shade. ANOVA was conducted to identify the variation of number of species (F=54.05, p<0.001) and among abundance (F=10.49, p<0.05) with the canopy cover. Species richness was high in moderate canopy cover (20±5%). Negative Pearson correlation coefficient stated butterfly abundance decreased with the canopy cover (r=-0.91) and species richness decreased with canopy cover (r=-0.85). Some butterflies were common in sunny areas and some species were confined to shady areas. However, most of the species were generally found throughout the area. Regenerating forest encountered more shrubs than in young secondary forest, which butterflies preferred to food on. Main findings of the study were that butterfly abundance was high in sunny areas and butterfly species richness was high in moderate shady areas.
{"title":"Impact of Canopy Cover on Butterfly Abundance and Diversity in Intermediate Zone Forest of Sri Lanka","authors":"Buddhika Weerakoon, A. Bandara, K. Ranawana","doi":"10.31357/JTFE.V5I1.2496","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2496","url":null,"abstract":"This study was designed to identify the influence of canopy cover on butterfly abundance in young secondary forest and regenerating forest at Maragamuwa area of Kumaragala forest reserve in Naula, Matale district of Sri Lanka. Line transect method was used to collect data. Hundred meter long five transects were established in each forest area. Butterfly abundance data were collected weekly for eight months from January to August 2014. Regenerating forest had low canopy cover (<50%) than young secondary forest (20-90%). Total of 2,696 butterflies belonging to 87 species in six families were recorded. Some butterfly species were restricted to shady areas, but most butterflies were abundant in sunny areas. Butterflies in some families (Family Lycanidae, Nymphalidae, Pieridae) were abundant in sunny conditions and some families (Family Hesperiidae, Papilionidae) abundant in shade. ANOVA was conducted to identify the variation of number of species (F=54.05, p<0.001) and among abundance (F=10.49, p<0.05) with the canopy cover. Species richness was high in moderate canopy cover (20±5%). Negative Pearson correlation coefficient stated butterfly abundance decreased with the canopy cover (r=-0.91) and species richness decreased with canopy cover (r=-0.85). Some butterflies were common in sunny areas and some species were confined to shady areas. However, most of the species were generally found throughout the area. Regenerating forest encountered more shrubs than in young secondary forest, which butterflies preferred to food on. Main findings of the study were that butterfly abundance was high in sunny areas and butterfly species richness was high in moderate shady areas.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"171 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78410157","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}
K. Krishnanantham, Y. Seneviratne, S. C. Jayamanne
The present study was carried out during the period from May to July 2014 to assess the vegetation pattern and to estimate biomass of the mangroves in Irakkandy Lagoon, Trincomalee. Five belt-transects of 10 m in width were laid perpendicular to the shoreline. Data were collected on tree diameter at breast height (dbh) and tree height from each sub-plot (100 m2) in belt transects using standard methods. Above ground biomass, basal area and relative density of the mangroves were also estimated. Diversity and evenness of each sub-plot was calculated using Shannon-Wiener diversity index and Pielou’s evenness index respectively. Results revealed that the study site is composed of 5 true mangrove species and highest density was recorded for Avicennia marina (414 trees/ha, 700 saplings/ha, 2354 seedlings/ha), followed by Lumnitzera racemosa, Excoecaria agallocha, Rhizophora apiculata and Heritiera littoralis. The greatest mangrove diversity (1.28) was observed in subplot 1 of transect 2. The least mangrove diversity (0) was found in transect 5. There is a significant difference among transects concerning the diversity and evenness (P<0.05). The results showed that Avicennia marina was the dominant species with Height (H) and dbh of 3.65±1.43 m and 5.06±1.07 cm respectively, followed by Lumnitzera racemosa (3.36±1.19 m and 5.81±1.06 cm, Excoecaria agallocha (4.92±2.45 m and 5.31±1.93 cm), Rhizophora apiculata (4.56±1.70 m and 4.89±0.96 cm) and Heritiera littoralis (8.80±0.849 m and 26.50±4.95 cm). The above ground biomass of Lumnitzera racemosa was recorded as 8334.89 kg/ha and Avicennia marina was recorded as 1361.13 kg/ha. Species diversity (H’) of whole mangrove area studied was 0.86 and evenness (E) was 0.54. It reveals that Irakkandy Lagoon consists of fairly high biological diversity (Diversity index=0.86) of mangroves and extremely valuable for stability of the ecosystem.
{"title":"A Preliminary Study on Vegetation Structure and Mangrove Diversity in Irakkandy Lagoon, Trincomalee","authors":"K. Krishnanantham, Y. Seneviratne, S. C. Jayamanne","doi":"10.31357/JTFE.V5I1.2498","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2498","url":null,"abstract":"The present study was carried out during the period from May to July 2014 to assess the vegetation pattern and to estimate biomass of the mangroves in Irakkandy Lagoon, Trincomalee. Five belt-transects of 10 m in width were laid perpendicular to the shoreline. Data were collected on tree diameter at breast height (dbh) and tree height from each sub-plot (100 m2) in belt transects using standard methods. Above ground biomass, basal area and relative density of the mangroves were also estimated. Diversity and evenness of each sub-plot was calculated using Shannon-Wiener diversity index and Pielou’s evenness index respectively. Results revealed that the study site is composed of 5 true mangrove species and highest density was recorded for Avicennia marina (414 trees/ha, 700 saplings/ha, 2354 seedlings/ha), followed by Lumnitzera racemosa, Excoecaria agallocha, Rhizophora apiculata and Heritiera littoralis. The greatest mangrove diversity (1.28) was observed in subplot 1 of transect 2. The least mangrove diversity (0) was found in transect 5. There is a significant difference among transects concerning the diversity and evenness (P<0.05). The results showed that Avicennia marina was the dominant species with Height (H) and dbh of 3.65±1.43 m and 5.06±1.07 cm respectively, followed by Lumnitzera racemosa (3.36±1.19 m and 5.81±1.06 cm, Excoecaria agallocha (4.92±2.45 m and 5.31±1.93 cm), Rhizophora apiculata (4.56±1.70 m and 4.89±0.96 cm) and Heritiera littoralis (8.80±0.849 m and 26.50±4.95 cm). The above ground biomass of Lumnitzera racemosa was recorded as 8334.89 kg/ha and Avicennia marina was recorded as 1361.13 kg/ha. Species diversity (H’) of whole mangrove area studied was 0.86 and evenness (E) was 0.54. It reveals that Irakkandy Lagoon consists of fairly high biological diversity (Diversity index=0.86) of mangroves and extremely valuable for stability of the ecosystem.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"122 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81548164","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}
N. Bai, T. Sasidharan, O. Remadevi, Priyadarsanan Dharmarajan
Eligma narcissus is recognised as a serious pest of Ailanthus in Southern India and defoliation of Ailanthus by this pest causes apparent loss of growth increment. The common control methods for this pest is mostly insecticides and the concern about the environmental effects of chemical insecticides, has emphasised the use of environmentally more benign microbial agents. Among entomopathogens, Fungi are the most explored and often act as important natural control agents that limit insect populations. On this point of view, Bio efficacy of 25 isolates of Metarhizium anisopliae was assessed to establish their virulence against E. narcissus in the laboratory and effective formulations of two potent isolates were subsequently evaluated in the field. MIS7 and MIS13 were more effective among the different isolates evaluated against E. narcissus. The median lethal concentration (LC50) of all the isolates ranged from 6.46×105 conidia/ml to 628.92×105 conidia/ml. Median lethal concentration of (LT50) of 4.9 and 5.4 days were recorded for MIS7 and MIS13 respectively at a concentration of 1× 107 conidia/ml. Virulence tests of the isolates MIS7 and MIS13 and 0.5% Pongamia pinnata seed oil, individually and in different combinations, indicated improved efficacy of the isolates when used in combination and also when combined with seed oil. Formulations composed of “MIS7+MIS13+0.5% Pongamia pinnata seed oil” and “MIS7+MIS13” proved to be superior against E. narcissus, causing 76.30% and 93.93% mortality, respectively. Field evaluation of the formulation MIS7+MIS13+0.5% Pongamia pinnata seed oil recorded 5.79 larvae per plant resulting in 60.53% reduction of infestation while the formulation, MIS7+MIS13 showed 53.76% reduction of infestation with 6.56 larvae per plant. The observations from this study suggest the prospects of using the entomopathogenic fungus, M. anisopliae for the control of E. narcissus.
{"title":"Biocontrol potential of Metarhizium anisopliae (Metsch.) Sorokin (Deuteromycotina: Hyphomycetes) against Ailanthus Defoliator, Eligma narcissus (Cram.).","authors":"N. Bai, T. Sasidharan, O. Remadevi, Priyadarsanan Dharmarajan","doi":"10.31357/JTFE.V5I1.2497","DOIUrl":"https://doi.org/10.31357/JTFE.V5I1.2497","url":null,"abstract":"Eligma narcissus is recognised as a serious pest of Ailanthus in Southern India and defoliation of Ailanthus by this pest causes apparent loss of growth increment. The common control methods for this pest is mostly insecticides and the concern about the environmental effects of chemical insecticides, has emphasised the use of environmentally more benign microbial agents. Among entomopathogens, Fungi are the most explored and often act as important natural control agents that limit insect populations. On this point of view, Bio efficacy of 25 isolates of Metarhizium anisopliae was assessed to establish their virulence against E. narcissus in the laboratory and effective formulations of two potent isolates were subsequently evaluated in the field. MIS7 and MIS13 were more effective among the different isolates evaluated against E. narcissus. The median lethal concentration (LC50) of all the isolates ranged from 6.46×105 conidia/ml to 628.92×105 conidia/ml. Median lethal concentration of (LT50) of 4.9 and 5.4 days were recorded for MIS7 and MIS13 respectively at a concentration of 1× 107 conidia/ml. Virulence tests of the isolates MIS7 and MIS13 and 0.5% Pongamia pinnata seed oil, individually and in different combinations, indicated improved efficacy of the isolates when used in combination and also when combined with seed oil. Formulations composed of “MIS7+MIS13+0.5% Pongamia pinnata seed oil” and “MIS7+MIS13” proved to be superior against E. narcissus, causing 76.30% and 93.93% mortality, respectively. Field evaluation of the formulation MIS7+MIS13+0.5% Pongamia pinnata seed oil recorded 5.79 larvae per plant resulting in 60.53% reduction of infestation while the formulation, MIS7+MIS13 showed 53.76% reduction of infestation with 6.56 larvae per plant. The observations from this study suggest the prospects of using the entomopathogenic fungus, M. anisopliae for the control of E. narcissus.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"40 1","pages":"47-58"},"PeriodicalIF":0.0,"publicationDate":"2015-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87067478","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}
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