Agarwood is an expensive resinous product extracted from some members of Aquilaria andGyrinops species of the family Thymalaeaceae. Agarwood essential oil is a highly valued perfumeryproduct in modern cosmetics and traditional Attar. Agarwood extraction from the above species andproduct manufacturing are done in India and Southeast Asian countries. However, overharvesting, lownatural regeneration, and legal restrictions at present, have limited the supply of this product.Gyrinops walla is recorded in the wet zone of Sri Lanka, and it had been very rarely recorded inextreme Southwest India. However, recent reports of the abundance of G. walla in India are hard to find.Studies were not conducted in the past for G. walla on its ability of agarwood resin production and thequality of that resin. This study is the first to identify the agarwood resin formation and the quality of G.walla which can be used as a substitute for that of Aquilaria and other species of Gyrinops.Resinous tissues were extracted from six G. walla trees for the present study from two differentareas, i.e., Labugama and Yagirala of the wet zone of Sri Lanka. The resins were solvent extracted in thelaboratory and the resin quality was tested using gas chromatography analysis. The results indicated anextreme similarity of the compounds of G. walla resin with that of commercially available agarwoodresins. However, further studies should be conducted to identify G. walla distribution and formation ofagarwood.
{"title":"Agarwood-type Resin from Gyrinops walla Gaertn: A New Discovery","authors":"S. Subasinghe, D. Hettiarachchi, E. Rathnamalala","doi":"10.31357/JTFE.V2I2.594","DOIUrl":"https://doi.org/10.31357/JTFE.V2I2.594","url":null,"abstract":"Agarwood is an expensive resinous product extracted from some members of Aquilaria andGyrinops species of the family Thymalaeaceae. Agarwood essential oil is a highly valued perfumeryproduct in modern cosmetics and traditional Attar. Agarwood extraction from the above species andproduct manufacturing are done in India and Southeast Asian countries. However, overharvesting, lownatural regeneration, and legal restrictions at present, have limited the supply of this product.Gyrinops walla is recorded in the wet zone of Sri Lanka, and it had been very rarely recorded inextreme Southwest India. However, recent reports of the abundance of G. walla in India are hard to find.Studies were not conducted in the past for G. walla on its ability of agarwood resin production and thequality of that resin. This study is the first to identify the agarwood resin formation and the quality of G.walla which can be used as a substitute for that of Aquilaria and other species of Gyrinops.Resinous tissues were extracted from six G. walla trees for the present study from two differentareas, i.e., Labugama and Yagirala of the wet zone of Sri Lanka. The resins were solvent extracted in thelaboratory and the resin quality was tested using gas chromatography analysis. The results indicated anextreme similarity of the compounds of G. walla resin with that of commercially available agarwoodresins. However, further studies should be conducted to identify G. walla distribution and formation ofagarwood.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85586123","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}
It is imperative that Sri Lanka grasps the concepts of green jobs to meet the most vital but intricatechallenge of the 21st Century, which is the transformation to a sustainable and a low-carbon economy.Such a transformation or a paradigm shift, which can be gradual or rapid depending on the circumstances,will undoubtedly have a considerable positive effect on the way we produce and/or consume goods andservices. The speed at which this transformation would occur is likely to accelerate in the near future asthere is a trend of global transition from a traditional to a low-carbon economy, in order to attainsustainable economies. Such trends will help create an array of different forms of green jobs across manysectors, and most probably can become a catalyst for further development. The International LabourOrganization (ILO) has defined green jobs as “Jobs created when they help in reducing the negativeenvironmental impacts ultimately leading to environmentally, economically and socially sustainableenterprises and economies”. Green jobs, in general, stand on two pillars: decent work and environmentalsustainability. Thus, green jobs can be defined as decent work that contributes to environmentalsustainability. In a broader sense decent work needs to address the core of international labour standardssuch as freedom of association and effective recognition of the right to collective bargaining, eliminationof all forms of forced or compulsory labour, effective abolition of child labour, elimination ofdiscrimination in respect of employment and occupation, occupational health and safety, etc. whilstaligning to laws applicable to Sri Lanka. Environmental sustainability addresses issues such as effectivelycombating climate change, pollution prevention and control, conservation of eco-systems and biodiversityetc. (ILO, 2007).
{"title":"Are Green jobs sustainable for Sri Lankan Economy","authors":"M. Jayaweera, J. Manatunge, Ayoma Witharana","doi":"10.31357/JTFE.V2I2.585","DOIUrl":"https://doi.org/10.31357/JTFE.V2I2.585","url":null,"abstract":"It is imperative that Sri Lanka grasps the concepts of green jobs to meet the most vital but intricatechallenge of the 21st Century, which is the transformation to a sustainable and a low-carbon economy.Such a transformation or a paradigm shift, which can be gradual or rapid depending on the circumstances,will undoubtedly have a considerable positive effect on the way we produce and/or consume goods andservices. The speed at which this transformation would occur is likely to accelerate in the near future asthere is a trend of global transition from a traditional to a low-carbon economy, in order to attainsustainable economies. Such trends will help create an array of different forms of green jobs across manysectors, and most probably can become a catalyst for further development. The International LabourOrganization (ILO) has defined green jobs as “Jobs created when they help in reducing the negativeenvironmental impacts ultimately leading to environmentally, economically and socially sustainableenterprises and economies”. Green jobs, in general, stand on two pillars: decent work and environmentalsustainability. Thus, green jobs can be defined as decent work that contributes to environmentalsustainability. In a broader sense decent work needs to address the core of international labour standardssuch as freedom of association and effective recognition of the right to collective bargaining, eliminationof all forms of forced or compulsory labour, effective abolition of child labour, elimination ofdiscrimination in respect of employment and occupation, occupational health and safety, etc. whilstaligning to laws applicable to Sri Lanka. Environmental sustainability addresses issues such as effectivelycombating climate change, pollution prevention and control, conservation of eco-systems and biodiversityetc. (ILO, 2007).","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80933870","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 U.S. has dramatically altered its wood product imports and exports during the past few years,and at present, it is the second largest wood product importer in the world. Hence, an understanding ofmarket structures, factors in selecting foreign suppliers, and the emphasis placed on environmentalissues/certification are critical to understand from the perspective of wood products importers in the U.S.This study provides an analysis of the U.S. wood products import sector with special emphasis on currentand future opportunities for tropical wood products exporters to the U.S. market.In this study, 158 wood products importers in the U.S. were surveyed using a mailingquestionnaire. The adjusted response rate was 40.6 percent. Results indicated that most of the respondentswere small to medium scale firms, but major importers of wood products. According to respondents,wood products to the U.S. mainly come from Brazil, Chile, and China. From the importers’ perspective,Brazilian wood products ranked first for its quality followed by wood products from Chile and Finland.Product quality, long term customer relationships, on-time delivery of orders, fair prices, and supplierreputation were the factors deemed important in selecting overseas suppliers. Majority of respondentswere importing certified wood products. FSC, SFI, and ISO 14000 were the mostly accepted certificationprograms. However, certification was not a major factor in foreign supplier selection criteria. Whenconsidered the U.S. wood products importers’ tendency to diversify their products and species imported,attractive opportunities exist for wood products suppliers from tropical countries.
{"title":"An Analysis of the U.S. Wood Products Import Sector: Prospects for Tropical Wood Products Exporters","authors":"W. Bandara, R. Vlosky","doi":"10.31357/JTFE.V2I2.595","DOIUrl":"https://doi.org/10.31357/JTFE.V2I2.595","url":null,"abstract":"The U.S. has dramatically altered its wood product imports and exports during the past few years,and at present, it is the second largest wood product importer in the world. Hence, an understanding ofmarket structures, factors in selecting foreign suppliers, and the emphasis placed on environmentalissues/certification are critical to understand from the perspective of wood products importers in the U.S.This study provides an analysis of the U.S. wood products import sector with special emphasis on currentand future opportunities for tropical wood products exporters to the U.S. market.In this study, 158 wood products importers in the U.S. were surveyed using a mailingquestionnaire. The adjusted response rate was 40.6 percent. Results indicated that most of the respondentswere small to medium scale firms, but major importers of wood products. According to respondents,wood products to the U.S. mainly come from Brazil, Chile, and China. From the importers’ perspective,Brazilian wood products ranked first for its quality followed by wood products from Chile and Finland.Product quality, long term customer relationships, on-time delivery of orders, fair prices, and supplierreputation were the factors deemed important in selecting overseas suppliers. Majority of respondentswere importing certified wood products. FSC, SFI, and ISO 14000 were the mostly accepted certificationprograms. However, certification was not a major factor in foreign supplier selection criteria. Whenconsidered the U.S. wood products importers’ tendency to diversify their products and species imported,attractive opportunities exist for wood products suppliers from tropical countries.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82269710","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. G. D. K. Bandara, M.R. Wijesinghe, W. D. Ratnasooriya, A. A. H. Priyani
This paper reports the histopathological responses of the gill, liver and tail muscle tissues in tadpoles of the Asian Common Toad Duttaphrynus melanostictus (Schneider, 1799) exposed to chlorpyrifos a common organophosphorus pesticide. Tadpoles of Gosner stages 24-26 were continuously exposed to low, mid and high (500, 1000 and 1500 µgl –1 ) concentrations of chlorpyrifos for two weeks. Histological alterations in the tissues of the surviving larvae were microscopically examined both at the end of the exposure period and after a week following the final exposure. Several histological alterations were noted in the gills, liver and tail muscles of the larvae exposed to 1500 µgl –1 of chlorpyrifos. The gills of exposed larvae showed architectural distortion resulting from reduced primary and secondary gill lamellae and blood vessels, and alterations in the gill epithelium. In the liver sinusoidal congestion and dilation, cytoplasmic vacuolation and changes in hepatocytes such as hyperchromatic nuclei and nuclear fragmentation were observed. The tail muscle tissue suffered from severe atrophy and myotomal disintegration. Although histological alterations in the gill and liver tissues were noted only at the high concentration, changes in the muscle tissue i.e. muscle degeneration and atrophy, were apparent at both low and mid concentrations. The degree of damage in surviving larvae in a week following the final exposure was lower than that observed during the exposure, probably indicating recovery or resistance. The findings of the present study emphasize the need to investigate possible sublethal damage induced by pesticides in amphibians inhabiting agricultural habitats.
{"title":"Chlorpyrifos-induced Histopathological Alterations in Duttaphrynus melanostictus (Schneider 1799) Tadpoles: Evidence from Empirical Trials","authors":"M. G. D. K. Bandara, M.R. Wijesinghe, W. D. Ratnasooriya, A. A. H. Priyani","doi":"10.31357/JTFE.V2I2.592","DOIUrl":"https://doi.org/10.31357/JTFE.V2I2.592","url":null,"abstract":"This paper reports the histopathological responses of the gill, liver and tail muscle tissues in tadpoles of the Asian Common Toad Duttaphrynus melanostictus (Schneider, 1799) exposed to chlorpyrifos a common organophosphorus pesticide. Tadpoles of Gosner stages 24-26 were continuously exposed to low, mid and high (500, 1000 and 1500 µgl –1 ) concentrations of chlorpyrifos for two weeks. Histological alterations in the tissues of the surviving larvae were microscopically examined both at the end of the exposure period and after a week following the final exposure. Several histological alterations were noted in the gills, liver and tail muscles of the larvae exposed to 1500 µgl –1 of chlorpyrifos. The gills of exposed larvae showed architectural distortion resulting from reduced primary and secondary gill lamellae and blood vessels, and alterations in the gill epithelium. In the liver sinusoidal congestion and dilation, cytoplasmic vacuolation and changes in hepatocytes such as hyperchromatic nuclei and nuclear fragmentation were observed. The tail muscle tissue suffered from severe atrophy and myotomal disintegration. Although histological alterations in the gill and liver tissues were noted only at the high concentration, changes in the muscle tissue i.e. muscle degeneration and atrophy, were apparent at both low and mid concentrations. The degree of damage in surviving larvae in a week following the final exposure was lower than that observed during the exposure, probably indicating recovery or resistance. The findings of the present study emphasize the need to investigate possible sublethal damage induced by pesticides in amphibians inhabiting agricultural habitats.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83944080","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 relationship between some physico-chemical parameters and bioindicators in Bolgoda canal and Waga stream in Colombo, Sri Lanka was assessed from February to July 2010. The objective of the study was to evaluate the quality of aquatic health in the two water bodies using some physico-chemical parameters and bioindicators. Physico-chemical parameters of the Water bodies were measured. Macro invertebrates and phytoplankton were studied as biological indicators. Quantification of macro invertebrates were carried out and Pollution Tolerant Index (PTI) of Bolgoda canal and Waga stream was calculated according to the standard manual published by the United States Environmental Protection Agency (USEPA). Macro invertebrate component in the Bolgoda canal represented both moderately pollution tolerant ( Nepa cinerea, Zygopteran nymphs) and pollution tolerant ( Planorbella trivolvis , Promacea bridgesi , Gerris sp, Lethocerus americanus , Plea frontalis , Cerithiidae sp, Tubifex tubifex ) organisms while in Waga stream only pollution sensitive organisms ( Paludomous loricatus , Paludomous zeylanicus , Cylindrostesthus productus , Plecopteran nymphs, Psephenidae larvae, Aegla sp, Ephemeropteran nymphs) were reported. The PTI value of Bolgoda canal ranged from 17.00 to 19.90 where as in Waga stream was ranged from 34.00 to 39.60 indicating poor and good water quality respectively. The phytoplankton composition of both water bodies were analyzed using Shannon Wiener Diversity Index (SWDI). SWDI for phytoplankton in Bolgoda canal was ranged between 0.674±0.36 and 1.513±1.80 and in Waga stream was ranged from 1.89±0.72 - 3.01±1.89 indicating low and high diversity respectively. Data analysis by Principle Component Analysis (PCA) showed that physico-chemical parameters, PTI and SWDI of the sampling locations in Bolgoda canal and Waga stream were clustered into three distinct groups according to the site selection. Regression analysis showed temperature, pH, DO, nitrate concentration and BOD had a significant effect on the PTI value of the Bolgoda canal and Waga stream.
{"title":"Aquatic Life Health Quality Assessment of the Bolgoda Canal and Waga Stream with respect to Selected Physico-chemical Parameters and Bioindicators","authors":"F. Idroos, P. Manage","doi":"10.31357/JTFE.V2I2.590","DOIUrl":"https://doi.org/10.31357/JTFE.V2I2.590","url":null,"abstract":"The relationship between some physico-chemical parameters and bioindicators in Bolgoda canal and Waga stream in Colombo, Sri Lanka was assessed from February to July 2010. The objective of the study was to evaluate the quality of aquatic health in the two water bodies using some physico-chemical parameters and bioindicators. Physico-chemical parameters of the Water bodies were measured. Macro invertebrates and phytoplankton were studied as biological indicators. Quantification of macro invertebrates were carried out and Pollution Tolerant Index (PTI) of Bolgoda canal and Waga stream was calculated according to the standard manual published by the United States Environmental Protection Agency (USEPA). Macro invertebrate component in the Bolgoda canal represented both moderately pollution tolerant ( Nepa cinerea, Zygopteran nymphs) and pollution tolerant ( Planorbella trivolvis , Promacea bridgesi , Gerris sp, Lethocerus americanus , Plea frontalis , Cerithiidae sp, Tubifex tubifex ) organisms while in Waga stream only pollution sensitive organisms ( Paludomous loricatus , Paludomous zeylanicus , Cylindrostesthus productus , Plecopteran nymphs, Psephenidae larvae, Aegla sp, Ephemeropteran nymphs) were reported. The PTI value of Bolgoda canal ranged from 17.00 to 19.90 where as in Waga stream was ranged from 34.00 to 39.60 indicating poor and good water quality respectively. The phytoplankton composition of both water bodies were analyzed using Shannon Wiener Diversity Index (SWDI). SWDI for phytoplankton in Bolgoda canal was ranged between 0.674±0.36 and 1.513±1.80 and in Waga stream was ranged from 1.89±0.72 - 3.01±1.89 indicating low and high diversity respectively. Data analysis by Principle Component Analysis (PCA) showed that physico-chemical parameters, PTI and SWDI of the sampling locations in Bolgoda canal and Waga stream were clustered into three distinct groups according to the site selection. Regression analysis showed temperature, pH, DO, nitrate concentration and BOD had a significant effect on the PTI value of the Bolgoda canal and Waga stream.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81230333","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}
T. Borokini, F. D. Babalola, T. O. Amusa, S. Ivande, Z. Wala, O. Jegede, D. Tanko, J. O. Ihuma
In Nigeria, human communities are found within or beside forest ecosystems, depending onthese ecosystems for survival. Their forest exploitation is considered a threat to conservation efforts,leading to constant conflicts between Government, law enforcement agencies and the communities. Thebest solution is a win-win system of participatory community-based forest resources management, inwhich the communities are regarded as stakeholders rather than as threats. This paper explains theadoption of this approach in Ngel Nyaki Forest Reserve, Mambilla Plateau, where the communities weretrained in establishment and management of forest plantations with readily available market for theirtimber; employment for some of the community youths as well as community development projects.This paper calls for the adoption of this system in other protected areas in Nigeria, while theGovernment should provide basic amenities for the communities as alternatives to those forest products. Keywords: Community-based forest management, Ngel Nyaki Forest Reserve, Protected areas, Nigeria.
{"title":"Community-based Forest Resources Management in Nigeria: Case study of Ngel Nyaki Forest Reserve, Mambilla Plateau, Taraba State, Nigeria","authors":"T. Borokini, F. D. Babalola, T. O. Amusa, S. Ivande, Z. Wala, O. Jegede, D. Tanko, J. O. Ihuma","doi":"10.31357/JTFE.V2I1.571","DOIUrl":"https://doi.org/10.31357/JTFE.V2I1.571","url":null,"abstract":"In Nigeria, human communities are found within or beside forest ecosystems, depending onthese ecosystems for survival. Their forest exploitation is considered a threat to conservation efforts,leading to constant conflicts between Government, law enforcement agencies and the communities. Thebest solution is a win-win system of participatory community-based forest resources management, inwhich the communities are regarded as stakeholders rather than as threats. This paper explains theadoption of this approach in Ngel Nyaki Forest Reserve, Mambilla Plateau, where the communities weretrained in establishment and management of forest plantations with readily available market for theirtimber; employment for some of the community youths as well as community development projects.This paper calls for the adoption of this system in other protected areas in Nigeria, while theGovernment should provide basic amenities for the communities as alternatives to those forest products. Keywords: Community-based forest management, Ngel Nyaki Forest Reserve, Protected areas, Nigeria.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"123 8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83669896","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}
Abstract The rice weevil Sitophilus oryzae is considered the major problem in stored rice in Sri Lanka. Due to the adverse effects of pesticide usage, research on the re-evaluation and use of many ethnobotanicals as alternative storage pest control agents has been intensified. Although plant materials with insecticidal properties provide small-scale farmers with a locally available, eco-friendly and inexpensive method of control of storage insect pests, lack of understanding and knowledge prevent their widespread application. The present study was therefore undertaken to investigate the effectiveness of the botanical Olax zeylanica in controlling infestations of the rice weevil with the view of fulfilling this lack. In two separate bioassays, c ontact/feeding and fumigant toxicity of powdered leaves of O. zeylanica were tested against 1-7 days old adults under laboratory conditions. All experiments were conducted using a no-choice bioassay apparatus. Contact/feeding toxicity was tested by directly exposing weevils to 1.0, 3.0, 5.0 and 7.5g of leaf powder mixed with 100g of rice grains while f umigant toxicity was evaluated by using the same doses where weevils were exposed to fumes emitted from the leaf powders. In both bioassays 100% mortality of the weevils was observed within 18 hours of exposure to 3.0, 5.0 and 7.5g doses of leaf powder. Percentage weevil mortality in treated rice tested with three doses of leaf powder at all the time intervals (except for 1.0g) was significantly higher (p < 0.05) than that of the corresponding control. No Contact/feeding toxicity was recorded when weevils were directly exposed to 1.0g leaf powder whereas only 14% weevil mortality was observed even after 24hours of exposure to fumes of leaf powder. Results also revealed that weevil mortality increased both with increasing dose and time of exposure. It is of interest to note that in both bioassays a 100% weevil mortality was obtained after 18 hours of exposure to a lower amount of leaf powder such as 3.0g, when the adults were either directly exposed to the leaf powder or to its fumes. Moreover, LD 50 values of 2.55g and 2.08g for leaf powders obtained after 12 hours of exposure to insects in contact /feeding toxicity test and fumigation test respectively indicated that leaf powder is more toxic to weevils when they were in direct contact with it. Findings of the present study bears out the exceptionally high efficacy of O. zeylanica leaves applied directly mixed with the food material or introduced as a fumigant to suppress weevil infestations in stored grains and strengthen the possibility of using this plant as an alternative to synthetic chemicals in storage pest management. Keywords : Olax zeylanica, Sitophilus oryzae, Direct Contact/Feeding Toxicity, Direct Fumigation Toxicity
{"title":"Ethnobotanicals for Storage Pest Management: Effect of powdered leaves of Olax zeylanica in suppressing infestations of rice weevil Sitophilus oryzae (Coleoptera: Curculionidae)","authors":"S. D. Fernando, M. Karunaratne","doi":"10.31357/JTFE.V2I1.38","DOIUrl":"https://doi.org/10.31357/JTFE.V2I1.38","url":null,"abstract":"Abstract The rice weevil Sitophilus oryzae is considered the major problem in stored rice in Sri Lanka. Due to the adverse effects of pesticide usage, research on the re-evaluation and use of many ethnobotanicals as alternative storage pest control agents has been intensified. Although plant materials with insecticidal properties provide small-scale farmers with a locally available, eco-friendly and inexpensive method of control of storage insect pests, lack of understanding and knowledge prevent their widespread application. The present study was therefore undertaken to investigate the effectiveness of the botanical Olax zeylanica in controlling infestations of the rice weevil with the view of fulfilling this lack. In two separate bioassays, c ontact/feeding and fumigant toxicity of powdered leaves of O. zeylanica were tested against 1-7 days old adults under laboratory conditions. All experiments were conducted using a no-choice bioassay apparatus. Contact/feeding toxicity was tested by directly exposing weevils to 1.0, 3.0, 5.0 and 7.5g of leaf powder mixed with 100g of rice grains while f umigant toxicity was evaluated by using the same doses where weevils were exposed to fumes emitted from the leaf powders. In both bioassays 100% mortality of the weevils was observed within 18 hours of exposure to 3.0, 5.0 and 7.5g doses of leaf powder. Percentage weevil mortality in treated rice tested with three doses of leaf powder at all the time intervals (except for 1.0g) was significantly higher (p < 0.05) than that of the corresponding control. No Contact/feeding toxicity was recorded when weevils were directly exposed to 1.0g leaf powder whereas only 14% weevil mortality was observed even after 24hours of exposure to fumes of leaf powder. Results also revealed that weevil mortality increased both with increasing dose and time of exposure. It is of interest to note that in both bioassays a 100% weevil mortality was obtained after 18 hours of exposure to a lower amount of leaf powder such as 3.0g, when the adults were either directly exposed to the leaf powder or to its fumes. Moreover, LD 50 values of 2.55g and 2.08g for leaf powders obtained after 12 hours of exposure to insects in contact /feeding toxicity test and fumigation test respectively indicated that leaf powder is more toxic to weevils when they were in direct contact with it. Findings of the present study bears out the exceptionally high efficacy of O. zeylanica leaves applied directly mixed with the food material or introduced as a fumigant to suppress weevil infestations in stored grains and strengthen the possibility of using this plant as an alternative to synthetic chemicals in storage pest management. Keywords : Olax zeylanica, Sitophilus oryzae, Direct Contact/Feeding Toxicity, Direct Fumigation Toxicity","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"176 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78499904","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}
With increasing private sector investments in commercial forestry, it is apparent that plantationforestry in Sri Lanka is moving in the direction of managing fast growing timber species for shorterrotations. However, there’s a perceptionthat accelerated growth rates induced by improved forestmanagement practices can result in inferior wood quality. This study tested this perceptionby studyingthe effect of growth rate on the specific gravity, as a proxy for wood quality, of three alternative timberspecies grown in Sri Lanka; Swietenia macrophylla, Khaya senegalensis and Paulownia fortunei.Specific gravity remained more or less uniform from pith to bark regardless of the fluctuation of ringwidth in K. senegalensis while S. macrophylla exhibited a slight increase in specific gravity from pith tobark. This increasing trend was more prominent in P. fortunei. Results revealed growth rates representedby ring width showed poor correlations with specific gravity in both S. macrophylla, and K.senegalensis. Although P. fortunei showed a statistically significant positive correlation, regressionanalysis indicated a poor relationship between growth rate and specific gravity. Hence it is unlikely thatwood specific gravity of the studied species to be influenced by accelerated growth rates.
{"title":"Effect of Growth Rate on Wood Specific Gravity of Three Alternative Timber Species in Sri Lanka; Swietenia macrophylla, Khaya senegalensis and Paulownia fortunei","authors":"P. Perera, H. Amarasekera, N. Weerawardena","doi":"10.31357/JTFE.V2I1.567","DOIUrl":"https://doi.org/10.31357/JTFE.V2I1.567","url":null,"abstract":"With increasing private sector investments in commercial forestry, it is apparent that plantationforestry in Sri Lanka is moving in the direction of managing fast growing timber species for shorterrotations. However, there’s a perceptionthat accelerated growth rates induced by improved forestmanagement practices can result in inferior wood quality. This study tested this perceptionby studyingthe effect of growth rate on the specific gravity, as a proxy for wood quality, of three alternative timberspecies grown in Sri Lanka; Swietenia macrophylla, Khaya senegalensis and Paulownia fortunei.Specific gravity remained more or less uniform from pith to bark regardless of the fluctuation of ringwidth in K. senegalensis while S. macrophylla exhibited a slight increase in specific gravity from pith tobark. This increasing trend was more prominent in P. fortunei. Results revealed growth rates representedby ring width showed poor correlations with specific gravity in both S. macrophylla, and K.senegalensis. Although P. fortunei showed a statistically significant positive correlation, regressionanalysis indicated a poor relationship between growth rate and specific gravity. Hence it is unlikely thatwood specific gravity of the studied species to be influenced by accelerated growth rates.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"9 1","pages":"26-35"},"PeriodicalIF":0.0,"publicationDate":"2012-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75357610","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 paper assesses the potential of forest plantations in Sri Lanka consisting of teak, mahoganyand two species of eucalyptus, to facilitate the conservation of biodiversity using two taxonomic groups,the plants and birds. Their diversity in plantations at a harvestable age were compared with that of anatural forest. Enumerations of plants and dbh/height measurements were conducted in quadrates, whileavifauna was recorded along transects. Results show that plantation forests supported a reasonably richcommunity of both plants and birds, including natives and endemics. A large proportion of species werecommon to both plantations and natural forests indicating that plantations hold a subset of forest species.The presence of plants of various height and girth classes together with the high diversity and evennessvalues indicate that, although timber plantations are initially established as mono-cultivations, theyfacilitate the colonization of additional species. These findings thus demonstrate that forest plantationscould make a significant contribution towards biodiversity conservation.
{"title":"Conservation Value of Forest Plantations: A Study of Four Timber Species in Sri Lanka","authors":"M.R. Wijesinghe, V. R. De Silva","doi":"10.31357/JTFE.V2I1.566","DOIUrl":"https://doi.org/10.31357/JTFE.V2I1.566","url":null,"abstract":"This paper assesses the potential of forest plantations in Sri Lanka consisting of teak, mahoganyand two species of eucalyptus, to facilitate the conservation of biodiversity using two taxonomic groups,the plants and birds. Their diversity in plantations at a harvestable age were compared with that of anatural forest. Enumerations of plants and dbh/height measurements were conducted in quadrates, whileavifauna was recorded along transects. Results show that plantation forests supported a reasonably richcommunity of both plants and birds, including natives and endemics. A large proportion of species werecommon to both plantations and natural forests indicating that plantations hold a subset of forest species.The presence of plants of various height and girth classes together with the high diversity and evennessvalues indicate that, although timber plantations are initially established as mono-cultivations, theyfacilitate the colonization of additional species. These findings thus demonstrate that forest plantationscould make a significant contribution towards biodiversity conservation.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85981917","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}
Macroinvertebrates have been identified as excellent indicators of stream (wetland) health as they respond rapidly to environmental changers and provide short to medium term pollution history records. Current study was aimed to develop a Macroinvertebrate-based Index of Biotic Integrity (M-IBI) to monitor stream health of Colombo-Sri Jayawardhanapura canal system. Macroinvertebrates were sampled using a D-framed kick net from ten stations during the period of Nov 2008 to June 2009. Habitat characteristics and some water quality parameters also recorded. For the index development, those ten stations were grouped into two as ’Reference’ and ‘Degraded’ based on their habitat characteristics and some water quality parameters. Then 41vcandidate metrics were nominated for statistical analysis process. After considering their sensitivity to stream impairment, ability of showing exceptionally strong discrimination between reference and degraded sites and less redundancy, ten candidate metrics were selected for M-IBI development. Validity of the index was tested with a new independent data set. Scores acquired for these data set were positively correlated with DO values (r = 0.578). That concluded the potential of using M-IBI developed for biological monitoring and improving biotic integrity of streams and wetlands.
{"title":"Development of a Macroinvertebrate - based Index of Biotic Integrity (M-IBI) for Colombo-Sri Jayawardhanapura Canal System (A new approach to assess stream/ wetland health)","authors":"R. Perera, J. Wattavidanage, N. Nilakarawasam","doi":"10.31357/JTFE.V2I1.32","DOIUrl":"https://doi.org/10.31357/JTFE.V2I1.32","url":null,"abstract":"Macroinvertebrates have been identified as excellent indicators of stream (wetland) health as they respond rapidly to environmental changers and provide short to medium term pollution history records. Current study was aimed to develop a Macroinvertebrate-based Index of Biotic Integrity (M-IBI) to monitor stream health of Colombo-Sri Jayawardhanapura canal system. Macroinvertebrates were sampled using a D-framed kick net from ten stations during the period of Nov 2008 to June 2009. Habitat characteristics and some water quality parameters also recorded. For the index development, those ten stations were grouped into two as ’Reference’ and ‘Degraded’ based on their habitat characteristics and some water quality parameters. Then 41vcandidate metrics were nominated for statistical analysis process. After considering their sensitivity to stream impairment, ability of showing exceptionally strong discrimination between reference and degraded sites and less redundancy, ten candidate metrics were selected for M-IBI development. Validity of the index was tested with a new independent data set. Scores acquired for these data set were positively correlated with DO values (r = 0.578). That concluded the potential of using M-IBI developed for biological monitoring and improving biotic integrity of streams and wetlands.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":"95 1","pages":"10-19"},"PeriodicalIF":0.0,"publicationDate":"2012-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79659884","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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