• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.51 no.3
• /
• pp.448-453
• /
• 2015

This study was performed to estimate biomass and to provide management plan through population ecological characteristics, including survival rate, instantaneous coefficient of natural and fishing mortalities, and age at first capture of Flathead grey mullet, Mugil cephalus, in the coastal waters of Yeosu. Survival rate (S) of the flathead grey mullet was 3.671. The instantaneous coefficients of natural mortality (M) and fishing mortality (F) was estimated to be 0.325/year, 0.962/year for flathead grey mullet. Also fist capure age of flathead grey mullet was 3.61year. The current biomass of the flathead grey mullet in the study area was estimated to be 19.6 M/T and $F_{0.1}$ and $F_{40%}$ were estimated 0.340/year, 0.225/year. For the stock assessment result, flathead grey mullet was not overfished but overfishing.

• Fisheries and Aquatic Sciences
• /
• v.26 no.9
• /
• pp.548-557
• /
• 2023

The purposes of this research were to identify fish species using DNA barcodes or partial sequences of cytochrome b (Cytb) and to assess the diversity of fish in the Mae Tam reservoir, Phayao province, Thailand. Fish samples were collected 3 times, during the winter, summer, and rainy seasons, from 2 sampling sites using gillnets with 3 mesh sizes (30, 50, and 70 mm). A total of 34 representative samples were classified into 12 species, 7 families and 6 orders by morphological- and DNA barcoding-based identifications. However, one cichlid species, Cichlasoma trimaculatum, could only be identified using DNA barcoding. Family Cyprinidae had the greatest diversity, 50.00%. The diversity, richness and evenness indices ranged from 0.43-0.65, 0.64-1.46, and 0.27-0.40, respectively, indicating that fish diversity at both sampling sites was relatively low. A comparison of the catch per unit effort (CPUE) with 3 different mesh sizes found that the 50 mm mesh size was the best (474.80 ± 171.56 g/100 m²/night), followed by the 70 mm (417.41 ± 176.24 g/100 m²/night) and 30 mm mesh sizes (327.88 ± 115.60 g/100 m²/night). These results indicate that DNA barcoding is a powerful tool for species identification. Our data can be used for planning the sustainable management of fisheries resources in the Mae Tam reservoir.

• Journal of Forest and Environmental Science
• /
• v.36 no.4
• /
• pp.298-310
• /
• 2020

Fuel management can play enormous role in fire management in tropical dry forests. However, unlike the temperate forests, knowledge on implications of different fuel management methods in tropical forests is often inadequate. In this study, the implications of prescribed burning and hand thinning treatments on implementation cost, fuel loading and post-treatment fire behaviour were tested and compared in degraded forests and teak plantations in two forest reserves of different levels of dryness in Ghana. The study found that prescribed burning was less expensive (62.02 US Dollars ha-1) than hand thinning (95.37 US Dollars ha-1). The study also indicated that the two fuel management methods were able to reduce fuel loading in degraded forests and teak plantations. However, prescribed burning was more effective in reducing fuel loading than hand thinning. While the relative change of fuel reduction was 13% higher in prescribed burning than the hand thinning in degraded forest, it was 41% higher in prescribed burning than hand thinning in teak plantations. The fire behaviour of post-treatment experimental fire was also lower in prescribed burning than the hand thinning and control plots. Fuel management, therefore, has a great potential in fire management in degraded forests and teak plantations in Ghana.

• Natural Product Sciences
• /
• v.23 no.4
• /
• pp.235-238
• /
• 2017

Colorado potato beetle is a most destructive insect pest of potato throughout the world. Although utilization of chemical insecticides is a main method for management of this pest, their negative side-effects such as threat to humans and the environmental pollution prompted researchers to search for natural alternatives. Recently plant essential oils with low or without side-effects against noun-targeted organisms and with high availability were considered as safe bio-pesticides. In the present study, toxicity of essential oil of Iranian lemongrass, Cymbopogon citratus Stapf, was evaluated against 3th instar larvae and adults of Colorado potato beetle by a leaf dipping method. Results displayed essential oil had notable toxicity against both larvae and adults after 24 and 48 h exposure times. Probit analysis revealed $LC_{50}$ values (lethal concentration to kill 50% of population) with 95% confidence limits were 10.32 (9.17 - 11.72) and 7.76 (6.80 - 8.74) ${\mu}l/ml$ for larvae and 6.27 (4.82 - 8.15) and 4.35 (3.24 - 5.62) ${\mu}l/ml$ for adults after 24 and 48 h, respectively. Based on regression analysis, a positive correlation between log concentration of essential oil and insect mortality was achieved. Results indicated C. citratus essential oil can be candidate as a natural alternative to the harmful chemical insecticides in the management of Colorado potato beetle.

• Korean Journal of Environment and Ecology
• /
• v.32 no.5
• /
• pp.532-540
• /
• 2018

Importance-performance analysis (IPA) is a simple and effective technique that can assist practitioners in prioritizing customer attributes to enhance service quality and visitor's satisfaction. The purpose of this study is to use the IPA-Kano model to examine the correlation of visitor's satisfaction and management matters and deduce the management priority. It classifies 14 visiting satisfaction attributes into basic factors (forest environments and staff/information center), performance factors (the natural landscape, trail facilities, forest status, easy access, and historical and cultural resources), and excitement factors (the value of natural monument, educational experiences, and entrance fee) to select the management priority according to the achievement (satisfaction). The management priority according to the performance is staff/information center > easy access > forest environment > trail facilities, historical and cultural resources, forest status, and natural landscape > entrance fee and educational experience > value of natural monument. By considering their performance, it further identifies development priorities for visitor's satisfaction improvement. These priorities allow local governments to deploy scarce resources to improve satisfaction.

• KCID journal
• /
• v.7 no.1
• /
• pp.69-73
• /
• 2000

• The Plant Pathology Journal
• /
• v.37 no.3
• /
• pp.205-214
• /
• 2021

The use of the supernatant from a Bacillus subtilis culture mixed with sodium bicarbonate was explored as a means of controlling stem brown spot disease in dragon fruit plants. In in vitro experiments, the B. subtilis supernatant used with sodium bicarbonate showed a strong inhibition effect on the growth of the fungus, Neoscytalidium dimidiatum, the agent causing stem brown spot disease and was notably effective in preventing fungal invasion of dragon fruit plant. This combination not only directly suppressed the growth of N. dimidiatum, but also indirectly affected the development of the disease by eliciting the dragon-fruit plant's defense response. Substantial levels of the pathogenesis-related proteins, chitinase and glucanase, and the phenylpropanoid biosynthetic pathway enzymes, peroxidase and phenyl alanine ammonia-lyase, were triggered. Significant lignin deposition was also detected in treated cladodes of injured dragon fruit plants in in vivo experiments. In summary, B. subtilis supernatant combined with sodium bicarbonate protected dragon fruit plant loss through stem brown spot disease during plant development in the field through pathogenic fungal inhibition and the induction of defense response mechanisms.

• Journal of Korean Society of Rural Planning
• /
• v.25 no.2
• /
• pp.99-117
• /
• 2019

Environmental impact assessment (EIA), which predicts, evaluates, and manages the influences on natural landscape, plays a role of monitoring natural resources for systematic management of natural landscape. However, the function of verification and correction of the system is still insufficient and feed-back, one of the most important features of EIA follow-up, has not been introduced in Korea's EIA system yet. As a procedure, it is required to check if the opinions of the evaluators are properly reflected to the outcomes of the project through a reviewing process after assessing environmental impacts of a development project. In reality, despite the awareness about the importance of follow-up inspection of the conformity with, the system mainly focuses on the agreement during the planning stage of the development project and fails to continuously manage after its completion. There have been various preceding studies related to prediction, evaluation, and management of environmental impacts on natural landscape for better management. They primarily dealt with the problems in the EIA process and suggested improvement measures, including directions for institutional development, step-by-step goals, and operation methods, to address the problems which arise in the EIA follow-up process. However, suggested measures are not actively applied with the focus only put on institutional operation, there are virtually no standardized methods to predict and assess landscape changes due to the development project and to manage landscape after the project. Against this backdrop, this study aims to explore the existing methods to analyze the impacts natural landscape and to establish a system where landscape management is continued after the development project. To this end, we will suggest reducing methods according to the predicted changes in landscape for post-project management of natural landscape. Characteristics of reduction methods by project type were examined through reviewing the guide to natural landscape rating and the importance of development project impacts on natural landscape by type of reduction was evaluated through questionnaire for experts. Evaluated types of reduction are classified and presented by characteristics of each development project and content of reduction type.

• Resources Recycling
• /
• v.29 no.3
• /
• pp.24-35
• /
• 2020

Management of resource productivity is important for the reduction of natural resources and energy consumption. This is closely linked to circular economy which has recently been stressed worldwidely. Resource productivity is a key indicator which is to be managed in various industry sectors. Especially Korea which is heavily dependent on the natural resources import from overseas needs to give attention to this point. Nevertheless resource productivity related domestic researches and policies are extremely rare. This paper thus presents trends on resources productivities and their management policies of European countries and OECD G7 countries compared to the situation of Korea. In addition, the decoupling phenomenon of DMC (domestic material consumption) and GDP of Europe is analyzed and the resource productivity promotion strategy of Korea is proposed.

• Journal of recreation and landscape
• /
• v.12 no.4
• /
• pp.59-66
• /
• 2018

The purpose of the present study was to compare the long-term management objectives, policy objectives, implementation plans, and detailed plans of four provincial parks established in 2013 using various analysis frameworks. Through this, the study aimed to identify the characteristics of the management plan and extract the implementation plan important to each park by analyzing the priorities in the detailed plan. The long-term management objectives of most parks were to maintain recreational functions by utilizing all the resources of the park, rather than merely preserving the ecosystem. From an ecological perspective, information on major plants and legal protection species are included for most parks, and geological and topographic features considered a major resource. For sustainable forests, it is important to induce the dispersion of concentrated use space. Efficient management systems are distinctively differentiated among the parks. For regional revitalization, the management of programs to link provincial parks and their surrounding areas has become most important. From an ecological perspective, priorities differed for the parks according to their ecological characteristics. For sustainable forests, Moaksan Provincial Park prioritized the visitor reservation system related to the overall park, while the other three parks prioritized alleviating the concentrated use of specific areas. From an efficient management perspective, Daedunsan Provincial Park prioritized aspects related to the cableway. Maisan Provincial Park prioritized inducing the linkage between the use of natural and cultural resources, and Seonunsan Provincial Park prioritized establishing an ecological and cultural commentary operating system. For the base-type leisure activity space, Moaksan Provincial Park prioritized the systematic management and operation of the pilgrimage route, Maisan Provincial Park the connection between the Maisan geography and residents' income, and Seonunsan Provincial Park providing a space for ecological education.