Seasonal changes in the CO2 fixation rate and water-use efficiency in the leaves of six evergreen and two deciduous broad-leaved tree species on Jeju Island, Korea, were measured using a portable photosynthesis analyzer, to identify which species are most efficient in taking up CO2 from the air. The CO2 fixation rate was high in the deciduous species in spring and summer and decreased in fall, whereas it was high in the evergreen species in summer and fall and decreased in winter. The rate remained high in the deciduous tree Prunus yedoensis from spring to fall (> 7.1 μmol CO2/m2/s) and in two evergreen trees, Castanopsis cuspidata var. sieboldii and Cinnamomum camphora, in summer and fall (7.0 9.9 μmol CO2/m2/s). Therefore, these tree species fix atmospheric CO2 effectively. The water-use efficiency was higher in evergreen species than in deciduous species regardless of the season. Exceptionally, it was high in the deciduous species Zelkova serrata in spring and summer (> 100 μmol CO2/mol H2O), suggesting that Z. serrata is a useful tree for dry conditions due to its tolerance of water stress. The regressions of the CO2 fixation rate versus the evaporation rate and stomatal conductance were linear and non-linear, respectively. This suggests that the stomatal activity of leaves plays an important part in CO2 fixation of plants. In conclusion, C. cuspidata var. sieboldii, C. camphora, and P. yedoensis should be planted along roads or in urban spaces for the greening of cities and mitigation of CO2 concentrations in the air.
The national parks of South Korea take up an area of 6,726 km2, which accounts for 6.7% of the national land. They are national conservation areas with their area made up of 59.1% of land (3,972.6 km2) and 40.9% of seawaters (2,753.7 km2). And in 2019, the national parks are classified by type into 17 mountainous, 4 maritime or coastal, and 1 historical site. Here, the maritime or coastal nation parks are lately spotlighted as landmarks in maritime tourism. However, the area of the maritime or coastal national parks is continuously dwindling due to conflicts between the residents in the parks and Korea national park service, the continued pressure with respect to the regional tourism development and private investments, and the abolition of parks in relation to allegedly breached private properties. This study identifies the issues with the operation and management of national parks as caused by the abolition of parks and the reduction of areas, and goes from there to do research with the aim of suggesting an institutionalized improvement plan with a view to more useful operation and management of the maritime or coastal national parks. As a result, the natural resources in the sea and on land should be surveyed again to establish the standard for use-specific zoning and reorganize the park areas in adjusting the national park areas. Second, the use-specific districts need to be reviewed for their reorganization that meets the designation requirements by focusing on the characteristics of the different national parks with a view to ensuring reasonable natural conservation in the maritime or coastal national parks. Third, various support facilities for residents such as public path, lodgings, and rentals need to be created to reduce the conflicts between Korea national park service and those who live in the parks.
The purpose of this study is to examine the differences of use behavior and environmental perception of a park and to analyze the influence of environmental perception factors on park satisfaction among 7 parks in Suseong-gu, Daegu. The data from the 255 questionnaires of young adults (30-59) and old adults (more than 60) who use the park more than once a week were used for the analysis. In terms of park use behavior, young adults used the park for walking and jogging mainly on weekday evenings, while old adults used the park for walking and rest mainly during weekday daytimes. In addition, old adults used the park more times a week than young adults, and spent more time in the park. In the analysis of the environmental perception of the park, similar results were found in both age groups but overall, old adults were more satisfied with the park environment than the young adults. As a result of analyzing the influence of environmental perception factors, it was determined that park satisfaction in young adults has a significant influence on 'use amenity', 'use convenience', 'facility suitability', and 'landscape diversity' in this order. On the other hand, park satisfaction for old adults has an influence on 'use amenity', 'facility suitability', and 'use convenience' in this order. The findings of this study can be used as an effective basic data for future park planning considering age groups.
This study was conducted to analyze the current situation of the logging operation system and to suggest an effective policy plan to secure important raw materials for the use of forest biomass. The dissemination of forestry mechanization and the establishment of the logging operation are important tasks to establish a system and reduce costs of timber production by increasing the use of forest biomass; this includes increasing the supply of timber for domestic products and increasing the production of wood chips and wood pellets. In particular, the efficiency of steep-slopes catenary system machinery for yarding such as tower-yarder and swing-yarder should be urgently supplied to cope with forest production and supply of forest biomass energy resources. In addition, it is necessary to continuously promote the dissemination of high-performance forestry machinery as is being done in Japan. At the same time, instead of distributing or retaining the spread of forestry machinery to the state and local governments, it is necessary to distribute timber production work centered on forest cooperatives or private timber producers to be carried out by wood producers, forest cooperatives and individuals.
The purpose of this study was to investigate the effect of shading on the growth and productivity of strawberries. Photosynthesis was normally achieved under natural light without shading treatment, and vegetative growth of under- and aboveground part of strawberry plants were excellent. Strawberry fruit productivity and quality were different depending on shading conditions. In natural light, they were improved possibly by balanced vegetative and reproductive growth. However, under light-shading conditions with insufficient sunshine, photosynthetic activity deteriorated and carbohydrate production was therfore inadequate; this adversely affected plant height and quality. The negative effects were more pronounced at 50% shading condition. Shading treatments resulting in insufficient sunshine had a detrimental impact on plant productivity and growth; this implies that proper shading conditions could heip improve yield and fruit quality.
We analyzed the recent characteristics of Particulate Matter (PM) including PM10 (PM with diameter of less than 10μm) and PM2.5 (PM with diameter of less than 2.5μm) observed in Busan metropolitan area, and compared them with those measured in Seoul metropolitan area. This analysis includes the monthly, seasonal, and annual variations and differences, in emissions and chemical compositions observed in both Busan and Seoul areas. Synoptic meteorological conditions were investigated at the time when high PM concentrations occurred in each of the two areas. The results showed clearly decreasing trends of annual mean concentrations with strong seasonal variations: lower in summer and higher in winter in both areas. In comparison with Seoul, the seasonal variation in Busan demonstrated relatively lower, but showed greater summer fluctuations than in Seoul metropolitan area. This is implying the importance of secondary generation of PM in summer via active photochemical reaction in Busan area. In high concentration days, Busan’s chemical composition of sulfate was higher than that of nitrate in summer, whereas nitrate was higher than sulfate in Seoul. The ratios of NO3 - to SO4 2-(N/S ratio) showed lower in Busan approximately by a factor of 1/2(half of N/S ratio) in Busan compared with that in Seoul. Others such as synoptic characteristics and emission differences were also discussed in this study.
This study provides a basis for research to establishing air quality standards in Gyeongnam. The trends and deviations in air quality concentrations and short-term environmental standards were analyzed. Furthermore, the regional standards and World Health Organization`s (WHO) air quality guidelines (AQGs) were taken into account. The annual average PM10 standard for cities anc counties ate 40㎍/㎥ and 30㎍/㎥ , respectively. SO2 and NO2 are achieving national standards and need to be strengthened to the minimum regional standard and WHO AQGs. The PM2.5 standard, which has not reached national standards, needs to be set at the level of national standards, and is also the target level for 2024 of the Gyeongsangnam and national PM2.5 management plans.
A new chemosensor based on a self-assembled system has been devised to detect Hg2+ions efficiently. We demonstrated that the amphiphilic building blocks consisting of pyrene and boronic acid (1) aggregate in aqueous solutions and provide an outstanding sensing platform for sensitive detection. The self-assembled 1 exhibited high selectivity and sensitivity for Hg2+ion detection via fluorescence quenching, where the Hg2+ion detection ensued from a fast transmetallation of 1. The Stern-Volmer (SV) quenching constant for its fluorescence quenching by Hg2+ions was approximately 1.58 × 108 M-1. In addition, self-assembled 1 exhibited excellent sensing abilities at nano-molar concentration levels when tap water and freshwater samples were contaminated with of Hg2+ ions.