• Journal of the Korean Wood Science and Technology
• /
• v.48 no.3
• /
• pp.405-413
• /
• 2020

Recycling of ionic liquid (1-ethyl-3-methylimidazolium acetate, [EMIM]Ac) after the pretreatment of Salix gracilistyla Miq. was conducted and the effect of the recycling number on the enzymatic saccharification yield was investigated. Enzymatic saccharification was performed using an enzyme cocktail (Acremonium cellulase and Optimash BG) at 50 ℃ for 72 h. All recycled [EMIM]Ac samples showed a lower amount of water soluble fraction than pure [EMIM]Ac. On increasing the recycling number from 1 to 4, the amount of water soluble fraction decreased from 18% to 15%. The X-ray diffraction pattern of the products pretreated with recycled [EMIM]Ac showed cellulose I crystalline polymorph. The crystallinity of the product pretreated with recycled [EMIM]Ac was 47-49%, which was lower than 33% of that with pure [EMIM]Ac. The yields of glucose and xylose decreased in the pretreatment with recycled [EMIM]Ac compared to that with pure [EMIM]Ac.

• Journal of Environmental Impact Assessment
• /
• v.11 no.3
• /
• pp.117-127
• /
• 2002

This study tested the usefulness of landscape indices for quantifying forest fragmentation due to linear development projects. Research was carried out in the middle-upper Nakdong River watershed, which has been affected by the expressway building, or national road-widening. Landscape indices were calculated from the forest cover maps before and after road-building using FRAGSTATS 3.1. We could successfully demonstrate the forest fragmentation based on landscape indices; (1) patch size decreased, and edge density and patch density increased (2) roads simplified patch shapes, especially in the larger patches, (3) patch core area size decreased, and core area density increased, (4) the distance increased between the focal patch and each of the other patches within the search radius (=1km) as a result of roads. We suggest several important needs for future researches, including continued investigation of scaling issues, development of indices that measure specific components of spatial pattern, and study of the relationships between forest fragmentation and ecological processes.

• Journal of Ecology and Environment
• /
• v.34 no.4
• /
• pp.393-400
• /
• 2011

The effects of the ectomycorrhizal fungus Pisolithus tinctorius and cadmium (Cd) on physiological properties and Cd uptake by Populus alba ${\times}$ glandulosa was investigated under greenhouse conditions. Cd treatment decreased the photosynthetic rate ($P_N$) of both non-mycorrhizal (NM) plants (16.3%) and ectomycorrhizal (ECM) plants (11.5%). In addition, the reduction in total dry weight by Cd treatment was greater in ECM plants (24.3%) than that in NM plants (17.6%). Mycorrhizal infection increased the $P_N$ and transpiration rate in both control and Cd-treated plants. Cd treatment increased superoxide dismutase (SOD) activity and decreased glutathione reductase activity, and the increase of SOD activity by Cd treatment was greater in NM plants (40.3%) than that in ECM plants (3.7%). Thiol content increased in both NM and ECM plants treated with Cd solution, and the increase in thiol content in NM plants (43.9%) was greater than that of ECM plants (15.6%). Cd uptake in the leaves, stems, and roots of ECM plants was 69.9%, 167.2% and 72.8%, respectively, higher than in the NM plants. However, the increase in Cd uptake ability of ECM plants resulted in a reduction in dry weight.

• Journal of Ecology and Environment
• /
• v.29 no.5
• /
• pp.445-452
• /
• 2006

The number of species and forest area has decreased as urbanization is progressed. The landscape degradation was examined by analyzing vegetation map, satellite image and characteristics of actual vegetation. The study was conducted in Mt. Baekja and its surroundings located on Gyeongsan city, southeastern Korea. As the result of landscape analysis, agricultural field was a characteristic attribute of the study area. Lowlands of this study area were occupied by agricultural field and various plantations. For 15 years from 1987 to 2002, forest area decreased from 2,072.9 ha to 1,853.2 ha, and shape index and fractal dimension of vegetation patches increased from 1.32 to 1.65 and from 1.05 to 1.09, respectively. Pinus densiflora Siebold & Zucco. community showed the highest species diversity, whereas Larix kaempferi (Lamb.) Carriere community showed the lowest species abundance. As forest management implications, monitoring of endangered plant species (Jeffersonia dubia (Maxim.) Benth. & Hook.f. ex Baker & S.Moore), and restoration of lowland forest from plantation to natural forest were discussed. Further, establishment of greenways utilizing existing streams, roadside, and public facilities were recommended.

• Journal of Korean Society of Rural Planning
• /
• v.25 no.4
• /
• pp.99-107
• /
• 2019

This paper analyzed the characteristics of population change from 2000 to 2018 in 466 mountainous areas using resident registration data from the Ministry of the Interior and Safety, and projected the population in those areas through 2050 with the cohort change ratio method. The population had dramatically decreased from 2000 to 2009. With the slowing population decrease after 2010, the population has increased gradually since 2014. Especially the population of ages over 65 in 2018 had increased 34% compared to 2000, while the working age population had decreased 29%. This shows that population aging becomes serious problems in the mountainous area. Assuming the cohort change ratios from 2010 to 2015 and child-woman ratio in 2015 remain constant, it appeared that the projected population of the mountainous area dropped to 1.26 million in 2030 and 820,000 in 2050. It is expected to have a population with an inverted pyramid structure showing a gender imbalance with more females in 60's and 70's. Although it continues to show the recent population growth in mountainous area, population in mountainous area is expected to consistently decrease. Therefore, it is required to develop policies and strategies to promote an influx of people into mountainous area for maintaining functionality and sustainability of mountainous areas.

• Korean Journal of Agricultural Science
• /
• v.50 no.2
• /
• pp.181-192
• /
• 2023

Appropriate fertilization methods are required according to species to supply necessary nutrients to plants and prevent soil environmental contamination in nurseries. In this study, the effects of nitrogen and phosphorus fertilization on the growth of Liriodendron tulipifera and soil characteristics were investigated. After 16 fertilization treatments (4 levels of nitrogen × 4 levels of phosphorus) were applied to one-year-old L. tulipifera seedlings at the Yongmun Nursery Station of the Korea Forest Service, height, root collar diameter (RCD), biomass, leaf nutrients, and soil characteristics were investigated. The height increased as the amount of nitrogen and phosphorus fertilization increased, and the RCD was the highest in the ×2 treatment. Biomass growth was on average 40.0% higher for the treatment with high nitrogen fertilization compared to the low nitrogen treatment. The seedling quality index was the highest with nitrogen and phosphorus ×2 treatment. Leaf phosphorus and magnesium concentrations decreased when nitrogen fertilization was applied, and leaf potassium concentrations decreased as nitrogen fertilization increased. Soil pH and exchangeable potassium decreased as the amount of phosphorus application increased, and exchangeable magnesium decreased as the amount of nitrogen application increased and increased as the amount of phosphorus application increased. Considering the growth of L. tulipifera seedlings and changes in the soil characteristics at the nursery stage, twice the standard fertilization amount is the appropriate fertilization amount for nursery of the Yongmun Nursery Station. It is expected that this study will contribute to improving nursery soil fertilization management technology for healthy seedling production.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.360-367
• /
• 2015

This study was performed to determine the effects of silicon on zoysiagrass after the application of drought stress. The daily amount of water or scilicon solution was 150 ml per a pot. For 14 days, plants were treated with 0.1 and 1.0 mM silicon (Si) and with distilled water for control and the drought only-treatment. Afterward, the plants in Si and drought treatment were exposed to a 21-day under drought stress condition but the plants in control received water. The results indicated that the growth and the moisture and chlorophyll contents decreased in the drought only-treatment and 0.1 mM Si compared to the control. However, 1.0 mM Si showed an increase in the growth with a significant increase of water and chlorophyll contents. The MDA and $H_2O_2$ concentrations and electrolyte leakage decreased, while the radical scavenging capacity increased in 1.0 mM Si. 1.0 mM Si showed little to no differences in the growth and no differences in water and chlorophyll contents, electrolyte leakage, MDA and $H_2O_2$ concentrations and antioxidant capacity compared to the control. These results suggested that application of silicon is useful for drought tolerance improvement of zoysiagrass under drought that is occurring in turf fields.

• Journal of Korea Soil Environment Society
• /
• v.3 no.2
• /
• pp.61-70
• /
• 1998

This research has been made for influence of forest environmental changes, such as tree-clearcutting affecting to soil chemical and physical properties, on water storage capacity at forest fire land in Keumsan, Chungnam. The analyzed factors were bulk density, porosity, field moisture saturated hydraulic conductivity air permeability and organic matter content, Field moisture saturated hydraulic conductivity and air permeability at uncutting sites were higher than those at clearcutting sites, especially the most differences were appeared at lower slope. After 2 years passed since forest fire, the most changeable parts of soil characteristics were 5-l5cm depth below soil surface. Total Porosity, coarse pore and fine pore at uncutting sites were higher than those at clearcutting sites. Also, as soil depth increased, total porosity and coarse pore were decreased. Bulk density at uncutting sites was lower than that at clearcutting sites, and was decreased as soil depth increased. The order of the change trend in field moisture saturated hydraulic conductivity, air permeability and porosity was slope lower>middle>upper. Organic matter content at uncutting sites were higher than those at clearcutting sites, and decreased as soil depth increased. As soil depth increased, bulk density had the positive correlation, in other hand, porosity, coarse pore, field moisture saturated hydraulic conductivity, air permeability and organic matter content had the negative correlation. It was concluded that forest environmental changes by forest fire degrade soil physical and chemical properties.

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.6
• /
• pp.455-463
• /
• 2018

Background: Sancho (Zanthoxylum schinifolium Siebold and Zucc) oil is used as a traditional medicinal material to treat severs stomach inflammation and as a diuretic. This study was carried out to investigate the effect of addition of antioxidants and blended oil the storage stability and safety of the biomaterial. Methods and Results: The effects of temperature and light on sancho oil were investigated, and the ability of antioxidants in preventing rancidity of the oil was discovered. Under fluorescent light and in darkness, the acidity of the oil was much lower than that under direct sunlight. The addition of antioxidants decreased the acid value of sancho oil; the antioxidant that showed the best results in this regard was 0.5% propolis. The acid value of canola oil, which had the lowest acid value compared with that of other oils, and blended oil, containing 5% canola oil in sancho oil, decreased by 5.5% and 15%, respectively. About one acid value decrease was observed for every 1% increase in blending with canola oil. As the concentration of canola oil increased, the viscosity and the elightness (L valu) of sancho oil increased slightly, while the blueness (b value) decreased. Conclusions: The results of this study may contribute to ensuring food safety during preservation and the industrialization of the presevation of sancho oil.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.9 no.4
• /
• pp.67-75
• /
• 2006

This study compared with the object of designation and the management practices for Protection Forests between Korea and Japan to establish the management and development directions of Korea's Protection Forest. 1. Water conservation forest from total areas of Protection Forests occupied 90.6 % in Korea and 68.4 % in Japan, respectively. The water conservation forest was the most important function among the Protection Forest's functions in both countries. 2. The 10 million ha of Protection Forest in Japan increased for last 100 years. The 100 thousand ha per year was designated as Protection Forest. In contrast, The 655,535 ha of Protection Forest in Korea decreased for last 42 years with decreasing of 15,000 ha per year. 3. In Japan, Protection Forest can be managed by forest silvicultural practices such as forest harvest, thinning, and pruning to recover and improve the Protection Forest's functions. 4. In case of Korea, it is necessary to a mid- or long-term counter plan to increase the area of Protection Forest by the government, and needs to the recovery and improvement of Protection Forest's functions.