• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.3
• /
• pp.303-309
• /
• 2013

Marine algal flora and community structure were investigated seasonally at three sites in Gijang on the south-east coast of Korea from February 2006 to January 2007. A Total of 74 species were collected and identified, including 8 green algae, 16 brown algae, and 50 red algae. Of these, 15 species were found throughout the survey period. Mean biomass was 823.2-1,615.4 g wet weight $m^{-2}$ in winter, 689.1-3,196.8 g wet weight $m^{-2}$ in spring, 574.5-1,219.9 g wet weight $m^{-2}$ in summer, and 747.6-1,616.2 g wet weight $m^{-2}$ in autumn. The flora could be classified into six functional groups: coarsely branched form (37.8%), thick leather form (18.9%), sheet form (13.5%), filamentous form (12.2%), jointed calcareous form (10.8%) and crustose form (6.8%). The R/P, C/P and (R+C)/P values reflecting the flora characteristics were 3.13, 0.50 and 3.63, respectively. The number of marine algae species and the biomass in Gijang area were markedly reduced when compared with previous studies. This result suggests possible future changes in the algal vegetation, considering the physical and chemical pollution loadings in the coastal marine environment of this area.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.5
• /
• pp.495-502
• /
• 2016

Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. The objective of this study was to evaluate the use of unmanned aerial vehicle (UAV) for the monitoring IRG growth. Unmanned aerial vehicle imagery obtained from middle March to late May in Nonsan, Chungcheongnam-do. Unmanned aerial vehicle imagery corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). We analyzed the relationships between $NDVI_{UAV}$ of IRG and biophysical measurements such as plant height, fresh weight, and dry weight over an entire IRG growth period. The similar trend between $NDVI_{UAV}$ and growth parameters was shown. Correlation analysis between $NDVI_{UAV}$ and IRG growth parameters revealed that $NDVI_{UAV}$ was highly correlated with fresh weight (r=0.988), plant height (r=0.925), and dry weight (r=0.853). According to the relationship among growth parameters and $NDVI_{UAV}$, the temporal variation of $NDVI_{UAV}$ was significant to interpret IRG growth. Four different regression models, such as (1) Linear regression function, (2) Linear regression through the origin, (3) Power function, and (4) Logistic function were developed to evaluate the relationship between temporal $NDVI_{UAV}$ and measured IRG growth parameters. The power function provided higher accurate results to predict growth parameters than linear or logistic functions using coefficient of determination. The spatial distribution map of IRG growth was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to power function. From these results, $NDVI_{UAV}$ can be used as a new tool for monitoring IRG growth.

• Journal of Environmental Impact Assessment
• /
• v.20 no.3
• /
• pp.381-395
• /
• 2011

Present work aims to establish an integrated management system of environmental data base for nine typical wind holes or air holes in Korea. It basically deals with definition, geographical distribution, morphological pattern, physical characteristics and anthropogenic environments of wind hole to propose systematic preservation strategy of their periglacial landscape and flora, which are known to be sensitive to global warming. Wind hole, in which cool air blows out during the summer, but mild air comes out during the winter from a cave or hole, is frequently found on northwest- and north-facing slopes on the terminal point of steep talus, block field, and block stream, and can be categorized into three types, i.e., talus, cave and sink types. Environmental characteristics of nine wind holes are analyzed on the basis of their geology, landform, climate, soil, hydrology, vegetation, road, footpath, land-use, and management system, and relevant DB are prepared. Wind hole areas with unique landscape and ecological values need to be designated as a nature reserve, and zoning of core, buffer, and transitional zones are required for the multi-dimensional preservation of periglacial landscape and ecosystem. Phytogeographical values of glacial relict plants, including mountain cranberry(Vaccinium vitis-idaea) at its global southernmost limit at Bangnaeri wind hole, Hongchon County, Gangwon Province of Korea are discussed in detail as a floristic refugia in connection with climate change during the Pleistocene Epoch and potential in-situ and ex-situ preservation sites in the future.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.10 no.3
• /
• pp.152-157
• /
• 1990

To find out the effect of different patterns of nitrogen and potassium distribution on dry matter yield and botanical composition of temperate pastures, a field experiment was conducted with 6 treatments replicated 3 times in a randomized complete block design. It was lasted from September, 1986 to October, 1989 at the Livestock Experiment Station in Suweon. The results obtained are summarized as follows: 1. In early spring, winter hardiness, growth vigour, cold damage and coverage of grasses with 30% dressing of the total amount of N and K20 fertilizer in spring and at the 4th cutting time respectively were better than those of the other treatments. 2. Average dry matter yield for 3 years with heavy dressing in spring and at the 1st cutting time(l1, 187 kg DM/ha) was much more increased by 9% than that of the equally fertilized treatment(l0,24lkg DM/ha). 3. Changes in the botanical composition showed, in general, the same tendency for all treatments except equal N and K20 distribution. However, grassland vegetation with heavy dressing in spring and at the 1st cutting time was changed into relatively good botanical composition with 76.7% grasses, 22.3% legumes and 1.0% herbs at the end of the experiment. 4. By DM yield and botanical composition treatment 3(40-30-15-0-1570) seemed to be an optimal nitrogen and potassium distribution pattern in a temperate pasture.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.63 no.5
• /
• pp.1-11
• /
• 2021

Soil moisture plays a critical role in hydrological processes, land-atmosphere interactions and climate variability. It can limit vegetation growth as well as infiltration of rainfall and therefore very important for agriculture sector and food protection. Recently, due to the increased damage from drought caused by climate change, there is a frequent occurrence of shortage of agricultural water, making it difficult to supply and manage stable agricultural water. Efficient water management is necessary to reduce drought damage, and soil moisture management is important in case of upland crops. In this study, soil moisture was calculated based on the water balance model, and the suitability of soil moisture data was verified through the application. The regional soil moisture was calculated based on the meteorological data collected by the meteorological station, and applied the Runs theory. We analyzed the spatiotemporal variability of soil moisture and drought impacts, and analyzed the correlation between actual drought impacts and drought damage through correlation analysis of Standardized Precipitation Index (SPI). The soil moisture steadily decreased and increased until the rainy season, while the drought size steadily increased and decreased until the rainy season. The regional magnitude of the drought was large in Gyeonggi-do and Gyeongsang-do, and in winter, severe drought occurred in areas of Gangwon-do. As a result of comparative analysis with actual drought events, it was confirmed that there is a high correlation with SPI by each time scale drought events with a correlation coefficient.

• Journal of Forest and Environmental Science
• /
• v.26 no.3
• /
• pp.219-223
• /
• 2010

It has long been recognized that wild vegetation are sort of improving fitness. Many peoples are now ingesting them instead of the vegetables that are grown in green house. In this regard, Parasenecio firmus, which is considered to be one of the rare species in Korea, has been given a lot of attentions as edible green plants recently. Hence it may be necessary to provide the information people who want to commercially cultivate the plants. Regarding appropriate forest stands that are fit for the cultivation. Firstly, we collected the seeds from 4 natural habitats to find out how many seeds are fully matured in the natural conditions. The quality of the seeds collected were found to be very low. However, it appeared as clear differences when screened seeds were grown in covered seed beds over winter. In this case the germination rate of the seeds was 95%, indicating that there may be no difficulty for mass production of plantlets. Secondly, in the field of planting test in an appropriate cultivating site among 6 of forest stands, those in Pinus koraiensis stand were the highest in survival rate, but somewhat low with those in Quercus mongolica and broad-leaved stands. Thus, it was demonstrated that forest stands dominated with conifer like P. koraiensis are more appropriate for the cultivation of P. firums.

• Korean Journal of Environment and Ecology
• /
• v.30 no.6
• /
• pp.1009-1021
• /
• 2016

The community structure and abundance of epilithic biofilm were bimonthly examined to know spatial and temporal patterns of biofilm biomass and taxonimical composition at the two study sites, Gosapo and Gyeokpo with different degrees of wave exposure levels from November 2010 to September 2011. Biomass was estimated by using chlorophyll a contents (Chl a), normalized difference vegetation index (NDVI), and vegetation index (VI). Cyanobacteria such as Aphanotece spp. predominated in the proportion of 57.53% at Gosapo and of 61.12% at Gyeokpo and they are abundant in mid shore and in summer at both study sites. The diatoms Navicula spp., Achnanthes spp. and Licmophora spp. were common species and they showed an increasing trend from high to low shore. NDVI, VI, and chl a contents were the greatest at mid shore for Gosapo (0.44, 3.05, $24.56{\mu}g/cm^2$) and at low shore for Gyeokpo (0.41, 2.73, $17.98{\mu}g/cm^2$). NDVI, VI, and chl a content were all maximal in January and minimal in March at the both sites. Average NDVI, VI, and chlorophyll a contents of biofilms were greater at Gosapo (0.43, 2.89, $22.84{\mu}g/cm^2$) than Gyeokpo (0.38, 2.48, $15.48{\mu}g/cm^2$).Of three shore levels(high, mid, and low) Chl a contents were positively correlated with NDVI and VI at the two study sites indicating that non-destructive NDVI and VI values can be used in stead of destructive Chl a extraction method. In conclusion, epilithic biofilm was more abundant seasonally in winter, vertically in mid and low intertidal zone, and horizontally at wave exposed shore than in summer, at high and sheltered shore in Korea.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.46 no.4
• /
• pp.61-75
• /
• 2018

This study aims to verify the effect of green buffers, built as urban planning facilities on the reduction of ultra-fine particulate($PM_{2.5}$) and analyze changes in ultra-fine particles by structure, green volume and planting types of wayside green buffers, thus drawing the factors that can be used when green buffers are built to reduce ultra-fine particulate based on the results. This study selected Songpa-gu, and investigated 16 sites on 5 green buffers adjacent to two of Songpa-gu's main roads, 'Yangjaedaero' and 'Songpadaero'. This study divided all the green spaces into three different types-slope type, plain type and mounding type, and analyzed the mean green volume. As a result of measuring the concentration of $PM_{2.5}$, this study found that it was $55.5{\mu}g/m^3$ on average in winter, which was a harmful level according to the integrated environmental index provided by Seoul City, saying that levels above $50{\mu}g/m^3$ may have a harmful effect on sensitive groups of people. Particularly, the concentration of $PM_{2.5}$ was $38.6{\mu}g/m^3$ on average in spring, which exceeded the mean concentration of $PM_{2.5}$ in Seoul City in 2015. The mean concentrations of $PM_{2.5}$ in every investigation spot were $46.6{\mu}g/m^3$ for sidewalks, $45.5{\mu}g/m^3$ for green spaces and $42.9{\mu}g/m^3$ for residential areas, all of which were lower than $53.2{\mu}g/m^3$ for roads, regardless of the season. The concentration of $PM_{2.5}$ for residential areas was the lowest. In the stage of confirming the effect of green buffers, this study analyzed the correlation between the green volume of vegetation and the fluctuated rate of ultra-fine particles. As a result, it was found that the green coverage rate of trees and shrubs was related to the crown volume in every investigation spot but were mutually and complexly affected by each other. Therefore, this study judged that the greater the number of layers of shrubs that are made, the more effective it is in reducing the concentration of $PM_{2.5}$. As for seasonal characteristics, this study analyzed the correlation between the concentration of $PM_{2.5}$ for residential areas in winter and the green coverage rate of each green space type. As a result, this study found that there was a negative correlation showing that the higher the shrub green coverage rate is, the lower the concentration value becomes in all the slope-type, plain-type and mounding-type green spaces. This study confirmed that the number of tree rows and the number of shrub layers have negative correlations with the fluctuated concentration rate of $PM_{2.5}$. Especially, it was judged that the shrub green volume has greater effect than any other factor, and each green space type shows a negative correlation with the shrub coverage rate in winter.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.2
• /
• pp.266-271
• /
• 2012

This study was carried out to evaluate the land suitability for southern-type garlic cultivation associated with both temperature and soil constraints. The suitability analysis was conducted with hourly temperature data from 2001 to 2010 at all fifty seven meteorological stations and the soil-based suitability map of garlic provided by Rural Development Administration. Firstly the temperature data were processed by the growth stages (germinating, bulbing, and winter vegetation season), and then were adopted to limit the irrelevant lands. Next, as a result of overlaying each soil and temperature suitability map, the total 274,339 ha of area was mapped as highly suitable or suitable for southern-type garlic cultivation and the top four of the largest classified si-guns were identified as Naju, Jeongeup, Gochang, and Jinju. On the other hand, the statistical records of KOSIS (KOrea Statistical Information Service) showed lower amount of cultivation area than the analyzed results in the major production sites, Goheung, Sinan, Haenam, and Muan. However, it should not be regarded as exceptional because farmer's preference might not correspond to potential land usability.

• The Korean Journal of Quaternary Research
• /
• v.18 no.2 s.23
• /
• pp.103-104
• /
• 2004

This paper discuss some results of observed changes of meteorological elements as temperature, precipitation and some extreme indexes in Mongolia. Mongolia is one of the largest landlocked countries in the world. The climate is characterized by a long lasting cold winter, dry and hot summer, low precipitation, high temperature fluctuation and relatively high number of sunny days per year. During last 60 years the annual mean air temperature has risen $1.66^{\circ}C$. Intensive warming of > $2^{\circ}C$ was observed at higher altitudes of high mountains when warming of < $1^{\circ}C$ was observed the Domod steppe and the Gobi Desert. Heat Wave Duration have statistically significant risen trend with increaded number of days by 8-18 at significance level of 95-99.9% depending on geography and Cold Wave Duration have shortened by 13.3 days significance level of 95-99%. In general, by the amount of precipitation, Mongolia falls in semi-arid and arid region. It is 300-350 mm in the high mountain regions while it is only 50-150 mm in Gobi Desert regions. The changes of annual precipitation have very localized character i.e.decreasing at one site and increasing at a sit nearby. Annual precipitation decreased by 30-90 mm in the northern-central region and increased by 2-60 mm in the western and eastern region. The magnitude of alteration changes in precipitation regardless increasing or decreasing is 5-25%. A trends, significant at the level of 90%, found where changes are more than 40 mm or more than 15% of annual mean value. Moreover, the soil moisture resources was decreased in the last 40 years. Specially, moisture contents of the top soil have decreased 2 times(N. Natsagsuren, 2002). Months of June and July in Mongolia is the year that moisture is not inhibiting vegetation growth. Unfortunately, its also found that moisture in this time tends to decrease. Increased temperature, decreased precipitation and soil moisture are most likely resulted in occurences of more intense drought spells that have taken place during the recent years. Intimately, these changes have considerable impact on livestock in Mongolia.