• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.4
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• pp.87-98
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• 2015

The natural monument forests (no.374) located at Pyeongdae-ri in Jeju island are described and classified by using phytosociological methods and numerical analysis. The purpose of this paper is to identify the ecological character of Torreya nucifera forests between natural habitat and artificial habitat, as well as their spatial and phytogeographical distribution in the Korea. The comparison of forests between Pyeongdae-ri and other regions was analyzed by using a non-metric multidimensional scaling analysis (NMDS) and hierarchical clustering. On the basis of the 12 phytosociological $relev{\acute{e}}s$, the vegetation of T. nucifera dominant forest in Jeju island was arranged in one syntaxon (Alangium platanifolium-Torreya nucifera community included typicum and one subcommunity) within Camellietea. The community of T. nucifera dominant forests were characterized floristically and ecologically. We discussed diagnostic species with references, and proposed a few important diagnostic species (Ilex crenata for. microphylla, Acer palmatum, Zingiber mioga, Mercurialis leiocarpa, Osmorhiza aristata, Mecodium wrightii etc.) to explain condition of the habitat and synecological character. The communities were described by concerning their edaphical and syndynamical niche; we discussed their total distribution in Korea. In most forests they are widespread in Korean peninsular and their distribution is primarily determined by artificial plantation and periodical management. The forests consisted of T. nucifera have developed from natural environment element and artificial management. As a result they have very unique characters with the floristic, structural characterization and distribution. Furthermore, we identified that they need to apposite management for sustainability.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.730-744
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• 2016

In this study, fish fauna and stream characteristics were surveyed from June to October of 2014 in 31 sites of 23 small streams of Namhae Island. During the study period, 38 species belonging to 30 genera under 13 families were collected. Cyprinidae and Gobiidae fish occupied 28.9% (11 species) and Cobitidae fish accounted for 10.5% (4 species). The dominant family was Cyprinidae, and the most dominant species was Zacco koreanus with 30.3% (1,089 individuals) of the total. Eight species (33.8%) such as Zacco koreanus, Squalidus gracilis majimae, Coreoleuciscus splendidus, Pseudobagrus koreanus, Iksookimia hugowolfeld, Iksookimia longicorpa, Silurus microdorsalis and Liobagrus mediadiposalis were Korean endemic and one species of Micropterus salmoides was exotic. According to the analysis of the community based on the diversity, evenness and richness indices, fish community seems to be more stable in the S7. The small streams were classified into three types of steep mountainous, mountainous-flatland, and flat land streams, and their types were categorized by their features of stream width, water depth, bottom substrate, riparian vegetation, and land use patterns. Principal component analysis based on species abundance classified fish communities into three main groups according to human impact and land-use pattern change. These results suggest that fish community structures were primary affected by the longitudinal environmental changes and these were modified by the habitat condition in accordance with the land use pattern change in the small streams.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.434-442
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• 2019

Low Impact Development(LID) techniques has been attracting attention as a countermeasure to solve frequent flood damage in urban areas. LID is a techniques for returning to the natural hydrological cycle system by infiltrating the runoff from the impervious surface into the soil. The Bio-retention, one of the LID element technology has outflow reduction effect by reserving and infiltrating storm water runoff from watersheds. Recently, a number of studies have been carried out as interest in the reduction of storm water runoff and non-point pollutants in Bio-retention has increased. However, quantitative analysis on the outflow reduction of Bio-retention applied to small watershed is insufficient. In this study, Bio-retention model was constructed in a small watershed using K-LIDM which is capable of hydrologic analysis. When the storage capacity was increased or dividing the Bio-retention and watershed, the outflow reduction effect was 20% according to the storage capacity increase and 5~15% in the distributed Bio-retention system. The results of this analysis will be used as the basic data of future Bio-retention research related to watershed characteristics, vegetation type and soil condition.

• Journal of the Korean Geosynthetics Society
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• v.20 no.1
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• pp.35-44
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• 2021

This research studies the stabilization method for improved soil sloped through the on-site application of Paper Flyash ground stabilizers. The target strength required for improved soil is 500 kPa, and the compressive strength for the slope surface needs to be less than 1,000 kPa after the improvement in order to plant vegetation. To meet this condition, we mixed soil from the site and the ground stabilization material, which is the main material for surface improvement material, performed mixing design and conducted various tests including strength test, permeability test and plantation test. After analyzing the results of the compression test on improved soil slope, we proposed soil constants for the improved soil. In order to evaluate the applicability of the improved soil on the slope, the site construction was carried out on the collapsed slope and the reinforcement evaluation of the surface of the improvement soil was conducted. The stability was not secured before the reinforcement, but the test shows after the reinforcement with improved soil, the safety rate is secured up to 48 hours during the raining period. In addition, the compressive strength of the improved soil at the site was secured at more than 200 kPa adhesion as planned, and the soil hardness test result was also found to be within the specified value of 18-23 mm, which increased the resistance to rainfall and ability to grow plant on the surface for improved soil.

• Korean Journal of Environment and Ecology
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• v.22 no.1
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• pp.35-42
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• 2008

This study was conducted to provide basic information that can be used to restore habitats of Nannophya pygmaea. Nannophya pygmaea is an endangered species of wildlife fauna in Korea and its habitats are distributed very scarcely in Korea. Ten wetland sites throughout Korea, where N. pygmaea inhabited (2 sites in Incheon Muui-do, 1 site in Gokseong Singi-ri, 4 sites in Gokseong Wolbong-ri, and 3 sites in Mungyeong Yulsu-ri) were investigated from June 2006 to August 2007. Investigation was made on landscape properties, habitat sizes, vegetation types, water environments, and water sources. N. pygmaea was generally found in the abandoned paddy fields surrounded by mountains. The habitats ranged from $113.4m^2$ to $1,153.1m^2$ in area, and were mostly dominated by Juncus effusus and Persicaria thunbergii. The water level was $2.6\sim7.3cm$, and the water temperature ranged from $16^{\circ}C$ to $27.8^{\circ}C$. The elevation of the habitats ranged from 139 to 243 m above sea level, which was mostly lower than that of other high mountain wetland habitats. In conclusion, the habitats of N. pygmaea can be restored at wetlands, which have similar condition with field habitat such as abandoned paddy fields in the beginning stage of oligotrophy. Because N. pygmaea is sensitive to microtopography and other surrounding environments, the approach to restore the habitats for N. pygmaea should consider those microhabitat conditions shown in this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.564-570
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• 1997

Field experiments were carried out to investigate the effects of different residue treatment of vetch sward on soil improvement, rice growth and grain yield from 1995 to 1996. With Chinese milkvetch, pH, Ca, and Mg of paddy soil were increased in subsoil(10~20cm soil depth), and organic matter, P$_2$ $O_{5}$, and K were increased in top soil (0~10cm soil depth). Redox potential of the paddy soil with milkvetch residue was severely reduced at earlier flooding period, and recovered gradually as rice growth continued. Weeds were more abundant in the paddy with unchanged vetch stand. The most dominant weed species in the paddy soil with vetch sward residue was Echinochloa crus-galli, followed by Leersia japonica, Polygonum hydropiper in the order of abundance. Seedling establishment ratio of rice directly sown over vetch-sward was lower than in conventional tillage paddy(no-vetch, tilled) condition. Rice growth pattern, however, was not significantly affected by vetch sward treatments. The number of tillers per square meter and plant height at heading date were not significantly different among the vetch-sward treatments. Grain yield was the highest in plough of vetch vegetation, followed by conventional (no-vetch, tilled), live-mulching of vetch, vetch-removed, and vetch-desiccated by weedcide. The whole grain rice yield was the lowest in vetch-desiccated by weedcide.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.82-88
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• 2021

Sun-induced fluorescence (SIF) retrieval using remote sensing technique has been used in an effort to understand the photosynthetic efficiency and stress condition of vegetation. Although optical devices and SIF retrieval methodologies were established in order to retrieve SIF, the SIF measurements are domestically sparse. SIF data of paddy rice w as measured in Naju, South Korea from June 10, 2020 to October 5, 2020. The SIFs based red (O2A) and far-red (O2B) w ere retrieved using a spectral fitting method and an improved Fraunhofer line depth, and photosynthetically active radiation was also produced. In addition, the SIF data was filtered considering solar zenith angle, saturation conditions, the rapid and sudden change of solar irradiance, and sun glint. The provided SIF data can help to understand a SIF product and the filtering method of SIF data can contribute to producing high-quality SIF data.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.261-266
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• 2001

Effects of elevated carbon dioxide ($CO_2$) on soil microbial processes were studied in a northern peatland. Intact peat cores with surface vegetation were collected from a northern Welsh fen, and incubated either under elevated carbon dioxide (700 ppm) or ambient carbon dioxide (350 ppm) conditions for 4 months. Higher algal biomass was found under the elevated $CO_2$ condition, suggesting $CO_2$ fertilization effect on primary production, At the end of the incubation, trace gas production and consumption were analyzed using chemical inhibitors. For methane ($CH_4$ ), methyl fluoride ($CH_3F$) was applied to determine methane oxidation rates, while acetylene ($C_2H_2$) blocking method were applied to determine nitrification and denitrification rates. First, we have adopted those methods to optimize the reaction conditions for the wetland samples. Secondly, the methods were applied to the samples incubated under two levels of $CO_2$. The results exhibited that elevated carbon dioxide increased both methane production (210 vs. $100\;ng\;CH_4 g^{-1}\;hr^{-1}$) and oxidation (128 vs. $15\;ng\;CH_4 g^{-1}\;hr^{-1}$), resulting in no net increase in methane flux. For nitrous oxide ($N_2O$) , elevated carbon dioxide enhanced nitrous oxide emission probably from activation of nitrification process rather than denitrification rates. All of these changes seemed to be substantially influenced by higher oxygen diffusion from enhanced algal productivity under elevated $CO_2$.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.459-465
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• 1998

To obtain the basic data for the conservation and cultivation of native herb species under the forest, the relations between distribution of native herb species and site factors, distribution of native herb species, and site factors were surveyed on natural forest at subalpine zone in Mt. Odae. Ainsliaea acerifolia, Pseudostellaria palibiniana and Pimpinedla brachycarpa were distributed mainly on broadleaved mixed forest, Clematis fusca var. coreana, Carex siderosticta. Isodon excisus and Vicia unijuga did mainly on gab sites. The distribution of Ligularia fisheri, Aconitum pseudo-laeve var. erectum, Cacalia hastata and Artemisia stolonifera were significantly differed between slope directions. Artemisia stolonifera was distributed more frequently in south directed slope, and Ligularia fisheri, Aconitum pseudo-laeve var. erectum and Cacalia hastata were distributed more frequently in north and west directed slope than the other. The distribution of Aconitum pseudo-laeve var. erectum and Artemisia stolonifera were significantly differed between soil moisture conditions. Artemisia stolonifera was distributed mainly on the dry site, but Aconitum pseudo-laeve var. erectum did mainly on the dry site. Negative correlations between density of Clematis fusca var. coreana, Carex siderosticta. Isodon excises and Vicia unijuga and crown coverage was proved. Aconitum pseudo-laeve var. erectum, Pimpinella brachycarpa, Meehania urticifolia, Smilacina japonica and Pseudostellaria palibiniana were mainly distributed on wet and shady sites under forest canopy, but Pedicularis resupinata, Clematis fusca var. coreana and Artemisia stolonifera did on sunny sites at forest edge or gab.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.733-744
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• 2013

This study was launched in order to collect basic data such as emergent species, a succession trend based on the actual vegetation at the ridge from Haneoryoung to Daetjae, thereby designating 46 quadrats($10m{\times}10m:100m^2$). As a result of classification by TWINSPAN, the plant community was categorized into eight different communities, such as Pinus densiflora-Quercus mongolica-Fraxinus rhynchophylla, P. densiflora-Q. mongolica, Ulmus davidiana var. japonica, Q. mongolica-Deciduous Broad-leaved, Q. mongolica, Q. mongolica-Betula davurica, Q. mongolica-F. sieboldiana, and Larix kaempferi. An analyzation of each communities indicated that P. densiflora dominant community will change into a Q. mongolica dominant community if there are no outside artificial disturbances. U. davidiana var. japonica community maintains its present condition, because it doesn't appear to be a competitive species. In the case of Q. mongolica dominant community, if nothing comes in a competitive species against Q. monglica, it is possible to succeed to a muture stand. These communities with competitive species such as F. rhynchophylla, B. davurica that do not emerge at a canopy layer will gradually progress to the Deciduous Broad-leaved community. With regard to the species diversity index per unit ($400m^2$), succession processing communities (P. densiflora: 1.0477~1.1283) tend to be higher than succession-processed communities (Q. mongolica dominant: 0.6446~0.9424).