• The Korean Journal of Ecology
• /
• v.27 no.6 s.122
• /
• pp.355-361
• /
• 2004

In order to elucidate the ecophysiological characteristics of coastal plants, we collected them on salt marsh and sand dune, and analyzed inorganic ($Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}$) and organic solutes (soluble carbohydrate, glycine betaine). Chenopodiaceous plant species (Atriplex gmelini, Salicornia europaea, Salsola collina, Suaeda glauca, Suaeda japonica) showed a tendency to accumulate inorganic ions such as $Na^+\;and\;Cl^-$ instead of $K^+$. However, Chenopodium serotinum which lives in ruderal habitat contained more $K^+$ and less $Na^+$ than the other Chenopodiaceous plants. Most Chenopodiaceous plant species maintained very low level of soluble $Ca^{2+}$ and relatively low concentration of carbohydrates and showed high concentration of glycine betaine which is among the most effective known compatible solutes in the leaves of plant under drought and saline conditions. On the other hand, plant species which belong to Gramineae (Ishaemum anthephoroides, Phragmites communis, Zoysia sinica) and Cyperaceae (Carex kobomugi, Carex pumila) absorbed $K^+$ selectively and excluded $Na^+\;and\;Cl^-$ effectively regardless of habitat conditions, and they accumulated more soluble carbohydrate as osmoticum than Chenopodiaceous plants. These results suggested that physiological characteristics such as high storage capacity for inorganic ions (especially alkali cations, chloride) and the accumulation of glycine betaine in chenopodiaceous plants and $K^+$-preponderance, an efficient regulation of ionic uptake (exclusion of $Na^+\;and\;Cl^-$) and the accumulation of soluble carbohydrate in monocotyledonous plants enable them to grow dry and saline habitats.

• Journal of Ecology and Environment
• /
• v.29 no.6
• /
• pp.573-580
• /
• 2006

A sediment core from the Cheollipo arboretum ($36^{\circ}$ 47' 57'N, $126^{\circ}$ 09' 04') was studied for pollen analysis in order to reconstruct postglacial vegetational change and environmental changes around the central western region of the Korean Peninsula. The record shows four pollen assemblage zones: Zone CHL-I, Quercus stage (ca. 9,300$\sim$6,200 yr BP): zone CHL-II, Quercus-Pinus stage (ca. 6,200$\sim$4,600 yr BP); zone CHL- III, Pinus-Quercus stage (ca. 4,600$\sim$1,160 yr BP): zone CHL-IV and Pinus stage (ca. 1,160 yr BP-present). During the 9,300$\sim$8,500 yr BP, the early Holocene, researchers have guessed a piece of cool-temperate norihern/altimontane mixed coniferous and deciduous broad-leaved forest. Between 8,500$\sim$4,600 yr BP the Quercus dominated the landscape of study area and the established dates of this typical cool-temperate central/montane deciduous broad-leaved forest vegetation might be ca. 6500 yr BP, and then the Pinus developed around the site at ca. 5,700 yr BP. The abrupt increase of Pinus and NAP (non-arboreal pollen) after ca. 1,100 yr BP indicates the vegetation changes due to human activities. From the dynamics of the Chenopodiaceae pollen indicating salt marsh and freshwater pollen flora such as Typha, Trapa, Nymphoides and so forth, we suggest that the tidal flat was altered into freshwater lake around 6,500 yr BP.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.6 no.2
• /
• pp.3-15
• /
• 2003

Recently more than 450 incidents of oil spill a year have occurred in nearshore of Korea, which caused unmeasurelable losses in fisheries and severe damage in marine ecosystem. Two approaches remain paramount in any response to marine oil spill : the enhancement of natural dispersion of the oil by using dispersants, and mechanical recovery using booms and skimmers. A technique currently receiving fresh attention is the enhancement of the natural bioremediation of oil through the application of micro-organisms and/or nutrient. Oil, like many natural substances, will biodegrade over a period of time into simple compounds such as carbon dioxide, water and biomass. Bioremediation is the term used to describe a range of processes which can be used to accelerate natural biodegradation. More specifically biostimulation is the application of nutrients, and bioaugremetation or seeding is the addition of microbes specially selected to degrade oil. Bioremediation is an economically attractive method for the clean-up of oil-contaminated area. Bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mud flat environment.

• Informatization Policy
• /
• v.24 no.3
• /
• pp.67-90
• /
• 2017

This study is conducted to find out problems in the implementation system of regional informatization policies in Korea and solutions to enhance the effectiveness in policy execution. The study uses research methodologies such as participant observation, interview and AHP for experts and employees of public organizations for regional informatization policies. Many implications were found in the analysis, including that policy relations, structure of the policy implementation system, and environment and contents of regional informatization policiesin Korea have to be innovated and re-organized. Especially, this paper emphasizes the horizontal and cooperative relationship between the central and local governments and redesigning of the legal system on the regional informatization. This paper also shows expectations on reshaping of the regional informatization policies with the paradigm shift of the government power toward decentralization. This paper also finds diverse views on the problems and solutions for the regional informatization policy implementation system based on different characteristics and interests of policy participants. This paper finds the possibility of applying the policy network model to regional informatization policy implementation, which can be supported by Rhodes & Marsh(1992)'s theory. Therefore, this paper shows the change of regional informatization policies can be expected through application of the policy network. Although the paper draws many academic and policy implications, they are limited to the implementation system of regional informatization policies only.

• Korean Journal of Remote Sensing
• /
• v.23 no.6
• /
• pp.575-581
• /
• 2007

Suaeda japonica is the one of halophyte species which is widely spread in the Ganghwado tidal flat. Halophyte affects to the vertical development of wetland by enhancing the adhesion force of sediments. If demineralization of tidal flat proceeds, the colony of halophyte moves to the seaside where has relatively high salinity content. The change of halophyte zonation can be an environmental indicator to understand the landization of tidal flat. To interpret the spectral characteristics of halophyte, we measured the reflectance of suaeda japonica, reed and sediment around Donggumdo tidal flat in Ganghwado. First and second-derivation analysis was applied to these transformed spectra in order to identify which spectral ranges were distinguished with different coastal wetland vegetation and artificial structures. From the result, red reflectance peak of suaeda japonica were appeared at 600-650nm and greed reflectance peak of reed were appeared at 500-570nm. Spectra of sediments were continuously increased from 350-550nm without any absorption by chlorophyll. These reflectance were easily identified among the spectra of halophyte.

• Korean Journal of Plant Resources
• /
• v.23 no.2
• /
• pp.197-205
• /
• 2010

This study was carried out to investigate the flora and vegetation in wetland of Mueuido. The forest vegetation was classified into 2 communities group (Utricularia bifida-Eriocaulon sikokianum and Alnus japonica) and 6 communities (Rhynchospora chinensis, Phragmites communis, Molinia japonica, Ischaemum crassipes, Quercus serrata and Pinus rigida-Miscanthus sinesis). Resources vascular plants were composed of 30 families, 53 genera, 50 species and 8 varieties, totaling 58 taxa. Among the investigated resources plants, Utricularia bifida and Utricularia racemosa were rare and endangered species. The special plants based on floral region by Ministry of Environment were 5 taxa; V rank species 2 taxa, II rank species 1 taxa and I rank species 2 taxa. A naturalized plants was 1 species of totaling 290 species appeared in South Korea. The Life-form were Hydatophytes (20.7%), Geophyte (19%), Microphanerophytes (19%), Hemicryptophytes (17.2%), Nanophanerophytes (17.2%), Chamaephytes (5.2%), Therophytes (1.7%). In marsh-type wetland of Mueuido, we predict that bog-type swamp, where various type of swamp plants are distributed, is starting to be formed based on the fact that Utricularia bifida and Utricularia racemosa, insectivorous plants, are dominant and sphagnum also is found. Along with the notion, there are reportedly found serious damages around wetland by human being and we have to prepare protection plans against it.

• Journal of vocational education research
• /
• v.37 no.6
• /
• pp.85-104
• /
• 2018

The purpose of this study was to identify the meditating effect of self leadership on the relationship between protean career attitude and subjective career success of lifelong learning educators. Based upon the results, several theoretical and practical suggestions were made to enhance self leadership, protean career attitude and subjective career success of lifelong learning educators. A survey questionnaire for this study was composed of four parts, such as the measurement tool of Protean Career Attitude(Briscoe, Hall & Demuth, 2006), Self Leadership Scale(Houghton & Neck, 2002), Subjective Career Success(Career satisfaction Scale: Greenhaus, Parasuraman & Wormley, 1990; Job Satisfaction Scale: Mobley, Jarret, Marsh & Lim, 1994; Employability Inventory: Johnson, 2001) and demographics. The subjects in this study were lifelong learning educators in Incheon. The survey questionnaires from 450 respondents were gathered, and the data from 426 respondents were used for analysis. The results of this study were as follows: First, protean career attitude of the lifelong learning educators had direct effect on subjective career success positively. Second, protean career attitude of the lifelong learning educators had indirect effect on the subjective career success with the partial mediating effect of self-leadership. Finally, based upon the above results, some implications and limitations of this study were discussed.

• Journal of Life Science
• /
• v.31 no.11
• /
• pp.980-986
• /
• 2021

Natural products have always been an attractive source in terms of novel anti-metastatic compounds which can hinder MMP expression and activity. Corydalis heterocarpa is a salt marsh plant found in the seashores throughout Korea. Its yellow flowers and spikes have been an ingredient in folk medicine to treat spasm and contractions. The present study assessed the potential of different solvent-based fractions from the crude extract of Corydalis heterocarpa (CHE), a halophyte with reported bioactivities, to suppress the PMA-induced MMP expression in human fibrosarcoma HT-1080 cells. The solvent fractions which were named after the solvent used for fractionation (n-hexane, 85% aqueous (aq.) methanol (MeOH), n-butanol (BuOH), and H₂O were shown to inhibit the both elevated mRNA and protein expression levels of MMP-2 and MMP-9 and simultaneously relieved the suppression on the expression of the endogenous MMP inhibitors TIMP-1 and TIMP-2. Results indicated that the CHE fractions might intervene with the PMA-induced activation of the MAPK signaling which is the upstream activator of MMP overexpression. Among tested samples, 85% aq. MeOH and n-hexane fractions of CHE was determined to be the most active and future studies to isolate the bioactive substances responsible for the regulation of the MMP expression are, therefore, urged. In conclusion, C. heterocarpa was shown to be a potential source of anti-metastatic compounds and n-Hexane and MeOH fractions might yield lead molecules to develop novel MMP inhibitors.

• Korean Journal of Ecology and Environment
• /
• v.55 no.3
• /
• pp.212-220
• /
• 2022

An estuary is a water ecosystem with a high abundance of the species diversity, due to a variety of complex physicochemical factors of the area where freshwater and ocean mixed. The identification of Corbicula species in the estuary environments is difficult because of various morphological characteristics. In this study, we provide taxonomic information on Corbicula species with taxonomic difficulties using morphological and genetic analysis. This study was conducted on clams from the Seomjin River-Gwangyang Bay, one of the major production area of marsh clam in Korea. As a result, we characterized Cytocrome C Oxidase subunit I (COI) sequences of the Corbicula. The 636 bp nucleotide sequences of COI have 98% homology among Corbicula species collected from 2 sites of Seomjin River-Gwangyang Bay. The phylogenetic analysis with 17 species of Corbicula indicated that most of the species collected from Seomjin River-Gwangyang Bay were brackish water clam (Corbicula japonica), and only one Asian clam (Corbicula fluminea). The evolutionary distance between C. japonica and C. fluminea was less than 0.003. Therefore, it was confirmed that C. japonica is phylogenetically closely related to C. fluminea. In 9 species of Cyrenidae, phylogenetic tree was classified into three lineages. These results will be used as an important data for an identification of clam species by providing genetic information for Corbicula species with a morphological diversity.

• Journal of Korean Society of Rural Planning
• /
• v.30 no.1
• /
• pp.15-31
• /
• 2024

The study primarily aims to examine the characteristics of the transition from natural landscape to modern agricultural landscape on the Daesan plain in Dong-myeon, Changwon-si, in the lower reaches of the Nakdong River. The periods covered in the transition include the late Joseon Dynasty, the early Japanese colonial period, and the late Japanese colonial period. The study concluded the following: It was found that the Daesan Plain used to function as a hydrophilic landscape before it formed into a rural landscape. This is characterized by the various water resources in the Plain, primarily by the Nakdong River, with its back marsh tributaries, the Junam Reservoir and Jucheon. To achieve its recent form, the Daesan Plain was subjected to human trial and error. Through installation of irrigation facilities such as embankments and sluices, the irregularly-shaped wetlands were transformed into large-scale farmlands while the same irrigation facilities underwent constant renovation to permanently stabilize the rural landscape. These processes of transformation were similarly a product of typical colonial expropriation. During the Japanese colonial period, Japanese capitalists initiated the construction of private farms which led to the national land development policy by the Governor-General of Korea. These landscape changes are indicative of resource capitalism depicted by the expansion of agricultural production value by the application of resource capital to undeveloped natural space for economic viability. As a result, the hierarchical structure was magnified resulting to the exacerbation of community and economic structural imbalances which presents an alternative yet related perspective to the evolution of landscapes during the Japanese colonial period. In addition, considering Daesan Plain's vulnerability to changing weather conditions, natural processes have also been a factor to its landscape transformation. Such occurrences endanger the sustainability of the area as when floods inundate cultivated lands and render them unstable, endangering residents, as well as the harvests. In conclusion, the Daesan Plain originally took the form of a hydrophilic landscape and started significantly evolving into a rural landscape since the Japanese colonial period. Human-induced land development and geophysical processes significantly impacted this transformation which also exemplifies the several ways of how undeveloped natural landscapes turn into mechanized and capitalized rural landscapes by colonial resource capitalism and development policies.