• Journal of The Geomorphological Association of Korea
• /
• v.20 no.4
• /
• pp.1-13
• /
• 2013

Padori beach is one of the representative composite mixed beach in Korea and shows divert geomorphic landscape change. It belongs to the Taean National Park. The purpose of this study is to clarify movement mechanism of sediments from sediment distribution of Padori beach associated with morphology. In addition, it is to explain morphological landscape change under different wave and tide condition in the composite mixed beach consisting of a dissipative low tide terrace and a reflective beach face with a high tide range of 5 to 7m. The results of this study are: First, the mean grain size of sediments becomes smaller from the south of the beach, where there is a wide wave-cut platform, to the north because gravels are supplied from the wave-cut platform as well as sea-cliff in the south of the beach. A sedimentation pattern of the sandy gravel on the beach face and gravel on the berm, and gradation phenomena of grain size on cross-shore and alongshore direction in the beach can be explained with a pattern of sediment movement, overpassing, in the composite mixed beach. Second, micro-topography on beach face and berm were changed depending on effects of wave height and tide. As a result, in low-wave energy environments, a berm is developed in large size, and beach cusps are formed on the upper beach face, while in high-wave energy environments, a berm is built up in relatively small size, and mixture of sediments occur on the upper beach face.

• Ecology and Resilient Infrastructure
• /
• v.4 no.1
• /
• pp.12-23
• /
• 2017

The Naeseong Stream is a meandering sand-bed stream flowing through mountains and has so long maintained its geomorphological uniqueness characterized by extensive braided bare bars. Recently, its long-lasting landscape has been changed due to encroachment of vegetation. In this study being a part of long-term monitoring research morphological changes of the 56.8 km long study reach of the Naeseong Stream, which occurred during the period of 2012 - 2016 were analyzed. Airborne LiDAR and terrestrial cross-section surveys were carried out. Hydrological and on-site investigation data were also collected. Among the main four sites, two bend reaches showed point bars enlarged, while along the other two straight reaches mid-channel bars were either newly formed or increased in area and height. At the highest deposition point of each bar, vertical changes which were caused by one or two times of sediment deposition amounted to 0.6 - 1.4 m. On the contrary channel bed degradation was not obvious. Overall morphological changes in the study reach were attributed to deposition of sediment which occurred during the flood in July 2016 on the bar surfaces vegetated during the precedent dry seasons. These kind of geomorphological processes are thought to be the same as those related to the existing mid-channel islands along the mid- and downstream reach of the Naeseong Stream.

• Research in Plant Disease
• /
• v.18 no.2
• /
• pp.133-138
• /
• 2012

In November 2009, a powdery mildew on glossy abelia (Abelia ${\times}$ grandiflora) was found in Seogwipo, Jeju Island, Korea. Further survey in the southern part of Korea, e.g., Jeju, Busan, and Tongyeong confirmed occurrence of the disease. White colonies were present on leaves, young stems, and flowers, detracting from their beauty in landscape plantings. Severely infected lesions were discolored to red-purplish. Based on the morphological characteristics and analysis of rDNA, the fungus associated with the symptoms was identified as Erysiphe abeliicola U. Braun & S. Takam. This work provides the morphological feature of its anamorph for the first time, which is characterized by having multi-lobed hyphal appressoria and short foot-cells of conidiophores. Morphological characteristics of mature chasmothecia were consistent with the previous Japanese record of this species. The sequence of internal transcribed spacer region of ribosomal DNA obtained from a Korean sample showed that this species places in the section Microsphaera of the genus Erysiphe in phylogenetic position, corresponding with the classical taxonomy. This is the first report of E. abeliicola and its host plant in Korea. The host plant A. ${\times}$ grandiflora is newly listed in the host range of E. abeliicola.

• Korean Journal of Ecology and Environment
• /
• v.57 no.2
• /
• pp.75-82
• /
• 2024

This study examined the spatial morphological patterns of forest habitats and the characteristics of roadkill occurrences in the forests of Mungyeong, Yecheon, Yeongju, Andong, and Bonghwa in Gyeongsangbukdo. It involved building a resistance map between habitats and analyzing connectivity based on the least-cost distance. The analysis of the distance between the forest habitat Cores derived from MSPA and roadkill points showed that roadkill occurrences were concentrated approximately 74.11 m away from the Cores, with most roadkills happening within 360m from the habitats. The connectivity analysis between core habitats larger than 1 km² revealed 141 core habitats and 242 least-cost paths between them. The corridor distance value was found to be highest in Mungyeong city, indicating an urgent need for strategies to enhance habitat connectivity there. This research is expected to serve as foundational data for developing strategies to enhance ecosystem connectivity and restore habitats, by analyzing ecosystem connectivity and roadkill issues due to habitat fragmentation.

• Atmosphere
• /
• v.25 no.2
• /
• pp.339-351
• /
• 2015

The purpose of this study is for the fundamental understandings about building morphological parameters and aerodynamic roughness parameters of Seoul, Korea using the detailed urban geographic information datasets. Applied roughness parameter calculations are based on a digital map of buildings with lot area polygons. The quality of the developed roughness length ($z_0$) of Seoul was evaluated with densely installed 107 automatic weather stations. The correlation coefficient results between averaged wind speeds of AWS data and averaged $z_0$ is -0.303 in night and -0.398 in day (200 m radii circles case). Further $z_0$ enhancement should follow by considering other surface features such as high tree and orography of Seoul. However, this study would meet the needs to for local- or meso-scale meteorological modeling applications of Seoul. However, further studies would require for enhancing the $z_0$ applications of Seoul.

• Journal of Environmental Impact Assessment
• /
• v.12 no.4
• /
• pp.291-302
• /
• 2003

This paper examined the impacts of the regional developments and dwellers behavior on the Seacoast. Seacoast features a variety of landforms which are created by the action of waves and tidal flows. The coastal landforms are found mainly in the interface between land and sea. Although erosional landforms constitute prominent landscape features as sea stack, sea arch, and rock cliff do, it is nonetheless the depositional features such as beaches, tidal flats, offshore bars, deltas, sanddunes, and coastal plains that have various ramifications for human communities. Among these, beaches and coastal sanddunes are special in that their formation is attributable to the combined action of waves, tidal flows, and winds. The main line of discussion in this dissertation is concerned with the transformation of group of beaches sanddunes along the coastline of Chungcheong-Namdo Province. To some extent, the erosion of coastal dunes has been a global phenomenon. The degradation process occurs most actively when the spring tides attack beaches, berms, and foredunes. Also involved in the transformation of coastal dunes are factors of human agency. The extent, speed, and pattern of their morphological changes are a function of land-use pattern. The reclamation of swale and the exploitation of sands as construction material and silica sand, for example, ruin the feature of coastal dunes.

• Weed & Turfgrass Science
• /
• v.6 no.4
• /
• pp.283-291
• /
• 2017

Zoysiagrass has been used in Korea as a native grass. Informations on distributions, classifications, breeding efforts and outputs, current production and uses of zoysiagrasses in Korea are summarized. During past a few decades, collection of naturally growing zoysiagrass ecotypes has been continued, followed by evaluation, selection and cross-pollination. Classification efforts using important morphological, biochemical traits and DNA polymorphisms resulted in the several suggestions of grouping zoysiagrass species and varieties. Zoysia japonica consistently form separate group, while Zoysia sinica and Zoysia macrostackya have been separately or inter-mixed. Z. matrella with some variations frequently grouped separately but with some similarity with Z. tenuifolia, which was recently renamed as Z. pacifica. Hybrid types of zoysiagrasses were frequently found in Korea. New varieties such as 'Kunhee' and 'Green Ever' etc. were bred by ecotype selections, while 'Senock', 'Semil', 'Millock' were bred through pollination. Molecular approaches were also used to introduce beneficial genes into zoysiagrasses with no practical outputs by legal regulations. Currently popular varieties are inter-specific hybrid types such as 'Anyang' and other local zoysiagrasses as well as common zoysiagrass (Zoysia japonica) Production area in Korea was estimated as 2,947 ha with increasing problems of mixed or contaminated species and varieties.

• The Plant Pathology Journal
• /
• v.19 no.6
• /
• pp.288-290
• /
• 2003

Shoot blight of suckers of common lilac plants (Syringa vulgaris) was found in an apartment garden in Daegu, Korea. The causal organism was a species of Phytophthora, which was homothallic with paragynous antheridium. Oogonia were globose and measured 21.5-34.0 $\mu\textrm{m}$ with an average of 29.7$\pm$3.2 $\mu\textrm{m}$ in diameter. Oospores in oogonia were round, light orange brown when mature, mostly plerotic, and measured an average of 25.6$\pm$3 $\mu\textrm{m}$ in diameter. Antheridia were ovoid and around 11.7$\times$7.8 $\mu\textrm{m}$. Sporangia seldom formed on agar media but formed abundantly in water. Sporangia that formed in water were semipapillate, ovoid obpyriform, non-caducous, and 23.4-66.3$\times$17.6-37.1 $\mu\textrm{m}$ in dimension with I/b ratio of 1.46. The causal organism was identified as Phytophthora citricola Sawada on the basis of morphological characteristics. This is the first report of shoot blight caused by P. citricola Sawada in lilac suckers in Korea.

• Korean Journal of Plant Resources
• /
• v.36 no.6
• /
• pp.580-587
• /
• 2023

Androsace septentrionalis is a grass species restricted to North Korea; however, it is at the brink of extinction due to habitat loss and environmental changes caused by natural disasters and anthropogenic activities. This study was conducted to characterize the dormancy conditions of A. septentrionalis in an effort to conserve this North Korean plant resource. For this purpose, the morphological characteristics and vigor of A. septentrionalis seeds were examined, and its germination characteristics under different temperature conditions (15/6℃ and 25/15℃ ), low-temperature stratification, and gibberellin (GA₃) treatment were determined. The results revealed that A. septentrionalis exhibits non-deep type morpho-physiological dormancy, and low-temperature stratification treatment was not effective in breaking the dormancy of A. septentrionalis seeds. Meanwhile, GA₃ treatment significantly increased the mean germination time, rate, and speed of the seeds. The optimal conditions for the germination of A. septentrionalis seeds were 25/15℃ fluctuating temperature and 500 mg·L¹ GA₃ treatment. The results of this study are useful for the mass propagation of A. septentrionalis.

• Asian Journal of Turfgrass Science
• /
• v.24 no.1
• /
• pp.9-15
• /
• 2010

During 2008~2009 winter season, yellow patch and gray snow mold occurred on turfgrass plants in golf courses in Kangwon and Jeonbuk provinces, respectively. The fungi associated with the diseases were identified as Rhizoctonia cerealis Van der Hoeven and Typhlua incarnata Lasch ex Fr., based on the morphological characteristics of hyphae and sclerotia. R. cerealis and T. incarnata were pathogenic to most turfgrass and crop species tested. R. cerealis infected crown, stem and leaf tissue of the host plants, and the symptom was light yellow circular patch. Individual infected leaf near the margin of patch developed red color first and finally turn brown. The symptoms caused by gray snow mold pathogen are water-soaked spots, and became a watery soft rot. Infection parts became yellow and then turned brown followed by death of the whole plant. White mycelia were developed on higher petioles, leaves, and on soil where these plant parts lay, and black sclerotia of variable size and shape formed in the mycelial mass. All isolates tested were pathogenic on most turfgrass and crop plants, and significantly different in aggressiveness. Disease severity increased with longer snow cover days on target plants, suggesting that disease severity was expressed over snow cover days. There were significant differences in disease severity among the graminious species, and among cultivars within each species, indicating varying levels of susceptibility to R. cerealis and T. incarnata.