• 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 Korean Society of Forest Science
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• v.95 no.6
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• pp.663-671
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• 2006

This study was performed for exploring the spatial distribution pattern of Pinus densiflora and Quercus spp. in Korea. Firstly, the spatial distribution map of Pinus densiflora and Quercus spp. was prepared in grid of $100m{\times}100m$ at national level, using digital forest type map and actual vegetation map. And thematic maps for topography, climate, and soil were also prepared in the raster form of $100m{\times}100m$. Through GIS based spatial analysis of the digital distribution map of Pinus densiflora and Quercus spp. and thematic maps, the spatial characteristics of Pinus densiflora and Quercus spp. distribution was explored in relation to the environmental factors such as topography, climate, and soil. And the occurrence frequency models of Pinus densiflora and Quercus spp. were derived. Pinus densiflora occurs more often than Quercus spp. at low elevation, low slope gradient, and high temperature areas. In addition, Pinus densiflora is mainly distributed at shallow and well-drained loamy soil from igneous rocks. In contrast, Quercus spp. is more common at shallow and well-drained loamy soil from metamorphic rocks. As a result, the prediction model for the spatial distribution of Pinus densiflora and Quercus spp. by topographical variables has proven successful with high statistical significance. The result of this study can contribute to rational management of Pinus densiflora and Quercus spp. stand in Korea, considering environmental factors such as topography, climate, and soil.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.150-161
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• 2005

Soraksan National Park and Odaesan National Park, that are 20.7 km apart, should play an important role as habitats and corridors for wildlife because they are located in the center of Baekdudaegan. However, landscape features such as small area, fragmentation, and geographic isolation seem to impede the proper ecological functions of these two national parks. Using GIS technique, we examined the pattern of fragmentation in these two national parks and adjacent regions (Sokcho-si, Goseong-gun, Inje-gun, Yangyang-gun, and Hongcheon-gun) encompassing a total of $4573.5km^2$ in area. We then selected the patches suitable for an endangered carnivorous species, leopard cat, based on habitat conditions, and identified the network and stepping stone among patches to enable leopard cats to migrate. Diverse roads and artificial facilities in the study area generated a total of 24,701 patches: 39 patches among these were selected as potential habitats upon considering the habitat condition such as vegetation types and minimum area for leopard cat. Three patches nearby Gyebangsan and Bangtaesan were identified as a potential network center to relieve the effects of fragmentation and isolation of the two national parks. Our results also showed that patches containing Jombongsan and Bangtaesan would act as a source patch from there leopard cats can disperse to both national parks. It is an urgent task to identify the pattern of fragmentation and the connectivity between patches in national parks and adjacent areas for wildlife conservation because almost all national parks confront land- scape problems similar to the two national parks examined in this study.

• The Korean Journal of Ecology
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• v.21 no.5_3
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• pp.649-663
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• 1998

The clarify the ecological properties, and to predict change of understory vegetation of mt. Nam Park, population dynamics and interspecific competition of D. smilacinum and D. viridescens, which grow in understory of deciduous broad-leaved forest and pseudo-annuals, were studied from May 20 to May 30 1998. The depth of litter layer, soil moisture content, soil organic matter and soil texture were surveyed in 18 populations (15 D. smilacinum populations and 3 D. viridescens populations). Mean litter layer of d. smilacimum population was thinner than that of D. viridescens populations). Mean litter layer of D. smilacnum population was thinner than that of D. viridescens population. The contents of soil moisture and organic matter of D. smilacinum population were lower than that of D. viridescens population. The D. smilacinum growed in broad range of soil texture but D. viridescens in loamy soil. Because D. smilacinum could tolerate more broad range of soil moisture and soil texture than D. viridescens, the former covered the herb layer in earlier stage and the latter introduced in later stage when rhizome could grow easily. The numbers of individual in two marginal parts were smaller than that in center in same D. smilacinum patch. And the total numbers of individuals grown in (10 ${\times}$ 10)cm were from 0 to 12. The rhizome (subterranean runner) weight, rhizome length, root weight, shoot weight, lea weight and leaf number per subquadrat (cell) increased along the number of individual, that is, increased from marginal part to center. But rhizome weight and rhizome length per individual were vice versa. Therefore, the individuals in marginal part reproduced longer and stronger asexual propagules than that in center. The distribution pattern of D. smilacinum was contageous and that of D. viridescens was random or regular. Therefore, population growth of former was independent on density and that of latter was dependent on density. The distributions of size-class showed normal curves in two population, but the curves based on data of total dry weight showed positive skewness and those of leaf number showed negative skewness The correlation coefficient (CC) values between the properties of each organ were high in two population and significant at 0.1% level. The CC values of D. viridescens were higher of the two. Therefore, the former allocated the energy to each organ stable. The rhizome depth of d. viridescens was 2 times deeper than that of D. smilacinum. And rhizome length and weight of D. viridescens were longer (2 times) or heavier (4 times) than those of D. smilacinum. The patch size of D. viridescens increased 60 cm per year and that of D. smilacinum 30 cm. On this results, the intrinsic increase velocity of d. viridescens patch was 2 times faster than that of d. smilacinum, therefore, on the competition, the former had an advantage over D. smilacinum. The reason why d. viridescens defeated D. smilacinum resulted from that the leaf area of former was 4 times broader than that of latter. in Mt. Nam Park, it was thought that two disporum Population would change with the 3 thpes of environmental change as followings. First, no human impact and increase of soil moisture content resulted in increase of D. viridescens population. Second, mild human impact and similar condition of soil moisture content resulted in slow increase or no changes of D. smilacinum and d. viridescens population. Third, severe human impact and dry condition resulted in decrease or vanishment of two disporum populations.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.534-545
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• 2010

To examine 1) rainfall pattern (i.e., type and intensity) regulating surface erosion on hillslopes in postwildfire area and 2) its effect on variation in sediment yield along the gradient of severity wildfire regimes and elapsed years, we surveyed the amount of sediment yield with respect to daily or net-effective rainfall in 9 plots in eastern coastal region, Republic of Korea. Before field investigation, all plots classified into three groups: low-, mixed- and high-severity wildfire regimes (3 plots in each group). We found that, with decreasing wildfire regimes and increasing elapsed years, the rainfall type regulating surface erosion changed from daily rainfall to net-effective rainfall (considering rainfall continuity) and its intensity increased continuously. In general, wildfires can destroy the stabilized forest floors, and thus rainfall interception by vegetation and litter layer should be reduced. Wildfires can also decrease soil pores in forest floors, and thus infiltration rates of soil are reduced. These two processes lead to frequent occurrence of overland flows required to surface erosion, and sediment yields in post-wildfire areas should increase linearly with increasing rainfall events. With the decreasing severity wildfire regimes and the increasing elapsed years, these processes should be stabilized, and therefore their sediment yields also decreased. Our findings on variations in sediment yields caused by the wildfire regimes and the elapsed years suggest understanding of hydrogeomorphic and ecologic diversities in post-wildfire areas, and these should be carefully examined for both watershed management and disaster prevention.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.699-717
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• 2021

South Korea is pushing for the advancement of crop production technology to achieve food self-sufficiency and meet the demand for safe food. A medium-sized satellite for agriculture is being launched in 2023 with the aim of collecting and providing information on agriculture, not only in Korea but also in neighboring countries. The satellite is to be equipped with various sensors, though reference data for ground information are lacking. Hyperspectral remote sensing combined with 1st derivative is an efficient tool for the identification of agricultural crops. In our study, we develop a system for hyperspectral analysis of the ground-based reflectance spectrum, which is monitored seven times during the cultivation period of three soybean crops using a PSR-2500 hyperspectral sensor. In the reflection spectrum of soybean canopy, wavelength variations correspond with stages of soybean growths. The spectral reflection characteristics of soybeans can be divided according to growth into the vegetative (V)stage and the reproductive (R)stage. As a result of the first derivative analysis of the spectral reflection characteristics, it is possible to identify the characteristics of each wavelength band. Using our developed monitoring system, we observed that the near-infrared (NIR) variation was largest during the vegetative (V1-V3) stage, followed by a similar variation pattern in the order of red-edge and visible. In the reproductive stage (R1-R8), the effect of the shape and color of the soybean leaf was reflected, and the pattern is different from that in the vegetative (V) stage. At the R1 to R6 stages, the variation in NIR was the largest, and red-edge and green showed similar variation patterns, but red showed little change. In particular, the reflectance characteristics of the R1 stage provides information that could help us distinguish between the three varieties of soybean that were studied. In the R7-R8 stage, close to the harvest period, the red-edge and NIR variation patterns and the visible variation patterns changed. These results are interpreted as a result of the large effects of pigments such as chlorophyll for each of the three soybean varieties, as well as from the formation and color of the leaf and stem. The results obtained in this study provide useful information that helps us to determine the wavelength width and range of the optimal band for monitoring and acquiring vegetation information on crops using satellites and unmanned aerial vehicles (UAVs)

• Journal of Wetlands Research
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• v.17 no.1
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• pp.26-37
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• 2015

Halophyte distribution pattern and area in the Suncheon-bay and Beolgyo estuary coastal wetlands were analyzed using KOMPSAT-2 landsat images were taken in 2008 and 2009, and field investigations were fulfilled for confirming the precise boundaries of individual halophyte areas. The salt-marsh vegetation in those areas can be classified mainly into two dominant communities: Suaeda japonica-dominant and Phragmites communis-dominant communities. In order to identify sedimentary characteristics, tidal-flat surface leveling and sedimentary facies analysis had been conducted. The sedimentary facies of marsh area are mostly silty clayey and clay facies with a little seasonal change and its slope is very gentle (0.0007~0.002 in gradient). Phragmites communis and Suaeda japonica communities were distributed in the mud-flat zone between 0.7 m and 1.8 m higher than MSL (mean sea level): zone of 1.1~1.8 m in the former and zone of 0.7~1.3 m in the latter. In the Suncheon-bay estuarine wetland, on the basis of 2009 distribution, Phragmites communis-dominant and Suaeda japonica-dominant communities are about $0.79km^2$ and $0.22km^2$ in distribution area, respectively. On the other hand, Bulgyo estuarine marsh shows that the distribution areas of Phragmites communis-dominant and Suaeda japonica-dominant communities are about $0.31km^2$ and 0.031km2 in distribution area, respectively. Individual 105 and 60 dominant community areas and their distribution patterns can be well defined and indicated in the Suncheon-bay and Bulgyo estuarine marshes, respectively. The distribution pattern and area of hylophyte communities analyzed in this study based on 2008/2009 satellite images would be valuable as a base of future monitoring of salt-marsh related studies in the study area which is the most important salt-marsh research site in Korea.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.381-402
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• 2017

In order to investigate distribution of vascular plants along elevational gradient in the Nodong valley of Gyebangsan, vascular plants of eight sections with 100-meter-high were surveyed from the Auto-camping site (800 m) to the top of a mountain (1,577 m). There were a total of 382 taxa: 89 families, 234 genera, 339 species, 7 subspecies, 34 varieties, and 2 forms. As a result of analyzing the pattern of species richness, it showed a reversed hump-shaped with minimum richness at mid-high elevation. As a result of analyzing habitat affinity types, the proportion of forest species increased with increasing elevation. But, the ruderal species decreased with increasing elevation, and then increased at the top of a mountain. As for the proportion of life forms, the annual herbs gradually decreased with increasing elevation, but it did not appear between 1,300 m and 1,500 m and then increased at the top of a mountain. The trees gradually increased with elevation and decreased from 1,300~1,400 m. The vascular plants divided into four groups by using DCA. The arrangement of each stands was arranged in order from right to left on the I axis according to the elevation. The distribution of vascular plants is determined by their own optimal ranges of vegetation. Also, rise in temperature due to climate change affects the distribution of vascular plants, composition, and diversity. Therefore, continuous monitoring is necessary to confirm ecological and environmental characteristics of vegetation, distribution ranges, changes of habitat. Furthermore, plans for conservation and management based on these data should be prepared according to climate change.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.29-44
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• 1999

Vegetation structure and distribution of the vascular hydrophytes and hygrophytes, and the growth pattern, standing crop and amounts of nutrient uptake by Salix species were investigated in the upper stream wetlands of the Namgang-Dam, Chinju-city, Gyeongsangnam-do, Korea from April to November in 1997. The flora was composed of 43 hydrophytes and 241 hygrophytes, or total 284 vascular plants. The life forms of the hydrophytes were classified as 27 kinds of emergent plants, 4 floating-leaved plants, 3 free-floating plants, and 9 submersed plants. In the herb layer, the dominant species was Persicaria hyciropiper, and the ranges of the species diversity indices (H'), equitabilities, (J') and community similarity indices (CCs) were 1.59~1.89, 0.87~0.96, and 0.35~0.83, respectively. In the shrub and subtree layers, 17 kinds of Salix species were supposed to the pioneer plants at the early stage of the succession. The number of branches per main stem of Salix species was 5.0. The DBH class-frequency histograms of Salix species were the reverse J type, and the natural regeneration of the Salix community was expected. Basal area of Salix species per square meter was $24.87cm^2$. Volume of Salix species per square meter was $12,008cm^3$ and total phytomass of the Salix species was estimated as 12,894 ton. Biomass distribution of Salix species in the stem, the branch and twig, and the leaf was 64.1%, 28.1%, and 7.8%, respectively. The amounts of nitrogen and phosphorus absorbed by Salix species were 68,022 and 19,823 kg. It was recommended that application and conservation of the wetland and other counterplans are indispensable to reduce the adverse effects of water pollution and to preserve the wetland ecosystem.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.1
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• pp.1-28
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• 2019

This study analyzed the density and mortality rate of Korean fir at 9 sites where individuals of Korean firs were marked into the live and dead trees with coordinates on orthorectified aerial images by digital photogrammetric system. As a result of the analysis, Korean fir in each site showed considerable heterogeneity in density and mortality rate depending on the location within site. This make it possible to assume that death of Korean fir can occur by specific factors that vary depending on the location. Based on the analyzed densities and mortality rates of Korea fir, we investigated the correlation between topographic factors such as altitude, terrain slope, drainage network, solar radiation, aspect and the death of Korean fir. The density of Korean fir increases with altitude, and the mortality rate also increases. A negative correlation is found between the terrain slope and the mortality rate, and the mortality rate is higher in the gentle slope where the drainage network is less developed. In addition, it is recognized that depending on the aspect, the mortality rate varies greatly, and the mean solar radiation is higher in live Korean fir-dominant area than in dead Korean fir-dominant area. Overall, the mortality rate of Korean fir in Mt. Halla area is relatively higher in areas with relatively low terrain slope and low solar radiation. Considering the results of previous studies that the terrain slope has a strong negative correlation with soil moisture and the relationship between solar radiation and evaporation, these results lead us to infer that excess soil moisture is the cause of Korean fir mortality. These inferences are supported by a series of climate change phenomena such as precipitation increase, evaporation decrease, and reduced sunshine duration in the Korean peninsula including Jeju Island, increase in mortality rate along with increased precipitation according to the elevation of Mt. Halla and the vegetation change in the mountain. It is expected that the spatial patterns in the density and mortality rate of Korean fir, which are controlled by topography such as altitude, slope, aspect, solar radiation, drainage network, can be used as spatial variables in future numerical modeling studies on the death or decline of Korean fir. In addition, the method of forest distribution survey using the orthorectified aerial images can be widely used as a numerical monitoring technique in long - term vegetation change research.