• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.363-373
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• 2022

On April 29, 2021 (1st), June 2 (2nd), and August 17 (3rd), we surveyed benthic macroinvertebrates fauna at Muljangori-oreum wetland in Bonggae-dong, Jeju Island, Korea. Muljangori-oreum wetland was divided into four areas. The survey was conducted in three accessible areas (areas 1-3). As a result of habitat environment analysis, the average monthly temperature from 2017 to 2021 was the highest in July and August and the lowest in December and February. This pattern was repeated. As a result of analyzing changes in vegetation and water surface area through satellite images, normalized difference vegetation index (NDVI) increased from February to July and decreased after July. Normalized difference water index (NDWI) was analyzed to show an inverse relationship. A total of 21 species from 13 families were identified in the qualitative survey and a total of 412 individuals of 24 species from 15 families were identified in the quantitative survey. A total of 26 species from 17 families, 8 orders, 3 classes, and 2 phyla of benthic macroinvertebrates were identified. The dominant species was Chronomidae spp. with 132 individuals (32.04%). Noterus japonicus was a subdominant species with 71 individuals (17.23%). As a result of comparative analysis of species identified in this study and the literature, it was confirmed that species diversity was high for Coleoptera and Odonata. Main functional feeding groups (FFGs) were found to be predators. Habitat orientation groups (HOGs) were found to be swimmers. In OHC (Odonata, Hemiptera, and Coleoptera) group, 17 species (73.91%) in 2021, 23 species (79.31%) in 2016, 26 species (86.67%) in 2018, and 19 species (79.17%) in 2019 were identified. Cybister japonicus, an endangered species II, was confirmed to inhabit Muljangori-oreum wetland in the literature. Ten individuals (2.43%) were also confirmed to inhabit Muljangori-oreum wetland in 2021. Therefore, continuous management and habitat protection are required to maintain the habitat environment of C. japonicus in Muljangori-oreum wetland.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.368-380
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• 2022

Biomonitoring of an invasive alien crayfish species, Procambarus clarkii (Girard, 1852), was performed from February to October 2021, along with environmental DNA analysis, at five locations including Wanju-gun, Hampyeong-gun, Naju-si, Gurye-gun, and Cheongju-si. For the investigation, an umbrella-shaped trap for adults and a hand net for young crayfish were used, and 8 to 10L of freshwater was collected for eDNA analysis. The current status and past distributional records of crayfish in Korea were analyzed along with benthic macroinvertebrates at each survey site. As a result of the investigation, a total of 122 individuals were identified, and Hampyeong-gun recorded the largest number of populations with 59 individuals (48.36%) and the highest environmental DNA (eDNA). The frequency of appearance of P. clarkii was highest in May. The ratio of females to males was 21:5, and the body size was 72.2±21.1mm for female, 80.5±15.6mm for male, and 25.3±9.8mm for young crayfish. P. clarkii introduced into Korea is mainly spreading in the southwest region and it has not been observed in Seoul where there had been a record of appearance in the past. No external symbiosis (Branchiobdellida) of P. clarkii has been identified, and P. clarkii that has appeared in Korea was presumed to be imported from Japan. There are more than eight kinds of exotic crayfish distributed in Korea, and among them, the marbled crayfish (P. virginalis) was identified as a harmful species to the ecosystem of Korea by the Ministry of Environment in 2021. The identified species of benthic macroinvertebrates inhabiting the survey area where P. clarkii has appeared were 69 belonging to 39 families, 15 orders, five classes, and three phyla. Among them, Odonata were the most abundant (16 spp.; 24.62%), followed by Coleoptera (11 spp.; 16.92%) and Hemiptera (11 spp.; 16.92%). In the survey area, one Korean endemic species (Rhoenanthus coreanus), one species (Helophorus auriculatus) classified as Near Threatened (NT) on the Korean Red List, and six species of Crustaceans appeared. In the functional feeding group, the predators appeared predominantly while in habitat oriented group, the climbers appeared to be abundant. It was confirmed that P. clarkii in the survey area prefers an area rich in aquatic vegetation with waterside vegetation, and has high resistance to turbid water quality. The omnivore invader P. clarkii is expected to maintain a competitive relationship with carnivorous benthic macroinvertebrates that are predominant in the same species, and is expected to continue to generate ecosystem disturbance along the food chains.

• 한국해양학회지
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• v.21 no.1
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• pp.1-12
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• 1986

A total of 40 surface samples(12 from the intertidal flat and 28 from the subtidal zone) from Gwangyang Bay, southern coast of the Korean Peninsula show a strong negative relationship between the total foraminiferal abundance and the ratios of the live to the total(L/T) assemblages. This suggests that the foraminiferal abundance is dependent on the dilution due to the input of detrital sediments, and that the L/T ratios show the relative rate of sedimentation in the study area. The intertidal flat and delta area are characterized by the relatively high sedimentation compared to the inner bay and shallow subtidal zone, and three major tidal channels where relatively low and no sedimentation is noted, respectively. Bathymetric occurrence of the species shows distinct boundaries at 9m, and between 21 and 30m, respectively. Cluster analysis shows three biotopes;intertidal flat including delay, inner bay and shallow subtidal zone, and major tidal channels. This suggests that these biotopes are formed by the ecology of the foraminifers as well as by the sedimentological setting of the study area. Several problems in relation to the relative rate of sedimentation inferred from the L/T ratios are briefly discussed.

• Mycobiology
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• v.44 no.3
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• pp.180-186
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• 2016

Trichoderma species are able to persist on living sapwood and leaves of cacao (Theobroma cacao) in an endophytic relationship. In this research, we evaluated the ability of Trichodema asperellum introduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application of T. asperellum was 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mL T. asperellum, the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations of T. asperellum listed above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application of T. asperellum to cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches.

• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.37-46
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• 2020

Vegetation carbon sequestration and regeneration are the two major parameters of forest research. In this study, we analyzed the vegetation carbon stock and regeneration of community-managed pine plantation of Kathmandu, central Nepal. Vegetation data were collected from 40 circular plots of 10 m radius (for the tree) and 1m radius (for seedling) applying a stratified random sampling and nested quadrat method. The carbon stock was estimated by Chave allometric model and estimated carbon stock was converted into CO₂ equivalents. Density-diameter (d-d) curve was also prepared to check the regeneration status and stability of the plantation. A d-d curve indicates the good regeneration status of the forest with a stable population in each size class. Diversity of trees was very low, only two tree species Pinus roxburghii and Eucalyptus citriodora occurred in the sample plots. Pine was the dominant tree in terms of density, basal area, biomass, carbon stock and CO₂ stock than the eucalyptus. The basal area, carbon stock and CO₂ stock of forest was 33±1.0 ㎡ ha^-1, 108±5.0 Mg ha^-1 and 394±18 Mg ha^-1, respectively. Seedling and tree density of the plantation was 4,965 ha^-1 and 339 ha^-1 respectively. The forest carbon stock showed a positive relationship with biomass, tree diameter, height and basal area but no relationship with tree density. Canopy cover and tree diameter have a negative effect on seedling density and regeneration. In conclusion, the community forest has a stable population in each size class, sequestering a significant amount of carbon and CO₂ emitted from densely populated Kathmandu metro city as the forest biomass hence have a potentiality to mitigate the global climate change.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.175-185
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• 2010

The effect of altitude and latitude on biodiversity (or species richness) has been a topic of great interest for many biogeographers for a long time. This study was conducted to examine the dynamics of species richness of aquatic insects along the altitudinal gradient in 24 wetlands on Mt. Halla, Jeju and test the Rapoport's rule. The species richness of aquatic insects monotonically decreased with increasing altitude, showing a significant inverse correlation (r = -0.64). However, the pattern of species richness with altitude showed a hump-shaped relationship, with a peak in species richness at intermediate elevations when the effects of area were removed. The altitudinal range of species tended to increase with increasing altitude, as Rapoport's rule predicts. There was a positive correlation between the altitudinal range size and the midpoint of the range size (Median) except for Hemiptera (Odonata: r = 0.75, Hemiptera: r = -0.22, Coleoptera: r = 0.72, Total: r = 0.55). Also, the extent of average altitudinal range of high-altitude species was 904.3m, and it was significantly wider than a 469.5m of low-altitude species. Consequently, the species richness of aquatic insects in wetlands on Mt. Halla along the altitudinal gradient well supported Rapoport's rule.

• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.461-475
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• 2020

This study was conducted in the southwestern area of Korea using a neuston net in September (14 stations) 2017 to understand the environmental factors affecting neustonic zooplankton. Temperature, salinity, chlorophyll a concentration, suspended solids, and microplastics were included as environmental factors. Based on the density of the copepods, the study area was divided into three regions: the Seomjin River water influence area, the frontal mixing area, and the warm water affected area (Jeju warm current and Tsushima warm current). In the latter two areas, the major species were Pontella chierchiae, Canthocalanus pauper, and Oncaea spp. Also, neustonic zooplankton showed a significant relationship between the density of phytoplankton and microplastics in the frontal mixing area, and temperature and suspended solids in the warm water affected area, respectively (p<0.05). This indicates that microplastics can affect the offshore zooplankton community.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.103-108
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• 1985

This paper is concerned with estimating equations of leaf area(A) obtained from linear measurements - leaf length(L) and leaf width(W) - on the leaves of 13 species composing a natural mixed stand in Mt. Jiri. This method is known to be rapid and non-destructive in estimating leaf area. The equation of A=bLW is frequently used in rough and rapid estimation. Each species in this study has its own coefficient b according to its geometrical leaf shape. The range of coefficients of 13 species was 0.579 to 0.717. This means that the relationship A=2/3LW is suitable to most broad leaf species in a natural mixed stand in Mt. Jiri. When more precise estimation of leaf area is needed, full regression equation is used. In this study, the form of ${\log}A=b_0+b_1{\log}LW$ was the most precise estimation equation in 8 species. In addition to this, the form of $A=b_0+b_1LW$ and $A=b_0+b_1L^2+b_2W^2$ were founded to be suitable for estimation of leaf area. In comparision of these two forms, the determination coefficient were about the same, but the F-value of the former was greater than that of the latter. Therefore, the use of the former seems to be more reliable and practical.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.749-759
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• 1998

Distribution of zooplankton abundance was studied in the front zone in the East Sea in November, 1996, Averaged total abundance in the front zone was less than that in the nearby cold surface water areas but more than that in the nearby warm surface water areas. The number of taxa was the greatest in the upper layer of mixing. Abundance and the number of tun in the front zone were contributed by the cold water and the warm water, respectively. Inspite of the differences in sampling time (day vs night), the species composition and abundance distribution were similar at two sites within cold or warm water area, However, they were quite different at two sites in the front zone although the sampling time of the day was the same. from this, the history of mixing was believed to be the most important factor for the species composition and abundance distribution in the front zone. Zooplankton distribution in the study area was mainly controlled by the dominant cold water Copepod Species Metridia paoifica, the only taxon that showed significant diet vertical migration. Most other taxa showed no significant diel vortical migration, Seawater temperature also affected zooplankton distribution. Positive correlations in the warm area, weak negative correlations in the cold water area, and no significant correlation in the front zone were obtained in general between the seawater temperature and the abundances of the major taxa.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.62-76
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• 2001

This study is to offer the basic information and materials for the restoration of the urban forest and the ecologically healthy and continuous green belt through the investigation and the analysis on the vegetation in Hwasan Park, Chonju-City. The flora of Hwasan Neighborhood park was composed of 86 families 230 genera, 261 species, 35 varieties, 1 formae or 298 Taxa. Among them, calculation of Pte-Q Index represented 0.60, Fisher's Index. Some characteristics of the plants in this area have represented such as Th-D1-R5 type in biological type, erect form(64.6%) in growth type, 30 taxa in naturalized plants. The life form spectra investigated from Hwasan neighborhood park was recognized as the following M"17.4%, N:11.4%, E:0.3%, Ch:0%, H:29.8%, G:6.7%, HH:0%, Th:34.2%. By the Z-M method 5 plant communities and 3 afforestation were recognized; Quercus variabilis community, Q.acutissima community, Q.serrata community, Sorbus alnifolia community, Pinus densiflora community, P.rigida afforestation, Robinia pseudo-acacia afforestation and Larix leptolepis afforestation. The actual vegetation map constructed on the grounds of the communities classified and other data. The pattern of successional trend of tree species might be suggested: L. leptoleipis, P. rigida and P. densifloralongrightarrowQ.variabilis and Q.acutissimalongrightarrowS.alnifolia and Q.serratalongrightarrowCarpinus tschonoskii community. Three measurements of species diversity (richness index(SR), Shannon-Wiener index(H'), evenness index(J')) and their relationship with community type were studied in the surveyed plant communities. Q.serrata community was higher in SR, H', J' than the other communities, whereas R.pseduo-acacia afforestation was low. Finally, The vegetation of the Hwasan neighborhood park must not allowed any more. Nothing ca be better than native states in preserving the ecosystems.tems.