• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.70-86
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• 2022

A survey was conducted to analyze seasonal dynamics of the phytoplankton community at 22 stations on the surface and bottom layers in the Anma Islands of Yeonggwang(AIY) in the southern West Sea, Korea from the spring of 2020 to the winter of 2021, using a marine survey vessel Ed Ocean. Based on the survey results, there were 87 phytoplankton species in 52 genera, diatoms accounted for 67.8%, dinoflagellates 26.5%, silicoflagellates 3.5%, and cryptomonads and euglenoids accounted for 1.1% each. By season, it was simple in spring and relatively varied in winter. The phytoplankton standing crop on the surface was low (28.8±30.1 cells mL^-1) in summer and high (87.0±65.1 cells mL^-1) in spring. In the phytoplankton community, diatoms showed a high share (over 80%) throughout the year, and Skeletonema costatum-ls was the dominant species with a dominance of more than 60% in spring and winter, and 34.6% and 24.2% in summer and autumn, respectively. The diversity expressing the characteristics of the community structure was high (2.79±0.45) in autumn and low (1.82±0.18) in spring, unlike the phytoplankton standing crop. However, the dominance was high at (0.86±0.08) in spring and low (0.44j0.13) in autumn. Based on the results of principal component analysis (PCA) using environmental and phytoplankton-related factors, it was estimated that the biological oceanographic environmental characteristics seen through the phytoplankton community in the AIY were dominated by nutrients supplied from open seawater and surface sediments by seawater mixing, such as tidal mixing.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.163-172
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• 2013

The aquatic insect collected at six areas (each 2 for mountain area, plain field, and urban area) from 2009 to 2011 were classified to analyze the distribution and diversity of species. Frequency (number of aquatic insect: N), number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) were investigated. Total N and S were 143 and 84, respectively. C matrix of 153 combinations was constructed with the average of 0.542. The average C of 3 years (0.659) was 9.9% P, more higher than the average C of 6 areas (0.560). The average values of the index of 18 plots were 2.28, 0.17, 1.24, 1.08, 0.07, 0.06, 0.01, 0.87, 0.31, 0.93 for R1, R2, V1, V2, E1, E2, E3, E4, E5, D1, respectively. The order in the coefficient of variation (CV) of the indicator for 18 plots was N (70.0%) > E3 (54.9%) > E1 (49.6%) > R2 (40.5%) > S (35.3%) > R1 (33.7%) > E2 (28.4%) > E5 (15.9%) > V1 (11.1%) > E4 (6.3%) > V2 (5.1%) > D1 (4.8%). The correlation matrix with 66 combinations between the indexes was constructed with statistical significance for 33 combinations. However, R1, V1, E2 and D1 were the proper indexes to represent species diversity of aquatic insect based on the correlation matrix and the theory of statistical independence. The richness index was highest in mountain, variety index in urban area, and evenness index in plain field. However, the dominance index was lowest in urban area.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.31-45
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• 2018

At present the biodiversity of the riparian forest is under threat due to various anthropogenic pressures. Hence study was conducted along the three unprotected zones of riparian forest in Dikhu river, Nagaland, north-east India in order to compared the diversity, distribution and population structure of riparian trees. In each zone $100{\times}100m^2$ plot were marked and subdivided into 20 plots of $10{\times}10m^2$. 10 plots on each side of the river were taken randomly covering 0.02 ha. Only tree with dbh ${\geq}10cm$ and dbh above 1.5 m above ground level were recorded as individual species. A total of 29 tree species belonging to 18 families were recorded from the three zones of the river. Tree species richness was highest at the middle zone (19) followed by upper (14) and lower zone (7). The most abundant species and family recorded at upper, middle and lower zones were Melia azaderach of Euphorbiaceae ($380\;stems\;ha^{-1}$), Terminalia chebula of Euphorbiaceae ($432.5\;stems\;ha^{-1}$) and Duabanga grandiflora of Lythraceae ($365\;stems\;ha^{-1}$) respectively. The ranges of diversity indices observed in the three zones were: Shannon-Wiener index (1.25-0.73), Simpson diversity index (0.42-0.93), Evenness index (0.47-0.37) and Index of co-dominance (0.75-0.94). Rest of other indices were also estimated and compared. Distribution of trees shows the contagious pattern common in the upper and middle zones and regular in the lower zone. The girth size class analysis demonstrated that the riparian forest is in less mature succession stage. This study emphasize the need for management and conservation of riparian forest by developing policy to declare the riparian zone as protected area to prevent further degradation and loss of biodiversity from these unregulated zones along the river.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.209-223
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• 2018

We investigated tree composition, stand characteristics, biomass allocation pattern and carbon storage variability in Sal forests (Shorea robusta Garten.) under two forest management regimes (Sal forest and Sal plantation) in Tripura, Northeast India. The results revealed higher species richness (29 species), stand density of $1060.00{\pm}11.12stems\;ha^{-1}$ and diversity index ($1.90{\pm}0.08$) in Sal forest. and lower species richness (4 species), stand density of $ 230.00{\pm}37.22stems\;ha^{-1}$ and diversity index ($0.38{\pm}0.15$) in Sal plantation. The total basal cover $33.02{\pm}4.87m^2ha^{-1}$) and dominance ($0.76{\pm}0.08$) were found higher in Sal plantation than the Sal forest ($22.53{\pm}0.38m^2ha^{-1}$ and $0.23{\pm}0.02$ respectively). The total vegetation carbon density was recorded higher in Sal plantation ($219.68{\pm}19.65Mg\;ha^{-1}$) than the Sal forest ($167.64{\pm}16.73Mg\;ha^{-1}$). The carbon density estimates acquired in this study suggest that Sal plantation in Tripura has the potentiality to store a large amount of atmospheric carbon inspite of a very low species diversity. However, Sal forests has also an impending sink of carbon due to presence of large number of young trees.

• Journal of Ecology and Environment
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• v.45 no.3
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• pp.97-104
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• 2021

Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m²) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (G_st = 0.548, N_m = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

• Journal of Forest and Environmental Science
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• v.35 no.4
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• pp.248-257
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• 2019

We chose the Mt. Dalum area (located in Gijang-gun, Busan, Korea) for our survey, particularly The pine wilt disease zone and the non-permanent control area. This study investigates the effect of pine wilt disease on the distribution of beetle species in the process of ecosystem change due to insect control; pine forests treated for pine wilt disease were divided into insect control and non-control sites, respectively. The results of this study are as follows. Twen tyseven species belongs to 12 families were identified from 969 ground beetles collected from this sites. Species richness was the highest in Coleoptera (6 species, 469 individuals). In the control site, 21 species belongs to 10 families were identified from 228 individuals, while 24 species of 11 families from 533 individuals in the non-control area. The highest number of species were noted in June and July from the non- control and control sites, respectively. The highest number of insects in control and non-control sites was observed in July, while the lowest in September. Sipalinus gigas gigas, Spondylis buprestoides, Plesiophthalmus davidis, Calosoma maximowiczi, Damaster jankowskii jankowskii, and Damaster smaragdinus were captured in both study sites. Episomustur ntus and Glischrochilus ipsoides were only captured in the control site, while Macrodorcas rectus rectus and Pheropsophus javanus were only captured in the non-control site. Six beetles and five species (such as Calosoma maximowiczi) were found in the control site and six species (including Damaster smaragdinus) in the non-control site. The species distributions by altitude were 163, 518, and 258 individuals, at 100, 200 and 300 m sites, respectively. The diversity, evenness, and dominance indices in the control area were 0.764, 0.812, and 0.367, respectively. The diversity, evenness, and dominance indices in the non-control area were 0.927, 0.837, and 0.352, respectively. The similarity index between the control and non-control area was 80%.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.332-342
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• 2007

Species composition and quantitative and body length composition of the ichthyoplankton were investigated by samples collected from the coastal waters of uljin in January, April, July and October, 2002. During the study, the collected fish eggs were identified as belonging to 7 taxa. The most of dominant species Engraulis japonicus, were accounted for 38.34% of the total fish eggs, followed by Sillago sihama (25.84%). The collected larvae and juveniles were identified into 25 taxa, 18 families, 7 orders. The domninant species Engraulis japonicus accounted for 90.46% of the total larvae and juveniles, followed by Sebastes schlegeli 2.04%. These 2 taxa constituted 92.50% of the total collected larvae and juveniles. The diversity index of species per months of the collected juveniles the coastal water of Uljin, 2002 was 0.0878~2.3855 and the evenness index was 0.0451~0.9300. in case of dominance index was 0.3000~0.9914 against the evenness index. The analyzed species diversity index by the each stations was 0.3035~0.7440 and the dominance index was 0.8919~0.9669 against the species diversity index. The similarity of community structure per season was very high because of the relative difference (0.010), which was the least in Summer and Fall. In addition, the community structure was very similar in state 1 and state 4 out of each stations because the relative difference was the least, 0.139.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.587-600
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• 2013

Juniperus chinensis forest were classified into 1 community group, 2 communities, 4 groups, 6 subgroups, and 7 vegetation units by phytosociological analysis(the method of ZM schools) with 79 vegetation data in south korea. By NMS analysis it appeared at first axis (13.8%) and second axis (69%) and comprehensive explanatory power was 31%. It was shown clearly in Donggang region, the East sea region and the Ulleungdo region. In INSPAN(Indicator species Analysis) of vegetation unit, 89 species were analyzed significantly. According to result of species diversity, evenness, dominance value, interspecific-competition and other related analyses for vegetation unit, the species diversity of vegetation unit 4 showed the lowest value 0.667, while the value of vegetation unit 6 showed the highest value 1.174. The dominance value of vegetation unit 7 showed the lowest value 0.163 and most vegetation units are on about 0.7, while the value of vegetation unit 1 showed highly above 0.8.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.1-10
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• 2012

The habitats characteristics of Polypodium vulgare L. in Ulleung-do were investigated to compile basic data for conservation and restoration. Natural habitats were located at altitudes of 410~748m with inclinations of $12{\sim}80^{\circ}$. Sixty six vascular plants were identified from 10 quadrats in 4 habitats. Dominant species among the woody plants, based on importance value, were Acer pictum subsp. mono(49.52%) in the tree (T1) layer, Sorbus amurensis(28.99%) in the subtree (T2) and Schizophragma hydrangeoides(51.99%), Ligustrum foliosum(8.82%), Fagus engleriana(7.25%) in the shrub (S) layer. Importance value for members of the herb (H) layer were as follows: Polypodium vulgare 23.23%; Maianthemum dilatatum 9.65%; Phryma leptostachya var. asiatica 9.23%; Dryopteris crassirhizoma 8.40%; Carex shimidzensis 6.75% and Dystaenia takesimana 5.42%. The importance value of the last five species were high, so they were at affinity with Polypodium vulgare in their habitats. Species diversity was 1.18, and dominance and evenness were found to be 0.11 and 0.84, respectively. The soil types were sandy loam. Average field capacity was 30.42%, and the organic matter and pH were 17.95%, and 4.70. Correlation coefficients based on environmental factors, vegetation and soil analysis were showed that positive correlations between species diversity and species richness, whereas between species diversity and dominance, coverage of Polypodium vulgare and species richness were showed negative correlations.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.96-101
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• 2021

In this study, we wanted to obtain the information of the ecological impact of alien species on native fish communities. The Ichthyofauna and fish community in Joongchosan Reservoir and Bukchosan Reservoir in Gunsan-si Korea were investigated over the period from March to October 2020. During the survey period, a total of 1,895 individuals representing eight species, five families, and four orders were caught in the Joongchosan Reservoir. In the Bukchosan Reservoir, a total of 171 individuals were caught, representing seven species, five families, and three orders. The dominant species and subdominant species of Joongchosan Reservoir were Pseudorasvora parva (661 individuals, RA: 34.7%), and Rhodeus ocellatus (660 individuals, RA: 34.7%). Conversely, Micropterus salmoides (77 individuals, RA: 45.0%), and Carassius auratus (60 individuals, RA: 35.1%), were the two most common species in the Bukchosan Reservoir. The community indices showed a dominance of 0.697, diversity of 1.483, evenness of 0.713, and species richness of 0.928 in the Joongchosan Reservoir. In comparison, the community indices in the Bukchosan Reservoir showed a dominance of 0.801, diversity of 1.304, evenness of 0.670, and species richness of 1.167. This study confirms that the number of native fishes and the associated community diversity have decreased due to the influence of Micropterus salmoides. This highlights the need for removal of alien species from reservoirs, while simultaneously preventing future introductions.