• Korean Journal of Environmental Biology
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• v.38 no.3
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• pp.355-370
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• 2020

We conducted a field survey to analyze the ecological structure and spatial distribution of microplankton (phytoplankton and ciliates) in relation to water masses at 21 stations on the surface and chlorophyll-a maximum layers (CML) in the Northern East China Sea (nECS; 32°-33°N; 124°00'-127°30'E) from August 3 to August 6, 2019. The results showed that the water masses were divided into Chinese Coastal Waters (CCW) and the Tsushima Warm Current (TWC). The CCW showed the environmental characteristics of high temperature and low salinity, and the TWC showed high temperature and high salinity. The characteristics of the phytoplankton community in the CCW showed various community structures related to the nutrients supplied from the large rivers of the Chinese continent. However, the TWC had simple community structures because it originated near the equator and moved northward. The standing crops of phytoplankton and ciliates were very high in the CCW but showed low at the TWC. In particular, from the higher standing crops of protozoa than plant plankton at the TWC, the energy flow at the lower tropic levels caused by the microbial loop that fed on heterotrophic bacteria played an important role in the production of resource organisms. In other words, the marine ecological structure of the nECS in summer could be estimated as a bottom-up system at the CCW and a top-down system at the TWC.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.142-149
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• 2004

To investigate the vegetation structure of subalpine region from Hyangjeukbong to 2nd Deogyusan, 20 plots(100$m^2$) set up with random sampling method were surveyed. Three groups Quercus mongolica community, Betula ermanii - Picea jezoensis - Taxus cuspidata community, Taxus cuspidata - Qurecus mongolica - Betula ermanii community were classified by cluster analysis. Quercus mongolica, Taxus cuspidata and Betula ermanii were found as a major woody plant species in the subalpine region from Hyangjeukbong to 2nd Deogyusan. In this area, Korean endemic species, Abies koreana was distributed small amounts. In future, importance percentage of Abies koreana might be decreased, but that of Betula ermanii might be increased. High positive correlations was proved between Betula ermanii and Rhododendron schlippenbachii, Rhododendron mucronulatum var. ciliatum ; Acer tschonoskii var. rubripes and Acer mono; Syringa velutina and Magnolia sieboldii and relatively high negative corrlations was proved between Betular ermani and Acer tschonoskii var. rubripes ; Quercus mongolica and Acer mono; Abies koreana and Tripterygium regelii, Weigela subsessilis. Species diversity(H') of investigated groups were ranged 1.0316∼1.1776 and it was similar to those of the ridge area of the national parks in Baekdudaegan.

• Korean Journal of Environment and Ecology
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• v.21 no.5
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• pp.400-414
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• 2007

This study has analyzed the vegetation structure to suggest a vegetation ecological restoration model by using the case of the afforestation for erosion control area with Pinus koreaiensis and Betula platyphylla, etc., on the hills of the Young-in mountains after its great fire in 2000. Of the area having a dimension of $1,152,404.3m^2$ selected as a survey site for the existing vegetation, the forest fire area accounted for 69.2% among which, brushwoods accounted the most for 24.67%. As a result of analysis of the 27 surveyed unit plots[unit dimension: $100m^2$] set up in consideration of the existing vegetation pattern and damaged state from the forest fire, the surveyed area was classified into 10 communities. Shrub layer's vegetation was found to be dominant in forest fire areas and the surveyed sites were classified into 5 plant communities, i.e. P. koraiensis community, Quercus variabilis community, P. thunbergii community, Q. serrata community, B. platyphylla community in forest fire areas, while non-forest fire areas were classified into 5 plant communities, such as P. densiflora community, Q. acutissima community, Q. serrata community, Q. mongolica-Q. serrata community, B. platyphylla community. Species diversity of forest fire areas was $0.3679{\sim}0.5907$ and that of non-forest fire areas was $0.5728{\sim}0.8865$. In addition, the number of the species in the forest fire areas was $5{\sim}8$ and that of non-forest areas was $8{\sim}12$; however, the population of forest fire areas$(156{\sim}456)$ was higher than that of non-forest fire areas$(61{\sim}227)$. In the analysis of growth density per layer$[of\;100m^2]$, there appeared $1{\sim}8$ trees of Q. mongolica and $3{\sim}5$ trees of Q. serrata in the upper layer species; $2{\sim}4$ trees of Q. serrata and one tree of Q. mongolica in the canopy layer. As for the characteristics of soil, acidity of forest fire areas was pH 5.45 and that of non-forest fire was pH 5.25. By setting up the middle D.B.H range of Q. mongolica-Q. serrata community as the vegetation restoration model, planting species, planting density and planting models are suggested.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.365-377
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• 2011

This study aims at classifying and interpreting on the second forest vegetation located in Mt. Duryun affiliated to the ecotone in southern part of Korea, and foreseeing vegetation change based on component species and dominant species on canopy. The second forest vegetation is classified into 3 community units as Quercus serrata-Quercus variabilis community, Dendropanax morbiferus-Quercus acuta community and Chamaecyparis obtusa plantation. This research is also expatiated on the relationship between the distribution of communities and the environmental conditions. Quercus serrata-Quercus variabilis community will be succession horizontally and gradually from the part where Quercus variabilis is dominated relatively at first to the other part in the community, according to the component species of deciduous broad-leaved forest in the warm-temperate zone and evergreen broad-leaved forest as Camellietea japonicae.

• Korean Journal of Environment and Ecology
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• v.3 no.1
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• pp.28-41
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• 1989

A survey of Hongryu-Dong and Chi-in district. Gaya National Park, was conducted using 40 sample sites of 500$m^2$ size. TWINSPAN classification confirmed a complex pattern of both local and geographical variation in the vegetation: Dry and wet community types. Within dry community types, two floristic assocation of Pinus densiflora were defined according to local variation. Within wet community types. two floristic association were defined according to altitude. Those associations can be further subdivided floristically into eight subassociation. The vegetation pattern presented by DCA ordination corresponds to one of TWINSPAN at the first two division. The DCA ordination was successful in separating Pinus densiflora from broad leaf forest. Ordination of samples produced arrangements reflectly environmental gradient of soil. The correlation between the first axe of DCA and soil moisture, soil acid, altitude, maximum species diversity and species diversity was significantly negative. The similarity index between each community was very low level.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.419-429
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• 2022

American ginseng (Panax quinquefolium L.) is a perennial herbaceous plant widely cultivated in China, Korea, the United States, and Japan due to its multifunctional properties. In northwest China, transplanting after 2-3 years has become the main mode of artificial cultivation of American ginseng. However, the effects of the cultivation process on the chemical properties of the soil and bacterial community remain poorly understood. Hence, in the present study, high-throughput sequencing and soil chemical analyses were applied to investigate the differences between bacterial communities and nutrition driver factors in the soil during the cultivation of American ginseng. The responses of soil nutrition in different ecological niches were also determined with the results indicating that the cultivation of American ginseng significantly increased the soluble nutrients in the soil. Moreover, the bacterial diversity fluctuated with cultivation years, and 4-year-old ginseng roots had low bacterial diversity and evenness. In the first two years of cultivation, the bacterial community was more sensitive to soil nutrition compared to the last two years. Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, Firmicutes, and Bacteroidetes dominated the bacterial community regardless of the cultivation year and ecological niche. With the increase of cultivation years, the assembly of bacterial communities changed from stochastic to deterministic processes. The high abundance of Sphingobium, Novosphingobium, and Rhizorhabdus enriched in 4-years-old ginseng roots was mainly associated with variations in the available potassium (AK), total phosphorus (TP), total potassium (TK), and organic matter (OM).

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.469-483
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• 2021

Background and objective: If the Nelumbo nucifera spreads in a wetland at a high density, it can have considerable positive and negative ecological effects on habitats. For this reason, it is necessary to precisely investigate the impacts of its rapid proliferation. This study was conducted to propose the distribution and management of N. nucifera, which can cause the degradation of wildlife habitats due to the rapid spread of internal and external environmental factors that may affect the Junam wetland ecosystem. Methods: For the investigation and analysis of physical and ecological characteristics, factors of the abiotic environment such as general weather conditions, topography and water depth structure, and soil and water quality analysis, and bioenvironment characteristics such as changes in the N. nucifera community distribution were evaluated. To assess whether the differences in the soil depth and physicochemical characteristics between the N. nucifera community and the aquatic plant community are statistically significant, a One-way ANOVA was executed. Results: N. nucifera was presumably introduced in approximately 2007 and observed at a prevalence of only 0.8% in 2009, but had expanded to 11.1% in 2014. After that, the area was increased to 19.3% in 2015 and 40.0% in 2017, about twice that of the previous survey year. The rapid diffusion of an N. nucifera colony can have adverse effects on wildlife habitats and biodiversity at Junam Wetland. To solve these problems, four management methods can be proposed; water level management, mowing management, installation of posts and removal of lotus roots. Control of the N. nucifera community using these methods was judged to be suitable for cutting and water level management when considering expansion rate, water level variation, and wildlife habitat impacts. Conclusion: As the biotic and abiotic environmental factors are different for each wetland, it is necessary to determine the timing and method of management through a detailed investigation.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.312-319
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• 2022

The species diversity of plant communities is quantitatively measured, and can be affected by plant monitoring methods. This study experimentally compared the structure and diversity of plant communities living in five waterfront park areas in Nak-dong River using three plant survey methods (modified Whittaker, modified Daubenmire, and modified point-line intercept method). According to the diversity profile, the modified Whittaker method produced the highest species richness regardless of the location, but which method makes the highest diversity of dominant species varies depending on the location. The Beta diversity of the communites calculated from the modified Whittaker and the modified Daubenmire suggested that structures of plant communities in five locations were similar, while the Point-line interception method suggested that a small number of dominant species were shared between communities.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.23-28
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• 2003

In order to identify plant species and communities characteristic of lithospheric condition, forest vegetations of igneous(mainly granite) and sedimentary(mainly sandstone) areas in Kyungpook province were compared. We collected 108 phytosociological releves from the older forests over 20 years old. 444 vascular plant species and 25 plant communities were identified. Results of Principal Coordinates Analysis (PCA) indicated that lithospheric conditions and human impacts were the most important factors related to the plant community diversity and species richness. In the igneous rock areas net contribution degree (rNCD) of 139 species including Quercus serrata, Q. mongolica, Lindera obtusiloba and Fraxinus sieboldiana increased and those of Carpinus laxiflora and Styrax japonica decreased. In the sedimentary rock areas, to a lesser extent, 96 species including Q. aliena, Zanthoxylum schinifolium, Potentilla fragarioides var. major, Rhus javanica, and Plectranthus japonicus increased, whereas character species of Lindero-Quercion mongolicae such as Q. mongolica, Q. serrata, Rhododendron schlippenbachii, Acer mono and Styrax obassia decreased, and particularily the species Sasa borealis, the Alangium-Zelkova serrata community and the Philadelphus-Fraxinus mandshurica community were absent. The vegetation of sedimentary rock area is characterized as a regional type shaping dwarf pine forests and sparse and light broad-leaved forests.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.2
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• pp.41-63
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• 2022

The purpose of this study is to secure objective and precise data through ecosystem monitoring, to reveal ecological characteristics through comparison and analysis with past survey data, and to accumulate basic data for diagnosing the current situation and predicting changes in the ecosystem. The target site is the 'Quercus mongolica forest on the Buksa-myeon of Namsan', which was designated as an Ecological Landscape Conservation Area (ELCA) of Seoul in July 2006. The research contents are analysis of soil environment change (1986~2016), change of actual vegetation (1978~2016), and change of plant community structure (1994~2016). A total of 8 fixed surveys (400~1,200m²) were established in 1994 and 2000. Analysis items are importance value, species and population, and Shannon's species diversity. The soil environment of Namsan is acidic (pH 4.40 in 2016), which is expected to have a negative impact on tree growth and vegetation structure due to its low capacity for exchangeable cations. Quercus mongolica forest in Namsan is mainly distributed on the northern slopes. The actual vegetation area changed from 49.4% in 1978 → 80.7% in 1986 → 82.4% in 2000 → 88.3% in 2005 → 88.3% in 2009 → 70.3% in 2016. In 2016, the forest decreased by 18% compared to 2009. While there was increased growth of Quercus mongolica in the tree layer from 2009 to 2016, the overall decline in vegetation area was due to logging and fumigation management following the spread of oak wilt in 2012. As for the changes in the plant community structure, Quercus mongolica of the tree layer was damaged by oak wilt, and the potential vegetation that can form the next generation was ambiguous. In the subtree layer, the force of urbanization tree species such as Styrax japonicus, Sorbus alnifolia, and Acer palmatum. was maintained or increased. In the shrub layer, the number of trees and species increased significantly due to the open tree crown, and accordingly, the species diversity of Shannon for woody plants also increased. In Quercus mongolica forest of Namsan, various ecological changes are occurring due to the effects of urban environments such as air pollution and acid rain, the limitation of Quercus mongolica pure forest due to oak wilt, and the introduction of exotic species, thus, it is necessary to establish a management plan through continuous monitoring.