• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.1
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• pp.79-94
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• 1985

This study was carried out to give basic information about the environmental conservation in Masan District. It included the actual vegetation the degree of human disturbance of vegetation, plant biomass and biomass production. The natural vegetation was nonexistent and the major plant communities of the secondary forest was P. thunbergii-Q. acutissima and Quercus forest. P. thunbergii-Q. acutissima community area was 29.2% of Masan District and the secondary forest and the afforestation area was 48% and 13% of Masan District respectively. The ecological diversity of the plant community was high value in Q. acutissima- P. thunbergii, Q.aliena and Carpinus laxiflora-Q.variabilis communicty. As the investigation of the ecological succession in Masan Forest, P. thunbergii community is edaphic climax and mixed forest will be changed gradually dominant species of Quercus species. It was implied that Genus Quercus hadnever beenso easily taken ever by the Genus Pinus which forms the edaphic climax at vast areas of forest land. In the degree of human disturbance of vegetation, the degree 7 (secondary forest 1) was 52.8% and the green spaces in Masan cover 65%, which nongreen spaces 35 %. Total amount of plant biomass produced from Masan District was estimated to be 160, 470.95 tons. Annual Production of dry matter biomass amounts to be 32,940.64 tons. Estimated amount for O$_2$produced annually from the vegetated area in Masan was 34,856 tons.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.34-39
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• 2006

The land use pattern, water quality and vegetation were investigated in the six tributaries, including Hanggeumcheon and Satancheon of the Namhan hydrosphere, Iksancheon, Jeonjucheon and Gosancheon of the Mankyung hydrosphere as well as Jongeupcheon of the Dongjin hydrosphere. Forest and farmland area were extensive in Hanggeumcheon, Satancheon and Gosancheon. Farmland and livestock area were wide in Iksancheon. Jeonjucheon were occupied with broad urban. Industrial and urban area were extensive in Jongeupcheon. The loading amounts of biochemical oxygen demand (BOD), total nitrogen (T-N), total phosphorus (T-P) of Iksancheon and chemical oxygen demand (COD) of Jeonjucheon were determined to be very high, respectively. The quality of water in Hanggeumcheon, Satancheon and Gosancheon were determined to be good quality. The species diversity was lower in the down stream than in the upper stream except for the Gosancheon. Life form of plane were mostly perennial plane in the upper stream and annual plants in the down stream of rivers. It was estimated that there is high level of disturbance in the down stream of rivers. The quality of water was significantly correlated with farmland and forest area. In conclusion, human impact, such as farmland and housing lot exerted an influence on the disturbance of down stream and the water quality of rivers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.215-231
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• 2020

Forest landscape models (FLMs) can be used to investigate the complex interactions of various ecological processes and patterns, which makes them useful tools to evaluate how environmental and anthropogenic variables can influence forest ecosystems. However, due to the large spatio-temporal scales in FLMs studies, parameterization and validation can be extremely challenging when applying to new study areas. To address this issue, we focused on the parameterization and application of a spatially explicit forest landscape model, LANDIS-II, to Mt. Gyebang, South Korea, with the use of the National Forest Inventory (NFI) and long-term ecological research (LTER) site data. In this study, we present the followings for the biomass succession extension of LANDIS-II: 1) species-specific and spatial parameters estimation for the biomass succession extension of LANDIS-II, 2) calibration, and 3) application and validation for Mt. Gyebang. For the biomass succession extension, we selected 14 tree species, and parameterized ecoregion map, initial community map, species growth characteristics. We produced ecoregion map using elevation, aspect, and topographic wetness index based on digital elevation model. Initial community map was produced based on NFI and sub-alpine survey data. Tree species growth parameters, such as aboveground net primary production and maximum aboveground biomass, were estimated from PnET-II model based on species physiological factors and environmental variables. Literature data were used to estimate species physiological factors, such as FolN, SLWmax, HalfSat, growing temperature, and shade tolerance. For calibration and validation purposes, we compared species-specific aboveground biomass of model outputs and NFI and sub-alpine survey data and calculated coefficient of determination (R²) and root mean square error (RMSE). The final model performed very well, with 0. 98 R² and 8. 9 RMSE. This study can serve as a foundation for the use of FLMs to other applications such as comparing alternative forest management scenarios and natural disturbance effects.

• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.318-335
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• 2007

Floral study and present vegetation survey were conducted at a representative reclaimed wetland located behind the Rural Research Institute at Ansan, Gyeonggi-do. The importance values were calculated from the ground cover and frequency of recorded species within quadrats and detrended canonical correspondence analysis was conducted using environment variables, such as total nitrogen, electric conductivity, available phosphate, nitrate nitrogen and the distance from the inner roads. And basal areas for the trees encroaching on the reclaimed wetland were estimated to take a look at the on-going situation about the succession routes on land. As a result, 46 families and 158 species of plants were recorded and Pragmites communis was found to be a dominant species as the present vegetation. The ordination analysis results showed that species distribution was purposely explained by total nitrogen in soil and its content in nitrate nitrogen. The invasion of Robinia pseudoacacia and Pinus rigida whose basal areas were $22.3m^2$ and $1.6m^2$ respectively, into the interior areas of the reclaimed wetland was found to cause a disturbance making some parts of the wetland into land. The zoning program using water level control and migratory roads is becoming a contributing factor in destroying a wetland, so it's suggested that some adjustments should be needed to take care of it.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.49-56
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• 2007

We placed and monitored 2,137 nest boxes to determine how the size of the entrance hole and the box placement influenced nest box selection by secondary cavity-nesting birds and to derive recommendations for the use of nest boxes for management of cavity-nesting birds in forested environments. A total of 566 pairs of seven bird species used the nest boxes from 1997 to 2006, 562 of which were secondary cavity-nesters. Sympatric tits such as varied tits (Parus varius), great tits (P. major), and marsh tits (P. palustris) were common breeding birds in nest boxes, and showed clear preferences for 4.0 cm, 3.5 cm and 3.0 cm nest holes, respectively. Tree sparrows (Passer montanus) and Eurasian nuthatches (Sitta europaea) preferred 4 cm and 3.5 cm holes, respectively. We did not detect selection for the directional orientation for the entrance hole, but the birds appeared to avoid nest boxes that faced steep or gentle upward slopes and those less than 1.8 m from the ground. These results are probably related to avoidance of disturbance and predation. We suggest that diverse species can be supported by the placement of nest boxes with entrance holes of various sizes and that specific species can be targeted by selecting the hole sizes preferred by those species. To attract secondary cavity-nesters, managers should avoid placing nest boxes close to the ground and facing hills. This study also suggests that careful selection and placement of nest boxes is needed to avoid biases in research using nest boxes.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.157-169
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• 2020

The purpose of this study is to investigate the ecological characteristics and vegetation structures of Eurya japonica in Busan. As a result of the TWINSPAN and DCA analysis, 89 plots of 100㎡ each were divided into 3 communities: Quercus serrata-Pinus densiflora-E. japonica community, Pinus thunbergii-E. japonica community, and P. thunbergii-Camellia japonica community. Community I consisted of the Quercus serrata-Pinus densiflora-E. japonica which was mainly located in the high altitude inland. While Q. serrata and P. densiflora competed in the tree layer, the dominant species of the understory layer was E. japonica. Since Carpinus tschonoskii, one of the climax species, was distributed evenly from shrub to tree layers, it was likely that deciduous oak trees or Carpinus tschonoskii would become dominant species in community I. In community I, E. japonica was found in higher altitude than the other evergreen broad-leaved tree and was expected to maintain their tree vigor even if the vegetation structure is converted into the deciduous forest. Community II, the P. thunbergii-E. japonica community, was predicted to maintain its tree vigor unless there were unexpected disturbance factors. Community III, consisting of P. thunbergii-C. japonica and located in Dongbaek Island, was under artificial management. In community III, P. thunbergii was the only species in the tree layer, while C. japonica was predominant in the understory layer. E. japonica and various evergreen broad-leaved tree species were present in the understory layer and shrub layer, which were unmanaged areas. Therefore, it is expected that unless C. japonica is continuously managed, E. japonica is likely to become the dominant species. There were also various evergreen broad-leaved species, such as Machilus thunbergii and Pittosporum tobira, present in the shrub layer. If the temperature continues to rise, the habitat is expected to become evergreen broad-leaved forests in the future as P. thunbergii community declines. The result of Pearson's correlation coefficient analysis of E. japonica and species appearing in 89 plots showed that 9 species were had a statistically significant relationship (p<0.05). Four species, including P. tobira and Q. dentata, had a positive correlation. Five species had a negative correlation, and C. japonica, which had the same ecological position as E. japonica, showed the most negative correlation at -0.384.

• Journal of Ecology and Environment
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• v.41 no.6
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• pp.152-164
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• 2017

Background: Natural regeneration of seedlings as well as saplings of Korean fir has been significantly impacted by the browsing from the early stages of their development, potentially, by roe deer for the last two to three decades at the study site since late 1980s. This study was carried out to investigate current status of the disturbance in the seedling development of Korean fir (Abies koreana) on Mt. Hallasan, Jeju Island, Korea. Methods: Field survey was carried out during June and August in 2016 to measure the characteristics of study site and understory vegetation by applying systematic sampling to 125 plots of $5m{\times}5m$ quadrat located on eastern slope of the mountain. Correlation and regression analyses were applied to the variables quantified from the data sets using the SAS software. Results: No saplings with their diameters at breast heights smaller than 5.0 cm were found at the study site indicating the serious disturbance in the natural regeneration of Korean fir at the study site. No seedlings with their heights taller than 36.0 cm were found at the study site indicating even more serious disturbance during earlier stage of the natural regeneration of Korean fir at the study site. A total of 616 individuals of the seedlings of Korean fir were found at 54 out of 125 sampling plots. One hundred thirty-eight seedlings (22.4%) out of 616 individual seedlings have the vestiges for being grazed, potentially, by roe deer. Conclusions: Due considerations should be given to the effects of browsing of the seedlings by roe deer to promote the natural regeneration of Korean fir, ultimately to restore Korean fir. It is needed for the managers of the forest to install fences around the forest area. Exclosure experiments as well as enclosure experiments of different densities of browsing should be carried out. In addition, treatment with different densities of Jeju dwarf bamboo should also be included in the experiment on Mt. Hallasan National Park, Jeju Island, Korea.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.267-283
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• 2011

Endangered species designated by The Ministry of Environment in region of Naejangsan National Park were found Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko, Iris koreana Nakai, Cymbidium macrorrhizum Lindl and Vexillabium yakushimensis (Yamam.) F.Maek.(4 taxa). The floristic special plants were recorded to a total of 159 taxa; that is, class I species (91 taxa) were containing as Chloranthus fortunei (A.Gray) Solms, Vicia anguste-pinnata Nakai and Euscaphis japonica (Thunb.) Kanitz, etc, class II species (17 taxa) were Pseudostellaria coreana (Nakai) Ohwi, Dryopteris expansa (C.Presl) Fraser-Jenkins et Jermy and Gymnocarpium dryopteris (L.) Newman, etc, class III species (32 taxa) were containing; Cirsium setidens (Dunn) Nakai, Parasenecio pseudotaimingasa (Nakai) B.U.Oh and Saussurea eriophylla Nakai, etc, class IV species (9 taxa) were Deutzia paniculata Nakai, Carex ligulata Nees and Thuja orientalis L., etc, and class V species (10 taxon) were Orobanche filicicola Nakai, Lycoris chinensis var. sinuolata K.H.Tae & S.T.Ko and Lycoris sanguinea var. koreana (Nakai) T.Koyama, etc. Endemic species of korea were identified 40 taxa such as Broussonetia kazinoki var. humilis Uyeki, Pseudostellaria coreana (Nakai) Ohwi and Silene seoulensis Nakai, etc. Plant species designated as Natural Monument were 2 species that Daphniphyllum macropodum forest(No. 91) and Torreya nucifera forest(No. 153) receive protection. The naturalized plants were identified 30 taxa; Fallopia dumetorum (L.) Holub, Persicaria orientalis (L.) Spach and Rumex crispus L., etc. Among them the ecosystem disturbance wild plants was not discovered.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.188-198
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• 2015

This study was conducted in order to investigate the distribution pattern of weeds and ecological characteristics on the dry field in the Eastern region of Korea. The weed species data were obtained from 12 regions in Gangwon-do and Gyeongsang-do. 150 taxa were recorded from three main distinguished habitats; inside of dry field (IDF), embankment around the end of dry field (EDF), levee slope of dry field (LS). The weed species of three different habitats were IDF 83 taxa, EDF 133 taxa and LS 105 taxa. The species showing higher rNCD value was Portulaca oleracea in IDF, Digitaria sanguinalis in EDF and Humulus japonicus in LS. Compositae was dominant family followed by Gramineae, Polygonaceae and Leguminosae. Life form was distinguished as Th-R5-D4-e and three different habitats showed the same results. Disturbance index was analysed as IDF 83.1%, EDF 68.4%, and LS 62.9%. Naturalized rate was analysed as IDF 28.9%, EDF 22.6%, and LS 20.0%. These results indicate that the weeding management, land use intensity, and human interference effect on the distribution index and naturalized rate of weed.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.431-440
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• 2008

Turbid water or suspended sediment is associated with negative effects on aquatic organisms; fish, aquatic invertebrate, and periphyton. Effects of turbid water on fish differ depending on their developmental stage and a level of turbidity. Low turbid water may cause feeding and predation rates, reaction distance, and avoidance in fish, and it could make fish to die under high turbidity and long period. Therefore, it is very important to find out how turbid water or suspended sediment can affect fish in domestic watersheds. The objectives of this study were 1) to introduce international case studies and their standards to deal with suspended sediment, 2) to determine acute toxicity in 4 major freshwater fishes, and 3) to determine in relation to adverse effect of macroinvertebrates and fish. Impacts of turbid water on fish can be categorized into direct and indirect effects, and some factors such as duration and frequency of exposure, toxicity, temperature, life stage of fish, size of particle, time of occurrence, availability of and access to refugia, etc, play important role to decide magnitude of effect. A review of turbidity standard in USA, Canada, and Europe indicated that each standard varied with natural condition, and Alaska allowed liberal increase of turbidity over natural conditions in streams. Even though acute toxicity with four different species did not show any fatal effect, it should be considered to conduct a chronic test (long-term) for more detailed assessment. Compared to the control, dominance index of macroinvertebrates was greater in the turbid site, whereas biotic index, species diversity index, species richness index, and ecological score were smaller in the turbid site. According to histopathological analysis with gills of macroinvertebrate and fishes, morphological and physiological modification of gills due to suspended sediments can cause disturbance of respiration, excretion and secretion. In conclusion, in order to maintain good and healthy aquatic ecosystem, it is the best to minimize or prevent impact by occurrence of turbid water in stream and reservoir. We must make every effort to maintain and manage healthy aquatic ecosystem with additional investigation using various assessment tools and periodic biomonitoring of fish.