• 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.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1523-1536
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• 2014

Restoration is the process of reducing or reversing damage to an ecosystem so that it can function in its original manner. However, many restoration programs do not achieve this. In the Nakdong Estuary, the largest migratory nesting site in the center of the East Asian-Australasian flyway, an estuarine barrage was constructed in the 1980s that required site restoration following its completion in 1987 and the expansion of several large industrial complexes(Noksan and Jangrim) and a residential development(Myeongji). The goal of the restoration was to restore the function of the wetland to its pre-disturbance state. To achieve this, a restoration program was designed consisting of three stages. The first stage(1993-1995), saw the construction of three artificial wetlands(Shinhori, Daemadeung, and Eulsuk), the second(2003-2005) involved the dredging and returning of farmed lands to their natural state, and the third(2008-2012) focused on the rehabilitation and vegetation development of the wetlands. However, the project has not achieved all of the desired goals, and it is an example of the lapses in ecological restoration following anthropogenic disturbance. Issues that resulted in an incomplete restoration included the timing of the stages, noncompliance with the restoration plan, not directly monitoring the restoration or continuing the monitoring following completion of the development project, and the political subversion of the restoration plan. For the success of the restoration plan, it is necessary to avoid mistakes such as inconsistent monitoring, unequal levels of stakeholder involvement, and political interference.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.368-378
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• 2005

Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.189-201
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• 1995

In order to clarify regeneration processes and mechanisms of the disturbed Pinus densiflora forest, responses of Pinus densiflora to gap formed by disturbance were analysed by growth of saplings and mature and growth equations were obtained from branch growth of mature trees and height growth of saplings, and age distribution of saplings and young trees recruited within gap was analysed in relation to gap age. Height growth of saplings within gaps was accelerated after gap formation. Such abrupt increases of growth of saplings after the gap formation might be resulted in the difference of growth of saplings between gap and non-gap areas. In fact, height and diameter of saplings in the central part of gap were larger than those of saplings in marginal parts of gap and non-gap area. However, density of saplings was not different in both parts. In addition, growth of annual rings of mature trees bordering on gap also increased after gap formation. Branch growth of mature trees bodering on gap was 6.3 - 6.5 cm /year and the mean radius of gaps created by death of only one canopy tree was about 3 m. Therefore, for those gaps to be closed by branch growth it will take 46 years. Growth of saplings within gap showed exponential equation. Fifty years will be required for the saplings to enter the forest canopy by the exponential growth equation. Therefore, gap created by only one tree might be closed by branch growth of surrounding canopy trees in advance of being done by height growth of saplings. But gaps created by death of trees more than 2 will be closed by the growth of saplings. Among the regenerating saplings and young trees within gaps, individuals established in advance of gap formation were more than those established after the gap formation. From these results, it was assumed that the disturbed Pinus densiflora forests in these sites were regenerated by height growth of saplings recruited in advance of gap formation.

• Journal of Wetlands Research
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• v.21 no.4
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• pp.290-297
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• 2019

The estuary is a transition zone where fresh water and salt water meet because the stream is connected to the open sea area. So estuaries have very high biodiversity and form a unique ecosystem. However, before the recognition of the ecological value of the estuaries, various damage and disturbances have been occurred so countermeasures are needed. The river master plan is acting as a disturbance factor. However, the river master plan has the public object such as water disaster defense, river function improvement, and national water resources management. Therefore, it is necessary to study the ways in which the opposite relationship of development and ecosystem protection coexist. In this study, the concept of environmental windows were used to estimate the low impact development duration. We expected that proposed method for low impact development duration estimation can be used as a basis and basic data to protected the ecosystem from development project and disturbance in the future.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.63-74
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• 2023

Background: Comparing with the several types of infrastructures, linear infrastructures are known to facilitate the spread of undesirable species in ecosystems. Recently, some new man-made habitats (e.g., gravel pads of the high-voltage towers, solid wastes and sewage habitats) were established along the Deltaic Mediterranean coast of Egypt as a result of the construction of the E-W coastal international highway. The current study evaluates the floristic composition associated with the pads of high-voltage towers that had been constructed for stabilizing the power line towers in the North Nile Delta. Plant cover was measured for 22 randomly stand. Results: Eighty-four species were recorded, of which 35 are perennials (41.6%), 2 biennials (2.3%) and 47 annuals (56.0%) belonging to 23 families. The largest families were Asteraceae (16 species), Poaceae (15 species), Chenopodiaceae (12 species), and Fabaceae (7 species). Ten aliens (10.7%) out of the 84 species were recorded. Therophytes have the highest percentage (58%), followed by hemicryptophytes (14%), chamaephytes (11%). Six vegetation groups were recognized in the study area after the application of two way indicator species analysis (TWINSPAN), Arthrocnemum macrostachyum, Phragmites australis, and Mesembryanthemum nodiflorum have the highest presence percentage. Both of Salsola cyclophylla and Solanum villosum were recorded for the first time in North Nile Delta. Natural habitat had the highest α-diversity, but the lowest β-diversity (4.9, 15.4), while gravel pads had the reverse (2.7, 30.8). Some species which are native to the desert habitats (e.g., Rumex pictus, Salsola kali, and Carthamus tenuis) were able to invade the North Nile Delta. Conclusions: Habitat of gravel pads is an expressing form about the intense of disturbance in Deltaic Mediterranean coast of Egypt. More of efforts should be carried out to avoid more human disturbances that creating as ruderal habitats which open the gate to invasive species in the flora of North Nile Delta.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.353-361
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• 2011

This study was conducted to examine the effects of sedimentation caused by highland agriculture on benthic macroinvertbrate assemblages in upper Song Stream from 2006 to 2009. The mean concentrations of water quality parameters (pH, DO, EC, TDS, TN, and TP) were gradually increasing toward downstream but ORP was decreased. Furthermore, biological habitats at lower reaches were more homogeneous and unstable due to sand deposition than those at upper sites. A total 106 species of benthic macroinvertbrates in 47 families, 11 orders, 6 classes, and 5 phyla were identified during whole field surveys. Song Stream showed great declines of overall biological attributes along its longitudinal gradients, particularly in taxa richness and abundance. Of all functional groups scrapers and clingers were most affected against the degradation of habitat quality, whereas collector-gatherers and burrowers showed the opposite case. It was found that such results had close correlations with water quality parameters and substrate composition which played an important role in structuring macroinvertebrate communities. In conclusion, this study represents that disturbance caused by highland agricultural activities had negative effects on benthic macroinvertebrate communities by leading to sand deposition at adjacent stream ecosystems.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.511-524
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• 2017

This study was carried out for the purpose of creating a restoration plan to improve the ecological quality of the Changwon and Nam streams. Based upon the results of comprehensive diagnostic assessment, restoration priority was given to the upstream reach, where conservation status is relatively superior. Restoration level was usually determined to practice active restoration as conservation, and the states of both Changwon and Nam streams were not so good. Restoration plans, by reach, were classified into "upstream", "midstream", and "downstream" were suggested in both terms of horizontal section frame and vegetation-based on the result of diagnostic assessment and the reference information. "Upstream", "mid-stream" and the "downstream" of Changwon and Nam streams were classified into "small-gravel- mountainous", "small-sand-plain", and "small-clay-plain streams" respectively (based on scale, and substrate and slope of river bed). The spatial arrangement of vegetation was laid out in diagram form by reflecting micro-topography and the water level of the horizontal section of river. Information regarding species composition was recommended as dominant species, which appear frequently in three vegetation zones composed of herbaceous plants, shrubs and trees and sub-tree- dominated zones divided by reflecting disturbance regime, depending on position on the horizontal section of river. Moreover, there have been prepared not only plans to improve the terrestrial ecosystems around the streams but also plans to create ecological networks, which can serve to improve the ecologic quality of the whole regional environment by serving to connect streams and terrestrial ecosystems, a process probably necessary and definitely recommended to realize true (genuine) restoration. Plans for ecological parks and networks were prepared by mimicking the species composition of Alnus japanica community, Zelkova serrata community, Carpinus laxiflora community, Quercus aliena community, and Q. serrata community.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.275-286
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• 2019

In order to prevent local extinction of organisms and to preserve biodiversity, it is important to ensure connectivity between habitats. Even if the habitat is exposed to various disturbance factors, it is possible to avoid or respond to disturbances if they are linked to other habitats. Habitat connectivity can be assessed from a variety of perspectives, but the importance of functional connectivity based on species movement has been emphasized in recent years due to the development of computational capabilities and related software. Among them, Circuitscape, which is a connectivity evaluation tool, has an advantage it can provide detailed reference data for the city planning because it maps ecological flows on individual grid based on circuit theory. Therefore, in this study, the functional connectivity of Suwon was evaluated by applying Circuitscape and then, the ecological corridor to be conserved and supplemented was suggested based on it. The results of this study are expected to effectively complement the methodology related ecological corridor/axis, which was previously provided only in the form of a diagram, and to be effective in management of development project and urban planning.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.441-448
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• 2008

The purpose of this study was to analyze chemical water quality, fish trophic guilds, tolerance indicators, and fish community conditions in the Gap Stream and to compare the stream conditions between the unimpacted site and impacted site. This study was conducted in the physically stable season (May 2008) to minimize physical impacts such as flow and hydrological disturbance, and applied the study in the Gap Stream with two sites of unimpacted upstream site (Unim-S), mainly surrounded by forested area and impacted site (Im-S), influenced by the wastewater disposal plants and industrial complex in the urban region. Chemical data analysis showed that the degree of organic matter pollution, based on BOD, and COD, was $2{\sim}3$ fold greater in the Im-S than the Unim-S, and that TP, as eutrophication indicators, was 4.7 fold greater in the Im-S. Also, $NH_3-N$ was in 8.2 fold greater in the Im-S ($6.25\;mg\;L^{-1}$) than the Unim-S ($0.76\;mg\;L^{-1}$), indicating a massive influence of wastewater from the disposal plant. Similar results were found in other chemical parameters. Thus, chemical impacts in the Im-S were evident, compared to the unimpacted site. Evaluations of tolerant indicator species indicated that sensitive species were dominant in the Unim-S (23.9%) and tolerant species were dominant (97.8%) in the Im-S. Condition factor (CF) was averaged 0.95 ($0.68{\sim}1.18$) in the Unim-S and 1.08 ($0.93{\sim}1.22$) in the Im-S. Fish community in the Unim-S and Im-S was categorized as Zacco-community and Hemibarbus-community, respectively, and the community diversity index (H') was significantly (p<0.05) higher in the Unim-S (0.810) than the Im-S (0.466). Overall, our results suggest that the comparison approach of various chemical and ecological indicators provide important information in identifying multiple stressors in the stream ecosystems.