• Journal of Ecology and Environment
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• v.36 no.2
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• pp.117-123
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• 2013

This study investigated the impact of the fire disturbance and the pattern of recovery of soil dwelling oribatid mite communities with respect to the resilience from the fire disturbance. Oribatid mites are important decomposer animals of plant debris in soil with the feeding habits of saprophagy and mycophagy. Massive wild fire reduced soil oribatid mite abundance and diversity. The impact varied relative to the intensity of the disturbance. The proportion of the species common to the non-disturbed natural site increased as the time after the disturbance elapsed, which implying some degree of naturalness occurring in reorganization phase of the oribatid mite community. From the sites with different degree of fire impact, we found higher diversity in intermediately disturbed sites than in severely disturbed or non-disturbed site, supporting the intermediate disturbance hypothesis. Also this study showed that with differential degree of disturbance plots, resilience pattern after the disturbance can be explored even with shorter period research relative to the ecological succession of community.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.347-355
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• 2011

Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.233-241
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• 1998

In order to test of intermediate disturbance hypothesis that an intermediate level of disturbance maximize biodiversity and to elucidate the effect of disturbance during the early old-field succession, the response of plant community along an experimental disturbance gradient was investigated in a five-year old-field. Response of plant community along an experimental disturbance gradient was connected with light condition because artificial disturbance gradient had been treat by clipping of plants and removing of litter. Artificial disturbance in five-year old-field plant community retarded rate of succession by increasing invasion and performance of the earlier successional species in the initial and middle stage of disturbance treatment. The species richness in the blocks of intermediate disturbance level showed the peak in early and mid-summer. This result did correspond with the prediction of intermediate disturbance hypothesis.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.207-225
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• 2013

Current ecological stream restoration is focusing on recovery of physical characteristic and ecological functions of individual stream. For effective stream restoration, the relationship between stream environment and riparian flora should be investigated. The purpose of this study is to analyze the relationship between disturbance of hydromorphological structures and naturalized plants ratio in small to mid-sized streams. For the study sites, Gwanpyeong stream, Dongdal stream, and Yongchoo streams were chosen as 'reference stream' while, Gunnam stream, Anchang stream, and Hwa stream were chosen as 'damaged stream'. The hydromorphological structures of streams were evaluated with LAWA and flora of the streams were completely enumerated to calculate naturalized plants ratio. The result showed that there was a significant correlation between the outcome of LAWA and naturalized plants ratio(r=0.675, p<0.01). The result of factor analysis of LAWA identified three factors, 'River front and land use', 'River bed materials and structures', and 'Crossing structure and bar'. Among the factors of hydromorphological structures given by the result of factor analysis, 'river front and land use' and 'bed materials and structures' have statistically significant relationship with naturalized plants ratio($R^2$=0.470, p<0.01). Given this results, quantitative analysis on the relationship between disturbance of hydromorphological structures of streams and naturalized plants ratio could provide some essential information for stream restoration. Also, as this study figured out major factors of hydromorphological structures that affect naturalized plants ratio, it might help monitor ecological states and current problems of small and mid-sized streams.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.677-683
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• 2017

The Korean aquaculture industry was generally began in the 1970s and has gradually increased. Now, the number of households is about 7,068 and the scale of an aquaculture farm is about 248,014 ha; the value of all production in the industry is estimated to be about 1602.2 billion won. The aquaculture industry is very valuable and important for future food resources. However, the aquaculture industry was damaged by several marine ecological disturbance causing organisms. The Ascdiella aspersa colonized on the shell of scallop and then scallops were detached from rope. The patterns of damage in the aquacultures were observed in Tongyeong (oyster), Geojedo (oyster), and Gangneung (sea squirt) in June, 2017, as well as in Tongyeong (oyster) in November, 2017 by SCUBA divers. The species Halichondria bowerbanki, Bugula neritina, Mytilus galloprovincialis, Balanus amphitrite, Ascidiella aspersa, Ciona intestinalis, Didemnum sp, Styela plicata in Tongyeong, M. galloprovincialis, A. aspersa, C. intestinalis, D. vexillum, S. plicata in Geojedo, and M. galloprovincialis in Gangneung were all usually found in their farms. The marine ecological disturbance causing organisms gave rise to a reduced number of aquaculture products.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.6
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• pp.66-78
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• 2003

The purpose of this study was to minimize the forest disturbance around an entry road of a power transmission tower construction site between Taean and Sinsesan, Chungnam. The main study field was classified into existing materials and a GIS, remote sensing analysis, and a field examination. This information was used to identify the most suitable entry road using a degree of green naturality map, eco-naturality map, actual vegetation map, and a forest state map as the existing materials. Also, the study used an normalized difference vegetation index, altitude and slope map in order to make the evaluation materials which used an remote sensing image, and GIS. This data was used to choose an optimum area, and diagnosed the current condition of the vegetation with a field survey of the area. It analyzed vegetation structure, species diversity, the age of trees in a field examination. Subsequently, we proposed four area types based on the analysis results--preservation area, transplantation area, restoration area and development area. As a result, the preservation area was categorized into 8 grades, according to the degree of green naturality, large area of breast diameter at Pinus densiflora community, competition area of Pinus densiflora and Quercus spp. and Quercus spp. community of over 20 years old. A transplantation area established 46 optimum areas according to the GIS analysis and vegetation investigation results. Vegetation restoration plan for disturbance area should be made based on ecological value of existing vegetation to worthwhile area as Quercus spp. mixing forest proposed. The development area selected a ecological worthless place as an artificial forest where Pinus densiflora and Pinus thunbergii growth is poor. This research results suggest that restoration of vegetation will be possible in the real world. Also, ecological restoration guidelines will be made through building and analyzing data base and routine monitoring of transplantation and restoration area.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.95.2-95.2
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• 1999

• 한국생태학회:학술대회논문집
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• 1998.05a
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• pp.96-96
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• 1998

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.279-289
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• 2012

This study conducted a comparative analysis of benthic macroinvertebrate communities in the Fosu and Benya lagoons in Ghana, based on the anthropogenic effect on the two lagoons. Salinity, oxygen, temperature, conductivity, turbidity and pH were measured, invertebrate richness and species densities were determined. The AZTI Marine Biotic Index (AMBI) and multivariate statistics were used to determine the different responses of fauna to pollution. The fauna were categorized into five ecological groups based on the degree of tolerance of the different species to pollution: disturbance-sensitive species; disturbance-indifferent species, disturbance-tolerant species, second-order opportunistic species; and first-order opportunistic species. The Fosu Lagoon supported more pollution tolerant species, whereas the Benya Lagoon had more species that were sensitive to organic enrichment under relatively unpolluted conditions. Chironomus sp., which is adapted to virtually anoxic conditions, was the most abundant in the Fosu Lagoon whereas Nemertea sp. was the most abundant in the Benya Lagoon. The numerical and relative abundance (%) of all 7 taxa in the Fosu Lagoon was 1,359 and 92.35%, respectively. The numerical and relative abundance (%) of all 34 taxa in the Benya Lagoon was 2,459 and 87.52%, respectively. Expectedly, the level of dissolved oxygen in the less saline Fosu Lagoon was higher than that in the more saline Benya Lagoon. The reduced photoperiod and photosynthetic activities of aquatic plants might account for this trend. There is a need to implement comprehensive monitoring and management initiatives for sustaining the ecological health of coastal lagoons in Ghana in order to support the many people that depend upon these ecosystems for their livelihood.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.69-73
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• 2007

The sources and the frequency of disturbances and the responses of shorebirds to disturbances were studied at four roosting sites on Ganghwa Island and Yeongjong Island. The mean frequency of disturbance to roosting shorebirds was 2.7 per hour. Human activities contributed to the disturbance in 65% of all cases. Disturbance frequencies in saltpans were higher than those in the upper tidal zone, fishponds and salt marshes. Response patterns of shorebirds to disturbances were associated with the source of the disturbance. Disturbance caused shorebirds to change their behavior and to reduce roosting time at their roosting sites. Four patterns of responses by roosting shorebirds to disturbance were found, including: (1) leaving the roosts, (2) changing their location within the site, (3) leaving and returning, and (4) remaining in place. In the latter three response patterns, the birds tended to remain in their initial roosting sites, in contrast with the leaving pattern, which involved departing from the roosting area. Factors affecting these response patterns were time from high tide and time of day. When the time from high tide was greater, and the time of day was later, more birds stayed at the roost. The absence of sufficient alternative roosts in the study areas forced the birds to choose between tolerating the current disturbance, or moving to distant roosts.