• Title/Summary/Keyword: ECOLOGICAL DISTURBANCE

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Analysis of Weed Vegetation in Vicinity of Abandoned Mines (폐광산 주변에 발생하는 잡초 식생의 특징)

  • Hong, Sun-Hee;Lee, Yong-Ho;Na, Chae-Sun;Kim, Dae-Yeon;Kim, Jeong-Gyu;Kang, Byeung-Hoa;Shim, Sang-In
    • Korean Journal of Weed Science
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    • v.30 no.1
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    • pp.17-24
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    • 2010
  • Field study to find appropriate species for phytoremediation and phytomonitoring with higher plants was carried out at four abandoned metalliferous mines. In order to know the tolerant degree of plant resources collected at heavy metal polluted sites, soil and plants were sampled at same sites and metal concentrations were determined. Most serious heavy metal polluted in the sites was As that showed range from 29.1 to 1372.2 mg $kg^{-1}$ in investigated area. The dominant species were Oenothera biennis, Commelina communis, Persicaria senticosa, Conyza annuus, Artemisia princeps, and Erigeron canadensis. These species were predominant species that were proliferated in any survey area. Compared with other sites, vegetational characteristics of Dal-Seong, a mine site abandoned early in 1973, showed higher diversity index and lower dominance index. Distributions of weed species according to life cycle indicated that the proportions of perennial plants were lowered in every investigated site. Although the polluted areas were distant from each other, similarity indices among these vegetation were relatively similar. These results means the vegetations of abandoned mine areas were beginning stage of vegetational succession, and the vegetations were adversely affected by disturbance with heavy-metals and lack of water in soil.

A Study on the Use Impact on the Trail in Gwanak Mountain, Korea (관악산 등산로 이용에 따른 영향에 관한 연구)

  • Yoo, Ki-Joon
    • Korean Journal of Environment and Ecology
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    • v.25 no.1
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    • pp.111-117
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    • 2011
  • The purpose of this study is to establish trail use impact indicators, and evaluate the degree of use impact based on the understanding of the causality among the impacts on the spot. Theoretical reviews developed three indicators in terms of three ecological impacts, four physical impacts, and five sociological impacts, respectively. With this indicators, observation and questionnaire survey were employed on Gwanak Mountain Trail to measure the levels of impacts forementioned. As for the ecological impact, Some loss of ground cover vegetation was reveled near the trail due to trail use, however the level of disturbance by the naturalized and exotic plants was insignificant. Physical impacts such as soil hardness, enlargement of trail width were found intensified. The result of measuring sociological impacts showed visitors had expected higher level of crowding and encounters before their visit, therefore overall satisfaction level was positive, despite higher awareness level of actual crowding. Intensified continuing use of the trail is aggravating ecological and physical impacts on Gwanak Mountain trail, because of its location in a metropolitan area. Sociological impacts seem favorable at present, however if ecological and physical impacts were deteriorated, sociological impacts would also be affected. To maintain the quality level of use experience, managerial efforts to improve climbing culture as well as ecological and physical environment such as restoration of damaged areas are needed.

Criteria selection of urban forestry sustainability evaluation in the view of ecology (생태적 측면에서의 도시림 지속성 평가 지표 선정)

  • Lee, Soo-Dong;Kim, Dong-Pil;Choi, Song-Hyun;Oh, Jung-Hak;Hong, Suk-Hwan
    • Korean Journal of Environment and Ecology
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    • v.28 no.4
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    • pp.472-483
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    • 2014
  • Major cities have strengthened their efforts to improve the environmental function of the urban forest through aspects of quantity and quality. Yet, it is difficult to propose both long-term improvement and management policy direction continuously due to a lack of evaluating method that social needs could be reflected. After all, effective strengthening of the function of an urban forest, composed of social and biotic environments, is essential to create evaluation criteria. Such data reflects a quantity variation and identifies the distribution and habitation of biotic sources as well. An assessment of utilization possibilities presents such values as a green connectivity, an ecological healthiness, and usage and access opportunities. Consequently, this research was executed to create an urban forest sustainability index that proposes a management and policy direction based on the evaluation of quantity and quality aspects. This study was processed by the following steps: a degree of importance of ecological aspect, a sub-classification index choice, and an examination of adequacy. This research was conducted from premises that urban forest had another functions comparisons to a natural forest. As a result, a criteria of sustainability should be considered to evaluate an ecological aspect, as well as the social and management aspects regarding human disturbance. This research is designed to develop an evaluation index for ecological aspect. In order to evaluate the ecological healthiness of an urban forest, a vegetation index considers aspects of related rarity, damage possibility, naturalness, area, and diversity. In a wildbird index-related study, forest duration and area were selected. Finally, a variance analysis is presented, inclusive of stability, naturalness, diversity, potentiality, and possibility of wildlife inhabitation, which is indicative of an urban forest sustainability index.

An Analysis of Hydrological and Ecological Characteristics of River Wetlands -Case Study of Wangjin District in Geumgang River- (하천습지의 수문생태적 특성 분석 -금강 왕진지구를 사례로-)

  • SeungWon Hong;MiOk Park;BonHak Koo
    • Journal of Wetlands Research
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    • v.25 no.4
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    • pp.315-325
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    • 2023
  • This study analyzed the disturbance process of river wetlands based on modern and contemporary maps and aerial photographs, and analyzed land cover and NDVI changes in the hydro-ecological impact zone around the Wangjin District. A stable sandbar was formed near Wangjinnaru and was naturally connected to the agricultural land within inland, but after the sandbar and river wetland were destroyed due to heavy floods, embankment construction, land readjustment, and comprehensive river management, artificial replaced wetlands and ecological parks were created, and sandbars in the form of river island were restored again. The change in land cover in the hydro-ecological impact zone showed that rice paddies and fields in agricultural areas decreased from 36.3% in 2013 to 22.9% in 2022, with the largest change in area to 814,476m2. It was confirmed that the land cover was undergoing vegetation over time. Since the vegetation condition is good, a healthy food chain is formed in the waterfront ecosystem, which can be expected to be biodiversity-positive. Summarizing seasonal changes in the vegetation index, the overall change in the vegetation index was the largest in spring (March), followed by summer (June), and the change in autumn (September) was the smallest except for water. By land use, the overall vegetation index (NDVI) increased, including 39.1% improvement in alternative wetlands, 38.2% improvement in load, 44.3% improvement in ecological parks, 35.6% improvement in agricultural areas, and -8.1% decrease in water.

Landscape Scale Ecosystem Assessment Modelling Using Spatial Pattern Analysis of GIS: A Case Study of Yongin, Korea (GIS 공간유형분석 모형을 이용한 경관 규모 생태계의 평가기법)

  • 손학기;김원주;박종화
    • Spatial Information Research
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    • v.8 no.2
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    • pp.233-241
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    • 2000
  • The objective of this study were to develop landscape scale ecosystem assessment model, and apply the model for the assessment of the state and change of ecosystem of the study area, Yongin, Korea. Since natural ecosystem of the site has been deteriorated significantly during recent extensive residential development, it is essential to correctly assess ecosystem of the study site. Traditional ecosystem assessment mainly utilizing intensive field survey requires high cost, but the outcome rarely represents spatial pattern of the regional ecosystems. Ecosystem assesment of landscape scale based on landscape ecology can resolve most of the shortfalls of the traditional approach. The research method can be summarized as follows. First, extensive literature review on such topics as spatial pattern of ecosystem, ecosystem assessment of landscape scale, ecological analysis was carried out. Second, a model for the ecosystem assessment of landscape scale emphasizing spatial pattern of ecosystem was developed. This model evaluates three indicators; ecological integrity and biological diversity, watershed integrity, and landscape resilience of 11 watersheds in the study area. Finally, ecological assessment utilizing two sets of indicators, enhancement of and disturbance of ecosystem stability, was carried out. This assessment method is based on Environmental Monitoring and Assessment Program´s Landscape component(EMAP-L) of EPA(1994). The results of this study are as follows. First, the ecosystem assessment of landscape scale of the study area of Yongin, Korea, showed that escosystems of Tanchun01 and Chungmichun01 watersheds had the worst state in the study site in 1991. On the other hand, the ecosystems of Jinwechun01, Kyunganchun02, and Bokhachun01 watersheds had the most stable ecosystem in 1991. Second, ecosystems of Tanchun01, Shingal reservoir, and Kyunganchun01 watersheds were evaluated to be the worst state in the study site in 1996. And, ecosystems of Jinwechun01 and Gosam reservoir watersheds had the most stable ecosystem. Third, ecosystem of Tanchun01 watershed which incudes Suji residential development project site changed the most drastically between 1991 and 1996. The ecosystem of the watershed the most drastically deteriorated due to it´s proximity to Seoul and Bundang new town.

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Landscape Structure in the Greenbelt Zone around the Seoul, the Metropolis of Korea

  • Lee, Chang-Seok;Hong, Sun-Kee;Moon, Jeong-Suk;You, Young-Han
    • The Korean Journal of Ecology
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    • v.24 no.6
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    • pp.385-394
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    • 2001
  • An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

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The Basic Theories for Restoration of Fragmented Habitats (파편화된 서식처 복원을 위한 기초이론 고찰)

  • Kim, Myoung-Soo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.52-61
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    • 2001
  • At least, there are intense pressures on the natural habitats from various disturbance, including urbanization, extension of industrial area, and road construction. These human land use result in fragmentation of landscape and natural habitat. The ecological consequences of habitat fragmentation include the direct effects of habitat loss and the indirect effects of reduced inter-patch dispersal. The decline of biological diversity has been rapidly declined by the habitat loss and fragmentation. Conservation strategists should consider not only the habitat amount of that must be preserved, but also the spatial configuration of habitat across the landscape. But, the paucity of available data for most species forces landscape ecologists to develop the concept, model, and theory. The developed theories are often misused in academic papers and practical applications. The development history, presumption of concept, model, theory is ignored. This tendency have leaded to failure of landscape restoration and the use of theory in conservation practice have come under increasing attacks. This paper will highlight the ecological theory that have proven the most influential in landscape ecology, restoration and conservation : the theory of island biogeography, the theory of nested subset analysis, minimum viable population(MVP), the theory of metapopulation dynamics. And, it find the problem and usefulness of four theory in application to real world. Consequently, the understanding of theoretical implication about landscape ecological theory is required. We must carefully apply the theory after examining the problem and availability of various theory because of no existence of only one general theory.

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The Process of River Landscape for 10years in Tan-chun Ecological Landscape Reserve (탄천 생태경관보전지역에서의 10년간 하천경관 형성과정)

  • Choi, Jung-Kwon;Choi, Mi-Kyoung;Lee, Ga-Yeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.6
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    • pp.107-115
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    • 2017
  • This study illustrated the process of bar structure and vegetation coverage to understand historical changes of riverbed and suppose adaptive management in Tan-chun ecological landscape reserve. The study site that lower reach of the Tan-chun are known as habitats of migratory bird and aquatic species with dynamic riverbed. Aerial photos from 2006 to 2016 and surveyed vegetation data in 2006 and 2016 were used by analysis of landscape changes and comparison of vegetation coverage. Study area is classified into 3 sites (A: straight site, B: meandering site, C: meandering and junction with Yangjae-cheon). The result showed that bar area of A and C sites gradually increased, B site decreased during 10 years. Also, ratio of bar area to vegetation coverage and level of vegetation coverage increased in all sites during 10 years. All sites seem to have experienced the terrestrialization with time. On the other hand, ratio of annual vegetation increased and ratio of perennial vegetation decreased in C site in 2016 compare to 2006. Because area of Japanese Hops (Humulus japonicas) as one type of annual vegetation increased, other vegetation could not grow up by its powerful expandability. It is time to make active adaptive management based on not only continuos monitoring but also revaluation of river conditions in order to enhance habitat quality and quantity in Tan-chun ecological landscape reserve.

Ecological Responses of Plants to Climate Change: Research Trends and Its Applicability in Korea (기후변화에 대한 식물의 생태적 반응: 연구동향과 한국에서의 적용가능성)

  • Kang, Hyesoon
    • Korean Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.319-331
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    • 2013
  • Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

Estimation of Characteristic of the Soil Physical using the Pipe Type Soil Sampler (원관형 토양샘플러를 이용한 토양물리특성 추정)

  • Ryu, Ji Hyun;Jung, Myung Kwan;Park, Seung Ki
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.1
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    • pp.95-104
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    • 2020
  • The purpose of this study is to develop a pipe type soil sampler that can easily collect soil cross section servey and soil samples to conduct ecological environment surveys while minimizing ecological disturbance in the area subject to soil survey. Furthermore, this study develop the exponential type estimation specific weight formula (ESWF) that uses pipe type soil sampler to easily carry out soil cross section survey and soil sample while estimating the specific weight of the area using water content and soil sample length variation ratio (SLVRs) and to obtain apparent specific gravity, hardness, and max. porosity which are used as growth of corps and ecological environment index. The calibration results of ESWF showed a high degree of significance, with NSE for actual specific weight (γ0) and calibration estimation specific weight (γec) 0.95, R2 for 0.954, and RMSE for 0.051. The verification results of ESWF showed a high significance, with NSE for actual specific weight (γ0) and verification estimation specific weight (γev) 0.881, R2 for 0.978, and RMSE for 0.055.