• Title/Summary/Keyword: evaluation to disturbed ecosystem

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A Study on the Disturbance and the Rehabilitation of Stream by Using Evaluation of Ichthyofauna to Disturbed Ecosystem (어류상 평가를 활용한 하천 생태계의 교란 및 회복 유형 고찰)

  • Lee, Seung-Hwi;Yang, Dae-Chang
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.242-254
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    • 2010
  • Streams changed by artificial factor those support positive functions but also negative function to humanbeing. Time and pathway exceed the lost of structure and negative function appearing as disturbance. Therefore, it is desirable to prepare right situation to break of a vicious circle. Stream ecology was evaluated with using ichthyofauna during three years at the three disturbed sites and reference sites in Nakdong River. Forty-one species belonging three orders and ten families were identified in six surveying sites of Nakdong River during 2007~2009. Korean endemic species (14 species, 34.1%) and alien (3 species, 7.3%) were identified in Nakdong River ichthyofauna. Species number, species diversity, ecosystem structure and habitat variability of ecosystem were applied to evaluate stream ecosystem. In view of three year comprehended data at six sites; numeric instability appeared Andong Dam and Naeseongcheon sites worse than Gamcheon and reference site, otherwise more numeric diversity appeared Gamcheon and reference site than Andong Dam and Naeseongcheon. As a result of integration, sand stream including downstream of Andong dam, Naeseongcheon and Gamcheon has been having more diversified biodiversity and habitat diversity than those in the pebble stream.

Habitat Potential Evaluation Using Maxent Model - Focused on Riparian Distance, Stream Order and Land Use - (Maxent 모형을 이용한 서식지 잠재력 평가 - 하천으로부터의 거리, 하천의 차수, 토지이용을 중심으로-)

  • Lee, Dong-Kun;Kim, Ho-Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.6
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    • pp.161-172
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    • 2010
  • As the interest on biodiversity has increased around the world, researches about evaluating potential for habitat are also increasing to find and comprehend the valuable habitats. This study focus on comprehending the significance of stream in evaluating habitat's potential. The purpose of this study is to evaluate habitat potential with applying stream as a main variable, and to comprehend the relationship between the variables and habitat potential. Basin is a unit that has hydrological properties and dynamic interaction with ecosystem. Especially, biodiversity and suitability of habitat in basin area has direct correlation with stream. Existing studies also are proposing for habitat potential evaluation in basin unit, they applied forest, slope and road as main variables. Despite stream is considered the most important factor in basin area, researchers haven't applied stream as a main variable. Therefore, in this study, three variables that can demonstrate hydrological properties are selected, which are, riparian distance, stream order and land use disturbance, and evaluate habitat potential. Habitat potential is analyzed by using Maxent (Maximum entropy model), and vertebrate's presence data is used as dependent variables and stream order map and land cover map is used as base data of independent variables. As a result of analysis, habitat potential is higher at riparian and upstream area, and lower at frequently disturbed area. Result indicates that adjacent to stream, upstream, and less disturbed area is the habitat that vertebrate prefer. In particular, mammals prefer adjacent area of stream and forest and reptiles prefer upriver area. Birds prefer adjacent area of stream and midstream and amphibians prefer adjacent area of stream and upriver. The result of this research could help to establish habitat conservation strategy around basin unit in the future.

Evaluation of the effects of the river restoration in Hwangji Stream, the upstream reach of the Nakdong River

  • Bong Soon Lim;Jaewon Seol;Chang Seok Lee
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.85-95
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    • 2024
  • Background: In Korea, riparian zones and some floodplains have been converted into agricultural fields and urban areas. However, there are essential for maintaining biodiversity, as they are important ecological spaces. There are also very important spaces for humanity, as they perform various ecosystem services in a changing environment including climate change. Due to the importance of rivers, river restoration projects have been promoted for a long time, but their achievement has been insignificant. Development should be pursued by thoroughly evaluating the success of the restoration project. Ecological restoration is to accelerate succession, a process that a disturbed ecosystem recovers itself, with human assistance. Ecological restoration can be a test bed for testing ecological theories in the field. In this respect, ecological restoration should go beyond a 'simple landscaping exercise' and apply ecological models and theories in restoration practice. Results: The cross-section of the restored stream is far from natural rivers due to its steep slope and artificial material. The vegetation profiles of the restored streams did not reflect the flooding regime of the river. The species composition of the vegetation in the restored stream showed a significant difference from that of the reference stream, and was also different from that of an unrestored urban stream. Although species richness was high and the proportion of exotic species was low in the restored stream, the effect was offset by the high proportion of gardening and landscaping plants or obligate terrestrial plants. Conclusions: Based on both the morphological and ecological characteristics of the river, the restoration effect in the restored stream was evaluated to be very low. In order to solve the problems, a systematic adaptive management plan is urgently required. Furthermore, it is necessary to institutionalize the evaluation of restoration effects for the development of river restoration projects in the future.

Development and Application of Participatory Ecological Restoration Program for BaigDooDaeGahn (백두대간 생태 복원을 위한 시민참여 프로그램 개발과 적용)

  • Kim, Chan-Kook;Ahn, Tong-Mahn;Kim, In-Ho;Lee, Jae-Young;Kim, Sung-Jin;Chae, Hye-Sung;Lee, Young;Lee, Jae-Won;Kim, Min-Woo;Shin, Min-Jong;Park, Hyo-In;Cho, Kyung-Jun
    • Hwankyungkyoyuk
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    • v.23 no.2
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    • pp.1-15
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    • 2010
  • Ecological restoration aims to reverse the degradation of ecosystems that occurred as humans have affected landscapes. This study was conducted in part of a larger project to develop participatory ecological restoration procedures for disturbed areas in Baigdoodaegahn which is a major mountain range in the Korean Peninsula. The case of alpine farmland at Kangwon-do was selected to apply the theoretical framework of participatory restoration since the nutrient contents in alpine solid under vegetable cultivation degrade water quality in the watershed while farmers in the region are economically struggling due to imports of vegetables from China. The reciprocal model of restoration was applied to cope with interactions between human and ecosystem needs in ecological restoration. A series of environmental education and eco-tourism programs were developed and incorporated into the participatory restoration project to rebuild social-cultural aspects of the community as well as to restore the biophysically disturbed area while meeting both ecological needs and human needs. This study suggests that participatory projects will be more successful when experts support the local residents and citizens in restoration process, when leadership are developed through social learning, and when ecological, financial and social factors of restoration are integratedly considered.

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The Comparative Evaluation of Plant Species Diversity in Forest Ecosystems of Namsan and Kwangneung (남산(南山) 및 광릉(光陵) 산림생태계(山林生態系)의 식물(植物) 종다양성(種多樣性)의 비교 (比較) 평가(評價))

  • Kim, Ji Hong;Lee, Byung Cheon;Lee, You Mi
    • Journal of Korean Society of Forest Science
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    • v.85 no.4
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    • pp.605-618
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    • 1996
  • Namsan area supposed to be a disturbed ecosystem and Kwangneung area considered to be a natural ecosystem were selected for the study. On the basis of the plant species composition, the study was planned to examine structural plant species diversity so as to provide basic ecological information to restore more stable and healthy ecosystem for Namsan. The stratified sample plot method was employed for collecting vegetation data, establishing $20m{\times}20m$ square plots for overstory trees, $4m{\times}4m$ plots for mid-story woody plants, and $1m{\times}1m$ plots for ground vegetation. The herbaceous plants were periodically investigated by taking into account for seasonal(spring, summer, and autumn) variation in presence. Ecological attributes were evaluated through analyzing species composition, species diversity, life forms, interspecies association, and growing habitat for various forest types, vertical layers, life forms, and seasonal variation. Even though the species diversity index of canopy trees in the deciduous forest of Namsan was estimated higher than that of the natural forest of Kwangneung, overall species diversity of plants in Kwangneung area was greater than that in Namsan area. Herbaceous plants presented in Kwangneung but not in Namsan were Aconitum pseudo-proliferum, Botrychium virginianum, Dryopteris tokyoensis, Scutellaria insignis, Tricyrtis dilatata, and Viola kamibayashii, most of them were endemic species of Kwangneung. Elaeagnus umbellata, and Prunes padus var. seoulensis were found only in Namsan. Such species typically composed of the natural deciduous forest as Acer mono, Acer triflorum, Carpinus laxiflora, Cornus controversa, Fraxinus mandshurica, and Phellodendron amurertse were limited growing in a small size of area in Namsan. The future project should be made for encouraging the growth and expansion of the distribution of such species to restore biodiversity in Namsan area.

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Comparison of automatic and manual chamber methods for measuring soil respiration in a temperate broad-leaved forest

  • Lee, Jae-Seok
    • Journal of Ecology and Environment
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    • v.42 no.4
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    • pp.272-277
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    • 2018
  • Background: Studying the ecosystem carbon cycle requires analysis of interrelationships between soil respiration (Rs) and the environment to evaluate the balance. Various methods and instruments have been used to measure Rs. The closed chamber method, which is currently widely used to determine Rs, creates a closed space on the soil surface, measures $CO_2$ concentration in the inner space, and calculates Rs from the increase. Accordingly, the method is divided into automatic or manual chamber methods (ACM and MCM, respectively). However, errors of these methods and differences in instruments are unclear. Therefore, we evaluated the characteristics and difference of Rs values calculated using both methods with actual data. Results: Both methods determined seasonal variation patterns of Rs, reflecting overall changes in soil temperature (Ts). ACM clearly showed detailed changes in Rs, but MCM did not, because such small changes are unknown as Rs values are collected monthly. Additionally, Rs measured using MCM was higher than that using ACM and differed depending on measured plots, but showed similar tendencies with all measurement times and plots. Contrastingly, MCM Rs values in August for plot 4 were very high compared with ACM Rs values because of soil disturbances that easily occur during MCM measurements. Comparing Rs values calculated using monthly means with those calculated using MCM, the ACM calculated values for monthly averages were higher or lower than those of similar measurement times using the MCM. The difference between the ACM and MCM was attributed to greater or lesser differences. These Rs values estimated the carbon released into the atmosphere during measurement periods to be approximately 57% higher with MCM than with ACM, at 5.1 and $7.9C\;ton\;ha^{-1}$, respectively. Conclusion: ACM calculated average values based on various Rs values as high and low for measurement periods, but the MCM produced only specific values for measurement times as representative values. Therefore, MCM may exhibit large errors in selection differences during Rs measurements. Therefore, to reduce this error using MCM, the time and frequency of measurement should be set to obtain Rs under various environmental conditions. Contrastingly, the MCM measurement is obtained during $CO_2$ evaluation in the soil owing to soil disturbance caused by measuring equipment, so close attention should be paid to measurements. This is because the measurement process is disturbed by high $CO_2$ soil concentration, and even small soil disturbances could release high levels into the chamber, causing large Rs errors. Therefore, the MCM should be adequately mastered before using the device to measure Rs.

Stream Ecosystem Assessments, based on a Biological Multimetric Parameter Model and Water Chemistry Analysis (생물학적 다변수 모델 적용 및 수화학 분석에 의거한 갑천생태계 평가)

  • Bae, Dae-Yeul;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.39 no.2 s.116
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    • pp.198-208
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    • 2006
  • This research was to apply a multi-metric approach, so called the Index of Biological Integrity (IBI) as a tool for biological evaluations of water environments, to a wadable stream. For the study, we surveyed 5 sampling locations in Kap Stream during August 2004 ${\sim}$ September 2005. We also compared the biological data with long-term water quality data, obtained from the Ministry of Environment, Korea and physical habitat conditions based on the Quantitative Habitat Evaluation Index (QHEI). We used ten metric systems for the IBI model to evaluate biological stream health. Overall IBI values in Kap Stream averaged 24 (range: 20${\sim}$30, n=5), indicating a "fair ${\sim}$ poor" conditions according to the modified criteria of Karr (1981) and US EPA(1993). Exclusive of 4th survey, average IBI values at the upstream reach (S1 ${\sim}$ S3)and downstream reach (S4 ${\sim}$ S5) were 20 and 24, respectively. However, in 4th survey the averages were 21 and 20 in the upstream and downstream reaches, respectively. This difference was larger in the upstream than in the downstream because of physical condition disturbed during summer monsoon. Values of the QHEI varied from 75(fair condition) to 148 (good condition) and values of QHEI in the S3 were significantly (P=0.001, n=5) lower than other sites. Biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were greater by 3 ${\sim}$ 8 fold in the downstream than in the upstream reach. We believe that present IBI approach applied in this study may be used as a key tool to set up specific goals for restoration of Kap Stream.