• Title/Summary/Keyword: ecological disturbance species

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Trail and Campground Deteriorations, and Their Environmental Changes of Soil and Vegetation in Chiak Mountain National Park (치악산 국립공원의 등산로 및 야영장 훼손과 주변 토양 및 식생환경의 변화)

  • 권태호;오구균;권영선
    • Korean Journal of Environment and Ecology
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    • v.2 no.1
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    • pp.50-65
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    • 1988
  • Trail and campground deteriorations and their environmental changes of soil and vegetation were studied in Guryong district of Mt. Chiak National Park in 1988. The Widths of both the entire trail and the bare portion as the trail condition were significantly greater on the more heavily used trail. and regressions showed the significant positive relationship between slope along the trail and maximum depth of the trail($R^2$=0.35). Deterioration types of trail which had higher frequency for a total of 63 observations were rock exposure(48%), trail deepening(29%) and root exposure(27%) in the high order. And occurence of trail deterioration was considerably influenced by slope along the trail Ecological changes of soil and vegetation of trailsides were not found at a uniform tendency but could be grouped, by the types of user's disturbance. On campsites. tree damage types and their frequencies were basic as a means of which grasp the limits of user's impact. The area with damaged trees on campsite in pine forest were larger than that in mixed forest and the frequency by damage type of trees varied according to the distance from the core of campsite and to the crown layer. Water content, pH and hardness of soil. coverage of lower trees, species and individuals per 100$m^2$, basal areas of upper and middle layer of trees had significant relationship with the distance from campsite to forest. The range influenced by user's disturbance was more than 70-80m, md Staphylea bumalda, Morns bombycis, Stephanandra incisa and Securinega suffruticosa were considered as tolerant species to user's impact.

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Population structure and regeneration of Himalayan endemic Larix species in three high-altitude valleys in Nepal Himalaya

  • Dhamala, Man Kumar;Aryal, Prakash Chandra;Suwal, Madan Krishna;Bhatta, Sijar;Bhuju, Dinesh Raj
    • Journal of Ecology and Environment
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    • v.44 no.3
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    • pp.196-206
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    • 2020
  • Background: The Himalayan forests are of great importance to sustain the nature and community resource demands. These forests are facing pressures both from anthropogenic activities and ongoing global climatic changes. Poor natural regeneration has been considered a major problem in mountainous forests. To understand the population structure and regeneration status of Larix (Larix griffithiana and Larix himalaica), we conducted systematic vegetation surveys in three high-altitude valleys namely Ghunsa (Kanchenjunga Conservation Area, KCA), Langtang (Langtang National Park, LNP), and Tsum (Manaslu Conservation Area, MCA) in Nepal Himalaya. The average values of diameter at breast height (DBH), height, and sapling height were compared for three sites and two species using Kruskal-Wallis test. Population structure was assessed in terms of proportion of seedlings, saplings, and trees. Regeneration was analyzed using graphical representation of frequencies of seedlings, saplings, and trees in histograms. Results: The results showed that the population structure of Larix in terms of the proportion of seedling, sapling, and tree varied greatly in the three study areas. KCA had the highest record of seedling, sapling, and tree compared to other two sites. Seedlings were the least among three forms and many plots were without seedlings. We found no seedling in MCA study plots. The plot level average DBH variation among sites was significant (Kruskal-Wallis χ2 = 7.813, df = 2, p = 0.02) as was between species (Kruskal-Wallis χ2 = 5.9829, df = 1, p = 0.014). Similarly, the variation in average tree height was significant (Kruskal-Wallis χ2 = 134.23, df = 2, p < 0.001) among sites as well as between species (Kruskal-Wallis χ2 = 128.01, df = 1, p < 0.001). All the sites showed reverse J-shaped curve but more pronounced for KCA and MCA. In comparing the two species, Larix griffithiana has clear reverse J-shaped diameter distribution but not Larix himalaica. Conclusion: The varied responses of Larix manifested through regeneration status from spatially distinct areas show that regeneration limitations might be more pronounced in the future. In all the three studied valleys, regeneration of Larix is found to be problematic and specifically for Larix griffithiana in MCA and Larix himalaica in LNP. To address the issues of disturbances, especially serious in LNP, management interventions are recommended to sustain the unique Himalayan endemic conifer.

Study on Community Structure of Benthic Macro-Invertebrates Inhabiting in an Urban Restoration Stream, Gongchon-cheon, in Incheon City (인천시 도시복원하천 공촌천의 저서성대형무척추동물의 군집 구조에 관한 연구)

  • Song, Yeong-Ju;Ju, Yong-Don;Park, Bo-Sun;Lee, Hee-Jo;Chae, Do-Young;Kim, Jong-Myung;Bae, Yang-Seop
    • Journal of Wetlands Research
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    • v.16 no.4
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    • pp.371-378
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    • 2014
  • The subject of this study is the Gongchon-cheon which is one of the largest streams in Incheon and is closely related to lives of citizen. Comparative analysis is made on the changes of the environment and the ecological condition of Gongchon-cheon after the stream naturalization construction which is completed in July 2009. From the results of the survey, 32 species in 2004, 22 species in 2009 and 46 species in 2010 have been recorded. The number of the species decreased from 2004 to 2009 due to the disturbance of the river environment, and it increased in a short time from 2009 to 2010 because of the recovery of the environment. It demonstrates the stream naturalization construction providing enough environments (dikes and rapids) for the benthic macro invertebrates. The result of the present study is similar with the river's biology index, ESB index, and KSI index, and also it is similar with the pattern of the appearance, which illustrates that the species decreased during the naturalization construction, and increased after the stabilization since the finish of the naturalization construction, and it has been confirmed that the naturalization construction provides the better environment for the inhabitation of organisms.

Fish Fauna and Ecological Characteristics of Dark Chub (Zacco temminckii) Population in the Mid-Upper Region of Gam Stream (감천 중 ${\cdot}$ 상류역의 어류상과 갈겨니 (Zacco temminckii) 개체군의 생태학적 특성)

  • Seo, Jin-Won
    • Korean Journal of Ecology and Environment
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    • v.38 no.2 s.112
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    • pp.196-206
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    • 2005
  • The fish community in the mid-upper region of Gam Stream was examined seasonally from 2001 to 2003 in order to perform an environmental impact assessment prior to a construction of Gamcheon Multipurpose Dam. Additional investigation was conducted in August 2004 to confirm the fish fauna reported and to examine the ecological characteristics of Zacco temminckii population. The total number of fish caught from the study sites was 1,081 fish representing 5 families 14 species. There were 6 Korean endemic species including Coreoleuciscus splendidus, Squalidus gracilis majimae, Microphysogobio yaluensis, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala, but no endangered or vulnerable species were found. Length-weight relation, condition factor (K) and relative condition factor (Kn) of Zacco temminckii were compared by the study sites and stream. The equations based on length-weight relation in Buhang and Gam Streams were TW\;=\;0.000004TL^{3.2357}$ and TW\;=\;0.000002TL^{3.3566}$, respectively indicating the fish in Gam Stream became more rotund as length increases. The condition factor (K) and relative condition factor (Kn) against total length of Zacco temminckii at two streams indicated that the fish (>70 mm) in Cam Stream (mean K and Kn= 1.116, 1.21 respectively) had better nutritional condition than those in Buhang Stream (mean K and Ln = 1.046, 1.14 respectively). The results were corresponded with natural disturbances such as drought and intensive rainfall from 2001 to 2003 followed by human activities such as stream repair works. Therefore, it is considered to perform environmental impact assessment with not only confirmation of fish composition but also examination of ecological characteristics in population- level.

Comparison of the National Park Ecosystem Health Assessment and an Advanced Assessment System (국립공원 생태계 건강성 평가 시스템 개선 연구)

  • Myeong, Hyeon Ho;Kim, Jeong Eun;Kim, Hye Ri;Oh, Jang Geun
    • Ecology and Resilient Infrastructure
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    • v.8 no.2
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    • pp.112-119
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    • 2021
  • In 2012, the National Park Service conducted an ecological health assessment to efficiently preserve and manage the ecosystem. The need for improving pre-existing management indicators was recognized from the revised Natural Park Act because, while the indicators of the existing evaluation system focused on endangered species, ecosystem disturbance, diversity, water quality (BOD, DO), and habitat fragmentation, they did not reflect the lack of indicators for marine ecological assessment, policy changes, and the time demands. The evaluation results comprised a five-point grading system, which made the analysis of immediate changes, difficult. Therefore, the benthic pollution index (BPI) and habitat restoration indicators were added to improve the evaluation system. The National Park was assessed using 10 classifications, however, only four classifications were evaluated. The ratings were divided into five states, and ten classes were presented as pictograms. The assessment results showed a similar trend as the indicators were improved, increasing from level 3 to level 5. However, the results of the Wolaksan National Park after improvement in the indicators were lower than that before the improvement, whereas, for the Juwangsan National Park, it was higher. This study aims at contributing to the scientific and systematic management of the national park ecosystem by improving the ecological health assessment system.

Characteristics of Marine Algal Communities in the Spring at Gijang-gun, Busan (부산시 기장군 연안의 춘계 해조 군집 특성)

  • Jung, Seung-Wook;Choi, Chang-Geun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.2
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    • pp.175-185
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    • 2020
  • Quantitative and qualitative surveys were conducted during scuba diving activity between May 2017 and June 2017 in order to analyze spring marine algal community structure at Gijang-gun, Busan. A total of 121 species including 13 (10.7 %) Chlorophyta, 18 (14.9 %) Phaeophyta, and 90 (74.4 %) Rhodophyta were identified. The species count in the subtidal zone (110 species) was twice as high as in the intertidal zone (56 species). In terms of regions, 88,76, and 75 species were found in Mundong, Gongsu, and Daebyeon, respectively. Mean biomass for the whole study area was 1,501.5 g·m-2, higher for the subtidal zone (1,869.4 g·m-2) than for the intertidal zone (1,133.5 g·m-2). Mean biomass by region values were 2,234.0 g·m-2, 1,228.1 g·m-2, and 1,044.4 g·m-2 for Mundong, Gongsu, and Daebyeon, respectively. Ulva australis, Sargassum thunbergii, and Corallina pilulifera had high biomass in the intertidal zone, while Sargassum macrocarpum, Undaria pinnatifida, and Phycodrys fimbriata had high biomass in the subtidal zone. The composition ratio of marine algal functional forms suggests that the entire study area had 'Low' status, and all sites fell within 'Low' to 'Moderate' status. Results indicate that opportunistic species are widely distributed throughout the Gijang-gun coast, hence potential effects of disturbance and environmental pollution should be considered. Seaweed farming in particular - a major activity along the Gijang-gun coast -, together with effects of other anthropogenic activities such as national fishing port development and the coastal improvement project, could have long-term effects on marine algal communities. Therefore, long-term monitoring and management plans for marine algal communities will be required.

Long-term distribution trend analysis of largemouth bass (Micropterus salmoides), based on National Fish Database, and the ecological risk assessments (전국자연환경조사 자료를 이용한 배스(Micropterus salmoides) 시공간 분포 분석 및 생태위해성 평가)

  • Kim, Jeong Eun;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.39 no.2
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    • pp.207-217
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    • 2021
  • Using the data from the national survey of fish, we determined the population size and the distribution of Micropterus salmoides, which is a translocated species into the aquatic ecosystem of Korea. . The spatial concentration of this species was determined by performing an optimized hot spot analysis. After determining potential invasiveness and risk assessment, we measured the disturbance of biodiversity in the aquatic ecosystem. The result of distribution analysis indicates that the population of M. salmoides was concentrated in the major basins of Han river, Geum river, Nakdong river, and Yeongsan-Seomjin river, including the Jeju island. In particular, Nakdong river basin showed the highest appearance rate. On the contrary, Yeongsan-Seomjin river basin showed the lowest appearance rate. The Nakdong river and the Nakdong river basin were the areas with the high spatial concentration of M. salmoides. On the other hand, only Han river basin and Geum river basin had the lowest spatial concentration. The fish invasiveness screening kit(FISK) was used to assess M. salmoides, which inhabited a broad region of aquatic ecosystem: the assessment score was 31.0, indicating its 'highly invasive' nature. Our study aims to encourage research that improves the biodiversity and the conservation of M. salmoides in a priority area.

Occurrence characteristics and management plans of Paspalum distichum and P. distichum var. indutum (습지에서 발생하는 생태계교란야생식물인 물참새피와 털물참새피의 발생특성과 관리방안)

  • In Yong Lee;Seung Hwan Kim;Yong Ho Lee;Adhikari Pradeep;Dong Gun Kim;Sun Hee Hong
    • Korean Journal of Environmental Biology
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    • v.40 no.3
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    • pp.325-334
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    • 2022
  • Paspalum distichum and P. distichum var. indutum are perennial weeds of the family Poaceae that prefer moist environments such as waterfronts and waterways. The origin of both species is North America. P. distichum is distributed all over the world. However, P. distichum var. indutum occurs only in the United States, Japan, and Korea. For this reason, in many countries, P. distichum and P. distichum var. indutum are classified as the same species. In other words, P. distichum var. indutum is a different ecological type of P. distichum. Both species can reproduce and spread mainly by rhizome fragments rather than seeds. This rhizome has a characteristic that it does not germinate if it is buried in the ground with depth of more than 3 cm. As a management method for P. distichum and P. distichum var. indutum in agricultural lands (paddy fields), it is effective to combine cultural control and chemical control methods. In other words, combining deep plowing and harrowing can suppress the budding of water sparrow that has invaded paddy fields or fallow paddy fields. After that, these two species that germinate can be controlled by spraying soil treatment herbicides such as butachlor and thiobencarb or foliar treatment herbicides such as cyhalofop-butyl and fenoxaprop-p-ethyl.

The Survey on Actual Condition Depending on Type of Degraded area and Suggestion for Restoration Species Based on Vegetation Information in the Mt. Jirisan Section of Baekdudaegan (식생정보에 기초한 백두대간 지리산권역 내 훼손지 유형별 실태조사)

  • Lee, Hye-Jeong;Kim, Ju-Young;Nam, Kyeong-Bae;An, Ji-Hong
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.558-572
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    • 2020
  • The purpose of this study was to classify the types of degraded areas of Mt. Jirisan section in Baekdudaegan and survey the actual condition of each damage type to use it as basic data for the direction of the restoration of damaged areas according to damage type based on the vegetation information of reference ecosystem. The analysis of the Mt. Jirisan section's actual degraded conditions showed that the total number of patches of degraded areas was 57, and the number of patches and size of degraded areas was higher at the low average altitude and gentle slope. Grasslands (deserted lands) and cultivated areas accounted for a high portion of the damage types, indicating that agricultural land use was a major damage factor. The survey on the conditions of 14 degraded areas showed that the types of damage were classified into the grassland, cultivated area, restoration area, logged-off land, and bare ground. The analysis of the degree of disturbance (the ratio of annual and biennial herb, urbanized index, and disturbance index) by each type showed that the simple single-layer vegetation structure mostly composed of the herbaceous and the degree of disturbance were high in the grassland and cultivated land. The double-layer vegetation structure appeared in the restoration area where the pine seedlings were planted, and the inflow of naturalized plants was especially high compared to other degraded areas due to disturbances caused by the restoration project and the nearby hiking trails. Although the inflow of naturalized plants was low because of high altitude in bare ground, the proportion of annual and biennial herb was high, indicating that all surveyed degraded areas were in early succession stages. The stand ordination by type of damage showed the restoration area on the I-axis, cultivated area, grassland, logged-off land, and bare ground in that order, indicating the arrangement by the damage type. Moreover, the stand ordination of the degraded areas and reference ecosystem based on floristic variation showed a clear difference in species composition. This study diagnosed the status of each damage type based on the reference ecosystem information according to the ecological restoration procedure and confirmed the difference in species composition between the diagnosis result and the reference ecosystem. These findings can be useful basic data for establishing the restoration goal and direction in the future.

Public Perception on Non-native Species: Based on the News Articles about the Alligator Snapping Turtle (Macrochelys temminckii) (외래생물에 대한 대중의 문제 인식: 악어거북 뉴스 기사를 바탕으로)

  • Kim, Hyunjung;Park, Seoung-Min;Jang, Yikweon;Koo, Kyo Soung
    • Korean Journal of Environment and Ecology
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    • v.34 no.5
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    • pp.396-401
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    • 2020
  • As the world becomes more globalized, the non-native species issue has emerged as a problem that is growing internationally. In particular, the number of non-native turtles found in the wild has been increasing sharply in South Korea. At least 15 species of non-native turtles, including the red-eared slider (Trachemys scripta elegans) first imported in the 1970s, have been found in Korea. On October 15, 2019, an alligator snapping turtle (AST, Macrochelys temminckii) was found in a stream located in Gwangju city, South Korea. The discovery of AST became a big issue in South Korea as the animal is known for its large body size and aggressiveness and was featured widely in the mass media. In this study, to learn the public's perception of non-native species, we examined comments (opinions) to the online news articles about the AST. We collected 1,100 comments from the Internet news articles on the AST. Out of the 1,100 comments, 342 (31.1%) comments were related to non-native species' issues. Most of the respondents (97.7%, n=334) stated that the non-native species are a problem. Forty two comments mentioned potential threats posed by non-native species: non-native species' aggressive nature (n=11, 26.2%) and ecological disturbance (n=31, 73.8%). Lack of responsibility (n=122, 51.7%) was the major causative factor for the introduction of non-native species, and followed by indiscriminate pet trade (n=99, 42.0%), absence of relevant legislation (n=13, 5.5%), and absence of treatment (n=2, 0.8%). Animal registration (n=59, 45.7%) was the most commonly mentioned as the way to deal with the issue of the non-native species' invasion. Our results show that the public is aware of the seriousness of the invasion of non-native species, including AST. This study highlights that researchers and government officials need to consider the public's perception and opinions. We believe that our study can serve as an essential reference for the policy direction and the management of non-native species.