• Title/Summary/Keyword: Anthropogenic disturbance

Search Result 54, Processing Time 0.022 seconds

The Influence of Environmental Variables on Macrobenthic Communities after Dike Construction in Asan Bay, Korea (방조제 건설이후 아산만 대형저서동물 군집 구조에 영향을 주는 환경요인)

  • Yu, Ok-Hwan;Lee, Hyung-Gon;Lee, Jae-Hac
    • Korean Journal of Environmental Biology
    • /
    • v.29 no.4
    • /
    • pp.326-344
    • /
    • 2011
  • Although anthropogenic disturbance of 20 years duration affects benthic habitats, few studies have examined its effects on the macrobenthic communities of a bay. The aim of this study was to determine the influence of environmental variables on the macrobenthic communities after the construction of the Hwaong dike. Macrobenthos were collected at 22 sites using a Smith McIntyre grab (0.1 $m^2$) in August 2007 and February 2008. Total organic content was very low around the Hwaong dike. Sediment grain size increased from the Hwaong dike to the outer bay. In total, 317 species of macrobenthic fauna were collected and the mean density was 1,155 ind. $m^{-2}$, both of which were higher than the results of previous studies. The dominant species, $Hetermastus$ $filiformis$, known to be a potential pollution indicator, was more abundant near the Hwaong dike. Conversely, species sensitive to organic pollution, such as the polychaete $Ampharete$ $arctica$ and the ophiuroid $Amphioplus$ $squamata$, exhibited higher mean densities in areas distant from the dike. A cluster analysis indicated that the macrobenthic community was divided into two distinct groups: group I near the dike and group II in the outer bay, which were affected by sediment grain size and total organic content. This study suggests that variations in sediment grain size and organic content after dike construction are important factors controlling the macrobenthic community in Asan Bay.

Vegetation Characteristics of Geumnamhonam·Honam Ridge Areas Understood through Quantitative Vegetation Analysis (정량적 식생분석을 통한 금남호남·호남정맥 마루금 일대의 식생 특성)

  • Park, Seok-Gon;Kang, Hyun-Mi
    • Korean Journal of Environment and Ecology
    • /
    • v.34 no.4
    • /
    • pp.304-317
    • /
    • 2020
  • This study conducted selected two sites in Geumnamhonam and four sites in Honam-Jeongmaek for vegetation survey with consideration to the location environment and anthropogenic impacts to investigate the vegetation structures of the Geumnamhonam-Jeongmaek·Honam-Jeongmaek ridge areas. Using TWINSPAN (two-way indicator species analysis), each of the two ridge areas were categorized into seven plant communities. The differential species in the TWINSPAN technique indirectly represent the environmental factors of plant communities, and the community types of the two ridge areas were divided based on environmental factors such as altitudes above sea level, soil moisture, and disturbance. These results were in harmony with the environmental factors of the DCA (detrended correspondence analysis) axis 1. In the low-lying areas of both ridge areas, afforestation tree species such as Pinus rigida and P. thunbergii were in competition with native tree species. As such, in the low-lying areas, artificial vegetation disturbance was severe due to afforestation and development projects. In relatively highland areas, such as upper slopes, and top areas, in the ridge, the vegetation type with the dominance of Quercus mongolica, Q. variabilis, and P. densiflora was preserved well. As for differences between the two ridge areas, communities dominated by Q. mongolica were distributed widely in Geumnamhonam-Jeongmaek because of the altitudes above sea level, and the latitude of this ridge area are higher than those of Honam-Jeongmaek. On the other hand, communities dominated by P. densiflora were distributed along with communities dominated by Q. mongolica, and communities dominated by Q. variabilis appeared in Honam-Jeongmaek because it is adjacent to the south coast. In quantitative vegetation analysis such as TWINSPAN and DCA, changes in species composition and the extracting environmental factors that cause the changes are important. To that end, the removal of accidental emergent species, the establishment of an investigation plan that assumes environmental factors, and the selection of the optimal analytical method suitable for the characteristics of the survey data are necessary.

Applications and Perspectives of Fluvial Biogeomorphology in the Stream Management of South Korea (우리나라 하천 관리에서 생물지형학의 적용과 전망)

  • Kim, Daehyun;Kim, Won;Kim, Eunsuk;Ock, Giyoung;Jang, Chang-Lae;Choi, Mikyoung;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
    • /
    • v.7 no.1
    • /
    • pp.1-14
    • /
    • 2020
  • In fluvial and riparian ecosystems, biogeomorphological research has considered the complex, multi-way relationships between biological and hydro-geomorphological components over a wide range of spatial and temporal scales. In this review, we discussed the scope and processes of fluvial biogeomorphology by explaining (1) the multi-lateral interactions between organisms and hydrogeomorphic conditions, (2) the relationships between biodiversity and habitat heterogeneity, and (3) the effects of disturbance on ecosystem patterns. Over time, an organism-landform complex along streams transitions in the sequences of geomorphic, pioneer, biogeomorphic, and ecological stages. Over space, water flow and sediment distributions interact with vegetation to modify channel topography. It is the habitat heterogeneity in streams that enhances riparian biodiversity. However, in the areas downstream of a dam, habitat types and conditions are substantially damaged and biodiversity should be reduced. In South Korea, riparian vegetation flourishes in general and, in particular, invasive species actively colonize in accordance with the changes in the fluvial conditions driven by local disturbances and global climate change. Therefore, the importance of understanding reciprocal relationships between living organisms and hydrogeomorphic conditions will ever increase in this era of rapid climate change and anthropogenic pressure. The fluvial biogeomorphic framework reviewed in this article will contribute to the ecological management and restoration of streams in Korea.

Vegetation structure and distribution characteristics of Symplocos prunifolia, a rare evergreen broad-leaved tree in Korea

  • Kim, Yangji;Song, Kukman;Yim, Eunyoung;Seo, Yeonok;Choi, Hyungsoon;Choi, Byoungki
    • Journal of Ecology and Environment
    • /
    • v.44 no.4
    • /
    • pp.275-285
    • /
    • 2020
  • Background: In Korea, Symplocos prunifolia Siebold. & Zucc. is only found on Jeju Island. Conservation of the species is difficult because little is known about its distribution and natural habitat. The lack of research and survey data on the characteristics of native vegetation and distribution of this species means that there is insufficient information to guide the management and conservation of this species and related vegetation. Therefore, this study aims to identify the distribution and vegetation associated with S. prunifolia. Results: As a result of field investigations, it was confirmed that the native S. prunifolia communities were distributed in 4 areas located on the southern side of Mt. Halla and within the evergreen broad-leaved forest zones. Furthermore, these evergreen broad-leaved forest zones are themselves located in the warm temperate zone which are distributed along the valley sides at elevations between 318 and 461 m. S. prunifolia was only found on the south side of Mt. Halla, and mainly on south-facing slopes; however, small communities were found to be growing on northwest-facing slopes. It has been confirmed that S. prunifolia trees are rare but an important constituent species in the evergreen broad-leaved forest of Jeju. The mean importance percentage of S. prunifolia community was 48.84 for Castanopsis sieboldii, 17.79 for Quercus acuta, and 12.12 for Pinus thunbergii; S. prunifolia was the ninth most important species (2.6). Conclusions: S. prunifolia can be found growing along the natural streams of Jeju, where there is little anthropogenic influence and where the streams have caused soil disturbance through natural processes of erosion and deposition of sediments. Currently, the native area of S. prunifolia is about 3300 ㎡, which contains a confirmed population of 180 individual plants. As a result of these low population sizes, it places it in the category of an extremely endangered plant in Korea. In some native sites, the canopy of evergreen broad-leaved forest formed, but the frequency and coverage of species were not high. Negative factors that contributed to the low distribution of this species were factors such as lacking in shade tolerance, low fruiting rates, small native areas, and special habitats as well as requiring adequate stream disturbance. Presently, due to changes in climate, it is unclear whether this species will see an increase in its population and habitat area or whether it will remain as an endangered species within Korea. What is clear, however, is that the preservation of the present native habitats and population is extremely important if the population is to be maintained and expanded. It is also meaningful in terms of the stable conservation of biodiversity in Korea. Therefore, based on the results of this study, it is judged that a systematic evaluation for the preservation and conservation of the habitat and vegetation management method of S. prunifolia should be conducted.

Review on the Conservation Value and Assessment Criteria of Vegetation (식생의 보전가치와 평가기준에 대한 검토)

  • Choung, Heung-Lak;Song, Jong-Suk;Lee, Kyu Song;Kim, In-Taek;Kim, Jong-Hong;Yang, Keum-Chul;Chun, Young-Moon
    • Journal of Environmental Impact Assessment
    • /
    • v.15 no.5
    • /
    • pp.339-355
    • /
    • 2006
  • In this paper, we reviewed the assessment criteria and conservation value used to evaluate vegetation. The Degree of Green Naturality (DGN) and the Grade of Vegetation Conservation (GVC) are both sets of criteria that estimate the degree of human disturbance or natural value of vegetation. The criteria are extensively used in decision-making about the natural environment conservation and environment impact assessment. Sometimes, social issues can rise because the criteria are not clear. This study aims to evaluate the criteria based on the many aspects of the related literatures and suggest reasonable revised criteria. In addition, criteria for representing the relative value of valuable vegetation conservation are suggested. The DGN and GVC are essentially same; both have 11 degrees and 5 grades. While the DGN is subdivided into levels of anthropogenic disturbances, the GVC indicates the priority for conserving valuable vegetation. Therefore, the DGN is very useful for assessing land development projects, etc., while the GVC is needed to delineate the Ecological Assessment Map(EAM). In conclusion, it is desirable that both criteria should be used together appropriately.

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
    • /
    • v.46 no.3
    • /
    • pp.319-331
    • /
    • 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.

Species Alterations Caused by Nitrogen and Carbon Addition in Nutrient-deficient Municipal Waste Landfills

  • Kim, Kee-Dae
    • Journal of Ecology and Environment
    • /
    • v.30 no.2
    • /
    • pp.161-170
    • /
    • 2007
  • The ultimate target of restoring waste landfills is revegetation. The most effective method for increasing species richness and biomass in nutrient limited waste landfills is the use of fertilizers. The aim of the present study was to investigate the effects of nitrogen fertilizer, and the addition of carbon through sawdust, sucrose and litter, on vegetation dynamics at a representative municipal waste landfill in South Korea: Kyongseodong. A total of 288 permanent plots $(0.25m^2)$ were established and treated with nitrogen fertilizer (5, 10 and $20Ng/m^2$), sawdust $(289g/m^2)$ sucrose $(222g/m^2)$ and litter $(222g/m^2)$. The aboveground biomass was significantly enhanced by nitrogen fertilizer at 5 and $10Ng/m^2$, compared with the control plots. The total cover of all plant species increased significantly on plots treated with 5 and $20Ng/m^2$, as well as on those treated with sawdust and sucrose, compared with the control plots. The higher species richness after nitrogen fertilization of 10 to $20Ng/m^2$, and the sawdust and sucrose treatment demonstrated that this was an appropriate restoration option for nutrient deficient waste landfills. This study demonstrated positive nutrient impacts on plant biomass and species richness, despite the fact that municipal waste landfills are ecosystems that are highly disturbed by anthropogenic and internal factors (landfill gas and leachate). Adequate N and C combined treatments will accelerate species succession (higher species richness and perennial increase) for restoration of waste landfills.

Island-Biogeographical Characteristics of Insular Flora in Southern Sea of Jeollanamdo, Korea (전라남도 남해안 도서식물상의 도서생물 지리학적 특성)

  • Kim, Hyun Hee;Kim, Da Bin;Won, Hyun Kyu;Kim, Chan Soo;Kong, Woo Seok
    • Journal of Climate Change Research
    • /
    • v.7 no.2
    • /
    • pp.143-155
    • /
    • 2016
  • Present work aims to establish the countermeasure for the better maintenance and preservation of insular floristic diversity at the South Sea of Jeollanamdo Province, ROK, where unique ecosystems are under threat due to climate change, anthropogenic disturbance and habitat destruction. Numerous flora reports from 15 inhabited islands and 60 uninhabited islands as well as field survey data are collated for the compilation of floristic data base and island biogeographical analysis. Out of the 1,940 vascular plant species from 180 families occurring in studies areas, 30.1 percentage or 584 plant species are physiognomically belonging to arboreal plants. Average number of species at individual island is numbered about 222 species, but it varies from about 591 species at the inhabited islands to 129 species at the uninhabited islands. Only 0.15 percentage of species with high proportion above 0.9 in its relative occurrence rate occurs at 68 islands and it includes three species, such as Pinus thunbergii, Eurya japonica and Pteridium aquilinum var. latiusculum. However, about 68 percentage of plant species occurring in study area is confined their distribution to less than seven islands. Presence of high proportion of notable plants in small islands, i.e., 10 critically endangered species compared with 5.5 species in average, 9 endangered species (average 4.2 spp.) at Sonjookdo, and 7 critically endangered species, 8 endangered species at Sokomundo may due to existence of diverse geological and topographical environmental diversity as well as lower human population density and remoteness from the mainland. Since island is small in size and geographically isolated, minor environmental and ecological burdens can cause the critical damages to the diversity of flora and vegetation, urgent island biogeographical research is needed for the scientific conservation and management of island biodiversity.

First Report on the Natural Movement of Introduced Turtle, Trachemys scripta elegans (국내로 유입된 외래생물 붉은귀거북(Trachemys scripta elegans)의 자연적인 이동 첫 보고)

  • Koo, Kyo Soung;Baek, Hae-Jun;Kim, Su Hwan;Jang, Hoan-Jin;Kim, Dae-In;Sung, Ha-Cheol
    • Korean Journal of Ecology and Environment
    • /
    • v.52 no.1
    • /
    • pp.9-12
    • /
    • 2019
  • The red-eared slider (Trachemys scripta elegans) is the one of the most popular pets, and the most commonly traded species in the world. It is designated as an ecosystem disturbance species that has been managed in South Korea. To date, no reports of natural or anthropogenic migration and spreading of T. s. elegans in South Korea are available. In the present study, we estimated the expected route and the movable path of one female T. s. elegans found in Namsan-myun, Gyeongsan-si, Gyeongsangbuk-do. Based on the movable path, the potential destination of the female turtle was estimated to be about 282 m and 468 m away. Therefore, the moving distance of the red-eared slider to the nearest water system will be at least 606 m and at most 792 m. Our results provide the first evidence about the natural migration and spreading of exotic turtles. This study can serve as a basis for the management and countermeasures against the introduced of T. s. elegans and other exotic species in South Korea.

Flora of a Cool Temperate Forest Around Restoration Center for Endangered Species, Yeongyang

  • Kim, Seongjun;Lee, Chang-Woo;Park, Hwan-Joon;Lee, Byoung-Doo;Hwang, Jung Eun;An, Jiae;Park, Hyung Bin;Baek, Ju Hyeong;Kim, Pyoung Beom;Kim, Nam Young
    • Proceedings of the National Institute of Ecology of the Republic of Korea
    • /
    • v.2 no.1
    • /
    • pp.70-75
    • /
    • 2021
  • The present study aimed to clarify flora living at the area of Restoration Center for Endangered Species in Yeongyang, Gyeongbuk Province. In May, August, and September 2019 and in May and July 2020, all of vascular plants were recorded, and endangered, Korea endemic, and exotic plant species were further identified. The study site contained a total of 418 floral taxa (98 families, 261 genera, 384 species, 4 subspecies, 27 variations, and 3 formations), in which Magnoliophyta accounted for larger proportion (95.2%) than Pteridophyta (3.6%) and Pinophyta (1.2%). In addition, 1 endangered (Cypripedium macranthos Sw.) and 5 Korea endemic species (Aconitum pseudolaeve Nakai, Eleutherococcus divaricatus var. chiisanensis [Nakai] C.H. Kim & B.-Y. Sun, Lonicera subsessilis Rehder, Paulownia coreana Uyeki, and Weigela subsessilis [Nakai] L.H. Bailey) were detected. The number of exotic species was 33, consisting of 4 invasive-exotic, 4 potentially invasive-exotic, and 25 non-invasive species. Compared to a previous assessment before the establishment of the center (in 2014), there were increases in total floral taxa (from 361 to 418), endangered species (from 0 to 1), and exotic species (from 26 to 33). These results possibly reflect temporal changes in floral community, which should be confirmed through subsequent long term monitoring.