• Title/Summary/Keyword: anthropogenic disturbance

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Recolonization of benthic macroinvertebrates after anthropogenic disturbance in natural streams, South Korea

  • Chun, Seung-Phil;Chon, Seung-Hoon;Lee, Seung-Oh;Im, Jang-Hyuk;Lee, Woo-Kyun;Kim, Myoung-Chul
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.228-235
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    • 2015
  • Stream ecosystems are closely related to many human activities. Therefore, streams are affected by anthropogenic disturbances such as riverine development and gravel-mining as well as deterioration of water quality. The goal of this study was to elucidate the recolonization process of the macroinvertebrate community after a small-scale anthropogenic disturbance. Field studies were conducted at three sites in a natural stream. The number of recolonizing species tended to increase slightly over time, exceeding the total species number of the control. Ephemeroptera contributed the most to shaping the recolonizing pattern of the entire community. From the result of changes in dominant species, the early recolonizers of each site were the species that showed more frequent occurrence particulary at each sites. But the late recolonizers are Chironomidae at all the sites commonly. This result implies that the actual differences exist among the recolonizing trends of each benthic macroinvertebrate taxon. Collector-gatherers and scrapers comprised about 70% of the recolonizing species. These results indicate that the recolonizing process of an aquatic community after an artificial disturbance depends on the environmental conditions(particularly substratum composition or organic pollution) of the habitat.

Rapid Ecoassessment Technique about Anthropogenic Disturbance Potentiality of Land Use (토지의 훼손 잠재성에 대한 신속한 생태평가기법)

  • 김종원
    • The Korean Journal of Ecology
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    • v.26 no.1
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    • pp.19-22
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    • 2003
  • In order to determine the degree of anthropogenic disturbance potentiality (ADP) of the area a rapid ecoassessment technique was developed on the basis of actual vegetation map. ADP degree of relevant unit cell was computed by using four criteria of land use patterns such as forested area, open water and stream, agricultural area, and urbanized area. Ultimate ADP degree of each cell was obtained by means of direct and indirect computation process. Finally the map of ADP was drawn and analyzed. Vulnerable cell and disturbance nuclei were determined according to disturbance vector which is a kind of potential disturbance pressure of relevant cell influenced by surrounding cell. A case study was accomplished in the Gijang area of Pusan metropolitan city. 973 meshes (500m×500m) were analyzed and a total of 79 meshes were currently threatened. Present technique of rapid ecoassessment was practically useful for diagnosing and planning land use.

Forest Floor Biomass, Litterfall and Physico-chemical Properties of Soil along the Anthropogenic Disturbance Regimes in Tropics of Chhattisgarh, India

  • Oraon, P.R.;Singh, Lalji;Jhariya, Manoj Kumar
    • Journal of Forest and Environmental Science
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    • v.34 no.5
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    • pp.359-375
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    • 2018
  • The long term ecological effects have been reported in natural forest ecosystem due to various anthropogenic disturbances, especially in tropics of the world. The present study was carried out in the sanctuary area of central India to assess the changes on litter biomass, litterfall pattern and soil attributes under different disturbance regimes. The study area includes three forest circles i.e., Bhoramdeo, Jamunpani and Salehwara each comprising three disturbances regimes viz., high, medium and low severity of biotic pressure. A noticeable variation and impact were recorded in different sites. The impact varies significantly from least disturbed sites to highly disturbed sites across the circle and among different disturbances level. The seasonal mean total forest floor biomass across the forest circles varied from 2.18 to $3.30t\;ha^{-1}$. It was found highest under lightly disturbed site and lowest under heavily disturbed site. Total litterfall varied from 5.11 to $7.06t\;ha^{-1}\;yr^{-1}$ across the forest circle. Lowest litterfall was recorded at heavily disturbed site while highest in lightly disturbed site. Annual turnover of litter varied from 69-73% and the turnover time ranged between 1.37-1.45 years. The turn over time was higher for heavily disturbed site and lower for lightly disturbed site. The heavily disturbed site of all the circle showed the sandy loam soil texture, whereas moderately and lightly disturbed site comprised of sandy loam, sandy clay loam and clay soil texture, respectively. The bulk density decreases from heavily disturbed site to lightly disturbed site and the pH of soils ranged from 5.57-6.89 across the circle. Across the circle the total soil nitrogen ranged from 0.12-0.21%, phosphorus from 10.03-24.00 kg and Potassium from $139.88-448.35kg\;ha^{-1}$, respectively. Our results demonstrate that anthropogenic disturbances regime significantly influences forest floors in terms of mass, composition and dynamics along with litterfall rate and soil properties.

Coral Reefs in Indonesia: A Review on Anthropogenic and Natural Disturbances

  • Meinita, Maria Dyah Nur
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.1
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    • pp.1-10
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    • 2007
  • Coral reefs are among the most dynamic and various ecosystems on tropical ecosystem. They provide a large number of important ecosystem services. Despite their importance, they appear to be one of the most susceptible marine ecosystems. Dramatic decreasing of coral reefs has been reported from every part of the world. Indonesia contains 18% of coral reefs of world's total. Unfortunately the status of coral reefs in Indonesia is already in critical and poor condition. Coral reefs communities in Indonesia are subjected to a variety of environmental disturbance. Threats to Indonesia's coral reefs resources can be divided into two main types: anthropogenic and natural disturbances. The major anthropogenic disturbances on coral reefs in Indonesia are destructive fishing, pollution, coastal development, mining and harvesting live fish and coral, tourism. The natural disturbances such as cyclones, volcanic eruptions, earthquakes, tsunami and predator also contribute to coral reefs destruction in Indonesia. In my paper I tried to compare between natural and anthropogenic disturbances on coral reefs in Indonesia and raised these questions: (i) how the natural disturbances differ from anthropogenic area (ii) which type of disturbances has caused the greatest impact on coral reef ecosystem. My finding is that both of anthropogenic and natural disturbances give major impact on coral reefs in Indonesia. The important issue here is coral reef resilience could be disturbed by synergistic effects between various anthropogenic and natural disturbances. This phenomenon has significant conservation and management implication. The appropriate management should be conducted to protect coral reefs ecosystem in Indonesia. Mangrove management will succeed only when local people are involved and get sustainable benefits from mangrove ecosystem. Community based management and Integrated Coastal Zone Management (ICZM) are type of management that can be applied on coral reef ecosystems in Indonesia.

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Comparison of Soil Pore Properties between Anthropogenic and Natural Paddy Field Soils From Computed Tomographic Images

  • Chun, Hyen Chung;Jung, Ki-Yuol;Choi, Young Dae;Jo, Su-min;Lee, Sanghun;Hyun, Byung-Keun;Shin, Kooksik;Sonn, Yeonkyu;Kang, Hang-Won
    • Korean Journal of Soil Science and Fertilizer
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    • v.48 no.5
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    • pp.351-360
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    • 2015
  • Human influence on soil formation has dramatically increased with human civilization and industry development. Increase of anthropogenic soils induced researches on the anthropogenic soils; classification, chemical and physical characteristics of anthropogenic soils and plant growth from anthropogenic soils. However there have been no comprehensive analyses on soil pore or physical properties of anthropogenic soils from 3 dimensional images in Korea. The objectives of this study were to characterize physical properties of anthropogenic paddy field soils by depth and to find differences between natural and anthropogenic paddy field soils. Soil samples were taken from two anthropogenic and natural paddy field soils; anthropogenic (A_c) and natural (N_c) paddy soils with topsoil of coarse texture and anthropogenic (A_f) and natural (N_f) paddy soils with topsoil of fine texture. The anthropogenic paddy fields were reestablished during the Arable Land Remodeling Project from 2011 to 2012 and continued rice farming after the project. Natural paddy fields had no artificial changes or disturbance in soil layers up to 1m depth. Samples were taken at three different depths and analyzed for routine physical properties (texture, bulk density, etc.) and pore properties with computer tomography (CT) scans. The CT scan provided 3 dimensional images at resolution of 0.01 mm to calculate pore radius size, length, and tortuosity of soil pores. Fractal and configuration entropy analyses were applied to quantify pore structure and analyze spatial distribution of pores within soil images. The results of measured physical properties showed no clear trend or significant differences across depths or sites from all samples, except the properties from topsoils. The results of pore morphology and spatial distribution analyses provided detailed information of pores affected by human influences. Pore length and size showed significant decrease in anthropogenic soils. Especially, pores of A_c had great decrease in length compared to N_c. Fractal and entropy analyses showed clear changes of pore distributions across sites. The topsoil layer of A_c showed more degradation of pore structure than that of N_c, while pores of A_f topsoil did not show significant degradation compared with those of N_f. These results concluded that anthropogenic soils with coarse texture may have more effects on pore properties than ones with fine texture. The reestablished paddy fields may need more fundamental remediation to improve physical conditions.

Disappearing Forest Tree Species Diversity in Tropical Moist Deciduous Forest and Its Implications: A Case Study in the Madhupur Tract of Central Bangladesh

  • Rahman, Mohammed Mahabubur;Rahman, Md. Motiur;Alam, Mahbubul
    • Journal of Forest and Environmental Science
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    • v.26 no.3
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    • pp.161-170
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    • 2010
  • A study was conducted for indentifying the floral biodiversity of woody species by calculating four diversity indices using data collected from 4 stands of different age groups and disturbance regimes in two areas of Madhupur tract. Results showed that highest species diversity in the old growth secondary coppice forest (>60 years) under moderate anthropogenic disturbances of Madhupur National Park area (delete (D=0.74, H'=3.36) followed by old growth secondary forest stands (>40 years) under moderate disturbances at Bhawal National Park area (D=0.65, H'=2.81). Plant species diversity of the young enrichment plantations (<20 years and <15 years) under high anthropogenic disturbances in both the areas are much low (D=0.54 and H'=2.16 and D=0.52 and H'=1.92 respectively), which indicate high anthropogenic disturbances coupled with introduction of invasive exotics that are rival for endemic species are detrimental for conservation of biological diversity of tropical moist deciduous forests of Madhupur tract in Bangladesh.

Disturbance, Diversity, Regeneration and Composition in Temperate Forests of Western Himalaya, India

  • Tiwari, Om Prakash;Sharma, Chandra Mohan;Rana, Yashwant Singh;Krishan, Ram
    • Journal of Forest and Environmental Science
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    • v.35 no.1
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    • pp.6-24
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    • 2019
  • We have investigated the impact of anthropogenic and natural disturbances on regeneration, composition and diversity in some temperate forests of Bhagirathi Catchment Area of Garhwal Himalaya. The forests were categorized on the basis of canopy cover and magnitude of disturbance into highly, moderately and least disturbed classes. The dominant tree species at lower elevation were Pinus roxburghii and Quercus leucotrichophora, while Abies pindrow, Q. semecarpifolia and Rhododenron arboreum were the dominant species at the upper elevational forests. Cythula tomentosa and Indegophera heterentha were the dominant shrub species present in all the forests. Similarly, Circium wallichii and Oxalis corniculata were the dominant herb species found in all forests (except Q. leucotrichophora forest), whereas Thalictrum foliolosum and Viola pilosa were noticed in each forest (except P. roxburghii forest). The tree density values oscillated between $400{\pm}10\;trees\;ha^{-1}$ to $750{\pm}89.1\;trees\;ha^{-1}$ which generally decreased from lower to higher disturbance regimes however, the total basal cover value was highest ($88.1{\pm}23.6m^2\;ha^{-1}$) in highly disturbed forest and lowest ($25.8{\pm}2.2m^2\;ha^{-1}$) in moderately disturbed forest. The shrub and herb densities were maximum in least disturbed forest, while the young regenerating individuals i.e., sapling and seedling were observed increasing from high to low disturbed forests which reflected that the forest fragmentation adversely affected the regeneration. However, A. pindrow and P. roxburghii were found invariably encroaching the habitats of R. arboreum and Q. leucotrichophora at various altitudes, respectively. The Canonical Correspondence Analysis clearly indicated that the elevation and lopping intensity have more impact on trees, while shrub and herbs were more influenced by elevation, canopy cover, light attenuation and soil erosion. Pinus roxburghii was the only species which was affected by heavy litter removal and forest fire.

Definition of Invasive Disturbance Species and its Influence Factor: Review (침입교란종 개념 정립 및 영향요인 고찰)

  • Kim, Eunyoung;Song, Wonkyong;Yoon, Eunju;Jung, Hyejin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.1
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    • pp.155-170
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    • 2016
  • This study established the definition of invasive disturbance species for a sustainable management and biodiversity, and derived the influence factors caused by the species. To define the species, the paper reviewed similar words such as alien species and invasive species, using standard definitions. Also reviewed the results of recent research on the factors of the species. The paper defined the invasive disturbance species as an species whose establishment and spread threaten ecosystems, habitats or species with economic or environmental harm including native and non-native. Through the reviews, The factors were classified as geographic (altitude, slope, and soil, etc.), climate (temperature, precipitation, climate change, etc.) and, anthropogenic (land use, population, road, and human activity, etc.), and species & vegetation structure (species property, local-species richness, and canopy, etc.). Especially, human activity such as urbanization and highways may be associated with both higher disturbance and higher propagule pressure. In the further study, it is required development of mitigation strategies and vegetation structure model against invasive disturbance species in urban forest based on this study.

Evaluating the Restoration of a Stream in an Abandoned Mine Land via Biomass Calculation of Benthic Macroinvertebrates

  • Mi-Jung Bae;Hyeon-Jung Seong;Seong-Nam Ham;Eui-Jin Kim
    • Korean Journal of Ecology and Environment
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    • v.55 no.4
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    • pp.415-420
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    • 2022
  • It is essential that continual assessments of the impact of mine-derived water as a long-lasting burden on freshwater environments. Abundance-based evaluations of benthic macroinvertebrates have been conducted to evaluate anthropogenic disturbances and devise policies to reduce their impact. In this study, the status of a stream habitat was evaluated based on the body length and biomass weight of benthic macroinvertebrates of the family Baetidae. Following the renewal of the mining water treatment plant, the abundance of Baetidae assemblages recovered to a level comparable to that of a reference site. However, relatively low values were found for both body length and biomass weight in Baetidae species inhabiting the reddened streambed area, suggesting that the habitat has not yet been completely recovered despite the recovery of the abundance of the Baetidae assemblages. Therefore, continuous investigation and evaluation of this disturbed stream are necessary until their growth conditions of the habitat have functionally recovered.