• Title/Summary/Keyword: Ecological Community

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Community Structure of Plankton in Eutrophic Water Systems with Different Residence Time (체류시간이 서로 다른 부영양 수계에서 플랑크톤군집의 생태학적 특성)

  • Lee, Uk-Se;Han, Myeong-Su
    • Korean Journal of Ecology and Environment
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    • v.37 no.3 s.108
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    • pp.263-271
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    • 2004
  • To collect the basic ecological information about the microbial food webs in eutrophic water system with different residence time, the monthly variation of bacterioplankon (bacteria and small-sized cyanobacteria) and nanoplankton (phytoplankton and protists) were examined from December 2000 to September 2001. Kyungan stream is shorter in resident time (ca.5.4 d) than Seokchon reservoir (ca.72 d), even though they showed the same pattern in precipitation. With the basic environments, we examined the biomass (standing crops and its carbon content) of each plankton collected from the surface water. Large-sized planktons flourished in the time of low temperature, while small planktons were in the time of the high temperature period. Especially, in the Kyungan stream with much disturbance by rainfall and outflow, high diversity showed in term of species and cell morphology, compared to that of Seokchon lake. The time-lag relationship remarkably showed between phytoplankton and bacteria in Seokchon reservoir, and between protists and bacteria in Kyungan stream, respectively.

Rethink the interlink between land degradation and livelihood of rural communities in Chilga district, Northwest Ethiopia

  • Gashu, Kassahun;Muchie, Yitbarek
    • Journal of Ecology and Environment
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    • v.42 no.4
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    • pp.139-149
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    • 2018
  • Background: Ethiopia is among the poorest countries where land degradation caused livelihood problem to its inhabitants. The livelihood of rural communities in Ethiopia is seriously threatened by land degradation. Land is the major natural resource that economic, social, infrastructure, and other human activities are undertaken on. Thus, land resources play an important role in shaping rural livelihoods, and lack of sustainable land management practices leads to land degradation. Thus, this study aimed to analyze interlink between land degradation and livelihood of rural communities in Chilga district, Northwest Ethiopia. It also addresses the factors which influence income diversification for livelihood of households in the study area. Result: The result depicts that the major causes of land degradation are both natural and anthropogenic. Land degradation and livelihood are negatively interlinked with each other. The livelihood of the majority of the population in the study area is dependent on subsistence agriculture both farming and animal husbandry with low diversification. The survey result showed that more than half (69%) of the sample households have farm size of less than 2 ha, nearly one third (31%) have 2.0-2.5 ha, and insignificant number of farmers have more than 2.5 ha. More than 80% of the respondents pointed out that land degradation has impacts both on crop yield and livestock production. Most of the explanatory variables such as gender, age, education level, farmland size, and family size have statistical significant influence (at P < .01 and P < .05 levels) for income diversification of households, while marital status on the other hand is not statistically significant though it has positive relation with income diversification in this study. Conclusions: Our results suggest awareness should be created in the community about the livelihood diversification mechanisms which enabled them to engage in different income-generating activities and comprehensive watershed management should be implemented.

Habitat selectivity of fresh water fishes of two second-order tropical streams in Tigray, Northern Ethiopia

  • Tesfay, Solomon;Teferi, Mekonen;Tsegazeabe, Haileselasie Hadush
    • Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.73-83
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    • 2019
  • Background: Habitat selectivity and ecology of freshwater fishes were studied in two selected streams and their junction point which consist a total of 39 microhabitats. The aims of this study were to describe the habitat preference and its availability to fish assemblage, as well as ecology, habitat use, and habitat characteristics. Methods: We collected fish with backpack electrofishing three times during August 2013, December 2013, and March 2014. Using a variation partitioning approach of R software, we studied the relationship of fish abundances with stream type, habitat type, and abundance of key macroinvertebrate taxa. Results: A total of 6554 fishes representing four species belonging to the family Cyprinidae were caught. A higher total fish abundance was recorded from Gereb Tsedo (4870; 74.3%) than from Elala stream (1684; 25.7%). Taking both streams together, the overall total relative fish abundance was significantly higher in pools (53%) than in runs (35%) and in riffles (12%) at P < 0.05. Species-wise comparisons showed that 71%, 15%, 13%, and 1% of the pool fish community were occupied by Garra blanfordii, Garra ignestii, Garra dembecha, and Garra aethiopica, respectively. Stream type, habitat type, and key macroinvertebrate taxa each explained a significant proportion of the variation in fish abundance. Based on the variation partitioning approach, fish abundance was higher in Gereb Tsedo stream (P < 0.01). Moreover, fish abundance increased with pool habitat type (P < 0.01) and with availability of key macroinvertebrate taxa (P < 0.01). Conclusion: Fish abundance differed between stream types, among habitats and among key macroinvertebrate taxa availability. Among the factors, habitat type was the most important driving factor behind variation among fish abundances, and pool supports the highest fish abundance.

Responses of Soil Bacterial and Fungal Communities to Organic and Conventional Farming Systems in East China

  • Zhang, Hanlin;Zheng, Xianqing;Bai, Naling;Li, Shuangxi;Zhang, Juanqin;Lv, Weiguang
    • Journal of Microbiology and Biotechnology
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    • v.29 no.3
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    • pp.441-453
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    • 2019
  • Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of Nodosilinea, Nitrospira, LCP-6, HB118, Lyngbya, GOUTA19, Mesorhizobium, Sandaracinobacter, Syntrophobacter and Sphingosinicella, and has the potential to strengthen soil metabolic ability with Novosphingobium. On the other hand, CF increased the intensity of nitrogen cycling with Ardenscatena, KD1-23, Iamia, Nitrosovibrio and Devosia, but enriched several pathogen fungal members, including Coniochaeta, Corallomycetella, Cyclaneusma, Cystostereum, Fistulina, Curvularia and Dissoconium.

Evaluation of Water Quality Characteristics and Ecosystem Health of Yongpung Reservoir, Korea

  • Lim, Dohun;Lee, Yoonjin;Kim, Kyung
    • Journal of Environmental Health Sciences
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    • v.45 no.1
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    • pp.42-53
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    • 2019
  • Objectives: The Yongpung reservoir in Korea is a crucial facility that supplies water to farms in its surrounding $2km^2$ area. However, its water quality is not suited to the needs of current residents who wish for the availability of environmentally friendly agricultural products and desire to use the waterfront area. The aim of this research was to evaluate the reservoir's fish and benthic macroinvertebrate distributions and determine its water quality and the heavy metal content in its sediment. This basic data can be used to establish environmentally protective plans for the Yongpung reservoir. Methods: Six sites were selected for analysis in this investigation. Three points (YP-1, YP-2, and YP-3) were evaluated for water quality and metal content in sediments; they were located upstream, midstream, and downstream of the reservoir. Samplings of the fish and benthic macroinvertebrate populations were performed at three other sites: St. 1, St. 2, and St. 3. Results: Based on chemical oxygen demand (COD) and total nitrogen (T-N) data, the quality of the Yongpung reservoir water corresponds to Class VI (very poor) according to Korea's lake environmental standards. The lead levels measured in the sediment at the midstream and downstream points of the reservoir were 76.7 and 72.7 mg/kg, respectively, while 8 orders, 15 families, and 16 species of benthic macroinvertebrates were identified in the reservoir. The ecological score of the benthic macroinvertebrate community (ESB) was between 8 and 23, denoting poor to very poor environmental conditions. Further, 4 families and 7 species of fish were identified in the reservoir, with Cyprinidae accounting for 94.3% of all observed freshwater fish. Conclusion: Based on these findings, we conclude that management plans, including the removal of lead from the sediment, are necessary to improve the quality of the agricultural water in this reservoir. The T. japonica, which cover almost 30% of the water area, must also be removed.

Elevational distribution ranges of vascular plant species in the Baekdudaegan mountain range, South Korea

  • Shin, Sookyung;Kim, Jung-Hyun;Dang, Ji-Hee;Seo, In-Soon;Lee, Byoung Yoon
    • Journal of Ecology and Environment
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    • v.45 no.1
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    • pp.62-71
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    • 2021
  • The climate is changing rapidly, and this may pose a major threat to global biodiversity. One of the most distinctive consequences of climate change is the poleward and/or upward shift of species distribution ranges associated with increasing temperatures, resulting in a change of species composition and community structure in the forest ecosystems. The Baekdudaegan mountain range connects most forests from the lowland to the subalpine zone in South Korea and is therefore recognized as one of the most important biodiversity hotspots. This study was conducted to understand the distribution range of vascular plants along elevational gradients through field surveys in the six national parks of the Baekdudaegan mountain range. We identified the upper and lower distribution limits of a total of 873 taxa of vascular plants with 117 families, 418 genera, 793 species, 14 subspecies, 62 varieties, two forms, and two hybrids. A total of 12 conifers were recorded along the elevational gradient. The distribution ranges of Abies koreana, Picea jezoensis, Pinus pumila, and Thuja koraiensis were limited to over 1000 m above sea level. We also identified 21 broad-leaved trees in the subalpine zone. A total of 45 Korean endemic plant species were observed, and of these, 15 taxa (including Aconitum chiisanense and Hanabusaya asiatica) showed a narrow distribution range in the subalpine zone. Our study provides valuable information on the current elevational distribution ranges of vascular plants in the six national parks of South Korea, which could serve as a baseline for vertical shifts under future climate change.

Spatial distribution of halophytes and environment factors in salt marshes along the eastern Yellow Sea

  • Chung, Jaesang;Kim, Jae Hyun;Lee, Eun Ju
    • Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.264-276
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    • 2021
  • Background: Salt marshes provide a variety of ecosystem services; however, they are vulnerable to human activity, water level fluctuations, and climate change. Analyses of the relationships between plant communities and environmental conditions in salt marshes are expected to provide useful information for the prediction of changes during climate change. In this study, relationships between the current vegetation structure and environmental factors were evaluated in the tidal flat at the southern tip of Ganghwa, Korea, where salt marshes are well-developed. Results: The vegetation structure in Ganghwa salt marshes was divided into three groups by cluster analysis: group A, dominated by Phragmites communis; group B, dominated by Suaeda japonica; and group C, dominated by other taxa. As determined by PERMANOVA, the groups showed significant differences with respect to altitude, soil moisture, soil organic matter, salinity, sand, clay, and silt ratios. A canonical correspondence analysis based on the percent cover of each species in the quadrats showed that the proportion of sand increased as the altitude increased and S. japonica appeared in soil with a relatively high silt proportion, while P. communis was distributed in soil with low salinity. Conclusions: The distributions of three halophyte groups differed depending on the altitude, soil moisture, salinity, and soil organic matter, sand, silt, and clay contents. Pioneer species, such as S. japonica, appeared in soil with a relatively high silt content. The P. communis community survived under a wider range of soil textures than previously reported in the literature; the species was distributed in soils with relatively low salinity, with a range expansion toward the sea in areas with freshwater influx. The observed spatial distribution patterns may provide a basis for conservation under declining salt marshes.

Calvin's Reformation in Geneva and the Urban Missional Direction of Christianity Today (도시 제네바에서의 칼빈의 종교개혁과 현대 기독교의 도시 선교적 방향성 모색)

  • Bong, Won Young
    • The Journal of the Korea Contents Association
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    • v.21 no.11
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    • pp.436-449
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    • 2021
  • The purpose of this study is to examine the characteristics of the Reformation Calvin undertook in Geneva and see what efficient functions Christianity can afford to reveal its value in urban settings today. Calvin's Reformation provided a clear place and role for the Church in the public domain. In addition, Calvin's process of religious reform has always been followed by interest and welfare practices for the socially disadvantaged, such as the poor and women. In this understanding, the study presented the following applications that modern churches can practice in urban settings today: First, the church should be able to clearly understand the diversity, liquidity, and dynamics of the urban environment and make changes through various situational applications supported by the Bible. Second, the church's missional approach should shift from a believing-belonging process to a sense of belonging-believing. Third, the transition from a familiar traditional church to a new social reality is necessary, and efforts are needed to clearly understand the interests and atmosphere of community communities and keep pace with them. And finally, modern churches need to maintain new ecological sensitivity than ever before.

Crisis in Women during COVID-19 Pandemic and Pastoral Theological Reflection on Care : Christian Educational Approach (코로나 19 팬데믹 시대 속 여성의 위기와, 돌봄에 대한 목회신학적 성찰 : 기독교 교육학적 접근)

  • Lee, Soo Young
    • Journal of Christian Education in Korea
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    • v.68
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    • pp.217-243
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    • 2021
  • As can be seen from the statement by the UN Secretary-General that "COVID-19 is a crisis with a woman's face," women have experienced great crisis, pain, and difficulties caused by the COVID-19 pandemic. This study examined the situations of women through statistical data and research studies. Through this study, economic, socio-cultural, and psycho-emotional aspects were dealt with in detail, and how these issues appeared in relation to "caring" were examined. In addition, as a response of the church to these problems and crises, pastoral theological reflection was promoted through "Ethics of Care" and "caring ministry". The "caring ministry" of the church extends not only to personal care within the church, but also to social, cultural, economic, political, and ecological issues, and the church has a missionary mission to respond to these issues related to disasters with a public nature. Furthermore, through educational ministry, the change of values and mindsets on "care" and inequality and Diakonia, the loving care of the church community, should be encouraged.

Effects of reforestation approaches, agroforestry and woodlot, on plant community composition, diversity and soil properties in Madhupur Sal forest, Bangladesh

  • Hasan, Mohammad Kamrul;Islam, Md. Tariqul;Akter, Rojina;Roshni, Nasima Akther
    • Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.204-217
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    • 2022
  • Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m2 ha-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.