• Title/Summary/Keyword: Global climatic changes

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Aboveground Net Primary Productivity and Spatial Distribution of Chaco Semi-Arid Forest in Copo National Park, Santiago del Estero, Argentina

  • Jose Luis Tiedemann
    • Journal of Forest and Environmental Science
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    • v.40 no.2
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    • pp.99-110
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    • 2024
  • According to the REDD+ program, it is necessary to monitor, quantify, and report forest conditions in protected land areas. The objectives of this work were to quantify the average monthly aerial net primary productivity (ANPPMONTH) of semi-arid Chaco Forest at Copo National Park (CNP), Santiago del Estero, Argentina, during the period 2000-2023, as well as its spatial distribution and relationship, and its use efficiency (RUE) of average monthly rainfall (AMR). The ANPPMONTH model accounted for 90% of the seasonal variability from October to May, the average seasonal ANPPMONTH was 145 tons of dry matter per hectare (t dm/ha), being the maximum in January with 192 t dm/ha and the minimum in May with 91 t dm/ha. The surface area covered by ANPPMONTH exhibited a consistent positive trend from October to May (t test=15.65, p<0.01). Strong and significant direct relationships were found between ANPPMONTH and AMRs, linear models explaining 90% and 96% of the variability, respectively. The results obtained become reference values for assessing the capacity of the forest systems to stock carbon for global warming mitigation and for monitoring and controlling their response to extreme climatic adversities. The average ANPPMONTH reduces uncertainty when defining the thresholds to monitor and quantify ANPP and forest area, thus facilitating the detection of negative changes in land use in CNP. Such results evidence the National Parks Administration's high effectiveness for the maintenance of protected area and for the high ANPP of the FCHS of CNP in the period 2000-2023.

Origin, Age and Sedimentation Rate of Mid-Geum River Sediments (금강 중류 하상 퇴적층의 기원과 형성시기 및 퇴적율)

  • Oh, Keun-Chang;Kim, Ju-Yong;Yang, Dong-Yoon;Hong, Sei-Sun;Lee, Jin-Young;Lim, Jae-Soo
    • Economic and Environmental Geology
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    • v.43 no.4
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    • pp.333-341
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    • 2010
  • Fluvial sediments are widely distributed in present and old river-beds of the mid-Keum River, the tributaries of which are the Yugu and Jeongan Rivers. The basement of the mid-Keum River area consists of Mesozoic granites which are easily eroded compared to Precambrian gneisses, which are exposed in the upper-Keum River area. The provenance of the fluvial sediments includes both the Precambrian gneisses and Mesozoic granites, which occur in the catchment of the mid-Keum River. The coarse-grained sediments were probably transported from the river-beds and the overbank floodings of the main Keum River and its tributaries when the climate was warm and wet. The oldest mud deposits were dated at ca. 9,400 yr BP by the radiocarbon method. It has been estimated that the sand deposits below the dated muds were formed in a period from the Late Pleistocene to the Early Holocene. However we have revealed that the major part of the present river-bed sediments was formed at ca. 3,000-6,000 yr BP, i.e., in the mid- to late Holocene, when summer monsoon was very strong due to climatic changes. We have calculated fluvial sedimentation rates of 0.12-0.16 cm/yr and 0.02-0.09 cm/yr for borehole KJ-29 river-bed sediments and borehole KJ-28 floodplain deposits, respectively. We conclude that the sedimentation rate is higher near the present stream channel than near the floodplain.

Impacts of Elevated $CO_2$ on Algal Growth, $CH_4$ Oxidation and $N_2O$ Production in Northern Peatland (이탄습지에서 이산화탄소의 농도가 조류의 증식, 메탄 산화 및 아산화질소 생성에 미치는 영향)

  • Freeman, Chris;Kang, Ho-Jeong
    • Korean Journal of Ecology and Environment
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    • v.34 no.4 s.96
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    • pp.261-266
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    • 2001
  • Effects of elevated carbon dioxide ($CO_2$) on soil microbial processes were studied in a northern peatland. Intact peat cores with surface vegetation were collected from a northern Welsh fen, and incubated either under elevated carbon dioxide (700 ppm) or ambient carbon dioxide (350 ppm) conditions for 4 months. Higher algal biomass was found under the elevated $CO_2$ condition, suggesting $CO_2$ fertilization effect on primary production, At the end of the incubation, trace gas production and consumption were analyzed using chemical inhibitors. For methane ($CH_4$ ), methyl fluoride ($CH_3F$) was applied to determine methane oxidation rates, while acetylene ($C_2H_2$) blocking method were applied to determine nitrification and denitrification rates. First, we have adopted those methods to optimize the reaction conditions for the wetland samples. Secondly, the methods were applied to the samples incubated under two levels of $CO_2$. The results exhibited that elevated carbon dioxide increased both methane production (210 vs. $100\;ng\;CH_4 g^{-1}\;hr^{-1}$) and oxidation (128 vs. $15\;ng\;CH_4 g^{-1}\;hr^{-1}$), resulting in no net increase in methane flux. For nitrous oxide ($N_2O$) , elevated carbon dioxide enhanced nitrous oxide emission probably from activation of nitrification process rather than denitrification rates. All of these changes seemed to be substantially influenced by higher oxygen diffusion from enhanced algal productivity under elevated $CO_2$.

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Optimum Delivery Frequency for Reducing Construction Logistics Cost under a Carbon Taxation (탄소세 부과시 건설 물류비용 최소화를 위한 운송빈도 최적화)

  • Park, Moon-Seo;Chun, Myung-Hee;Lee, Hyun-Soo;Hwang, Sung-Joo;Jang, Myung-Houn
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.3
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    • pp.73-82
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    • 2011
  • The term 'green' has become an important way of survival for the construction industry in 21th century in accordance with the emergence of the environmental crisis due to the climatic change. Especially the policy of carbon taxation, planed to be introduced from 2012, is expected to be a considerable burden to the construction industry which has abundant carbon emission during the resource transportation due to the complexity of resources and local distribution of the construction sites. In this regard, this study shows an optimizing strategy for delivery frequency, which downsizes the net distribution costs based on the assumption that, despite of its other advantagements, the frequent small lot mode of JIT delivery would take negative effects due to the increase of costs of transportation and carbon emission once the carbon taxation policy carried out. To simulate the efficiency of the management strategies, the System Dynamics modeling has been used. The results show that the frequent small lot transportation strategy is now always efficient method to these changes, and that the frequency of transportation should be re-determinated according to the extent of the imposition of carbon tax. This study provides the conceptual frame for an efficient management of transportation system of the construction industry, showing necessity of change of the resource transportation systems through analysing JIT deliver system in accordance with the global changes in environmental economy.

Production and Spatiotemporal Analysis of High-Resolution Temperature-Humidity Index and Heat Stress Days Distribution (고해상도 온습도지수 및 고온 스트레스 일수 분포도의 제작과 이를 활용한 시공간적 변화 분석)

  • Dae Gyoon Kang;Dae-Jun Kim;Jin-Hee Kim;Eun-Jeong Yun;Eun-Hye Ban;Yong Seok Kim;Sera Jo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.4
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    • pp.446-454
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    • 2023
  • The impact of climate change on agriculture is substantial, especially as global warming is projected to lead to varying temperature and humidity patterns in the future. These changes pose a higher risk for both crops and livestock, exposing them to environmental stressors under altered climatic conditions. Specifically, as temperatures are expected to rise, the risk of heat stress is assessable through the Temperature-Humidity Index (THI), derived from temperature and relative humidity data. This study involved the comparison of THI collected from 10 Korea Meteorological Administration ASOS stations spanning a 60-year period from 1961 to 2020. Moreover, high-resolution temperature and humidity distribution data from 1981 to 2020 were employed to generate high-resolution TH I distributions, analyzing temporal changes. Additionally, the number of days characterized by heat stress, derived from TH I, was compared over different time periods. Generally, TH I showed an upward trend over the past, albeit with varying rates across different locations. As TH I increased, the frequency of heat stress days also rose, indicating potential future cost increases in the livestock industry due to heat-related challenges. The findings emphasize the feasibility of evaluating heat stress risk in livestock using THI and underscore the need for research analyzing THI under future climate change scenarios.

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.

Remote Sensing Applications for Malaria Research : Emerging Agenda of Medical Geography (원격탐사 자료를 이용한 말라리아 연구 : 보건지리학적 과제와 전망)

  • Park, Sunyurp
    • Journal of the Korean association of regional geographers
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    • v.18 no.4
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    • pp.473-493
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    • 2012
  • Malaria infection is sensitively influenced by regional meteorological conditions along with global climate change. Remote sensing techniques have become an important tool for extraction of climatic and environmental factors, including rainfall, temperature, surface water, soil moisture, and land use, which are directly linked to the habitat qualities of malaria mosquitoes. Improvement of sensor fidelity with higher spatial and spectral resolution, new multinational sensor development, and decreased data cost have nurtured diverse remote sensing applications in malaria research. In 1984, eradication of endemic malaria was declared in Korea, but reemergence of malaria was reported in mid-1990s. Considering constant changes in malaria cases since 2000, the epidemiological management of the disease needs careful monitoring. Geographically, northmost counties neighboring North Korea have been ranked high in the number of malaria cases. High infection rates in these areas drew special attention and led to a hypothesis that malaria dispersion in these border counties might be caused by north-origin, malaria-bearing adult mosquitoes. Habitat conditions of malaria mosquitoes are important parameters for prediction of the vector abundance. However, it should be realized that malaria infection and transmission is a complex mechanism, where non-environmental factors, including human behavior, demographic structure, landscape structure, and spatial relationships between human residence and the vector habitats, are also significant considerations in the framework of medical geography.

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An Empirical Study on the Impact of Quality Oriented Corporate Culture on Sustainability Management Performances (공급사슬 내에서 품질지향적 기업문화가 지속가능경영성과에 미치는 영향에 관한 실증연구)

  • Woo, Moo-Jin;Park, Jong-Woo;Jung, Byeong-Yeong
    • Journal of Distribution Science
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    • v.12 no.6
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    • pp.31-39
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    • 2014
  • Purpose - Environmental issues, climatic changes, and greenhouse gases are problems to be solved at a global level. With an increased emphasis on the environmental and social responsibility of the management of companies, the manner in which companies approach quality-oriented culture and their individual sustainability management are being discussed as truly important issues to help them secure their competitiveness and growth strategies. This study proposes strategic directions to help manufacturers not only in expanding their competitive quality-oriented company culture but also in strengthening their sustainability management abilities. This study conducts a literature review and empirical research to examine how significantly the variables of a quality-oriented company culture, customer-centered management, and process-centered and supply chain management-centered cooperation affect sustainability management performance in relation to economic profitability, environmental integrity, and social responsibility. Research design, data, and methodology - To verify research models and hypotheses, the study examined 170 companies using a questionnaire survey conducted over six weeks, and involved the performance of data analysis on 146 samples. Questionnaire responses were calibrated based on a Likert scale. The study used the Smart PLS 2.0 program designed for PLS (partial least squares), an analysis instrument of SEM (structural equation modeling). The study then verified empirical research hypotheses working on reliability analysis, validity analysis, factorial analysis, and path analysis. Results - Among the nine hypotheses, four are accepted and the rest are rejected. A quality-oriented company culture focusing on customer-centered management significantly influenced the maintainability management performance of environmental integrity and social responsibility, while economic profitability was dismissed. A process-focused quality-oriented company culture was significantly concerned with economic profitability but not with environmental integrity or social responsibility. A supply-chain cooperative company culture had a significant effect on economic profitability but not on environmental integrity or social responsibility. Conclusion - This study proposes strategic directions to help manufacturers expand their competitive quality-oriented company culture as well as strengthen abilities with sustainability management. It conducts a literature review and empirical research to examine how significantly the variables of quality-oriented company culture, customer-centered management, and process-centered and supply chain management-centered cooperation affect sustainability management performance in relation to economic profitability, environmental integrity, and social responsibility. There are two main conclusions. First, companies should consider the need for social responsibility management and environmental transparent management-focused maintainability management as avenues to create new markets and business, thereby helping the companies secure a reputation for having a customer and process-centered quality-oriented company culture by creating shared values between supply chains and enabling win-win situations through cooperation. Second, we are marching towards a creative win-win era from a society of conflicts and ruptures. Companies should understand that social responsibility management and supply chain management (SCM)-focused cooperation are the foundations of sustainable development, as they try to improve their culture while pursuing both win-win relationships with interested parties and equity in various conflictive relations.

Seasonal Onset and Duration in South Korea (우리나라 사계절 개시일과 지속기간)

  • Choi, Gwang-Yong;Kwon, Won-Tae;Robinson David A.
    • Journal of the Korean Geographical Society
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    • v.41 no.4 s.115
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    • pp.435-456
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    • 2006
  • This study examines the long-term spatial patterns and recent trends of seasonal onsets and durations defined by daily temperatures in South Korea for the period 1973-2004. Spatially, spring and winter onset dates show approximately 44 day and 63 day maximum difference respectively between south and north (Seongsanpo to Daegwallryeong) attributable to the impacts of latitudes and altitudes. In contrast, summer onset, which is more affected by proximity to oceans and altitudes than by latitudes, begins earlier in interior low elevated areas than in the coastal areas but earliest at higher latitudes than Jeiu Island. Five climatic types regarding the seasonal cycles in South Korea are spatially clustered according to the combination of longer seasonal durations. As a reflection of recent climate changes on seasonal cycles in South Korea, winter duration was shortened by 10 days during the post-1988 period due to a late winter onset of 4 days and an early spring onset of 6 days. The winter reduction began in the southern regions of the Korean Peninsula in the mid-1980s and spread northward during the 1990s period, ultimately appearing everywhere. In urbanized cities, where much of the surface is covered with asphalt or concrete, the winter reduction was intensified and summer duration was locally incremented. The reduced winter duration in recent decades shows significant teleconnections with variations of geopotential height (925hPa) in the eastern Arctic region ($0-90^{\circ}E$, $65-85^{\circ}N$) during the cold season. The reduction in winter duration in South Korea agrees with results in overall global warming trends as a climate change signal.

Marine Heat Waves Detection in Northeast Asia Using COMS/MI and GK-2A/AMI Sea Surface Temperature Data (2012-2021) (천리안위성 해수면온도 자료 기반 동북아시아 해수고온탐지(2012-2021))

  • Jongho Woo;Daeseong Jung;Suyoung Sim;Nayeon Kim;Sungwoo Park;Eun-Ha Sohn;Mee-Ja Kim;Kyung-Soo Han
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1477-1482
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    • 2023
  • This study examines marine heat wave (MHW) in the Northeast Asia region from 2012 to 2021, utilizing geostationary satellite Communication, Ocean, and Meteorological Satellite (COMS)/Meteorological Imager sensor (MI) and GEO-KOMPSAT-2A (GK-2A)/Advanced Meteorological Imager sensor (AMI) Sea Surface Temperature (SST) data. Our analysis has identified an increasing trend in the frequency and intensity of MHW events, especially post-2018, with the year 2020 marked by significantly prolonged and intense events. The statistical validation using Optimal Interpolation (OI) SST data and satellite SST data through T-test assessment confirmed a significant rise in sea surface temperatures, suggesting that these changes are a direct consequence of climate change, rather than random variations. The findings revealed in this study serve the necessity for ongoing monitoring and more granular analysis to inform long-term responses to climate change. As the region is characterized by complex topography and diverse climatic conditions, the insights provided by this research are critical for understanding the localized impacts of global climate dynamics.