• Title/Summary/Keyword: ECOLOGICAL RESPONSES

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Monitoring of Land Surface Dynamics in Northeastern Asia with NOAA/AVHRR Data from 1984 to 1993

  • Oyoshi, K.;Takeuch, Wataru;Yasuoka, Yoshifumi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1128-1130
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    • 2003
  • This study investigated interannual variations in Northeastern Asian vegetation activity inferred from NOAA/AVHRR data during 1984 to 1993. Firstly, original NOAA/AVHRR data was radiometrically and atmospherically corrected in order to produce a consistent and calibrated time series NDVI by eliminating the effect of atmospheric effects and sensor degradation. Next, the NDVI data was analyzed to detect terrestrial ecosystem responses to climate change. A larger increase in growing season NDVI magnitude was observed in Northeastern Asia. Especially, vegetation activity is increasing in north part of Northeastern Asia. However, satellite drift and eruption effect have affect on interannual NDVI variations and it has affected the result in some degree. To improve accuracy of the result, it is necessary to correct these effects.

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Effects of Global Warming and Environmental Factors of Light, Soil Moisture, and Nutrient Level on Ecological Niche of Quercus acutissima and Quercus variabilis (지구온난화와 환경요소인 광, 토양수분, 영양소가 상수리나무와 굴참나무의 생태 지위에 미치는 영향)

  • Cho, Kyu-Tae;Jang, Rae-Ha;Lee, Seung-Hyuk;Han, Young-Sub;You, Young-Han
    • Korean Journal of Ecology and Environment
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    • v.46 no.3
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    • pp.429-439
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    • 2013
  • This study was conducted to determine the changes of the ecological niche breadth and niche overlap of Quercus acutissima and Quercus variabilis under elevated $CO_2$ concentrations and under elevated temperature conditions. We investigated the growth responses by environmental factor, $CO_2$ concentration, air temperature, light, soil moisture and nutrients. Rising $CO_2$ concentration was treated with 1.6 times than control (ambient) and increased temperature with $2.2^{\circ}C$ above the control (ambient) in the glass greenhouse. Ecological niche breadth and niche overlap was calculated the two oak species (Q. acutissima and Q. variabilis), which were cultivated with light, soil moisture and nutrient gradients at four levels. As a result, the ecological niche breadth of Quercus acutissima was determined to be increased under the warming treatment, but decreased under soil moisture and nutrient environments. The ecological niche breadth of Quercus variabilis was increased under light, soil moisture and nutrients of the warming treatment than control. Ecological niche overlap between Quercus acutissima-Quercus variabilis was increased under light of the warming treatment than control, but decreased under soil moisture and nutrient environments. These results means that two oak species are more severe competition in light environments than soil moisture and nutrient environments. According to analyses of the Cluster and PCA, the two oak species were more sensitive react under light environment than to elevated $CO_2$ concentration or elevated temperature.

Responses of Shorebirds to Disturbance at Roosting Sites

  • Kim, Hwa-Chung;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • v.30 no.1
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    • pp.69-73
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    • 2007
  • The sources and the frequency of disturbances and the responses of shorebirds to disturbances were studied at four roosting sites on Ganghwa Island and Yeongjong Island. The mean frequency of disturbance to roosting shorebirds was 2.7 per hour. Human activities contributed to the disturbance in 65% of all cases. Disturbance frequencies in saltpans were higher than those in the upper tidal zone, fishponds and salt marshes. Response patterns of shorebirds to disturbances were associated with the source of the disturbance. Disturbance caused shorebirds to change their behavior and to reduce roosting time at their roosting sites. Four patterns of responses by roosting shorebirds to disturbance were found, including: (1) leaving the roosts, (2) changing their location within the site, (3) leaving and returning, and (4) remaining in place. In the latter three response patterns, the birds tended to remain in their initial roosting sites, in contrast with the leaving pattern, which involved departing from the roosting area. Factors affecting these response patterns were time from high tide and time of day. When the time from high tide was greater, and the time of day was later, more birds stayed at the roost. The absence of sufficient alternative roosts in the study areas forced the birds to choose between tolerating the current disturbance, or moving to distant roosts.

The responses on elderly shared group house as a socially integrated housing alternative in aging society (고령화미래 사회통합방안으로서의 기존 주거지역내 노인공동사용주택에 대한 태도연구)

  • Lee, Junghwa;Lee, Yeunsook;Lee, Soojin
    • KIEAE Journal
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    • v.7 no.4
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    • pp.63-74
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    • 2007
  • While the importance of social integration has been mainly emphasized in the fields of social welfare services for the elderly, disabled and lower income citizens, many types of elderly housing had been developed in a way of segregating the elderly from society rather than integrating. Meanwhile, shared group house may allow older people to 'age in place' within the communities where they used to live by providing them with social, economic and practical benefits. The purpose of this study is to carry out empirical research on responses to elderly shared group house. Interview survey with questionnaire was conducted among 138 elderly people between 60-75 years old, living in Seoul and its metropolitan area. Responses of the elderly included awareness, perception and preference. It was revealed that the respondents had negative perceptions on existing shared group house in Korea. Most of the respondents showed preference to moving into socially-integrated type of shared group houses developed within their communities. This study indicated the potential of such type shared group house to become a favorable housing alternative for elderly people which supports their sustainable independent living within community.

Growth and Photosynthetic Responses of One C3 and Two C4 Chenopodiaceae Plants to Three CO2 Concentration Conditions

  • Ishikawa, Shin-Ichi
    • Journal of Ecology and Environment
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    • v.31 no.4
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    • pp.261-267
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    • 2008
  • Growth and photosynthetic responses of one $C_3$ and two $C_4$ plants in the family Chenopodiaceae in three $CO_2$ concentration $([CO_2])$ conditions-low (about $243{\mu}mol\;mol^{-1}$, LC), present (about 378, PC), and high (about 465, HC)-were investigated in open top chambers. The relative growth rate (RGR) and net assimilation rate in the $C_3$ plant, Chenopodium album, increased with increasing $[CO_2]$, though the RGR was not enhanced significantly in the HC condition. The leaf area ratio and leaf weight ratio of the $C_3$ plant drastically decreased with increasing $[CO_2]$, suggesting that the $C_3$ plant invests more biomass to leaves in lower $[CO_2]$ conditions. The two $C_4$ plants, Atriplex glauca and A. lentiformis, showed relatively small changes in those growth parameters. These photosynthetic-pathway-dependent responses suggest that growth patterns of $C_3$ and $C_4$ plants have been altered by past increases in atmospheric $[CO_2]$ but that there will be relatively little further alteration in the future high-$CO_2$ world.

Characterization of macro-benthic fauna for ecological health status of the Fosu and Benya lagoons in coastal Ghana

  • Armah, Frederick A.;Ason, Benjamin;Luginaah, Isaac;Essandoh, Paul K.
    • Journal of Ecology and Environment
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    • v.35 no.4
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    • pp.279-289
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    • 2012
  • This study conducted a comparative analysis of benthic macroinvertebrate communities in the Fosu and Benya lagoons in Ghana, based on the anthropogenic effect on the two lagoons. Salinity, oxygen, temperature, conductivity, turbidity and pH were measured, invertebrate richness and species densities were determined. The AZTI Marine Biotic Index (AMBI) and multivariate statistics were used to determine the different responses of fauna to pollution. The fauna were categorized into five ecological groups based on the degree of tolerance of the different species to pollution: disturbance-sensitive species; disturbance-indifferent species, disturbance-tolerant species, second-order opportunistic species; and first-order opportunistic species. The Fosu Lagoon supported more pollution tolerant species, whereas the Benya Lagoon had more species that were sensitive to organic enrichment under relatively unpolluted conditions. Chironomus sp., which is adapted to virtually anoxic conditions, was the most abundant in the Fosu Lagoon whereas Nemertea sp. was the most abundant in the Benya Lagoon. The numerical and relative abundance (%) of all 7 taxa in the Fosu Lagoon was 1,359 and 92.35%, respectively. The numerical and relative abundance (%) of all 34 taxa in the Benya Lagoon was 2,459 and 87.52%, respectively. Expectedly, the level of dissolved oxygen in the less saline Fosu Lagoon was higher than that in the more saline Benya Lagoon. The reduced photoperiod and photosynthetic activities of aquatic plants might account for this trend. There is a need to implement comprehensive monitoring and management initiatives for sustaining the ecological health of coastal lagoons in Ghana in order to support the many people that depend upon these ecosystems for their livelihood.

Which Environmental Factors Caused Lammas Shoot Growth of Korean Red Pine?

  • Lee, Chang-Seok;Song, Hye-Gyung;Kim, Hye-Soo;Lee, Bit-Na-Ra;Pi, Jeong-Hoon;Cho, Yong-Chan;Seol, Eun-Sil;Oh, Woo-Seok;Park, Sung-Ae;Lee, Seon-Mi
    • Journal of Ecology and Environment
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    • v.30 no.1
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    • pp.101-105
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    • 2007
  • Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.