• ALGAE
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• 제19권3호
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• pp.207-216
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• 2004

Characteristics of photosynthesis-light and photosynthesis-temperature relationships were seasonally compared among 4 species, two temperate Sargassurn (S. ringgoldianum and S. spathulophyllum) and two temperate kelp (Ecklonia cava and Eisenia bicyclis), growing in the same habitat in Oura Bay, Shimoda, central Japan. The photosynthesis-irradiance (P-I) curve of each species at the in situ temperature and the photosynthesis-temperature (P-T) curve at near saturation irradiance (400μmol·m^(-2)·s^(-1)) were determined by using differential gas-volumeters. Maximum photosynthetic rates (Prnax) for P-I curves of the two Sargassurn species were higher from summer to autumn than from winter to spring, while those of the two kelp species showed little difference among seasons. Net photosynthetic rates (Pn) at 100-400μmol·m^(-2)·s^(-1) of the Sargassurn species were higher than those of the kelp species in autumn, spring and summer, while in winter the rates were about the same between the Sargassurn and kelp species. Among seasons, the light saturation index (1k) values, dark respiration rates and light compensation points of Sargassurn species differed more than those of kelp species. Optimum temperature for P-T curves of Sargassurn species was 29℃ and that of kelp species was 27℃ in summer, while in winter the former was 27℃ and the latter was 25℃. Pn at 400 μmol·m^(-2)·s^(-1) at 10-33℃ of Sargassurn species were considerably higher than those of kelp species from spring to summer, while from autumn to winter the rates at 5-27℃ were about the same between the two. At supra-optimum temperatures, Pn of kelp species decreased more sharply than those of Sargassurn species in each season. These facts indicate that the two temperate Sargassurn species have a higher potential photosynthetic performance under warmer conditions than the two temperate kelp species even though they grow in the same habitat.

• KIEAE Journal
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• 제13권4호
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• pp.103-112
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• 2013

The Federal Democratic Republic of Nepal(Nepal) is one of the poorest country in the world. People in Nepal are having lots of housing problems including the lack of housing provision. Even Habitat for Humanity Nepal (HfH_Nepal) has developed various programs to diffuse ecological housing, still there are many problems due to financial and technological shortage. The purpose of this study is to verify the effects of suggestion of performance improvement for HfH_Nepal eco house with introduction of the housing situation and efforts to provide sustainable housing by HfH_Nepal in Terai plain. Ideas on CGI sheet roof with poor insulation, double panel bamboo wall and adobe brick wall which can overcome structural and waterproof flaws of the thin single panel bamboo wall. The experiment result shows that both ideas adapted to adobe brick house reduces daily temperature range 50.8% and humidity adjust effect. For the effective provision of adobe brick house, compressive strength was tested for the bricks made with locally available fiber materials. Brick with jute displayed 41.1% betterment than plain brick with closest packing condition while coconut and straw showed 25.1% and 7.9% improvement respectively. Technical and economic problems brought up during the building and experiment process were listed and countermeasures established. This kinds of building prototype houses and experiments can improve the living conditions of people in developing countries with little supplement of resources. Furthermore, consideration of locally available and affordable material can help the social and ecological sustainability in the world.

• Journal of Ecology and Environment
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• 제40권2호
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• pp.107-119
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• 2016

Background: Previous studies on the biological integrity on habitat and landuse patterns demonstrated ecological stream health in the view of regional or macrohabitat scale, thus ignored the mesoscale habitat patterns of pool, riffle, and runs in the stream health analysis. The objective of this study was to analyze influences on the mesohabitat structures of pool, riffle, and run reaches on the fish guilds and biological integrity in Geum-River Watershed. Results: The mesohabitat structures of pool, riffle, and run reaches influenced the ecological stream health along with some close relations on the fish trophic and tolerance guilds. The mesoscale components altered chemical water quality such as nutrients (TN, TP) and BOD and these, then, determined the primary productions, based on the sestonic chlorophyll-a. The riffle-reach had good chemical conditions, but the pool-reach had nutrient enrichments. The riffle-reach had a predominance of insectivores, while the pool-reach has a predominance of omnivores. Also, the riffle-reach had high proportions of sensitive fish and insectivore fish, and the pool-reach had high proportions of tolerant species in the community composition. The intermediate fish species in tolerance and omnivorous fish species in the food linkage dominated the community in the watershed, and the sensitive and insectivorous fishes decreased rapidly with a degradation of the water quality. All the habitat patterns were largely determined by the land-use patterns in the watershed. Conclusions: Trophic guilds and tolerance guilds of fish were determined by land-use pattern and these determined the stream health, based on the Index of Biological Integrity. This study remarks the necessity to include additional variables to consider information provided by mesohabitats and land-use distributions within the selected stream stretch. Overall, our data suggest that land-use pattern and mesohabitat distribution are important factors to be considered for the trophic and tolerance fish compositions and chemical gradients as well as ecological stream health in the watershed.

• Journal of Ecology and Environment
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• 제41권10호
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• pp.281-289
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• 2017

Background: In this study, the growth and reproductive response of seedlings, grown in plastic pots with sand, to moisture and nutrients were analyzed in order to study the environmental conditions required to create an alternative habitat for Epilobium hirsutum L., an endangered plant. Results: Vegetative and reproductive growths of Epilobium hirsutum L. are accelerated with increase in moisture and organic matter content in the soil. Among vegetative organs, the number of runners related to asexual reproduction was the highest when the moisture content was over 25% and nutrient content between 7 and 14% in the soil. But the number of flowers related to flowering responses, among reproductive organs, was the highest when the moisture content was maintained at 75% and when nutrient content was 21% in the soil. The number of seeds, related to sexual reproduction, was the highest when the moisture content was over 25% and nutrient content between 14 and 21%. Conclusions: The study results show that a place with high moisture and nutrient content in the soil is advantageous to asexual and sexual reproduction of Epilobium hirsutum L. Therefore, we must serve periodically nutrient and seeds to sustain population in in situ conservation. Furthermore, it is advisable to create in riverside where abundant nutrient content have, making alternative habitat of Epilobium hirsutum L. Also, we must find species that have high contribution degree index through vegetation survey.

• 식물분류학회지
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• 제48권4호
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• pp.278-288
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• 2018

Polyploidization plays an important role in generating the current high diversity of plants. Studies of the distributional patterns of diploid and derivative polyploid races have provided important insights into the evolutionary process and cryptic speciation by polyploidization within and between closely related taxa defined on the basis of their morphology. Allium thunbergii and A. sacculiferum, occurring throughout eastern Russia, eastern China, Korea, and Japan, are examples of closely related species with unsolved taxonomic relationships. A total of 97 and 65 individuals from 26 and 13 populations of A. thunbergii (including var. thunbergii, var. deltoids, and var. teretifolium) and A. sacculiferum, respectively, were studied to determine their ploidy. The geographic structure and habitat differentiation of the cytotypes were also analyzed. The main cytotype of A. thunbergii was diploid (92.3% in total; the rest were tetraploids). In contrast, the majority of A. sacculiferum plants were tetraploids (69.2% of the total; the rest were diploids). No populations of the studied taxa harbored both cytotypes. Allium thunbergii was more often found at higher elevations than A. sacculiferum, and it tended to occur more frequently on rocky slopes and below forests in mountainous areas. On the other hand, A. sacculiferum occurred at forest margins and in lowland pastures. The cytotypes differed with respect to the elevation; diploids were found more frequently at higher elevations than tetraploids. The results of this study and additional biosystematics data indicate that the morphological characteristics of A. thunbergii and A. sacculiferum may be influenced by polyploidization and by their adaptation to various habitat conditions and that A. thunbergii and A. sacculiferum do not clearly fulfill the requirements of any species concept. Consequently, we propose that A. sacculiferum be considered as an additional synonym of A. thunbergii. Additionally, Allium thunbergii var. deltoides is unified into A. thunbergii var. thunbergii.

• Journal of Species Research
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• 제10권3호
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• pp.246-254
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• 2021

Subalpine and alpine ecosystems are especially vulnerable to temperature increases. Betula ermanii Cham. (Betulaceae) is a dominant broad-leaved tree species in the subalpine zone and is designated as a 'Climate-sensitive Biological Indicator Species' in South Korea. This study aimed to predict the potential distribution of B. ermanii under current and future climate conditions in South Korea using the MaxEnt model. The species distribution models showed an excellent fit (AUC=0.99). Among the climatic variables, the most critical factors shaping B. ermanii distribution were identified as the maximum temperature of warmest month (Bio5; 64.8%) and annual mean temperature (Bio1; 20.3%). Current potential habitats were predicted in the Baekdudaegan mountain range and Mt. Hallasan, and the area of suitable habitat was 1531.52 km², covering 1.57% of the Korean Peninsula. With global warming, future climate scenarios have predicted a decrease in the suitable habitats for B. ermanii. Under RCP8.5-2070s, in particular, habitat with high potential was predicted only in several small areas in Gangwon-do, and the total area suitable for the species decreased by up to 97.3% compared to the current range. We conclude that the dominant factor affecting the distribution of B. ermanii is temperature and that future temperature rises will increase the vulnerability of this species.

• 한국어류학회지
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• 제34권4호
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• pp.270-276
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• 2022

2020년과 2022년에 걸쳐 강원도 춘천시 소양강에서 외래종인 브라운송어의 서식을 조사한 결과, 43개체(2.3%)가 서식하는 것이 확인되었다. 2020년 19개체, 2022년 24개체의 서식이 확인되었다. 조사된 개체의 전장이 60 cm 이상의 대형 개체부터 10 cm 미만의 소형 개체까지 폭 넓게 분포하고 있으며, 2020년 1월 St. 1 지점인 세월교에서 확인된 암, 수 개체에서 포란과 방정이 관찰되어 소양강 일대에서 안정적으로 정착하여 꾸준히 서식하고 있음을 확인하였다. 또한 먹이원으로 작용할 수 있는 저서성대형 무척추동물이 풍부하게 서식하고 있으며, 하상구조도 잔자갈과 자갈 등이 고르게 구성되어 있어 서식과 산란에 필요한 조건을 구성하고 있다. 하지만 아직 산란장, 산란된 알, 부화된 치어 등이 명확히 밝혀지지 않아, 지속적인 연구가 필요한 실정이다.

• 생태와환경
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• 제39권4호통권118호
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• pp.498-507
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• 2006

본 연구에서는 2002년 8월부터 2003년 7월까지 우포늪 수계에서의 이온농도, 부유물 농도 및 서식지 특성에 대한 계절성 강우패턴의 영향을 평가하였다. 총부유물질(TSS)의 공간적 변이는 하절기의 장마기간 동안 가장 현저하게 나타났다. TSS 중 무기부유물의 상대비율(ISS:TSS)은 크게 증가했으며 이는 상류에서 하류로 갈수록 증가하는 양상을 보였다. 이런 현상은 낙동강 본류로부터 역류하는 탁수에 기인하는 것으로 사료되었다. 장마기간 동안 ISS:TSS의 비율은 상류(43%)보다 하류(92%)에서 크게 증가한 수치를 보였다. 또한 투명도는 하류역으로 갈수록 감소였으며 (평균=0.13 m, 범위=0.08-0.21), 탁수는 조류생장 및 1차생산력에 직접적으로 영향을 미쳐 낮은 엽록소-a값 (범위=$4.2-8.6\;{\mu}g\;L^{-1}$)을 보였다. 2차 조사 시 ISS 농도는 평균 4 mg $L^{-1}$ (범위=3.3-4.8 mg $L^{-1}$)였고, 이런 값은 홍수기 조사인 1차 조사에 비해 14배나 감소한 수치였다. 한편, ISS는 크게 감소한데 비해 OSS의 상대비는 높게 증가했다. 이러한 현상은 3차 조사에서도 같은 양상으로 나타났으나 5월에 실시된 4차 조사에서는 상이한 결과를 보였다. 10개 변수를 기반으로 한 정량적 서식지 평가에 따르면, QHEI는 4차 조사에서 최대값을 보였으며, 2차 조사에서는 가장 큰 공간적 변이를 보였다. 결과적으로, 장마기간의 집중강우는 토평천과 우포늪에서의 토사 침전 및 영양물질 순환에 크게 기여하는 것으로 사료되었다.

• 국제초고층학회논문집
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• 제7권4호
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• pp.313-325
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• 2018

Concrete-filled steel tubular (CFST) members are commonly used as composite columns in modern construction. However, the current guidelines for members' fire design (EN1994-1-2) have been proved to be unsafe in case the relative slenderness is higher than 0.5. In addition, the simplified design methods of Eurocode 4 are limited to circular and square CFST columns, while in practice columns with rectangular and elliptical hollow sections are being increasingly used because of their architectural aesthetics. In the last years a large experimental research has been carried out at Coimbra University on the topic. They have been tested concrete filled circular, square, rectangular and elliptical hollow columns with restrained thermal elongation. Some parameters such as the slenderness, the type of cross-section geometry as well as the axial and rotational restraint of the surrounding structure to the column have been tested in order to evaluate their influence on the fire resistance of such columns. In this paper it is evaluated the influence of the boundary conditions (pin-ended and semi-rigid end-support conditions) on the behavior of the columns in case of fire. In these tests it could not be seen a marked effect of the tested boundary conditions but it is believed that the increasing of rotational stiffness increases the fire resistance of the columns.

• 국제초고층학회논문집
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• 제10권1호
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• pp.9-16
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• 2021

Being the origin of Shanghai City, the Old Town presents a high-density spatial texture, a characteristic of local living conditions in the Shanghai context. However, the Old Town is faced with competing interests: the preservation of historic urban features and the improvement of contemporary living conditions. In view of its high density and poor living conditions, this paper focuses on two types of blocks for urban design research, and proposes two spatial regeneration strategies, as "overlapping lilong" and "texture continuity". It is expected to inherit the regional characteristics of urban space, improve the plot ratio and supplement the mix of functions, through the translation of the traditional lilong typology and the reproduction of historical streets and alleys, so as to provide operable spatial strategies and design methods for the organic renewal of Old Town and other historic districts.