• The Korean Journal of Ecology
• /
• 제24권6호
• /
• pp.377-380
• /
• 2001

Herbivory is an important selective forces on plants by reducing the ability of the plant to compete with its neighbors and to produce offspring. Oak nut weevil(Mechoris ursulus Roelofs) females lay eggs in unmatured acorns and cut off the branch of oviposited acorns. To investigate the influences of branch-cutting behavior of oak nut weevils on oak production, we surveyed the horizontal and vertical distribution ranges of damaged oaks and depth of sites of overwintering larvae and quantified the amounts of biomass and acorn removed by the weevils on deciduous oak species. All of the endemic oak species in Korea were damaged by oak nut weevils in all of the study sites including Mt. Halla and Mt. Seorak. The upper limit of vertical distribution of damaged oaks by the weevils raried from 700 m to 900 m. Mostly their larvae were found in soil from 8.1 cm to 10.0 cm depth in winter. Percentage of annual net primary productivity($720g{\cdot}m^{-2}{\cdot}day^{-1}$) of oak species removed by the weevils was about 7%, which is higher than the percentage removed by all the herbivores in typical temperate forest(5%) and equivalent to that by all the herbivores in tropical forest. The predation percentage of annual acorn production by oak nut weevil was 27% in Q. mongolica and 33% in Q. acutissima. This results indicate that the branch-cutting behavior of oak nut weevil may be the most important factor regulating oak population and affecting other predators dependent on acorns.

• 수산해양기술연구
• /
• 제48권2호
• /
• pp.128-136
• /
• 2012

Hybrid surveys using hydroacoustic and fish sampling gears such as trammel net, trap were conducted to investigate total biomass, distribution and dominant fish species of the demersal fishes in the marine ranching area (MRA) of Jeju. Four surveys were carried out in June, August, October and November using 38kHz quantitative echo sounder. Catch data using trammel net and trap were used to calculate biomass and to examine dominant fish species. Fish schools were mainly detected in the waters of 20 meters below and around Chagwido waters. By the result of fishing experiments, fish species living in MRA of Jeju were about 40 species, dominant fish species of a detectable fish such as Family Sparidae and Family Monacanthidae etc. were identified 59.4~68.8% of total biomass. Based on the hydroacoustic data, fish length-weight function and target strength information, mean density of the demersal fish estimated were as follows; 0.88g/$m^2$ on June, 1.12g/$m^2$ on August, 1.35g/$m^2$ on October and 1.18g/$m^2$ on November. An estimated average biomass in MRA of Jeju was founded 20.5 tons in 2007, 20.6 tons in 2008, 23.0 tons in 2009, 25.9 tons in 2010. The results showed that biomass of MRA is getting increased slowly. Therefore the hybrid survey method using hydroacoustic and fish sampling gears is assured an effective biomass survey in the waters of mixed species.

• 대한환경공학회지
• /
• 제31권2호
• /
• pp.139-146
• /
• 2009

본 연구에서는 두부공장에서 발생된 폐수를 이용한 생물학적 수소생성 특성과 미생물의 군집 변화를 살펴보았다. 두부 폐수는 산 또는 알카리 조건에서 전처리 된 후 수소생성량을 비교 하였으며, 산처리와 열처리를 병행하여 전처리 하였을 때 가장 왕성한 수소생산을 보였으며, Gompartz 방정식을 이용한 수소가스 발생량($P_h$)은 약 661.01 mL이고 최대 수소 생성율($R_h$)은 12.21 mL/g dry wt biomass/hr 이였다. 16S rDNA의 PCR-DGGE 결과 대부분 군집은 Streptococcus sp. 미생물로 규명되었으며 수소생성에 기여도가 큰 미생물은 Streptococcus gallolyticus sub sp.으로 판단되었다.

• The Korean Journal of Ecology
• /
• 제21권1호
• /
• pp.27-33
• /
• 1998

Arisaema robustum, which has the ability to change sex, was studied in a temperate broadleaf forest of Sanseong-ri, Joongbu-myeon, Gwangju-gun, Kyonggi Province, Korea. \ulcornerThe study, carried out from 1993 to 1997, focused on population dynamics energy budget among organs, size distribution, mortality, the relationships between sex and size, seed production and germination rate. In terms of energy budget among the organs, the ratio of aboveground to belowground biomass was 36.6 : 63.4 in non-female plants, and 81.4 : 18.6 in female plants. Also, in female plants, the ration of leaf to sexual organ biomass was 39.5 : 41.9. Therefore, the belowground ratio of female plants was lower than that of non-female plants. Plants were classified into 8 levels relative to the amount of leaf area by $100cm^2$. The rates of the smallest and the largest classes were 49% and 1%, respectively, and population distribution by size was relatively stable. The mortality averaged 13.1% per year and decreased in inverse proportion to leaf size (6.6% in the smallest and 0.0% in the largest size classes). Leaf areas were $64.1{\pm}48.5cm^2$ in non-flowering plants, $232.1{\pm}123.9cm^2$ in males and $444.8{\pm}153.9cm^2$ in females. The increase rates of leaf area per year varied from 1.9% in plants changing from female tomale, to 152.4% in plants changing from non-flowering to female. But plants which remained female for 2 years showed a decrease of 34.7%. >From this result, it is thought that the female plants invest more energy to reproduction than to vegetative organs. The correlation coefficient (CC) value between plant size and the number of seeds produced (0.55) was larger than the CC value between plant size and total seed weight (0.73). That is, the larger the plant size, the heavier the seed produced. The germination rate increased along with seed weight, and it was 95% in plants which were over 60mg fresh weight/seed.

• 한국산림과학회지
• /
• 제69권1호
• /
• pp.28-35
• /
• 1985

전남(全南) 광주(光州)에 소재(所在)하는 22년생(年生)의 리기다 및 리기테다소나무임분(林分)에 $200m^2$의 표준지(標準地)를 설정(設定)하고, 지상부(地上部)의 현존량(現存量) 및 년순생산량(年純生産量)을 분석(分析) 추정(推定)하였다. 각(各) 표준지(標準地)에 직경급별(直徑級別)로 안배한 9 주(株)의 표본목(標本木)을 벌채(伐採)하여 1m의 계층(階層)으로 절단(切斷)하고 간(幹)(Ws), 지(枝)(Wb), 엽(葉)(Wl) 부위(部位)로 나누어 건중량(乾重量)을 계산(計算), $D^2H$와의 상대생장식(相對生長式)을 이용(利用)하여 물질생산량(物質生産量)을 추정(推定)하였다. 생산구조면(生産構造面)에서 광합성부(光合成部)가 리기다소나무는 지상(地上) 6.2m, 리기테다소나무는 지상(地上) 9.2m 높이에서 시작되었고, 수관(樹冠)의 최대광합성층(最太光合成層)은 각각(各各) 11.2m, 12.2m 높이에서 나타났다. 지상부(地上部)의 현존량(現存量)은 리기다소나무가 71.61 t/ha, 리기테다소나무가 142.32 t/ha이었고, 년순생산량(年純生産量)은 각각(各各) 10.81 t/ha/yr, 10.46 t/ha/yr이었다. 현존량밀도(現存量密度)는 리기다소나무가 $0.56kg/m^3$, 리기테다소나무가 $0.96kg/m^3$ 이었다. 잎의 생산능률(生産能率)을 추정(推定)한 바 NAR은 리기다소나무가 1.32 kg/kg/yr, 리기테다소나무가 1.00 kg/kg/yr이었고, 잎의 간재생산능률(幹材生産能率)은 각각(各各) 0.97 kg/kg/yr, 0.81 kg/kg/yr 이었다.

• Journal of Ecology and Environment
• /
• 제38권4호
• /
• pp.425-436
• /
• 2015

The carbon cycle came into the spotlight due to the climate change and forests are well-known for their capacity to store carbon amongst other terrestrial ecosystems. The annual organic carbon of litter production, forest floor litter layer, soil, aboveground and belowground part of plant, standing biomass, net primary production, uptake of organic carbon, soil respiration, etc. were measured in Mt. Worak in order to understand the production and carbon budget of Quercus serrata forest that are widely spread in the central and southern part of the Korean Peninsula. The total amount of organic carbon of Q. serrata forest during the study period (2010-2013) was 130.745 ton C ha^-1. The aboveground part of plant, belowground part of plant, forest floor litter layer, and organic carbon in soil was 50.041, 12.510, 4.075, and 64.119 ton C ha^-1, respectively. The total average of carbon fixation in plants from photosynthesis was 4.935 ton C ha^-1 yr^-1 and organic carbon released from soil respiration to microbial respiration was 3.972 ton C ha^-1 yr^-1. As a result, the net ecosystem production of Q. serrata forest estimated from carbon fixation and soil respiration was 0.963 ton C ha^-1 yr^-1. Therefore, it seems that Q. serrata forest can act as a sink that absorbs carbon from the atmosphere. The carbon uptake of Q. serrata forest was highest in stem of the plant and the research site had young forest which had many trees with small diameter at breast height (DBH). Consequentially, it seems that active matter production and vigorous carbon dioxide assimilation occurred in Q. serrata forest and these results have proven to be effective for Q. serrata forest to play a role as carbon storage and NEP.

• Journal of Microbiology and Biotechnology
• /
• 제19권3호
• /
• pp.291-298
• /
• 2009

The carbon metabolism of newly isolated Clostridium tyrobutyricum JM1 was investigated at varying initial glucose concentrations (27.8-333.6mM). Because an understanding of metabolic regulations was required to provide guidance for further effective metabolic design or optimization, in this case, maximizing hydrogen production, carbon and energy balances by C. tyrobutyricum JM1 were determined and applied in anaerobic glucose metabolism. The overall carbon distribution suggested that initial glucose concentrations had strong influence on the stoichiometric coefficients of products and the molar production of ATP on the formation of biomass. C. tyrobutyricum JM1 had a high capacity for hydrogen production at the initial glucose concentration of 222.4 mM with high concentrations of acetate and butyrate.

• 수산해양기술연구
• /
• 제54권2호
• /
• pp.146-156
• /
• 2018

Acoustic surveys were conducted in the seas surround the South Korea (South Sea A, South Sea B (waters around the Jeju Island), West Sea and East Sea) in spring and autumn in 2016. First, the vertical and horizontal distributions of fisheries resources animals were examined. In most cases vertical acoustic biomass was high in surface water and mid-water layers other than South Sea A in autumn and West Sea. The highest vertical acoustic biomass showed at the depth of 70-80 m in the South Sea A in spring ($274.4m^2/nmi^2$) and the lowest one was 10-20 m in the West Sea in autumn ($0.4m^2/nmi^2$). With regard to the horizontal distributions of fisheries resources animals, in the South Sea A, the acoustic biomass was high in eastern and central part of the South Sea and the northeast of Jeju Island ($505.4-4099.1m^2/nmi^2$) in spring while it was high in eastern South Sea and the coastal water of Yeosu in autumn ($1046.9-2958.3m^2/nmi^2$). In the South Sea B, the acoustic biomass was occurred high in the southern and western seas of Jeju Island in spring ($201.0-1444.9m^2/nmi^2$) and in the southern of Jeju Island in autumn ($203.7-1440.9m^2/nmi^2$). On the other hand, the West Sea showed very low acoustic biomass in spring (average NASC of $1.1m^2/nmi^2$), yet high acoustic biomass in the vicinity of 37 N in autumn ($562.6-3764.2m^2/nmi^2$). The East Sea had high acoustic biomass in the coastal seas of Busan, Ulsan and Pohang in spring ($258.7{\sim}976.4m^2/nmi^2$) and of Goseong, Gangneung, Donghae, Pohang and Busan in autumn ($267.3-1196.3m^2/nmi^2$). During survey periods, fish schools were observed only in the South Sea A and the East Sea in spring and the West Sea in autumn. Fish schools in the South Sea A in spring were small size ($333.2{\pm}763.2m^2$) but had a strong $S_V$ ($-49.5{\pm}5.3dB$). In the East Sea, fish schools in spring had low $S_V$ ($-60.5{\pm}14.5dB$) yet had large sizes ($537.9{\pm}1111.5m^2$) and were distributed in the deep water depth ($83.5{\pm}33.5m$). Fish schools in the West Sea in autumn had strong $S_V$ ($-49.6{\pm}7.4dB$) and large sizes ($507.1{\pm}941.8m^2$). It was the first time for three seas surrounded South Korea to be conducted by acoustic surveys to understand the distribution and aggregation characteristics of fisheries resources animals. The results of this study would be beneficially used for planning a future survey combined acoustic method and mid-water trawling, particularly deciding a survey location, a time period, and a targeting water depth.

• 한국수소및신에너지학회논문집
• /
• 제28권6호
• /
• pp.697-703
• /
• 2017

This study investigated the high-efficient process for bioethanol from barley by various condition. First, higher concentrations of ethanol could be produced without loss of yield by using reducing water consumption. This is because it could prevent to increase viscosity despite reducing water consumption. Second, the ethanol yield could be improved by using reducing particle size of biomass (increase of enzyme reactive surface). Third, The addition of protease could have a considerable effect on yield of fermentation, which provides nutrients to the yeast. This results showed that bioethanol production would provide efficient ethanol production and lower production costs.

• Ocean and Polar Research
• /
• 제44권2호
• /
• pp.127-137
• /
• 2022

This study examined the growth pattern and environmental factors affecting the growth of the halophyte, Suaeda japonica, which is prevalent on tidal flats in the west coast of Korea in order to calculate annual carbon production. Quantitative sampling was conducted every month for three years from 2018 to 2020 on salt marshes located on the southern coast of Ganghwa Island. In terms of annual density affected by the germination rate at first period, especially when air temperature for winter time was constantly below 0℃ for long periods of time, germination decreased and precipitation in summer also exerted an influence. In terms of annual growth with regard to length, the part below the ground grew rapidly in the beginning after budding, while the part above ground grew at a relatively steady rate at all times. With regard to biomass, the part below the ground also increased from April in a manner similar to length growth, but decreased drastically from September with leaves falling off and water loss occurring. The part above ground showed a rapid increase from the beginning of the rainy season. Size-frequency distribution revealed broader patterns after the rainy season as individual growth varied, but from September, it stopped at all year. High growth rates were recorded in the initial phase of growth after budding and growth was rapid, but growth declined in summer when biomass increased. The annual mean production based on growth rate was calculated at 352 gDWt/m²/yr, and the highest production was 519 gDWt/m²/yr in 2018, but it has decreased since 2019. Annual carbon production was at calculated 143.41 gC/m²/yr for Suaeda japonica in the vicinity of the southern coast of Ganghwa Island.