• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 춘계학술대회
• /
• pp.448-451
• /
• 2005

This paper presents the methodology to analyze flow duration characteristics and performance prediction for small hydro power(SHP) plants and its application. The flow duration curvecan be decided by using monthly rainfall data at the most of the SHP sites with no useful hydrological data. It was proved that the monthly rainfall data can be characterized by using the cumulative density function of Weibull distribution and Thiessen method were adopted to decide flow duration curve at SHP plants. And, the performance prediction has been studied and development. One SHP plant was selected and performance characteristics was analyzed by using the developed technique. Primary design specfications such as design flowrate, plant capacity, operational rate and annual electricity production for the SHP plant were estimated. It was found that the methodology developed in this study can be a useful tool to predict the performance of SHP plants and candidate sites in Korea.

• Journal of Ecology and Environment
• /
• 제33권3호
• /
• pp.253-260
• /
• 2010

It has been well established that leaf longevity is linked to the carbon economy of plants. We used this relationship to predict leaf lifetime carbon gains from leaf lifespan, and estimated the gross primary production (GPP) of a young deciduous forest of Japanese beech (Fagus crenata) located in central Japan. The light-saturated photosynthetic rates of the leaves were measured repeatedly during the growing season. We used the leaf lifespan to calculate the conversion coefficient from the light-saturated photosynthetic rate into the realized leaf lifetime carbon gain under field conditions. The leaf turnover rate was estimated using litter traps. GPP was estimated as the product of lifetime carbon gain per unit of leaf mass, and the annual leaf turnover rate. The GPP of the forest in 2007 was estimated to be $1.2{\times}10^3gCm^{-2}y^{-1}$, which was within the range of previously reported GPP values of beech forests in Japan, and was close to the GPP of a European beech forest, as estimated by eddy flux measurements.

• 한국습지학회지
• /
• 제12권1호
• /
• pp.15-22
• /
• 2010

남한강과 낙동강의 버드나무군락에서 생태계 기능의 지표인 식물군집의 1차 순 생산량, 탄소흡수량과 낙엽분해율을 각각 측정하였다. 순 1차 생산량과 유기탄소흡수량은 각각 22.5ton/ha/yr(16.7ton/ha/yr-31.2ton/ha/yr), 9.7ton C/ha/yr(7.5ton C/ha/yr-14.0ton C/ha/yr)로서 최대값은 우리나라에서 보고된 값 중에서 가장 높았다. 이는 다른 군락보다 버드나무군락을 하천변에 조성하면, 이산화탄소를 빠르게 제거할 수 있음을 의미한다. 낙엽분해는 버드나무군락의 주변에서 가장 빠르게 분해가 일어났고, 버드나무군락 안, 초본군락 순으로 느리게 일어났다. 그 분해속도는 수생식물보다는 느리고, 육상식물보다는 빨랐다.

• 생태와환경
• /
• 제34권3호통권95호
• /
• pp.166-174
• /
• 2001

소양호로 유입되는 유기탄소량을 측정하였으며, 유기탄소 부하량에 대한 유기물 기원의 기여도를 계산하기위해서 내부생성유기탄소와 외부기원유기탄소를 측정하였다. 내부생성유기탄소는 EOC를 고려한 식물플랑크톤의 1차생산력으로부터 계산하였으며, 외부기원유기탄소는 유입수의 유기탄소 농도와 양어장의 유기탄소 배출량으로부터 구하였다. 1차생산력은 가두리 양식장이 설치된 1987견부터 증가하여 1995견가지 높은 분포를 보였으며 가두리가 철거된 1998년 이후 급격히 감소하였다. 내부생성유기탄소와 외부기원유기탄소의 부하는 여름철에 집중되었으며, 7${\sim}$9월에 연간 부하량의 43.2%와 71.7%가 각각 유입되었다. 1차생산력은 여름철에 $1,000\;mgC\;m^{-2}\;d^{-1}$ 이상으로 증가하였으며 겨울철에 비교적낮았다. 식물플랑크톤의 EOC배출율도 1차생산이 증가하여 수체의 DOC농도가 높은 여름철에 높았다. 전체조사기간동안 내부생성과 외부기원유기물의 평균적인 기여도는 각각 총부하량의 53.6%와 46.4%를 차지하였다. EOC 배출율은 1차생산력의 4.4${\sim}$21.2%를 차지하였으며, 1차생산력 산정에서 식물플랑크톤의 EOC 배출율이 고려되어야 할 것으로 보인다.

• Ocean and Polar Research
• /
• 제23권4호
• /
• pp.395-400
• /
• 2001

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait from December 25, 1998 to December 24, 1999. About 99 % of total mass fluxes were observed during the austral summer and fall (January, February, and March). The annual total mass flux was $49.2g\;m^{-2}$. Biogenic materials including biogenic silica, organic matter, and carbonate accounted for about 67% of total particle flux, and lithogenic materials contributed about 29%. Biogenic silica was the most dominant (42% of the total flux) in these components. The next most important biogenic component was organic matter, comprising 24% of total mass flux. Calcium carbonate contributed a small fraction of total mass flux, only 0.6%. The annual organic carbon flux was $5.2g\;C\;m^{-2}$ at 1,034m water depth. The annual primary production was estimated to be $21.6g\;C\;m^{-2}$ at the sediment trap site, which seems to be highly underestimated. About 5.5% of the surface water production of organic carbon sinks below 1,034m water depth.

• 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.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제3권3호
• /
• pp.189-196
• /
• 1999

The community structure, phytomass, and primary productivity in Thuja orientalis stands on a limestone area located in Maepo-up, Chungbuk province in Korea were estimated quantitatively. Seven species including a small proportion of Quercus dentata were identified in the tree layer, 26 species including Ulmus macrocarpa in the shrub layer, and 79 species including Carex lnceolata in the herb layer of the Thuja stands. The vertical distribution of the fine root phytomass exhibited a power functional decrease relative to the soil depth. The seasonal changes in the fine root phytomass at a soil depth of 5 cm were closely related to the pecipitation in the study area. The productivity of the stand of stems, branches, leaves, and roots were 10.72, 0.82, 0.45 and 6.46 ton DM. $ha^{-1}$ .$yr^{-1}$, respectively. The Thuja stand had a high foliage(25%) and low rate of production per unit of foliage. The annual turnover rate of the fine roots int he Thuja stand was 6.71 $yr^{-1}$. The net primary production of the overstory including the understory was estimated at 19.48 ton DM.$ha^{-1}$.$yr^{-1}$ including an underground section of 6.46 ton DM.$ha^{-1}$.$yr^{-1}$(33%). The allocation ratio of net production to root was lower in the limestone Thuja communities than at the nearby non-limestone ones, whereas the production efficiency to leaf weight was higher in the limestone communities. These results would seem to indicate that the limited production capacity is due to the calcium toxicity and low availability of iron and phosphorus in a limestone soil with a high pH, calcium, and bicarbonate content with a strategy for survival in a hostile habitat.

• 한국농림기상학회:학술대회논문집
• /
• 한국농림기상학회 2005년도 추계 학술발표논문집
• /
• pp.41-44
• /
• 2005

• 한국산림과학회지
• /
• 제71권1호
• /
• pp.33-39
• /
• 1985

여천공업단지주변(麗川工業團地周邊)의 곰솔림(林)에 6개(個)의 조사지(調査地)를 설정(設定)하고, 대기오염물질(大氣汚染物質)이 곰솔림(林)의 물질생산량(物質生産量)에 미치는 영향(影響)을 조사(調査)하였다. 곰솔의 활력도(活力度)와 엽내(葉內)의 수용성(水溶性) 황(黃) 및 불소(弗素)의 함량(含量)은 오염원(汚染源)에 가까울수록 그 값이 증가(增加)하였다. 현존량밀도(現存量密度) 및 순생산량(純生産量)은 조사지(調査地)4가 각각(各各) $1.01kg/m^3$, 5.90t/ha/yr으로 가장 큰 값을, 조사지(調査地) 3이 각각(各各) $0.66kg/m^3$, 0.32t/ha/yr으로 가장 작은 값을 나타냈다. 잎의 순동화율(純同化率) 및 간재생산능률(幹材生産能率)은 각각(各各) 0.4~1.6kg/kg/yr, 0.3~1.3kg/kg/yr이었다. 최근(最近)의 연년재적생산율(連年材積生産率)은 피해(被害)가 경미한 지역(地域)이 16.0%이었으며, 심한 지역(地域)이 4.0%내외(內外)이었고, 단목당(單木當) 최대총평균생산량(最大總平均生産量)은 경미한 지역(地域)이 $0.0040m^3$이었고, 심한 지역(地域)이 $0.0008m^3$이었다.

• 한국농림기상학회지
• /
• 제3권4호
• /
• pp.220-237
• /
• 2001

Over the 20th century global temperature increase has been 0.6$^{\circ}C$. The globally averaged surface temperature is projected to increase by 1.4 to 5.8$^{\circ}C$ over the period 1990 to 2100. Nearly all land areas will have higher maximum temperature and minimum temperature, and fewer cold days and frost days. More intense precipitation events will take plate over many areas. Over most mid-latitude continental interiors will have increased summer continental drying and associated risk of drought. By 2100, if the annual surface temperature increase is 3.5$^{\circ}C$, we will have 15.9$^{\circ}C$ from 12.4$^{\circ}C$ at present. Also the annual precipitation will range 1,118-2,447 mm from 972-1,841 mm at present in Korea. Consequently the average crop periods for summer crops will be 250 days that prolonged 32 days than at present. In the case of gradual increase of global warming, an annual crop can be adapted to the changing climate through the selection of filial generations in breeding process. The perennial crops such as an apple should be shifted the chief producing place to northern or high latitude areas where below 13.5$^{\circ}C$ of the annual surface temperature. If global warming happens suddenly over the threshold atmospheric greenhouse gases, then all ecosystems will have tremendous disturbance. Agricultural land-use plan, which state that farmers decide what to plant, based on their climate-based advantages. Therefore, farmers will mitigate possible negative imparts associated with the climate change. The farmers will have application to use agricultural meteorological information system, and agricultural long-range weather forecast system for their agroecosystems management. The ideal types of crops under $CO_2$ increase and climate change conditions are considered that ecological characteristics need indispensable to accomplish the sustainable agriculture as the diversification of genetic resources from yield-oriented to biomass-oriented characteristics with higher potential of $CO_2$ absorption and primary production. In addition, a heat-and-cold tolerance, a pest resistance, an environmental adaptability, and production stability should be also incorporated collectively into integrated agroecosystem.