• Journal of Plant Biology
• /
• 제18권3호
• /
• pp.101-108
• /
• 1975

The nitrogen economy and primary production of a Helianthus annuus "Manchurian" population were studied with special reference to the pattern of seasonal changes of vertical distributions of dry matter and nitrogen quantities, and its quantitative significance was discussed in relation to the pattern of the plant population growth, distribution ratios among organs, and turnover rates of dry matter and nitrogen. The population was established in plant density of 11.1plant/$m^2$ at the experimdntal field of Kyungpook National University, Daegu. During the period of population developemnt (April-September, 1973), the annual inflow rates and outflow rates of dry matter and nitrogen were 5560 gDM/$m^2$/year and 89 gN/$m^2$/year, respectively. The distribution ratios of dry matter and nitrogen to leaves were 28% and 45%, to stems 48% and 18%, to roots 13% and 5%, and to flowers and seeds 11% and 32%, respectively. The maximum turnover rates of inflow of dry matter and nitrogen were attained in May-June, and were 216%/month and 210%/month, respectively. The amount of nitrogen demand was 52gN/$m^2$/year (58%) for the foliage growth, 13 gN/$m^2$/year(15%) for the stem growth, 20 gN/$m^2$/year(23%) for the reproductive organs, and 4 gN/$m^2$/year(4%) for the growth of the underground parts. The amount of nitrogen supply by the nitrogen withdrawn from senescing leaves and stems was 25gN/$m^2$/year(28%) and the amount of nitrogen absorption by the root from the environmental soil was 64 gN/$m^2$/year(72%). The ratiio of the a mount of produced dry matter to that of assimilated nitrogen during a year was calculated for this annual plant population as 60, which can be used as the nitrogen utility index.ity index.

• Journal of Ecology and Environment
• /
• 제30권4호
• /
• pp.293-305
• /
• 2007

This study examined the distribution, population and vegetation structure of Corylopsis coreana in South Korea. C. coreana is distributed around the Suncheon area, Jeollanam-do, on the southern part of the Korean Peninsula, but the species is also found in Pocheon and Gangneung, on the central and central east parts of the peninsula. This discontinuous pattern of distribution is coupled with the unusual feature of only growing on northern exposed slopes. The mean density of C. coreana populations is 35 individuals per 100 $m^2$, ranging up to a maximum of 92 individuals per 100 $m^2$. Cut specimens sprouted a maximum of 38 stems per plant. Based on DCA analysis, the species' habitats was divided into three types by species composition and stratification structure. These types include: habitats affected strongly by human activities, valley and mantle communities which are affected relatively little by human activities, and stable forests. Populations affected by artificial intervention have actually flourished, while some populations in the stable forest system have declined. We conclude that the species, now endangered, should be maintained by means of specific external interventions such as cutting or removal of the canopy. To this end, further ecological data should be collected through monitoring and research to identify appropriate interventions to support threatened C. coreana populations.

• 한국잠사곤충학회지
• /
• 제52권1호
• /
• pp.16-24
• /
• 2014

2010년부터 2012년까지 전국 각지 야외에서 조사한 바둑돌부전나비의 생태학적 특성은 다음과 같다. 1. 이대에 서식하는 일본납작진딧물은 바둑돌부전나비 유충의 먹이로서 지표로부터 폭넓게 분포하였으며, 조사 8회 차인 6월 13일부터 밀도가 현저히 감소하였다. 2. 일본납작진딧물과 바둑돌부전나비가 가장 많은 밀도를 보이는 곳은 줄기와 가장 인접한 부위이었다. 3. 바둑돌부전나비의 유충 예상 령수는 4령으로 추측된다. 4. 바둑돌부전나비 성충의 야외 노출 시 생존시간 조사 결과, 2분 이내에 사망하는 것으로 조사 되었다.

• Journal of Forest and Environmental Science
• /
• 제30권2호
• /
• pp.179-188
• /
• 2014

This research reports the effects of shifting cultivation on soil environment collecting samples from 0-5 cm soil depth from five locations viz. at Burburichhara, Maichchari, Longadu, Sukurchhari and Muralipara in Rangamati district of Chittagong Hill Tracts (CHTs). Soil analyses showed that fungal and bacterial population, microbial respiration and active microbial biomass, maximum water holding capacity, conductivity and moisture contents were significantly (at least $p{\leq}0.05$) lower in shifting cultivated soil compared to adjacent mixed tree plantations at all the sites. On an average in soils of 5 different shifting cultivated lands fungal population was $1.33{\times}10^5$ CFU/g dry soil and bacterial population $1.80{\times}10^7$ CFU/g dry soil and in mixed plantations fungal population was $1.70{\times}10^5$ and bacterial population $2.51{\times}10^7$ CFU/g dry soil. Organic matter and exchangeable Ca and Mg contents were significantly (at least $p{\leq}0.05$) lower and bulk density significantly (at least $p{\leq}0.05$) higher in shifting cultivated land in most of the locations compared to adjacent mixed tree plantations. Ratios of microbial respiration and organic carbon as well as active microbial biomass and organic carbon were distinctly lower and pH higher at 3 locations in shifting cultivated soils compared to mixed plantations. Findings of various soil properties, therefore, suggest that shifting cultivation has deteriorating effects on soil environment.

• Ocean Science Journal
• /
• 제43권1호
• /
• pp.49-59
• /
• 2008

To examine the population development of the dinoflagellates, Ceratium furca and Ceratium fusus, daily field monitoring was conducted between April and July 2003 in the temperate coastal water of Sagami Bay, Japan. During the study period, the concentrations of C. furca were always lower than those of C. fusus. A sharp increase in the densities of both species was recorded on 5 May showing the maximum cell concentrations (C. furca = $14,800\;cells\;L^{-1}$, C. fusus = $49,600\;cells\;L^{-1}$). In the 7 days prior to the May bloom of the Ceratium species (29 April to 1 May), the highest density of the heterotrophic dinoflagellate Noctiluca scintillans was observed. Additionally, a second bloom of C. fusus occurred on 22 July. Here, two causes of the significant increases in the Ceratium populations during the two blooming periods (first time; 1 to 8 May, second time; 15 to 22 July) are presented. First, an increase in the nutrients of the surface layer regenerated by the breakdown of blooms by N.scintillans could be considered as a major cause of the population increase of the two Ceratium species. Second, a decrease in salinity (to 27 psu) was correlated with the later bloom of C. fusus. These results suggest that the population development of the two Ceratium species requires nutrients regenerated after the reduction of the diatom population by N. scintillans and, for C. fusus, continuous low salinity conditions, compared to other environmental factors during the rainy season.

• 대한토목학회논문집
• /
• 제38권1호
• /
• pp.29-39
• /
• 2018

본 연구에서는 IPCC에서 제시한 기후변화 취약성 평가 이론, OECD에서 개발한 PSR 모형, EEA에서 개발한 DPSIR 모형을 활용하여 산정된 홍수위험지수들의 적용성을 분석하였다. 홍수위험지수 산정을 위하여 세부 지표로 일 최대 강수량, 1시간 최대 강수량, 10분 최대 강수량, 연평균 강수량, 1일 강수량이 80mm 초과한 일수, 인구 밀도, 자산 밀도, DEM, 도로연장, 하천개수율, 유수지용량, 하수도 보급률, 배수펌프시설 등의 2000년에서 2015년도 자료를 정규화하여 전국 113 중권역 단위로 구축하였다. 산정된 홍수위험지수는 4개의 홍수피해유형 즉 인명피해, 피해면적, 피해액, 피해빈도와 비교 분석하였다. 홍수위험지수와 피해유형별 상관분석 결과 피해액, 인명피해 및 피해면적에 대해서는 PSR 기법이, 홍수발생빈도에 대해서는 DPSIR 기법에 따른 지수의 적용성이 높은 것으로 나타났다.

• 한국수자원학회논문집
• /
• 제51권spc1호
• /
• pp.1149-1159
• /
• 2018

본 연구는 우리나라 113개 중권역에 대한 기후변화에 따른 미래 홍수 피해액의 예측을 위하여 26개 GCM 모형에서 생산한 강우자료와 1시간 최대 강수량, 10분 최대 강수량, 1일 강수량이 80 mm 초과한 일수, 일 최대 강수량, 연강수량, 유역고도, 시가화율, 인구 밀도, 자산 밀도, 도로와 같은 사회 간접 시설, 하천개수율, 하수도 보급률, 배수펌프시설, 유수지용량 및 과거 홍수 피해액 자료를 활용하였다. 구축된 자료에 대하여 구속 다중선형회귀 모형(Constrained Multiple Linear Regression Model)을 적용하여 홍수 피해액과 여타 입력자료 사이의 상관관계를 구축하고 RCP 4.5와 8.5에 대한 26개 GCM 모형 산정자료를 활용하여 미래 홍수 피해액을 예측하였다. 홍수피해에 주된 요인이 되는 연강수량, 극치 강우량 등 강우관련 요소들이 전반적으로 증가하며 이로 인하여 과거 홍수로 인한 피해액이 광범위하게 증가할 것으로 판단되고 특히 동해안 및 남강댐 유역에 미래의 홍수피해액이 높게 예측되는 경향을 보인다.

• 한국응용곤충학회지
• /
• 제22권4호
• /
• pp.244-250
• /
• 1983

자연조건하에서 인위적으로 접종시킨 벼멸구가 증식하였을 때, 벼의 생육단계별 벼멸구피해가 수량에 미치는 영향을 조사하여 다음과 같은 결과를 얻었다. 1. '81년의 경우 출수기이후 방제구의 수량은 최고 분얼기, 수잉기, 완전방제구에 비하여 수량감소현상이 있었고, '82년의 경우느 수잉기 방제구부터 수량감소 현상이 나타났다. 2. 벼멸구 제1세대 개체군에 의한 초장과 경수에의 영향은 없었으나 벼멸구 제2세대, 3세대 개체군에 의한 천립중$(Y_1)$과 등숙율$(Y_2)$에의 영향은 수량감소의 결과로 나타났다. 이 영향은 특히 출수후부터 유숙기 까지의 벼멸구 개체군(제 2세대 개체군)과 상당한 관계가 있었으며 다음과 같은 회귀방정식을 구하였다. $$Y_1(g)=25.602-0.0213X(r=0.5205^{**})$$ $$Y_2(\%)=76.97-0.1370X(r=-0.4820^{**})$$ 3. 충접종후 수확시까지의 벼멸구 개체군에 수당총밀도(X)와 수량(Yg)과의 관계는 $Y(g)=-24.684-0.576X(r=-0.6956^{**})$였다. 4. 벼멸구 대발생의 근원은 비래후 제1세대에 있은 고로 이 세대의 밀도, 연령구성, 시형, 기타의 개체군 특성에 관한 지식은 해충 방제의 합리화를 위한 기초가 된다.

• Journal of Plant Biology
• /
• 제12권2호
• /
• pp.28-42
• /
• 1969

Field studies were conducted with the split plot design of 20 treatment with a combination of 4 levels of 3, 5, 7 and 9 plants per hill and 5 levels of 60, 80, 100, 120 and 140 hills per 3.3$m^2$ on non-, low- and high-salty areas. Rice variety, Kusabue was grown under jthe standard fertilization and cultivating. Investigation was made on the productive structure of plant population, leaf-area index, light intensity curve by stratum of crop population at the panicle differentiation stage. The competition density effect on the photosynthetic capacity was low as the salt concentration became higher. This seemed to suggest the possiblity of an increased yielding capacity by closer planting in the salty areas. The effect of an increased number of hills per unit area was greater than that of an increased unmber of plants per hill due to the total leaf area and space distribution of the actie assimilation parts of rice plants. The number of ppanicle per unit area in the salty areas were increased when the number of hill per 3.3$m^2$ increased over an increased number of plants per hill, and the panicle weight was reduced by close planting in the non-lalty area, while it was not reduced so much in the salty areas. The number of grains per panicle was significantly decreased by close planting in the salty areas as in the non-salty area, and ratio of matured grain was not decreased even by close planting in the salty areas, while it was significantly decreased by close planting in the non-salty area. An increase in the rice yield was possible by close planting and greatly related to leaf area index in the salty areas but not in the non-salty area. Increasing the number of hills per unit area showed greater effect on the increase of the rice yield than an increased number of plants per hill in the salty areas. Relationships between the growth characteristics and the rice population affected by plant spacing mode for maximum production were discussed.

• 약학회지
• /
• 제56권1호
• /
• pp.48-54
• /
• 2012

Enviromental differences in gentamicin pharmacokinetics by using population pharmacokinetic methods were compared with 20 Korean patients and 24 Korean-American appendicitis patients. Two to six blood specimens were collected from all patients at the following times : just before a regularly scheduled infusion and at 0.5 hour after the end of a 0.5 hour infusion. Nonparametric expected maximum (NPEM) algorithm for population modeling was used. The estimated parameters were the elimination rate constant (K), the slope (KS) of the relationship between K versus creatinine clearance ($C_{cr}$), the apparent volume of distribution (V), the slope (VS) of the relationship between V versus weight, gentamicin clearance (CL) and the slope (CS) of the relationship between CL versus $C_{cr}$ and the V. The output includes two marginal probability density function (PDF), means, medians, modes, variance and CV%. The mean K (KS) were $0.402{\pm}0.129\;h^{-1}(0.00486{\pm}0.00197\;[h{\cdot}ml/min/1.73\;m^2]^{-1})$ and $0.411{\pm}0.135\;h^{-1}(0.00475{\pm}0.00180\;[h{\cdot}ml/min/1.73\;m^2]^{-1})$ for Korean and Korean-American populations, respectively. The mean V (VS) were not different at $14.3{\pm}3.6l(0.241{\pm}0.0511l/kg)$ and $15.1{\pm}3.84l(0.239{\pm}0.0492l/kg)$ for Korean and Korean-American populations, respectively (p>0.2). The mean CL (CS) were $5.68{\pm}1.69l/h(0.0714{\pm}0.0222l/kg[h{\cdot}ml/min/1.73\;m^2])$ and $5.70{\pm}1.77l/h(0.0701{\pm}0.0215l/kg[h{\cdot}ml/min/1.73\;m^2])$ for Korean and Korean-American populations, respectively. There were no enviromental differences in gentamicin pharmacokinetics between Korean and Korean-American appendicitis patients.