• 한국조경학회지
• /
• 제33권2호
• /
• pp.60-70
• /
• 2005

This study was carried out to elucidate the vertical characteristics of soil properties at six planted sites of land reclaimed from the sea, in Gwangyang Bay, Jeollanam-do Province, Korea. Based on the types of planting site, the chemical properties of the vertical soil layers varied. The vertical variation was great in the planting sites $Z_1\;and\;Z_2$, but less varied in the mounded planting sites $Z_3,\;Z_5,\;and\;Z_6$. Major reasons for the vertical variation in soil chemical properties included differences in the accumulation of organic matter, soil disturbance by heavy construction equipment, and heterogeneity of soil properties between soil horizons. As soil depths increased, soil salts varied. The electrical conductivity (ECe) increased in the lower areas of planting sites $Z_1\;and\;Z_2$, and the disturbed, saline planting site $Z_3$, but decreased in the lower areas of $Z_3,\;Z_5,\;and\;Z_6$. These tendencies did not coincided with exchange cation concentrations $(Na^+,\;K^+,\;Mg^{++},\;Ca^{++})$. Both total carbon (T-C) and total nitrogen (T-N) accumulated more in the lower areas of planting sites than in the higher areas, and levels were higher closer to the surface than in the soil depths. It is supposed that these tendencies are related to the accumulation of fallen leaves or other organic matter at the soil surface, and the soil chemicals then slowly move downward from the surface. Impediments to tree growth included soil hardiness, high soil salinity and exchangeable cation concentration, low soil moisture content, acidic or alkaline soil, low organic matter, heterogeneity of soil texture and establishment of soil stratification.

• The Plant Pathology Journal
• /
• 제22권2호
• /
• pp.125-130
• /
• 2006

An isolate of Peanut stunt virus (PSV) isolated from black locust tree (Robinia pseudo-acacia L.) showing severe mosaic and malformation symptoms, was designated as PSV-Rp. PSV-Rp was characterized by the tests of host range, physical properties, RNA and coat protein composition and RT-PCR analysis. Nucleotide sequences of the cucumoviruses CP genes were also used for identification and differentiation of PSV-Rp. Six plant species were used in the host range test of PSV-Rp. PSV-Rp could be differentiated from each Cucumovirus strain used as a control by symptoms of the plants. The physical properties of PSV-Rp virus were TIP $65^{\circ}C$, DEP $10^{-3}$, and LIP $2{\sim}3$ days. In dsRNA analysis, PSV-Rp consisted of four dsRNAs, but satellite RNA was not detected. Analysis of the coat proteins by SDS-PAGE showed one major protein band of about 31 kDa. RT-PCR using a part of Cucumovirus RNA3 specific primer amplified ${\sim}950bp$ DNA fragments from the crude sap of virus-infected black locust leaves. RFLP analysis of the RT-PCR product could differential PSV-RP from CMV The nucleotide sequence identity between the PSV-Rp CP and the TAV-P CP genes and the PS-V-RP CP and CMV-Y CP genes were 61.6% and 40.5%, respectively. On the other hand, the nucleotide sequence identity of the PSV-Rp CP gene was $70.9%{\sim}73.4%$ in comparison with those of PSV subgroup I (PSV-ER and PSV-J) and 67.3% with that of PSV subgroup II(PSV-W). Especially, the nucleotide sequence identity of PSV-Rp CP gene and that of PSV-Mi that was proposed recently as the type member of a novel PSV subgroup III was 92.4%.

• 한국환경복원기술학회지
• /
• 제7권1호
• /
• pp.30-39
• /
• 2004

This research is of the rapid industrialization taking place resulting in the destruction of forests. The method that is implemented needs the vegetation to work well with the topsoil in order to restore the environment. In November the researcher collected a depth of 5 cm of topsoil from a well developed forest, after the fallen leaves were cleared. The results of the essential research are as follows : In the case of using the forest topsoil to plant trees latency seeds, during the early stages of tree planting, time is necessary for the desired vegetation to reach a similar state to the vegetation being restored. The results conclude that the best possible affect is obtained through a method utilizing seeded species. Utilizing forest topsoil, slopes that have been too damaged for trees to be planted can be sown with seeds. In addition the rearing of naturally-emerging species had a tendency to decline. When considering rearing naturally-emerging species to flourish in the topsoil, in the early stages of tree planting, the beginning foundation of sowing seeded species has to have a standard of about 1,000parts/$m^2$ This standard has been found to the most successful.

• 자연과학논문집
• /
• 제19권1호
• /
• pp.65-75
• /
• 2008

교통량이 많은 대전광역시 유성구의 32번 국도변 배 과수원의 토양과 수체의 중금속 오염 실태를 조사하였다. 도로에 인접한 과수원 토양의 표토와 심토 모두 Pb, Cu 및 Zn 함량은 도로에서 원거리에 위치한 과수원(대조구) 토양에 비하여 많았고 도로에 가까운 지점일수록 함량이 많았다. 도로에서 10m 지점의 표토 중금속 함량은 대조구보다 Pb는 4배, Cu는 3배 그리고 Zn은 2.5배 많았다. 대조구 토양에 비하여 도로변 과수원 토양 표토의 Cd 함량이 많았으나 심토에서는 차이가 없었다. 도로변 과수원 배나무 잎의 중금속 최대 함량은 Pb 20.08, Cu 7.02, Zn 30.83, Cd $1.68\;mm.kg^{-1}$으로 대조구보다 많았다. 과실의 Cd 함량과 과경의 Pb 함량은 대조구보다 도로변 과수원에서 많았고 도로에서 가까울수록 많았다.

• 한국산림과학회지
• /
• 제89권2호
• /
• pp.249-255
• /
• 2000

충청북도 충주지역에서 식재된 22년생 자작나무와 24년생 가래나무 인공림의 지상부 현존생물량 및 연순생산량을 분석하기 위하여 임분별 9주씩 총 18주의 표본목을 선정 벌목하였다. 수식 $Wt=aD^b$를 사용하여 추정한 자작나무와 가래나무의 지상부 총 현존생물량은 자작나무림에서 79.33t/ha와 가래나우림에서 67.47t/ha으로 가래나무림보다 연령이 작은 자작나무림에서 높은 현존생물량을 보였다. 부위별 구성비는 자작나무림과 가래나무림 모두에서 수간목질부, 가지, 수피, 그리고 잎의 순으로 높았다. 총 연순생산량은 자작나무림이 9.92t/ha, 가래나무림이 11.79t/ha으로 총 현존생물량이 많았던 자작나무림보다 가래나무림에서 높게 나다났는데, 이 결과는 잎을 제외한 수간목질부, 수피, 소지 그리고 가지에서의 연순생산량이 가래나무림에서 높았기 때문이다.

• 한국환경생태학회지
• /
• 제19권2호
• /
• pp.188-192
• /
• 2005

이 연구는 큰 나무 아래 어린 나무를 심어 (수하식재) 새로운 숲을 가꾸는 방법 (임분갱신법)을 찾고자 낙엽송 간벌지에 음나무, 물푸레나무 및 층층나무 묘목을 1998년 봄에 수하식 재 한 것과 이웃에 위치 한 동일한 묘령의 임간포지에서 생육하는 개체들과의 엽록소항량과 광합성율을 2000년 7월에 측정$\cdot$비교하였다. 이는 식물종에 따른 광량에 대한 적응력 차이 (내음성)를 생리학적으로 확인하고자 시도하였다. 낮은 광도에 적응하기 위하여 음나무 잎은 다른 수종들에 비하여 보다 많은 엽록소함량과 광합성능을 증가시 키는 반응을 보였다고 판단된다. 이러한 결과로 보아 내음성은 음나무, 물푸레나무, 층층나무의 순으로 낮아지는 것이라 판단된다.

• 한국통신학회논문지
• /
• 제33권12B호
• /
• pp.1058-1065
• /
• 2008

인터넷의 대부분의 데이터가 이미지, 음성, 비디오 등의 고용량 데이터임을 감안할 때 이를 고속으로 처리할 수 있는 네트워크 상에서의 멀티미디어 데이터의 처리 요구가 증가하고 있다. 네트워크 상에서 IP 멀티캐스트의 대안으로 고려되어지는 오버레이 멀티캐스트는 하드웨어적인 인프라의 구축 없이도 시스템의 자원과 네트워크 대역폭을 효율적으로 사용할 수 있는 기법이다. 하지만 고용량의 멀티미디어를 요구하는 다중 사용자들에 대한 요구서비스에 대한 적합한 모델과 중간 노드의 이탈 시 발생하게 되는 멀티캐스트 트리의 복구에 대한 적절한 모델이 필요하다 본 논문에서는 시간적 스케일링을 통해 패킷 간 지연(Jitter)을 적용하여 현재 네트워크 상태를 파악한다. 파악된 네트워크 정보에 따라 제안한 다중 사용자 서비스 제어 알고리즘을 적용함으로써 멀티미디어 요구에 대한 지연시간의 영향을 최소화하였다. 시뮬레이션 결과를 통해 제안된 모델이 기존의 기법들 보다 적은 복구시간이 소요되고 멀티미디어 서비스 요구에 대한 다중 사용자 노드의 이탈로 인해 많은 수의 노드가 영향을 받는 상황일수록 더욱 효과적인 방안임을 보여주고 있다.

• The Plant Pathology Journal
• /
• 제31권4호
• /
• pp.379-387
• /
• 2015

Melon necrotic spot virus (MNSV) was recently identified on watermelon (Citrullus vulgaris) in Korea, displaying as large necrotic spots and vein necrosis on the leaves and stems. The average occurrence of MNSV on watermelon was found to be 30-65% in Hapcheon and Andong City, respectively. Four isolates of the virus (MNSV-HW, MNSV-AW, MNSV-YW, and MNSV-SW) obtained from watermelon plants in different areas were non-pathogenic on ten general indicator plants, including Chenopodium quinoa, while they infected systemically six varieties of Cucurbitaceae. The virus particles purified by 10-40% sucrose density gradient centrifugation had a typical ultraviolet spectrum, with a minimum at 245 nm and a maximum at 260 nm. The morphology of the virus was spherical with a diameter of 28-30 nm. Virus particles were observed scattered throughout the cytoplasm of watermelon cells, but no crystals were detected. An ELISA was conducted using antiserum against MNSV-HW; the optimum concentrations of IgG and conjugated IgG for the assay were $1{\mu}l/ml$ and a 1:8,000-1:10,000 dilutions, respectively. Antiserum against MNSV-HW could capture specifically both MNSV-MN from melon and MNSV-HW from watermelon by IC/RT-PCR, and they were effectively detected with the same specific primer to produce product of 1,172 bp. The dsRNA of MNSV-HW had the same profile (4.5, 1.8, and 1.6 kb) as that of MNSV-MN from melon. The nucleotide sequence of the coat protein of MNSV-HW gave a different phylogenetic tree, having 17.2% difference in nucleotide sequence compared with MNSV isolates from melon.

• 한국농공학회논문집
• /
• 제63권6호
• /
• pp.39-47
• /
• 2021

Reduction effect of the spread of odorant and fine dust through windbreak trees can be predicted through numerical analysis. However, there is a disadvantage that a large space and destructive experiments must be carried out each time to calculate the aerodynamic coefficient of the tree. In order to overcome these shortcomings, In this study, we aimed to estimate the aerodynamic coefficient (C₀, C₁, C₂) by using image processing. Thuja occidentalis, which can be used as windbreak were used as the material. The leaf area index was estimated from the leaf area ratio using image processing with leaf weight, and the optical porosity was calculated through image processing of photos taken from the side while removing the leaves step-by-step. Correlation analysis was conducted with the aerodynamic coefficient of Thuja occidentalis calculated from the wind tunnel test and leaf area index and optical porosity calculated from the image analysis. The aerodynamic coefficient showed positive and negative correlations with the leaf area index and optical porosity, respectively. The results showed that the possibility of estimating the aerodynamic coefficient using image processing.

• Journal of Ecology and Environment
• /
• 제48권2호
• /
• pp.152-162
• /
• 2024

Background: Plant species of the alpine treeline ecotone are highly sensitive to climate change and may adjust their population dynamics, and functional traits in response to changing climate. This study examined regeneration patterns and leaf traits variations in an important treeline ecotone element Rhododendron campanulatum along the elevation gradient in western Nepal to assess its potential adaptive responses to climate change. The distribution range of R. campanulatum (3,400-3,800 m above sea level [a.s.l.]) was divided into five horizontal bands, each with a 100 m elevational range. Eight plots (10 m × 10 m) were sampled in each band, resulting into a total of 40 plots. In each plot, all R. campanulatum individuals and co-occurring tree species were counted. From each elevation, R. campanulatum leaf samples were collected to determine leaf dimensions, leaf density, specific leaf area (SLA), and stomatal density (SD). Results: The density-diameter curve indicated that R. campanulatum was regenerating well, with enhanced regeneration at higher elevation (3,800 m a.s.l.) than at lower. Tree canopy cover appeared to be the major determinant of R. campanulatum regeneration, as indicated by a higher number of seedlings in treeless stands. With increasing elevation, the leaf length, width, SLA, and stomata length decreased but leaf thickness and SD increased. Conclusions: Overall, a higher regeneration and lower SLA with the high SD in the leaves at the upper limit of the species distribution suggested that R. campanulatum is well adapted at its upper distribution range with the possibility of upslope range shift as temperature increases.