• Journal of Plant Biology
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• 제14권3호
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• pp.43-46
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• 1971

Losses of nitrogenin the gaseous form were determined with closed systems in the filed under different vegetation types. Ammonia volatilization was greatest from the pine stand, and least from the sod stand, and was greatly reduced in all three sites in the rainy season due to the low temperature. There were only insignificant differences in the nitrogen dioxide volatilization from the soil of the three vegetation types. Losses of ammonia and nitrogen dioxide at various soil depth also showed little variation. Evidently the microbial activity responsible for the $NO_2$ loss was relatively unaffected by the changes in temperature and soil moisture content during the investigation.

• 한국토양비료학회지
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• 제41권2호
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• pp.83-93
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• 2008

간척지에서 식생의 분포에 대한 평가는 토양관리 및 환경적 연구를 위해 필요하다. 본 연구는 한국 중부 서해안 경기만 내의 3개 간척지에서 식생의 분포와 토양 염농도 간의 관계를 규명하기 위하여 실시하였다. 식생이 연속분포를 보이는 지점에서 토양 염농도를 측정하고 출현식물종을 분류하여 연속분포의 특성을 기술하였다. 간척지 내에 나타나는 식생의 공간변이는 부분적으로 이루어지지만 각각의 공간변이를 토양 염농도를 기준으로 연결한 결과 토양 염농도 구배와 내염성 식물종의 분포가 일치하는 연속분포(continuum distribution)를 보여, 토양 염농도가 높은 곳은 내염성 식물종이, 낮은 곳은 비내염성 식물종이 분포하였다. 연속분포는 간척 경과 년 수가 오래된 곳에서 유형이 다양하고 명확하게 구분되나, 간척 초기 지역에서는 연속분포 현상이 뚜렷하지 않았다. 연속분포 유형은 순차적 유형과 비순차적 유형으로 구분되었다. 순차적 유형은 토양 염농도가 높은 곳을 기점으로 할 경우 토양 염농도가 연속적으로 낮아지는 방향으로 이어지며 식물종도 이에 따라 선구종 염생식물(pioneer halophyte)에서 저염생식물(facultative halophyte), 중성식물(glycophyte)의 순으로 변화하였다. 비순차적 유형은 비연속적 토양 염농도의 변화에 의해 형성되며, 식생의 분포도 단계적 변화를 보이지 않고 비정형적이다. 간척 경과 년 수가 오래된 지역에서는 토양 염농도가 높은 식생 고사지역이 있고 식생 비분포지와 함께 이 지점을 기점으로 식생의 연속분포가 형성되었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.25-28
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• 2002

The aim of the present study was the evaluation of methods for estimating the vegetation information in the field on the basis of spectral reflectance measured farm field, in particular the estimation of Leaf Area Index(LAI). Variability in tissue optical properties was wavelength-dependent. For rice and bean, the lowest variation was in the visible spectral region and the highest in the near-infrared. The structural attributes of ecosystems determine the relative contribution of tissue and canopy factors that drive variation in a reflectance signal.

• 한국수산과학회지
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• 제41권3호
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• pp.201-207
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• 2008

The seasonal variation and vertical distribution of the marine algal community were investigated using the quadrat method from February 2006 to January 2007 at 10 sites in Gwangyang Bay, Korea. In total, 48 red, 17 brown, and 13 green algal taxa were identified. The algal vertical distribution in the intertidal zone was characterized by Ulva pertusa, while the upper tidal zone was dominated by Gelidium divaricatum. The middle zone was primarily composed of Enteromorpha linza, Sargassum thunbergii, and Chondracanthus intermedia, whereas Hizikia fusiformis, Sargassum thunbergii, Gelidium amansii, and Corallina pilulifera characterized the low tidal zone. Results of cluster analysis indicated that algal composition fell into two groups, which were composed of species in the inland and open sea. In conclusion, the number of species, diversity, and abundance of vegetation in this area were remarkably reduced compared to previous studies in Gwangyang Bay.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1152-1153
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• 2005

• 한국물환경학회지
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• 제32권2호
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• pp.135-141
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• 2016

This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

• 대한원격탐사학회지
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• 제22권3호
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• pp.183-197
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• 2006

Combinations of visible and near-infrared (NIR) bands in an image are widely used for estimating vegetation vigor and productivity. Using this approach to understand within-field grain crop variability could allow pre-harvest estimates of yield, and might enable mapping of yield variations without use of a combine yield monitor. The objective of this study was to estimate within-field variations in crop yield using vegetation indices derived from hyperspectral images. Hyperspectral images were acquired using an aerial sensor on multiple dates during the 2003 and 2004 cropping seasons for corn and soybean fields in central Missouri. Vegetation indices, including intensity normalized red (NR), intensity normalized green (NG), normalized difference vegetation index (NDVI), green NDVI (gNDVI), and soil-adjusted vegetation index (SAVI), were derived from the images using wavelengths from 440 nm to 850 nm, with bands selected using an iterative procedure. Accuracy of yield estimation models based on these vegetation indices was assessed by comparison with combine yield monitor data. In 2003, late-season NG provided the best estimation of both corn $(r^2\;=\;0.632)$ and soybean $(r^2\;=\;0.467)$ yields. Stepwise multiple linear regression using multiple hyperspectral bands was also used to estimate yield, and explained similar amounts of yield variation. Corn yield variability was better modeled than was soybean yield variability. Remote sensing was better able to estimate yields in the 2003 season when crop growth was limited by water availability, especially on drought-prone portions of the fields. In 2004, when timely rains during the growing season provided adequate moisture across entire fields and yield variability was less, remote sensing estimates of yield were much poorer $(r^2<0.3)$.

• 보존과학회지
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• 제37권6호
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• pp.659-669
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• 2021

이 연구에서는 초분광 영상을 기반으로 산출된 식생지수를 활용하여 2014년부터 2020년까지 울주 천전리 각석에 대한 모니터링을 수행하였다. 모니터링에 적합한 식생지수 선정을 위해 실내분석을 수행하였고, 생물오염에 대한 민감도를 고려하여 NDVI와 TVI를 선정하였다. 선정된 식생지수를 활용하여 모니터링을 수행한 결과, NDVI는 2014년부터 2018년까지 증가하는 경향을 보이고 보존처리 이후인 2020년 감소하였으나, TVI는 모니터링 시점에 따른 경향성을 확인하기 어려웠다. 이러한 경향은 연도별 촬영조건에 따른 분광반사율 편차에서 기인하는 것을 확인하였다. 이때 NDVI는 TVI보다 분광반사율 편차에 대한 민감도가 낮아 모니터링에 활용할 수 있을 것으로 판단되며, TVI의 활용을 위해서는 심화연구가 필요하다.

• 한국환경복원기술학회지
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• 제12권1호
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• pp.44-51
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• 2009

In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.

• 한국농공학회논문집
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• 제61권1호
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• pp.131-144
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• 2019

The purpose of study was to determine the hygrophyte index of each plant(HIP) considering the moisture environment condition (MEC) of the native plants on the downstream slope of the fill dam and evaluate its applicability which to develop a method to search for leaks and saturated zones of the fill dam for status evaluation of precision safety diagnosis. The HIP was weighted average and consisted of 19 ranks. The weighted average was calculated according to the following three procedures: First, the linear assumption was made according to the actual habitat environmental conditions, the second one was weighted to 10% of the optimal habitat condition, and finally the average value of the distribution range values. The Hygrophyte index of vegetation at each plot (HIV) was obtained from the Sinheung reservoir (Yesan-gun, Chungcheongnam-do) using the results of vegetation survey of the Sinheung reservoir with precision safety diagnosis and suggested the use of the hygrophyte index of the cultivated vegetation. The average HIP range of plant species that emerged in 50 survey sites on the downstream slope of the Sinheung reservoir is 2.99 to 3.56. The coefficient of variation showed a large difference depending on the appearance of the leakage indicator plant(LIP) species. The range of HIV is 2.80 to 4.26, the mean value is 3.37, standard deviation is 0.37 and the coefficient of variation is 9.7%. As a result, the value of the coefficient of variation showed a large difference depending on the appearance of the plant species.