• Journal of Ecology and Environment
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• 제41권2호
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• pp.34-44
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• 2017

Background: Monitoring terrestrial vegetation cover condition is important to evaluate its current condition and to identify potential vulnerabilities. Due to simplicity and low cost, point intercept method has been widely used in evaluating grassland surface and quantifying cover conditions. Field-based digital photography method is gaining popularity for the purpose of cover estimate, as it can reduce field time and enable additional analysis in the future. However, the caveats and uncertainty among field-based vegetation cover estimation methods is not well known, especially across a wide range of cover conditions. We compared cover estimates from point intercept and digital photography methods with varying sampling intensities (25, 49, and 100 points within an image), across 61 transects in typical steppe, forest steppe, and desert steppe in central Mongolia. We classified three photosynthetic groups of cover important to grassland ecosystem functioning: photosynthetic vegetation, non-photosynthetic vegetation, and bare soil. We also acquired normalized difference vegetation index from satellite image comparison with the field-based cover. Results: Photosynthetic vegetation estimates by point intercept method were correlated with normalized difference vegetation index, with improvement when non-photosynthetic vegetation was combined. For digital photography method, photosynthetic and non-photosynthetic vegetation estimates showed no correlation with normalized difference vegetation index, but combining of both showed moderate and significant correlation, which slightly increased with greater sampling intensity. Conclusions: Results imply that varying greenness is playing an important role in classification accuracy confusion. We suggest adopting measures to reduce observer bias and better distinguishing greenness levels in combination with multispectral indices to improve estimates on dry matter.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1076-1080
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• 2003

$CO_2$ uptake of vegetation is one of the important variables in order to estimate photosynthetic activity, plant growth and carbon budget estimations. The objective of this research was to develop a new estimation method of $CO_2$ uptake of vegetation based on airborne hyperspectral remote sensing measurements in combination with a photosynthetic rate curve model. In this study, a compact airborne spectrographic imager (CASI) was used to obtain image over a field that had been set up to study the $CO_2$ uptake of corn on August 7, 2002. Also, a field survey was conducted concurrently with the CASI overpass. As a field survey, chlorophyll a content, photosynthetic rate curve, Leaf area, dry biomass and light condition were measured. The developed estimation method for $CO_2$ uptake consists of three major parts: a linear mixture model, an enhanced big leaf model and a photosynthetic rate curve model. The Accuracy of this scheme indicates that $CO_2$ uptake of vegetation could be estimated by using airborne hyperspectral remote sensing data in combination with a physiological model.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.447-449
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• 2003

Remotely sensed data can be used to estimate biomass production using methodologies relating vegetation indices to light absorption or to leaf photosynthetic capacity. The considerations of both light absorption and photosynthetic capacity in remote sensing-based modeling to estimate biomass production or NPP was introduced based upon Monteith model NPP is one of a evaluation of land degradation. NPP was estimated from annual maximum NDVI by MODIS data. It was known that NPP of the grassland that except the forest and the farming ground was distributed between 50-200g /m2.

• Weed & Turfgrass Science
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• 제4권4호
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• pp.338-347
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• 2015

Reinforcement cells are used to aid grass growth and taken together, this serves to extend greenery beyond the conventional spaces of lawns, tree pits, gardens, and parks, and is advantageous to urban cities since space for greening is often limited. Drought has variable effects on plant life and the resilience of turf to drought resistance also varies with species. Changes in photosynthetic ability were more pronounced for media rather than grass species. The media of sand without organic matter was found to be least suited for drought resistance. Normalized difference vegetation index (NDVI) and digital image analysis (DIA) data were generally in favour of Zoysia species as oppose to A. compressus. In A. compressus, selective traits such as, a more extensive root system and lower specific leaf area (SLA) were not an underlying factor that assisted this grass with enhanced drought resistance. Generally, WUE was found to be strongly related to plant characterises such as overall biomass, photosynthetic features as well as the lushness indexes, and specific leaf area. This study found a strong relationship between WUE and a suite of plant characteristics. These traits should serve as useful selection criteria for species with the ability to resist water stress.

• The Korean Journal of Ecology
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• 제6권2호
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• pp.128-141
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• 1983

The districbution of $C_3; and; C_4$ type plants in Korea were studied. In the standpoint of photosynthetic types, plant distribution in Korea is classified as $C_3; and; C_4$ type plant zones. The forest destroyed by man interference, cultivating areas, and seashore areas are characterized by the dominant of $C_4$ type plants.(Figs. 2, 3, 4, 5) According to the results of this study, $C_3; and; C_4$ type plant distribution in Korea has a great relation to the habitat of plant vegetation (Table 1). The arid areas were in high proportion of C4 flora percenntages, while the well-developed woody forests or the vegetation of humid areas were in lower proportion(Fig.8).

• Asian Journal of Atmospheric Environment
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• 제5권2호
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• pp.65-78
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• 2011

Ozone ($O_3$) is a main component of photochemical oxidants, and a phytotoxic anthropogenic air pollutant. In North America and Europe, the current concentration of $O_3$ has been shown to have significant adverse effects on vegetation. In this review, we summarize the experimental studies on the effects of $O_3$ on the growth and photosynthetic activity of Japanese forest tree species to understand the present knowledge and provide sound basis for future research toward the assessment of $O_3$ impacts on Japanese forest ecosystem. Since the 1990s, several Japanese researchers have conducted the experimental studies on the effects of ambient levels of $O_3$ on growth and physiological functions such as net photosynthesis of Japanese forest tree species. Although the sensitivity to $O_3$ of whole-plant growth is quite different among the species, it was suggested that the current ambient levels of $O_3$ in Japan are high enough to adversely affect growth and photosynthetic activity of Japanese forest tree species classified into high $O_3$ sensitivity group such as Japanese beech. The N load to soil has been shown to reduce the sensitivity to $O_3$ of Japanese larch and increase that of Japanese beech. To establish the critical level of $O_3$ for protecting Japanese forest tree species, therefore, it is necessary to take into account the N deposition from the atmosphere. There is little information on the combined effects of $O_3$ and other environmental factors such as elevated $CO_2$ and drought on growth and physiological functions of Japanese forest tree species. Therefore, it is necessary to promote the experimental study and accumulate the information on the combined effects of $O_3$ and any other abiotic environmental factors on Japanese forest tree species.

• 대한원격탐사학회지
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• 제34권6_1호
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• pp.1055-1066
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• 2018

식생의 광학적 특성을 기반으로 만들어진 식생지수들은 식물의 생물생산량뿐만 아니라 생리적 활성을 나타내고 있다. 식생지수의 활용은 위성에 장착된 다중분광 광학 센서의 발달에 힘입은 바가 크지만, 관측 공간규모에 따라 식생지수의 민감도가 달라질 수 있어 여러 규모에서의 비교 관측이 요구된다. 특히 광화학반사지수(PRI, Photochemical Reflectance Index)는 광합성능과 식물 스트레스 탐지에 유용한 것으로 알려져 있지만 올바른 해석을 위한 다양한 공간규모에서의 선행연구가 드물다. 본 연구에서는 드론에 장착된 다중분광 카메라, 소형 필드 초분광계, 휴대용 잎 반사계를 이용해 마늘 작물을 대상으로 서로 다른 공간규모의 PRI를 평가하였다. 잎 규모에서 하루 중 PRI는 잎의 윗면이 향하는 방위에 따라 서로 다른 시간에 최저값을 보였으며, 이는 어떤 순간에 잎마다 다른 광이용효율(LUE, Light Use Efficiency) 상태라는 것을 의미한다. 잎 규모에서는 식생피복율에 영향을 받지 않으므로 PRI 생물계절적 변화는 생육 초기에 개체 및 군락 규모보다 값이 높게 나타났다. 개체 및 군락 규모에서 PRI는 생물량을 나타내는 NDVI(Normalized Difference Vegetation Index)와는 달리 공간적 변동성이 크게 나타났다. 반면, 지상의 개체들 규모의 식생지수를 드론 영상의 관측 지점 값과 비교해 보면 NDVI에 비해 PRI가좀더 좋은 일치도를 보였다. 이러한 결과는 서로 다른 공간규모에서 관측된 PRI를 이해하고 활용하는데 도움이 될 것이다.

• 한국산림과학회지
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• 제99권6호
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• pp.922-928
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• 2010

겨울철 제설제로 사용되고 있는 염화칼슘($CaCl_2$)이 산벚나무(P. sargentii) 가로수에 미치는 영향을 조사하기 위해서, 염화칼슘 농도가 다른 수용액을 2회 처리 후 엽록소형광이미지와 광반응-광합성속도와 같은 광합성기구의 반응, 엽과 근원경 생장을 조사하였다. 3년생 산벚나무를 대상으로 개엽 전에 염화칼슘 0.5%(9 mM), 1.0%(18 mM), 3.0%(54 mM)를 2(1 L)회 뿌리둘레 부위에 처리하였다. 염화칼슘의 처리결과, 염화칼슘의 농도가 짙어짐에 따라 대조구에 비해 염화칼슘처리구의 총엽록소함량과 엽록소 a/b, 광합성속도, 양자수율, 암호흡이 감소하였다. 반면 광보상점은 염화칼슘의 농도가 높아짐에 따라 증가였다. 광합성과 양자수율, 암호흡, 광보상점과의 상관관계에서 양자수율과 광보상점에서 유의성이 나타났다(p<0.05). 한편, 최대형광($F_M$)과 최소형광($F_0$)의 차이인 Fv값의 형광이미지를 통해 빛을 이용하는 능력의 차이가 처리구와 대조구간에 확실하게 나타나는 것을 알 수 있었으며, 광계의 활성(Fv/$F_M$과 비광화학적 소멸(NPQ)의 처리 80일째 값이 모든 처리구에서 대조구에 비해 급격히 감소하였다. 이와 같은 결과로 염화칼슘 수용액에 의해서 산벚나무의 광합성, 동화기관 및 비대생장이 장애를 받고 있음을 알 수 있었다.

• 한국농림기상학회지
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• 제11권4호
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• pp.143-150
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• 2009

겨울철 도로의 안전을 위해서 사용되고 있는 제설제가 가로변의 식생에 축적이 되면 식물에 피해를 가져올 수 있는데, 특히 이른 봄의 제설제 사용은 식물이 다량의 수분을 요구하게 되는 개엽 시기와 맞물리게 되면서 그 피해가 가속화 될 수 있다. 우리나라에서 주로 사용하고 있는 제설제인 $CaCl_2$ 으로 산딸나무(C.kousa) 3년생 유묘를 대상으로 개엽 전 대조구를 포함해 각 처리구당 3본씩 선정하여 배치하고 각각 $CaCl_2$ 0.5%, 1.0%, 3.0% 를 2회 근권부에 처리하였다. 먼저, 가시적 피해 현상으로 잎눈에서 개엽이 어려워지며, 잎의 전개 후에도 시들음 현상과 잎끝마름 현상 등이 나타났다. $CaCl_2$ 의 농도가 높아짐에 따라 산딸나무의 피해가 가중되었는데, $CaCl_2$ 처리에 따른 생리적 반응은 총엽록소함량, 엽록소 a:b, 광합성속도, 양자수율, 기공전도도, $F_V/F_M$, NPQ의 감소를 가져왔다. 반면 광보상점과 암호흡속도의 증가를 나타냈다. 기공의 닫힘으로 인한 엽육내 $CO_2$ 농도 저하와 이로 인한 광합성속도의 감소가 1차적으로 일어나고 이후 물질대사량의 감소, 광화학계의 피해가 동반되는 것을 알 수 있었다. 모든 $CaCl_2$ 처리농도에서 산딸나무의 생리적 활동이 급격히 저하되는 경향으로 볼 때 $CaCl_2$ 에 민감한 수종으로 판단된다.

• 한국조경학회지
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• 제21권1호
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• pp.139-148
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• 1993

The present experiments have been conducted to find out the plant's growth environments habitate, mode of life, characteristic of photosynthesis, habit of growth and propagation. The results of this study are as follows: 1. Sambucus williamsii var. Coreana distributes around all sides of native site without having any relation to altitude, inclination and direction. 2. In the native site, Robinia pseudo - acacia and its neighboring species were Prunus yedoensis, Acer pseudo-sieboldianum, Lindera obtusiloba and Staphylea bumalda. From 21 to 41 types of species were located in the vegetation of the quadrat area. 3. According to the variation of leaf temperature with the result of the change of net photosynthetic rate, the optimum temperature for growth is $25^{\circ}C$. 4. The rooted rate of vegetative propagation was the highest at 100ppm IBA plot and the lowest at 200ppm BA plot. 5. The rooted rates of Sambucus williamsii var. coreana in perlite 50% bed, vermiculite bed and peatmoss 50%+sand 50% bed are higher than others.