• 제목/요약/키워드: Canopy Density

검색결과 163건 처리시간 0.04초

Effects of Canopy and Settlement Density on the Performance of the Brown Seaweed Fucus serratus Germlings

  • Choi, Han-Gil
    • Animal cells and systems
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    • 제7권4호
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    • pp.295-301
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    • 2003
  • Effects of the settlement density of germlings and canopy on settled germlings of Fucus serratus were investigated on the rocky shore of the Isle of Man. The survival of transplanted germlings was mainly determined by parent canopy rather than by initial settlement density of germlings. However, germling growth was greater at low density than at high density and enhanced by canopy removal. Recruitment by natural propagules was stimulated at high settlement density and maximal recruits occurred on caged slides under the canopy. On the experimental slides, tiny snails and sedimentation were ,found. The number of snails was positively related with the settlement density of germ lings indicating that they fed the germlings. Sedimentation and snail number were greater with canopy removal treatments than in canopy intact ones. These indicate that ,canopy sweeping gives benefits to germlings by removing sediment from substrata and protecting them from herbivores. In conclusion, the survival of settled F. serratus germlings is mainly determined by canopy sweeping and their growth is retarded in the presence of a canopy and at high settlement density.

REMOTELY SENSED INVESTIGATIONS OF FOREST CANOPY DENSITY DYNAMIC IN TROPIC COMBINE WITH LANDSAT AND FIELD MEASUREMENT DATA

  • Panta, Menaka;Kim, Hye-Hyun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.102-105
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    • 2006
  • Forest canopy density is an essentially important for maintaining the diversify flora and fauna in the tropic. But, the natural and human disturbances have an influence over the inconsistency of forest canopy density. So, forest canopy density (FCD) has been threatened in the tropic since a decade. The objective of this study was to examine the dynamics change of the forest canopy density in tropical forest Chitwan, Nepal combine with field survey and remote sensing data. The field survey data of 2001 such as canopy cover percentage, dbh so on and some human disturbances were used. Similarly, Landsat TM 1988 and ETM+ 2001 have also used to predict the dynamic changes of the FCD over the period. Moreover, nonparametric Kruskal- Wallis test has performed for the validation of the results. Data analysis revealed that very few factors i.e. the number of trees, path, and fire had realized statistically significance at P=<0.05. Therefore we concluded that detail analysis could be needed incorporate with additional socioeconomic, climatic, biophysical and institutional factors for the better understanding of the forest canopy dynamic in particular location.

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Study on the Relationship between the Forest Canopy Closure and Hyperspectral Signatures

  • Lin, Chinsu;Chang, Chein-I
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.72-74
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    • 2003
  • Forest canopy density is an ideal representative of the forest habitat situations. It can directly or indirectly depict the canopy structure and gap size in the forestland, thus could be applied to assessment of wildlife’s diversit y. Since population survey of vegetation and wildlife diversities is a key issue for sustainable forest ecosystem management, many research efforts have been focused on forest canopy density using multispectral data in the last two decades. Unfortunately, prediction of canopy density using large scaling remote sensing data remains a challenging issue. Due to recent advances in hyperspectral image sensors hyperspectral imagery is now available for environmental monitoring. In this paper, we conduct experiments to monitor complicated environments of forestland that can be captured by using hyperspectral imagery and further be analyzed to test a prediction model of forest canopy density. The results show that 95% of canopy density could be well described by using 2 difference vegetation indices (DVIs), which are difference of blue and green reflectances rband_100-rband_150 and difference of 2 short wave infrared reflectancse rband_406-rband_410 With the wavelengths of band no. 100, 150, 406, and 410 specified by 462.39 nm, 534.40 nm, 918.22 nm and 924.41 nm respectively.

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Spatial Relationship of Suburb, Road and River in respect to Forest Canopy Density Change Using GIS and RS

  • ;김계현
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2005년도 추계학술대회
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    • pp.257-270
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    • 2005
  • Many studies states that improperly uprising of infrastructure may cause leading the forest degradation and canopy reduction in many tropical forest of Asian countries. Other studies revealed that habitat destruction and fragmentation, edge effects, exotic species invasions, pollution are provoked by roads. Similarly, environmental effects of road construction in forests are problematic. Similarly, many researches have been indicated that roads have a far greater impact on forests than simply allowing greater access for human use. Moreover, people using river as means of transportation hence illegal logging and felling cause canopy depletion in many countries. Therefore, it is important to comprehend the study about spatial relation of road, river and suburb followed by temporal change of forest canopy phenomena. This study also tried to examine the effect of road, river and suburb in forest canopy density change of Terai forest of Nepal from you 1988 to 2001. So, Landsat TM88, 92 and 001 and FCD (Forest Canopy Density) mapper were used to perform the spatial .elation of canopy density change. ILWIS (Integrated Land and Water Information System) which is GIS software and compatible with remote sensing data was used to execute analysis and visualize the results. Study found that influence of distance to suburb and river had statistically significance influenced in canopy change. Though road also influenced canopy density much but didn't show a statistical relation. It can be concluded from this research that understanding of spatial relation of factors respect with canopy change is quite complex phenomena unless detail analysis of surrounding environment. Hence, it is better to carry out comprehensive analysis with other additional factors such as biophysical, anthropogenic, social, and institutional factors for proper approach of their effect on canopy change.

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옥수수 초형교정이 군락 투광성 및 수량성에 미치는 영향 (Effect of Canopy Reforming on Light Penetration into Crop Community and Yielding in Corn)

  • 이호진;조명제;이홍석
    • 한국작물학회지
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    • 제30권1호
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    • pp.76-83
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    • 1985
  • 옥수수의 밀도를 소(60cm$\times$40cm), 적(60cm$\times$24cm), 밀식(60cm$\times$16cm)으로 심고 초형처리로서 자연초형(남북이랑), 동서향교정(남북이랑), 동서향교정 및 엽각조정(남북이랑), 남북향교정(동서이랑)을 실시하였다. 초형교정은 엽출현이 완료된 뒤 철사가를 옥수수군락에 설치하고 옥수수잎들은 동서향이 되록 유인하여 고정시키고, 엽각조정은 수평에서 80$^{\circ}$가 되도록 직입화시켰다. 옥수수의 자연초형은 남북이랑이든 동서이랑이든 관계없이 모든 방위로 고루 분포하였고 약간의 남북향 경향을 보였으나 현저하지 않았고 엽각은 직입~중간엽형의 분포를 나타내었다. 군락내부에서 광투과는 초형을 동서향으로 교정하거나 엽각을 직립화시킴에 따라 초고의 중간높이에서 일평균 광도가 5~10% 가량 향상되었다. 반면 남북향 초형교정에서는 2~10% 정도 낮아졌다. 황숙기의 건물중집적은 밀식시 동서향초형이 자연초형 보다 6% 증가하였으나 남북향초형은 차이가 없었다. 완숙기의 종실수량에서는 동서향 초형교정은 3~11% 증가하였으나, 엽각조정까지 하였을 때에는 소식에서 10% 감소, 적. 밀식에서는 10%, 3%씩 각각 대조구보다 증가하였다. 반면 남북향초형은 차이가 없거나 감수로 나타난다. 초형을 태양의 방위와 고도를 고려하여 변형한다면 밀식에서도 일사광의 군낙내부로 침투를 용이하게 하며 증수할 수 있음이 확인되었다.

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Forest Canopy Density Estimation Using Airborne Hyperspectral Data

  • Kwon, Tae-Hyub;Lee, Woo-Kyun;Kwak, Doo-Ahn;Park, Tae-Jin;Lee, Jong-Yoel;Hong, Suk-Young;Guishan, Cui;Kim, So-Ra
    • 대한원격탐사학회지
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    • 제28권3호
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    • pp.297-305
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    • 2012
  • This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

Spatio-temporal Dynamic Alteration of Forest Canopy Density based on Site Associated Factor: View from Tropical Forest of Nepal

  • Panta, Menaka;Kim, Kye-Hyun
    • 대한원격탐사학회지
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    • 제22권5호
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    • pp.313-323
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    • 2006
  • Forest Canopy Density is a dynamic process mediated by various natural and anthropogenic factors. It can be changed over time and locations in the same forest type and landscape. However, human dimensions are considered as the primary force of landscape change and subsequent forest canopy loss in tropical regions of the world. Many studies have been indicated that roads have a far greater impact on forests than simply allowing access for human use. Similarly, rivers have been used as means of transportation, hence illegal logging and felling further deplete forest canopy density. The main objective of this study was to investigate the spatio-temporal dynamic alterations of Forest Canopy Density (FCD) across with site associated factors such as biophysical, physical and human interferences in tropical region of Nepal from 1988 to 2001. Landsat TM and ETM+ of 1988 and 2001 were used to assess the spatial and temporal dynamic alterations of FCD. This analysis revealed that distance to human settlements at P=<0.01, rivers, human interferences (path and fire) and species composition had a statistically significance at P=<0.05 level. However, other factors did not show any significant relation. So, we concluded that understanding of dynamic alterations of FCD with respect to factors was quite complex phenomena. Other surrounding environment could also playa significant role. A comprehensive analysis could be required to understand such complexities. Therefore, additional factors such as climatic, biophysical, social, and institutional with respect to spatio-temporal variability should be considered for the better understanding of canopy dynamic.

벼의 생산력 분석 - (III) 군락구조의 동적변화 - (Analysis of Productivity in Rice Plant - (III) Dynamic Change of Canopy Structure -)

  • 박훈;박영선
    • Applied Biological Chemistry
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    • 제15권1호
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    • pp.41-47
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    • 1972
  • 새로 육종된 다수성 품종인 IR 667-수원 213과 진흥을 사용하여 출수후 군락구조의 등적 변화를 질소영양과 관련하여 비교분석한 결과 다음과 같았다. 1. 군락주조 패턴 (출수기 건물중 수직분포)은 진흥에서는 수직형이고 IR 667에서는 수평형이었다. 2. 엽면적 밀도 (또는 무게)의 수직분포 패턴이 IR 667은 중앙부 우세형으로 진흥은 상부 우세형으로 분류되었다. 3. 군락구조 보존패턴과 엽면적 백분율 분포패턴은 엽면적밀도의수직분포패턴을 따랐다. 4. 군락보존력은 IR 667이 약하여 군락보존율이 낮으며 이는 엽의노화가 빠른것을 나타낸다. 5. 질소영양이 군락구조패턴에 거의 영향을 주지 않지만 질소의 느린공급(유황입힌요소)은 구조의 중앙부를 보존하여 상부우세형을 중앙부 우세형으로 변환 시키려는 경향을 보였으며 그것이 수량 증가의 원인이 된것같다. 6. 증앙부우세형과 상부우세형은 곡실생산에서의 상위엽의존형과 하위엽 의존형에 각기 잘 적합한것 같다.

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영상처리에 의한 식물체의 형상분석 (Analysis of Plants Shape by Image Processing)

  • 이종환;노상하;류관희
    • Journal of Biosystems Engineering
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    • 제21권3호
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    • pp.315-324
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    • 1996
  • This study was one of a series of studies on application of machine vision and image processing to extract the geometrical features of plants and to analyze plant growth. Several algorithms were developed to measure morphological properties of plants and describing the growth development of in-situ lettuce(Lactuca sativa L.). Canopy, centroid, leaf density and fractal dimension of plant were measured from a top viewed binary image. It was capable of identifying plants by a thinning top viewed image. Overlapping the thinning side viewed image with a side viewed binary image of plant was very effective to auto-detect meaningful nodes associated with canopy components such as stem, branch, petiole and leaf. And, plant height, stem diameter, number and angle of branches, and internode length and so on were analyzed by using meaningful nodes extracted from overlapped side viewed images. Canopy, leaf density and fractal dimension showed high relation with fresh weight or growth pattern of in-situ lettuces. It was concluded that machine vision system and image processing techniques are very useful in extracting geometrical features and monitoring plant growth, although interactive methods, for some applications, were required.

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수목차폐율을 고려한 가시선 분석 시뮬레이션 (LOS Analysis Simulation considering Canopy Cover)

  • 공성필;송현승;어양담;김용민;김창재
    • 대한공간정보학회지
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    • 제20권2호
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    • pp.55-61
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    • 2012
  • 가시선 분석 결과에 영향을 미치는 주요 요인으로는 지형고도, 장비의 성능 그리고 수목에 의한 차폐를 들 수 있다. 수목 차폐는 계절별로 달라지고, 수목의 밀도, 수목고 등에 의해 그 값이 변화하므로, 현실적인 가시선 분석 결과에 많은 영향을 미친다고 볼 수 있다. 본 연구에서는 NDVI와 수치지도 속성자료인 수목차폐 자료를 상관시켜 수목차폐율 값을 생성하고 이에 의한 가시선 분석을 실험지역 6개 관측지점에 대하여 수행하였다. 실험 결과, 식생 지수 NDVI와 차폐율은 상관성이 있으며, 이를 기반으로 새로운 차폐율 지도를 생성할 수 있었다. 또한 가시선 분석 결과 기존 차폐율을 고려한 가시선 분석 결과와 가시면적 차이가 있었으며, 특히 가시영역의 공간적 분포 차이가 두드러졌다.