• Title/Summary/Keyword: phenology

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Analysis of Phenological Changes by Phenocams on Some Major Species Distributed in Wetland and Forest Ecosystems in Korea (Phenocam을 활용한 국내 습지 및 산림생태계 대표 수종의 계절적 변화 분석)

  • Minki Hong;Hyohyemi Lee;Jeong-Soo Park
    • Ecology and Resilient Infrastructure
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    • v.10 no.4
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    • pp.226-236
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    • 2023
  • As climate change intensifies, the importance of studying plant phenology has increased, leading to a surge in research employing automated video recording devices like Phenocams. In this study, using the Phenocams operated by the National Institute of Ecology, we examined the trends in plant phenological changes across diverse ecosystem types in South Korea and analyzed their correlations with climate factors. The patterns of plant phenological changes varied by region and tree species. Pinus thunbergii and Pinus densiflora typically show an overall increase in their growth period, positively correlating with temperatures and precipitation during winter. However, uniquely, for Abies koreana on Hallasan Mt., a higher amount of precipitation in August leads to an earlier end of season (eos), and the correlation analysis with the recent phenomenon of dying A. Koreana seems necessary. beyond the analysis, solutions for handling missing data issues during the data collection process were proposed. Furthermore, to expand future research scope and encompass diverse ecosystem types, a suggestion to combine Phenocam research with satellite observations was presented.

Morphological Characteristics of Brown Alga Spatoglossum crassum Tanaka (Dictyotaceae, Dictyotales), New to Korea

  • Hwang, Il-Ki;Kim, Hyung-Seop;Lee, Wook-Jae
    • ALGAE
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    • v.19 no.3
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    • pp.191-199
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    • 2004
  • Morphological and phonological characteristics of brown alga Spatoglossum crassum Tanaka new to Korea were described based on the field and the indoor cultured plants. The taxonomic characteristics of the plants were agreed to those from the type locality-submerged reproductive organs in cortex, anatomical features, and absence of phaeophycean hairs on the surface. But they have rudimentary midrib on lower portion of thallus. We can observe the young plants on November, adult ones in June, and senile ones in August. This species has an annual life-cycle in the field, starting with germ lings in early November. The differentiation of thallus is quite different from other species of genera in tribe Zonarieae, e.g. Zonaria and Homoeostrichus. Three different tissues, meristoderm, cortex and medulla are discerned. The outmost cortical one celled layer as a meristoderm produce cortex by unequal periclinal division. In the apical cell division, the primary inner cells are developed into 3-4 cell layered medulla of thallus. The distribution of this species extends from Korea to Shizuoka Peninsula (34°40'N) Japan, which is the type locality of this species.

CONSTRUCTING DAILY 8KM NDVI DATASET FROM 1982 TO 2000 OVER EURASIA

  • Suzuki Rikie;Kondoh Akihiko
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.18-21
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    • 2005
  • The impact of the interannual climatic variability on the vegetation sensitively appears in the timing of phenological events such as green-up, mature, and senescence. Therefore, an accurate and temporally high-resolution NDVI dataset will be required for analysis on the interannual variability of the climate-vegetation relationship. We constructed a daily 8km NDVI dataset over Eurasia based on the 8km tiled data of Pathfinder A VHRR Land (PAL) Global daily product. Cloud contamination was successfully reduced by Temporal Window Operation (TWO), which is a method to find optimized upper envelop line of the NDVI seasonal change. Based on the daily NDVI time series from 1982 to 2000, an accurate (daily) interannual change of the phenological events will be analyzed.

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Determining Canopy Growth Conditions of Paddy Rice via Ground-based Remote Sensing

  • Jo, Seunghyun;Yeom, Jongmin;Ko, Jonghan
    • Korean Journal of Remote Sensing
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    • v.31 no.1
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    • pp.11-20
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    • 2015
  • This study aimed to investigate the canopy growth conditions and the accuracy of phenological stages of paddy rice using ground-based remote sensing data. Plant growth variables including Leaf Area Index (LAI) and canopy reflectance of paddy rice were measured at the experimental fields of Chonnam National University, Gwangju, Republic of Korea during the crop seasons of 2011, 2012, and 2013. LAI values were also determined based on correlations with Vegetation Indices (VIs) obtained from the canopy reflectance. Three phenological stages (tillering, booting, and grain filling) of paddy rice could be identified using VIs and a spatial index (NIR versus red). We found that exponential relationships could be applied between LAI and the VIs of interest. This information, as well as the relationships between LAI and VIs obtained in the present study, could be used to estimate and monitor the relative growth and development of rice canopies during the growing season.

Multi-temporal analysis of vegetation indices for characterizing vegetation dynamics

  • Javzandulam, Tsend-Ayush;Tateishi, Ryutaro;Kim, Dong-Hee
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.405-407
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    • 2003
  • An attempt has been in this study to delineate the characteristics of spectral signatures of the vegetation in terms of various VIs, particularly made the Normalized Difference Vegetation Index(NDVI), Modified Soil Adjusted Vegetation Index2(MSAVI2) and Enhanced Vegetation Index(EVI). Multitemporal SPOT-4 VEGETATION data from 1998 to 2002 have been used for the analysis. They have been compared with each other for their similarities and differences. The correlations between the vegetation indices observed at various degree of vegetation coverage during their different stages of growth were examined. All of the VIs have shown qualitative relationships to variations in vegetation. Apparently, the NDVI and MSAVI2 are highly correlated for all of the temporal changes, representing the different stages of phenology.

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Analysis of a crop growth model using Unified Modeling Language

  • Kim, Kwang Soo;Kim, Do-Gyeom;Kim, Sey Hyun;Hwang, Grim;Jeong, Haneul
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2011.11a
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    • pp.12-14
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    • 2011
  • Crop growth simulation models have been developed as research and management tools. When these models are needed to incorporate new knowledge on phenology and physiology of crops, programming languages have been used for development and documentation of these models. However, researchers may have limited skill in programming languages. Furthermore, software developer may find it challenging to improve the crop models because documentation of the models are rarely available. The Unified Modeling Language (UML) can provide a simple approach for development and documentation of model. A template for implementation of the model can be obtained using the UML, which would facilitate code re-use and model improvement.

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Application of Light Emitting Diodes (LEDs) Sensor to Monitor Multi-layer Canopy Phenology in Gwangneung Forest (LED 분광계를 활용한 광릉숲의 다층군락 생물계절 모니터링)

  • Lee, Galam;Ryu, Youngryel
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2013.11a
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    • pp.25-25
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    • 2013
  • 식생의 생물계절학적 특성은 지표면과 대기의 에너지와 물 순환에 큰 영향을 미친다. 일반적으로 상층군락과 하층군락의 식생은 미기후의 차이 등에 의해 서로 다른 생물계절학적 특성을 가진다. 이러한 식생의 생물계절학적 특성은 반사도 관측을 통해 추정할 수 있다. 과거부터 원격탐사 기법을 활용하여 식생의 생물계절학적 특성을 추정하는 많은 연구가 수행되어 왔다. 그러나 대부분의 연구는 상층군락과 하층군락의 반사특성을 구분하지 않았다. 본 연구에서는 상층군락과 하층군락 식생의 생물계절학적 특성을 구분하여 탐지하기 위해 red, green, blue 그리고 near-infrared 의 네 가지 파장대를 가진 LED 센서를 이용하였다. LED 센서는 광릉 시험림 내의 활엽수림과 침엽수림 관측지에 서로 다른 네 군데의 높이에 설치되어 각 파장대의 반사도를 산출하였다. 또한 반사도를 이용하여 세 가지 식생지수(NDVI, EVI, Greenness index)를 산출하여 상층식생과 하층식생의 개엽기를 추정하였다.

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Tripterygium wilfordii (Celastraceae): A new generic and species record for the flora of Vietnam

  • HAI, Do Van;QUANG, Bui Hong;BACH, Tran The;BINH, Tran Duc;CHOUDHARY, Ritesh Kumar;LEE, Joongku
    • Korean Journal of Plant Taxonomy
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    • v.51 no.3
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    • pp.319-325
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    • 2021
  • Tripterygium wilfordii Hook.f. (Celastraceae), collected from Phia Oac-Phia Den National Park of Vietnam, is reported here as a new generic and species record for the flora of Vietnam. The genus Tripterygium differs from other genera of Celastraceae by its samara fruits, which become three-winged at maturity, and a scandent shrub. Taxonomic notes, descriptions, line drawing and photographs are provided, together with short notes on the distribution, ecology and phenology of Tripterygium wilfordii Hook.f. (Celastraceae).

Taxonomic notes on Leycesteria Wall. (Caprifoliaceae): a newly recorded genus for the flora of Vietnam

  • Quang, Bui Hong;Choudhary, Ritesh Kumar;Lee, Joongku
    • Korean Journal of Agricultural Science
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    • v.46 no.2
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    • pp.335-340
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    • 2019
  • Two species of Leycesteria, L. gracilis (Kurz) Airy Shaw and L. formosa Wall. (Caprifoliaceae), from the Lao Cai and Yen Bai Provinces are reported here as a new generic record for the flora of Vietnam. During floristic surveys of northern Vietnam, L. gracilis and L. Formosa were encountered. A critical morphological study of all the collected specimens and the type of materials consulting the relevant literature led us to confirm the identity of our collected specimens as L. gracilis and L. formosa. The genus differs from other Vietnamese genera of Caprifoliaceae by the presence of a spike inflorescence or flowers in sessile whorls of 6. Taxonomic notes, description, and photographs are provided, together with short notes on the distribution, ecology and phenology of the two species.

A new record of Viola inconspicua (Violaceae) from Korea

  • KIM, Kyeonghee;KIM, Jung-Hyun;KO, Soon Yeol;LEE, Kang-Hyup;KIM, Jin-Seok
    • Korean Journal of Plant Taxonomy
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    • v.51 no.2
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    • pp.166-170
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    • 2021
  • Distribution of Viola inconspicua is newly discovered in Korea. This species was collected from grassy fields and roadsides in Jeju-si and Seogwipo-si, Jejudo Island. V. inconspicua shares several characteristics (i.e., purple or pale purple flowers, triangular leaf blades, winged petioles, and a linear-lanceolate stipules) with the related species V. mandshurica and V. yedoensis. However, V. inconspicua can be easily distinguished from other species by the following characteristics: leaf base (cordate vs. truncate to attenuate), and spur (short, 2-4 mm long vs. longer, 5-8 mm long). Here, we describe and illustrate of V. inconspicua. In addition, the identification key to allied species, photographs in its habitat, distribution, ecology, and phenology are provided as well. The Korean name for the species is given as 'Hwa-sal-ip-je-bi-kkot', considering the shape of its leaves.