• 식물병연구
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• 제24권3호
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• pp.182-192
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• 2018

화상병은 우리나라에서 그동안 존재하지 않았던 금지병으로서 2015년 최초로 발병한 후 아직 박멸되지 않아, 국내 확산 연구가 필요하다. 병 삼각형 원리를 바탕으로 화상병 발병에 적합한 환경 요인을 추론하기 위해서, 최근 4년(2014-2017년) 우리나라 기상관측 자료 및 미래(2020-2100년) 기후변화 시나리오 RCP8.5 예측 기상자료를 입력하여 화상병 발병 예측프로그램인 MARYBLYT로 꽃감염을 예측하였다. 이 예측 프로그램은 신고배 개화기간을 먼저 계산한 후, 개화기간 중 매일매일의 화상병 꽃감염 위험 경보를 출력하였다. 최근 4년 동안 꽃감염 결과 화상병 발생지인 경기 안성과 천안뿐만 아니라 인근 주산지인 평택, 아산 모두 2014년과 2015년에 "Infection" 경보가 나타났다. 또한 배 주산지인 전남 나주는 2016-2017년 "Infection" 경보가 나타났다. 최근 4년간 방제 권고 수준인 "Infection" 또는 "High" 경보 발령은 우리나라 전체 중 80% 지역에서 나타나 우리나라는 화상병 발병에 적합한 환경이었다. 80년간 미래 기후변화 기상자료로 개화기간 동안 화상병 꽃감염을 예측한 결과 해마다 감염위험 지역이 급변하였다. 하루 이상 "Infection" 경보가 발령되는 지역이 전국의 50%가 넘을 정도로 광범위할 것으로 예측되는 해는 총 20년이었던 반면 "Infection" 경보가 전국의 10% 미만 지역일 것으로 예측된 해는 8년이었다. 이들 두 그룹의 환경요인 비교분석 결과, 개화기간 중 평균온도와 누적 강수량이 유의하게 달랐다. 본 연구 결과는 외래 침입균인 화상병 관리를 담당하는 정책 당국에 적절한 정보를 제공할 것이다.

• 한국산림과학회지
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• 제109권4호
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• pp.361-370
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• 2020

매년 반복되는 식물의 생활사를 장기적으로 관측하는 것은 기후변화 반응을 감지하는데 있어 가장 단순한 방법이며, 중요한 지표로 인식되고 있다. 반복 디지털 이미지를 이용한 식물계절 변화 관찰 방법은 전통적(현장에서 전문가에 의해 관찰) 방법과 위성원격탐사(위성영상의 식생지수를 활용한 위성원격 관찰)의 한계를 보완한 방법이다. 본 연구는 디지털 카메라를 기반으로 한 반복 이미지로부터 식물계절 변화 관측과 계절현상을 정량화하기 위하여 점봉산 산림생태계를 대상으로 하였다. 한반도 전역에 분포하는 신갈나무림(낙엽활엽수림)과 상록침엽수림의 대표 수종인 소나무를 선정하여 식물계절 특성에 따른 경향성을 파악하고자 하였다. RGB 채널 이미지 데이터로부터 식생지수(Gcc)를 산출하였다. Gcc 진폭의 크기는 상록침엽수림이 낙엽활엽수림 보다 작았으며, Gcc의 기울기(봄철 증가와 가을철 감소)는 상록침엽수림이 낙엽활엽수림과 비교하여 완만하였다. 소나무림은 생장의 시작(UD)이 신갈나무림에 보다 빨랐고, 생장의 종료(RD)는 늦은 것으로 나타났다. 식물계절 현상의 정확도 검증은 RMSE가 0.008(ROI1)과 0.006(ROI3)으로 높은 정확도를 보였다. 이러한 결과는 온대북부형 낙엽활엽수림의 Gcc 궤적의 경향성을 잘 반영하였으며, 디지털 카메라를 이용한 반복 이미지 관측 방법이 식물계절 변화 관측에 있어 유용할 것으로 판단된다.

• 한국농림기상학회지
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• 제25권1호
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• pp.37-47
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• 2023

The black cutworm, Agrotis ipsilon (Hufnagel), is an important crop pest worldwide that feeds more than 80 plant species including cabbage, potato, maize, wheat and bean, and this moth is a typical pest attacking underground parts of crops. It has been known in farm booklets that the larvae of A. ipsilon overwinter in the soil in Korea, but no definitive data exist yet. This study was conducted to evaluate that the specific appearance time of A. ipsilon observed actually in the field could be explained when we assumed that this pest overwinters in a form of larvae or pupae. Degree day-based phenology models were applied for tracking forward or backward to find the predicted developmental stage which developed at a specific stage found in the field. As a result of the analysis, it was confirmed that an initial population could be established in a group that does not overwinter as larvae or pupae in Korea. In other words, the appearance of adults in early March to April could not be explained by the presence of domestic overwintering populations. Populations that overwinter as larvae or pupae in Korea were able to emerge as adults in June to July at the earliest. Therefore, the group of adults appearing in early spring is highly likely to be a population that migrated from outside Korea. Taken together, it was estimated that the colony of A. ipsilon in Korea would be formed by a mixture of a migrant population through long-distance migration and a overwintering population.

• 한국농림기상학회지
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• 제25권3호
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• pp.208-217
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• 2023

정확한 자발휴면 타파일 및 개화기간 추정은 사과 화상병의 효과적 방제를 위해 매우 중요하다. 자발휴면 타파일부터 개화 개시일까지 기간은 이 기간 동안의 일 최저기온에 의해 영향을 받았다. 본 연구는 이 기간의 일 최저기온이 사과 생육단계 중 개화기간에 미치는 영향을 조사함으로써 화상병 방제를 위한 병모델 구동이 목적이었다. 원예특작과학원에서 제공하는 우리나라 사과나무 재배지역을 대표하는 8개 과수원에서 2019년부터 2023년까지 웹캠으로 관측한 영상자료로부터 최초 개화 관측일을 얻었다. 또한 같은 과수원에서 자발휴면 타파일은 전년도 10월 1일부터 자동기상 측정 장비로부터 받은 기상자료를 활용하여 자발휴면 타파일은 -100.5 DD에 도달하는 날로 추정하였다. 본 연구에서 실시한 회귀분석은 자발휴면 타파일부터 개화 개시일까지의 기간(Y)을 종속변수로 이 기간 중 일 최저 기온이 0℃ 이하인 날(X₁)이 며칠 인지를 독립변수로 하는 회귀식으로서 Y = 0.87 × X₁ + 40.76, R²= 0.83의 결과로서 뚜렷한 양의 상관관계를 얻었다. 또한 같은 기간(Y)을 종속변수로 하고 자발휴면 타파일을 줄리안데이(X₂)를 독립변수로 하는 회귀분석을 실시하여 Y = -1.07 × X₂ + 143.62, R²=0.92의 결과로서 뚜렷한 부의 상관관계를 얻었다. 따라서 자발휴면 타파일부터 개화 개시일까지의 기간은 월동 중 최저기온에 영향을 받으며, 이것이 사과 화상병 감염에 중요한 개화기간 변동에 영향을 준다는 것을 확인하였다.

• Journal of Ecology and Environment
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• 제47권4호
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• pp.228-240
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• 2023

Growing complexity in ecosystem structure and functions, under impacts of climate and land-use changes, requires interdisciplinary understandings of processes and the whole-system, and accurate estimates of the changing functions. In the last three decades, observation networks for biodiversity, ecosystems, and ecosystem functions under climate change, have been developed by interested scientists, research institutions and universities. In this paper we will review (1) the development and on-going activities of those observation networks, (2) some outcomes from forest carbon cycle studies at our super-site "Takayama site" in Japan, and (3) a few ideas how we connect in-situ and satellite observations as well as fill observation gaps in the Asia-Oceania region. There have been many intensive research and networking efforts to promote investigations for ecosystem change and functions (e.g., Long-Term Ecological Research Network), measurements of greenhouse gas, heat, and water fluxes (flux network), and biodiversity from genetic to ecosystem level (Biodiversity Observation Network). Combining those in-situ field research data with modeling analysis and satellite remote sensing allows the research communities to up-scale spatially from local to global, and temporally from the past to future. These observation networks oftern use different methodologies and target different scientific disciplines. However growing needs for comprehensive observations to understand the response of biodiversity and ecosystem functions to climate and societal changes at local, national, regional, and global scales are providing opportunities and expectations to network these networks. Among the challenges to produce and share integrated knowledge on climate, ecosystem functions and biodiversity, filling scale-gaps in space and time among the phenomena is crucial. To showcase such efforts, interdisciplinary research at 'Takayama super-site' was reviewed by focusing on studies on forest carbon cycle and phenology. A key approach to respond to multidisciplinary questions is to integrate in-situ field research, ecosystem modeling, and satellite remote sensing by developing cross-scale methodologies at long-term observation field sites called "super-sites". The research approach at 'Takayama site' in Japan showcases this response to the needs of multidisciplinary questions and further development of terrestrial ecosystem research to address environmental change issues from local to national, regional and global scales.

• ALGAE
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• 제19권3호
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• pp.175-190
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• 2004

The morphological and molecular characteristics of Pachydictyon coriaceum (Holmes) Okamura (1899) are described. Plants are collected from Korea all year round and have maximum height from August to September. The monthly variability of thallus growth is in the way with that of the seawater temperature. Two types of thallus structures, thick cortical layer tallus type and thin cortical cell layer type, are distinguished according to growing seasons. The habit of Korean plants is also classified into two thallus types, slender type and wide type, based on the length and the width of internodes, but this distinction between two types is not supported by either anatomical or molecular characteristics. P. coriaceum shares typical morphology in branching pattern and morphogenetic processes with the other species of Dictyota: 1) multi-cellular cortical and medullar layer in the partial of thallus, 2) same development of thallus from apical meristem cell, and 3) sub-lineage within Dictyota species lineage in rbcL, psaA and psbA gene sequences analyses. These characteristics lead to propose the new combination of Dictyota coriacea (Homes) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov.

• Journal of Forest and Environmental Science
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• 제28권1호
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• pp.1-7
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• 2012

Tropical forests whether fragmented or undisturbed or be they equatorial or deciduous, remain the storehouse of biodiversity for hundreds of thousands of plant and animal species. This unique characteristic continues to attract a wide range of scientists and international organizations to study and attempt to understand tropical forest ecosystems. Gene flow is mediated by pollen, seed and seedling dispersal, and factors affecting this gene flow include phenology, spatial distribution, population structures, seed predation, sexual and mating systems as well as physical and biological barriers to gene flow. Two methods are used in measuring gene flow: direct method that relies on the actual observation of seed and pollen dispersal, whereas indirect methods involve the use of genetic markers such as allozymes and DNA techniques. Political strife, extreme natural and artificial disasters, the lack of a comprehensive forestry research vision, coupled with difficult socio-economic conditions in Africa have made the environment quite difficult for sustained research activities on the part of those undertaking or wishing to undertake such studies. Gene flow studies in this region are few and far between. This review elaborates on the mechanisms of gene flow mediation in Sub-Saharan Africa.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.127-135
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• 2012

Urbanization has led to a reduction in green spaces and thus transformed the spatial pattern of urban land use. An increase in air temperature directly affects forest vegetation, phenology, and biodiversity in urban areas. In this paper, we analyze the changing land use patterns and urban heat distribution (UHD) in Seoul on the basis of a spatial assessment. It is necessary to monitor and assess the functions of green spaces in order to understand the changes in the green space. In addition, we estimated the influence of green space on urban temperature using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery and climatic data. Results of the assessment showed that UHD differences cause differences in temperature variation and the spatial extent of temperature reducing effects due to urban green space. The ratio of urban heat area to green space cooling area increases rapidly with increasing distance from a green space boundary. This shows that urban green space plays an important role for mitigating urban heating in central areas. This study demonstrated the importance of green space by characterizing the spatiotemporal variations in temperature associated with urban green spaces.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.193-200
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• 2008

We obtained quantitative information on leaf unfolding and leaf shedding by observing 45 species of cool temperate deciduous trees in an arboretum over 5 growing seasons. These trees were in leaf (the foliage period) for 207 days on average after 1 April; 50% of leaves had been shed by 192 days after 1 April. Duration from the start of leaf unfolding to 50% leaf shedding was 157 days on average. Leaf unfolding began 35 days on average after 1 April. For leaf unfolding to begin, a$ 51^{\circ}C{\cdot}day$ of cumulated daily mean air temperature above $5^{\circ}C$ from 1 January (modified Kira's warmth index) was needed. Fifty-nine days elapsed between initiation and the final stage of leaf unfolding. The period of net photosynthetic assimilation was 157 days. The species with succeeding- type leaf unfolding associated with the anemochore seed type dominated the early stage of succession, while the species with flush-type leaf unfolding tended to dominate the late stage of succession. Few species were found in regions where late frosts occur after the day when the cumulative temperature for leaf unfolding is achieved. Biological characteristics include time of leaf unfolding, which affects the life history of each species, so that each species occupies its own niche in the stand. We conclude that that leaf phenology, such as timing of leaf unfolding and leaf shedding, is one of the components of each species' ecological characteristics.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.207-211
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• 2008

We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan, Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence, Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed, However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives, As a result, small ramets were semi-evergreen, whereas large ramets were deciduous, The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.