• Title, Summary, Keyword: Phenology

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A Study on Changes of Phenology and Characteristics of Spatial Distribution Using MODIS Images (MODIS 위성영상을 이용한 식물계절의 변화와 공간적 분포 특징에 관한 연구)

  • Kim, Nam-Shin;Lee, Hee-Cheon;Cha, Jin-Yeol
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.5
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    • pp.59-69
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    • 2013
  • Global warming also has effects on the phenology. The limitation of phenology study is an acquisition of phenology data. Satellite images analysis can make up limitation of monitering data. This study is to analyze spatial distribution and characteristics of phenology changes using MODIS images. Research data collected images of 16 day intervals of 11 years from year 2001 to 2010. The data analyzed 228 images of 11 years. It can figure out changes of phenology by analyzing enhanced vegetation index of MODIS image. We made a comparison between changes of phenology and flowering of cherry blossoms. As a results, Startup of season spatially was getting late from southern area to north area. Startup of Phenology was foreshortened 13 days during 11 years, and change ratios of cherry blooming was getting more faster from 0.18 dat to 0.22 day per year during that same period.

Nodule Phenology and Nitrogen Mineralization of Rhizosphere in Autumn-olive(Elaeagnus umbellata) Stand (보리수나무 군락의 근류계절학 및 근계의 질소무기화)

  • You, Young-Han;Kyung-Bum Kim;Chung-Sun An;Joon-Ho Kim;Seung-Dal Song
    • The Korean Journal of Ecology
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    • v.18 no.4
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    • pp.493-502
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    • 1995
  • Nodulation phenology in relation to plant phenology, vertical distribution of nodul and root biomass in different soil, correlation between nodule and root size, and nitrogen mineralization around the rhizosphere by ion-exchange resin bag buried at 10 cm of soil were studied in Elaeagnus nmbellata (autumn-olive) stand, Korea. Nodulation appeared from spring to autumn and nodule phenology was coincided with the timing of root activity rather than that of foliation. Nodul size increased in proportion to the root size. In the sand dune with the lower root biomass, nodule appeared up to 80 cm deep in soil and the nodule biomass was 1,070 kg/ha, which was the highest value reported for several actinorhizal plants in the temperate regions. It is suggested that nodule distribution and production are mainly influenced by soil aeration among environmental factors. The higher ammonification or lower nitrification rate contrasted markedly with the earlier studies that reported lower ammonification or higher nitrification in actinorhizal plant soil. Nitrogen mineralization rate around the rhizosphere with root and nodule was characterized by higher nitrification rate than that in the control soil without root and nodule.

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Comparative Anatomy of Diffuse-Porous Woods Grown in Korea(II) -Characteristics by Habit and Phenology- (한국산(韓國産) 산공재(散孔材)의 해부학적(解剖學的) 특성(特性)에 관한 비교연구(比較硏究)(II) -Habit과 Phenology에 따른 특성(特性)-)

  • Chung, Youn-Jib;Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.1
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    • pp.1-10
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    • 1996
  • The frequency distribution diagrams of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens in relation to habit and phenology were analyzed. As the habit character changes from shrub to tree, such quantitative features as vessel frequency, percentage of solitary vessels, length/diameter(L/D) ratio of vessel element decreased but tangential vessel diameter, fiber length/vessel element length(F/V) ratio increased. Qualitative features such as helical vessel wall thickening, diffuse distribution of longitudinal parenchyma, heterogeneous ray composition decreased, while alternate intervessel pits, libriform wood fiber, simple perforations increase. As the phenology character changes from evergreen to deciduous species, such quantitative features as percentage of solitary vessels, vessel element length and L/D ratio decreased but tangential vessel diameter, F/V ratio increased. Diffuse distribution of longitudinal parenchyma, heterogeneous ray composition, and crystals in qualitative features decreased, while alternate intervessel pits, libriform wood fiber, simple perforation of vessel element, ray width and ray height increased.

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A Study on Plant Phenological Trends in South Korea (우리나라 식물계절 시기의 변화 경향에 관한 연구)

  • Lee, Kyoung-Mi;Kwon, Won-Tae;Lee, Seung-Ho
    • Journal of the Korean association of regional geographers
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    • v.15 no.3
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    • pp.337-350
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    • 2009
  • The phenological change of plants is an indication of local and regional climate change. An increase in temperature due to global warming is manifest in the change of phytophenological events. In this study, trends in the plant phenology and its correlation with air temperature in South Korea were examined using observational data for 18 phenological phases. The spring phenological phases, such as sprouting and flowering, occurred earlier (from 0.7 to 2.7 days per 10-year) during 1945 ${\sim}$2007. while the autumn phases, such as full autumn tinting, moved later (from 3.7 to 4.2 days per 10-year) during 1989 ${\sim}$2007. The correlation between the plant phenology in spring with the air temperature from February to March is relatively high. The warming in the early spring (February March) by $1^{\circ}C$. causes an advance in the spring plant phenology of 3.8 days. The plant phenology in autumn also correlates with the average temperature in October. The autumn plant phenology for a $1^{\circ}C$ increase in October temperature occurs about 3.1 days later.

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Floral Biology and Flowering Phenology of Jatropha Curcas

  • Singh, Amritpal S.;Patel, Mukesh P.;Patel, Tanmay K.;Delvadia, D.R.;Patel, Diwaker R.;Kumar, Nitish;Naraynan, Subhash;Fougat, Ranbir S.
    • Journal of Forest and Environmental Science
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    • v.26 no.2
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    • pp.95-102
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    • 2010
  • Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant. Plant flowering and breeding characteristics are important for us to understand the reproduction of plant populations. The present study describes the floral biology and flowering phenology of J. curcas which is a prerequisite for hybridization program for genetic improvement through conventional breeding. The plant produces flowers in dichasial inflorescences. Normally, the flowers are unisexual, and male and female flowers are produced in the same inflorescence. Only a few male flowers are produced in an inflorescence, and fruits are produced only through pollination between different flowers from the same or different plants. This study includes a description of the inflorescence, flower anatomy of both male and female flowers, female : male ratio, pollen : ovule ratio, flowering phenology, pollen viability, stigma receptivity, comparison of selfing methods and a comparison of geitonogamy and xenogamy. This information may be useful in J. curcas breeding programmes.

Monitoring canopy phenology in a deciduous broadleaf forest using the Phenological Eyes Network (PEN)

  • Choi, Jeong-Pil;Kang, Sin-Kyu;Choi, Gwang-Yong;Nasahara, Kenlo Nishda;Motohka, Takeshi;Lim, Jong-Hwan
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.149-156
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    • 2011
  • Phenological variables derived from remote sensing are useful in determining the seasonal cycles of ecosystems in a changing climate. Satellite remote sensing imagery is useful for the spatial continuous monitoring of vegetation phenology across broad regions; however, its applications are substantially constrained by atmospheric disturbances such as clouds, dusts, and aerosols. By way of contrast, a tower-based ground remote sensing approach at the canopy level can provide continuous information on canopy phenology at finer spatial and temporal scales, regardless of atmospheric conditions. In this study, a tower-based ground remote sensing system, called the "Phenological Eyes Network (PEN)", which was installed at the Gwangneung Deciduous KoFlux (GDK) flux tower site in Korea was introduced, and daily phenological progressions at the canopy level were assessed using ratios of red, green, and blue (RGB) spectral reflectances obtained by the PEN system. The PEN system at the GDK site consists of an automatic-capturing digital fisheye camera and a hemi-spherical spectroradiometer, and monitors stand canopy phenology on an hourly basis. RGB data analyses conducted between late March and early December in 2009 revealed that the 2G_RB (i.e., 2G - R - B) index was lower than the G/R (i.e., G divided by R) index during the off-growing season, owing to the effects of surface reflectance, including soil and snow effects. The results of comparisons between the daily PEN-obtained RGB ratios and daily moderate-resolution imaging spectroradiometer (MODIS)-driven vegetation indices demonstrate that ground remote sensing data, including the PEN data, can help to improve cloud-contaminated satellite remote sensing imagery.

Comparison of the phenological characteristics of woody species in 2007 and 2018 at Daegu University Forest

  • Lee, Su-Ho;Park, Yeong Dae
    • Korean Journal of Agricultural Science
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    • v.46 no.3
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    • pp.529-538
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    • 2019
  • This study examined the changes in plant phenology of 12 woody species in Daegu University Forest, Gyeongsan-si, Gyeongsanbuk-do in 2007 and 2018. The Hobo was installed at a height of 1.2 meters to measure the microclimate such as air temperature and relative humidity to identify its effects on the changes in plant phenology. The number of trees surveyed were 42 individuals that included 12 species in 9 families, all of which are deciduous broad-leaved trees. The trends in temperature change in 2018 were similar to that in 2007, except for the temperatures in the warmest and coldest month. Compared to 2007, the average temperature of the warmest month in 2018 was $2.5^{\circ}C$ higher, and the coldest month was $3.3^{\circ}C$ lower. The lowest temperature from February to April in 2018 had the highest correlation with the blooming dates of the trees (r = 0.692) in 2018, and the highest temperature showed the lowest correlation (r = 0.392). The blooming date by species was significantly different (p < 0.05). The blooming date of 8 species (75%), including Prunus padus, was earlier by 1 to 16 days, while 4 species, such as Prunus armeniaca var. ansu, was later by 1 to 7 days in 2018 than that in 2007. However, the flowering duration did not have a significant effect on the plant phenology. The results can be used as basic data for long-term monitoring of plant phenology in the future, and follow-up studies on other environmental factors and physiological factors are needed.

Seasonal Growth, Phenology and Spore Shedding in Polysiphonia platycarpa Børgesen (Ceramiales, Rhodophyta) of Visakhapatnam Coast, India

  • Rangaiah, G.Subba;Sudhakar, S.;Kumari, E.Vanilla
    • ALGAE
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    • v.18 no.2
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    • pp.177-181
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    • 2003
  • Variation in seasonal growth, phenology and periodicity in spore shedding in Polysiphonia platycarpa $B{\oslash}rgesen$ occurring on the coast of Visakhapatnam, India, have been described to know the growth behaviour, reproductive periodicity and spore producing capacities. This alga occurs for a short period from December to May in the intertidal region of the Visakhapatnam coast, showing maximum growth during January/February. Tetrasporophytic, carposporophytic and antheridial plants were observed in all months of their occurrence in the field. But the vegetative plants were not seen in January and February and all the plants collected were reproductive. The tetraspore and carpospore shedding was observed during all the six months of their occurrence.

Growth Simulation of Ilpumbyeo under Korean Environment Using ORYZA2000: III. Validation of Growth Simulation

  • Lee Chung-Kuen;Shin Jae-Hoon;Shin Jin-Chul;Kim Duk-Su;Choi Kyung-Jin
    • Proceedings of the Korean Society of Crop Science Conference
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    • pp.104-105
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    • 2004
  • [ $\bigcirc$ ] In the phenology model of ORYZA2000, the effect of photoperiod on the developmental rate was a little ignored because most crop parameters were measured with IRRI varieties which are insensitive to photoperiod, therefore it is very difficult to apply this phenology model directly to Korean varieties which are usually sensitive to photoperiod. $\bigcirc$ After introducing PPFAC and PPSE to improve the phenology model, the precision of heading date prediction was improved but not satisfied. $\bigcirc$ In the growth simulation using data from several regions, yield tended to be overestimated under high nitrogen applicated condition. $\bigcirc$ The precision of yield was much improved by introducing nitrogen use efficiency, but still different between regions because of different soil fertility or property of irrigation water between regions

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Reproductive Phenology of Gracilaria verrucosa (Rhodophyta) in Cheongsapo near Pusan, Korea

  • Kim Young Sik;Choi Han Gil;Kim Hyung Geun;Nam Ki Wan;Sohn Chul Hyun
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.147-151
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    • 1998
  • The reproductive phenology of Gracilaria verrucosa was studied in Cheongsapo near Pusan, Korea. Among the life history phases, tetrasporic plants occurred dominantly in varying degrees of abundance throughout the year except from July to September. Cystocarpic plants increased rapidly during summer, and then recorded maximum abundance in July. Whereas, seasonal peaks of spermatangial plants were observed in April and September. However, they were less than cystocarpic plants in abundance. Vegetative plants dominated from December to May for long period, with a occurrence peak in February. Even though fertile plants in both gametophytes and tetrasporophytes occurred throughout the year, their seasonal abundance suggests that the positive correlation between reproduction and water temperature is basically found in the reproductive pattern of Gracilaria verrucosa. The distributional aspect of life history phases appears to be related with differences of their longevity, fecundity or survivorship.

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