• Journal of Plant Biology
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• 제26권2호
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• pp.101-117
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• 1983

The phenological phenomena in terms of year day index (YDI) in South Korea were studied. The YDI was proposed here, because the remainer index such as Nuttonson's index is unadequate for the interpretation on the phenological phenomena of early spring season in sourthern coastal area. The YDI was calculated by summing daily mean temperature of the year days (YD) above physical zero degree in centigrade, based on the data of the Monthly Weather Reports from 1967 to 1980 by the Central Meteorological Office. The pattern of YDI increase with the increase of YD was similar to that of the remainder index such as the Nuttonson's index. The some YDI distribution maps were made by Yim and Kira (1975), dividing into 30'$\times$40' meshes, in latitude and longtude, on the topographical map(1 : 500,000) of the Korea Peninsula. According to the year day of different localities flowering dates of Prunus yedoensis and other phenological phenomena in various species delayed about 3.5 day as the increase of 1 degree of latitude, which coincides with the Hopkins bioclimatic law. It was found that the YDI is useful to interprete the phenology of plant and animal species and to select the optimum range of cultivars in South Korea.

• The Korean Journal of Ecology
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• 제1권1호
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• pp.17-23
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• 1977

Flowering dates of 389 plant species in the Hongneung Arboretum, Seoul, had been recorded from 1968 through 1975. The thermal analysis on the air temperature as the key factor determining the first flowering date, with climatological data obtained in the Arboretum, were undertaken by Nuttonson's Index (1948) and Lindsey & Newman's Index (1956). The results and conclusion in this study are as follow; Peak in the bell shape distribution curve of the species and first flowering dates, largely, was early May. Flower spans of most species were 10 to 20 days, neverthless, some species flower only a few days while others may stay flowering a hundred days even more. Increase-curves of summation temperature from early spring through late-summer showed almost the same mode in both Nuttonson;s Index (Tn) and Lindsey & Newman's Index (T1). These Indices manifested the exponential curve, increasing slowly at the beginning of spring chiefly but rapidly from the middle part of April. The equation of the linear relationahip between Tn and Tl as far as in thisstudy is as follow. Tl=230Tn It appears that the distribution of summation temperature, below Tn=400°C·day, affects the first flowering, even though it could be modified somehow by the distribution of precipitation, day length and others. Nuttonson's Index (Tn.f) and Lindsey & Newman's Index (Tl.f) upon the thermal amount first flowering dates have been respectively simulated as follow. Tn.f=θa + C Tl.f=230θa + 230C where θ is air temperature 10°C, a and C are a constant.

• Journal of Ecology and Environment
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• 제30권2호
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• pp.143-149
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• 2007

To certify predictability for the times of phenological stages from cumulative air temperature in springtime, the first times of budding, leafing, flower budding, flowering and deflowering for 14 woody plants were monitored and air temperature was measured from 2005 to 2006 at Namsan. Year day index (YDI) and Nuttonson's Index (Tn) were calculated from daily mean air temperature. Of the 14 woody species, mean coefficient of variation was 0.04 in Robinia pseudo-acacia and 0.09 in Alnus hirsuta. However, mean coefficient of variation was 0.30 in Forsythia koreana and Stephanandra incisa and 0.32 in Zanthoxylum schinifolium. Therefore, the times of each phenological stage could be predicted in the former two species but not in latter three species by two indices. Of the five phenological stages, mean coefficient of variation was the smallest at deflowering time and the largest at budding time. In five phenological stages, mean coefficient of variation of YDI was in the range of $0.11{\sim}0.21$ but that of Tn was in the range of $0.15{\sim}0.26$. Therefore, the former was a better index than the latter. Of the species-phenological stage pair, coefficient of variation of YDI was 0.01 in Acer pseudo-sieboldianum - flower budding and below 0.05 in 11 pairs, whereas the YDIs over 0.40 were 4 pairs comprising of Prunus leveilleana - budding (0.51). Coefficient of variation of Tn was 0.01 in A. hirsuta - budding and below 0.05 in 8 pairs. The Tns over 0.40 were 5 pairs comprising of F. koreana - flower budding (0.66).

• Journal of Ecology and Environment
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• 제37권4호
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• pp.155-163
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• 2014

Adonis multiflora is a spring ephemeral herb growing in temperate deciduous forests. To determine the flowering properties of a natural population of A. multiflora, air temperature, flowering time, and flower-falling were monitored from February 2009 to May 2011. The A. multiflora population in this study started flowering in early March and ended it in mid-April. The average flowering duration of a flower was 14.4 days in 2009 and 19.6 days in 2011. The average duration of flower-falling was between 3.4 days and 4.2 days for three years. Cumulative flowering rate (CFR) was correlated with year day (YD), year day index (YDI), and Nuttonson's index (Tn), with correlation coefficients (CC) of over 0.9 at the 1% significance level; CC value between CFR and YD was the largest and that between CFR and YDI was the smallest. However, at the 5% significance level, CFR was closely related with Tn more than any other factors. The CCs between flowering times of two years in each plant were high and significant at 1% level. The YD value of flowering time of a flower was inversely related to its flowering duration significantly for three years. In a given plant, when more flowering started early, the flowering duration was longer. The first flower blossomed on 73.4 YD in 2010 and 78.9 YD in 2011, and remained for 16.7 days in 2009 and 27.4 days in 2011, respectively; the fifth flower developed on 92.5 YD in 2010 and 96.6 YD in 2011, and remained for 8.0 days in 2009 and 14.6 days in 2011. The YD differences between the flowering times of two flowers decreased in the order of inflorescence.

• The Korean Journal of Ecology
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• 제16권4호
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• pp.477-487
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• 1993

온대낙엽수림의 수 종 목본식물에서 생육초기의 기온과 개엽시기와 관계를 규명하기 위하여 남한산성과 지역에서 1991, 1992 및 1993년 대관령 지역에서 1992년, 3월부터 5월까지 겨울눈의 파열 시기, 개엽이 완료된 시기, 개화 및 낙화의 시기를 관찰 조사하고 이것을 기상자료와 관련시켜 분석하였다. 남한산성 지역에서 개엽이 이른 종은 신갈나무, 진달래, 개벚나무, 노린재나무 등으로 4월 초순이었으며, 늦은 종은 굴참나무, 떡갈나무, 다릅나무 등으로 4월 하순이었다. 그리고 가장 빠른종인 진달래 (4월 8일)와 가장 늦은 종인 굴참나무, 다릅나무 및 떡갈나무 (5월 4일)의 차이는 27일 이었다. 두 지여간 동일 수종의 개엽시기를 비교하면, 남한산성의 것은 대관령 지역의 것보다 8~24일 빨랐다. 한편, 두 지역간 개화시기의 차이는 0~22일로 개엽시기의것보다 적었다. 겨울눈의 파열시기는 일적사온량지수(YDI)와 관계가 있지만 개엽이 완료되는 시기나 개화시기를 예측하는 데는 YDI보다 Nuttonoson의 온량지수(Tn)가 더욱 유효한 것으로 나타났다.

• 한국환경생태학회지
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• 제22권3호
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• pp.221-229
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• 2008

본 연구는 우리나라 중부지방에 위치한 점봉산과 봉의산에서 일부 자생수목을 대상으로 봄철 식물계절 변화를 관찰 비교하고, 관련 환경인자를 함께 측정하여 미기후 변화에 따른 식물계절 차이를 구명하였다. 점봉산 조사지의 2004년 $1{\sim}5$월 평균 기온은 봉의산 조사지보다 $4.1^{\circ}C$ 더 낮았다. 점봉산 내 조사구별 4월의 토양온도는 남사면에 비해 서사면에서 $1.8^{\circ}C$, 북서사면에서 $4.4^{\circ}C$ 각각 낮았다. 표본목 중 개화시기가 가장 이른 종은 생강나무로 봉의산에서 3월 하순에, 점봉산에서 4월 초순에 각각 개화하였다. 동일 수종의 개화시기는 점봉산보다 봉의산에서, 그리고 서사면이나 북사면보다 남사면에서 더욱 빨랐으며, 이른 봄 개화하는 수종의 경우는 지역간 약 2주의 차이를 나타냈다. 개엽시기는 대개 봉의산에서 4월 중순, 점봉산에서 5월 초순이었으며, 동일 수종의 개엽시기 역시 점봉산보다 봉의산에서 2주정도 빨랐다. 개화 및 개엽시기의 Nuttornson 온량지수(Tn)와 일적산온량지수(YDI)는 동일 수종에서 지역간 유사한 값을 나타냈다. 지역간 식물계절 변화는 주로 온도에 의해 영향을 받는 것으로 분석되며, 기후변화와 온도상승은 식물계절 변화를 현재보다 더욱 촉진시킬 수 있음을 시사한다.