• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.191-200
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• 2013

This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.477-487
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• 1993

To investigate phenological differences among species, and relationship between phenology and air temperatures, we surveyed foliation and flowering times of several woody plants in two temperate forests, Namhansansung and Taegwallyong area, for three years, 1991, 1992 and 1993. In Namhansansung area, the leaves of Quercus mor~golica, Rhododendron mucronulatum, Prunus levezlleana and Symplocos chinensis for. pilosa expanded in the early season(about 10 April), and those of Quercus variabilis, Quercus dentata and Maackia amurensis in the late season(about 5 May). The foliation time of the earliest species(Rhododendron mucronulatum) was 27 days earlier than thzt of the latest(Maackia amurensis, Quercus variabilis and Quercus dentata). In Taegwallyong area, the leaves of Staphylea bumalda and Rhamnus yoshinoi foliated on 25 April and those of Rhus verniciflua and Fraxinus rhynchophylla on 25 May. The annual mean air temperature of Narnhansansung area was $5.5^{\circ}C$ higher than that of Taegwallyong area. Foliation times of the same species were earlier in the former: the differences between two areas were 8~24 day among species. In contrast, flowering times of the same species were 0~22 days earlier in the former. It is concluded that the budding time of leaves was related to year day index(YDI), and foliation time of leaves was related to Nuttonson's index(Tn).

• Journal of agriculture & life science
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• v.45 no.1
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• pp.49-58
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• 2011

Characteristics of leaf unfolding and flowering of 31 chestnut varieties cultivated in southern Korea was conducted to provide basic data for chestnut varieties improvement. There were slight differences among varieties in leaf unfolding time and leaf unfolding was late in 2010 compared to 2008 and 2009. Leaf unlolding took about 8 days to complete in 2008 and 2009, but that took about two weeks to complete in 2010. In 2008 and 2009, flowering beginning and flowering end of staminate flower occurred in early May and June, those were detained by low temperature of April in 2010. Although pistallte flower in flowering characteristics showed very similar to flowering period of staminate flower, The flowering beginning for pistillate flower was earlier approximately 20 days than for staminate flower.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.229-235
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• 2012

This study was conducted to investigate the climatic factors affecting bud phenology of Pinus densiflora provenances. Data were collected from Jungseon, Chungju and Jeju plantations which were parts of the 11 provenance trials established by Korea Forest Research Institute in 1996. The 36 provenances were included in this trial ($33^{\circ}30^{\prime}{\sim}38^{\circ}08^{\prime}$ in latitude and $126^{\circ}30^{\prime}{\sim}129^{\circ}20^{\prime}$ in longitude). The bud swelling date and bud burst date of the provenances were investigated from March to May in 2004 in two-day interval. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology. Our results suggested that the major factors affecting the timing of bud swelling and burst are the differences in latitude, longitude, extremely low temperature (during December-February), extremely high temperature (during November-February) and annual mean growing days between test plantation and provenance. The provenances with lower winter temperature than that of plantation showed the faster bud swelling and bud burst. Based on these results, the implication on the seed transfer of P. densiflora was discussed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.213-218
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• 2014

Effects of elevated $CO_2$ on leaf phenology of Quercus acutissima were examined using open-top chambers, which had ambient and elevated $CO_2$ concentrations (ambient ${\times}1.4$, ambient ${\times}1.8$). To analyze the effect of chamber, non-treatment block was established near outside of the chambers. In 2013, budburst, leaf unfolding, coloring, and shedding were surveyed, and spring phenology was surveyed in 2014. Thermal sum (base temperature $+5^{\circ}C$) of each phenological event occurred was recorded. In addition, bud samples were collected and analyzed for carbohydrate contents in March 2014. Elevated $CO_2$ concentration advanced budburst and leaf unfolding, and delayed shedding in 2013. However, in 2014, the temperature of the spring season was high, and there was no significant effect of elevated $CO_2$ concentration on spring phenology. Carbohydrates content, such as starch, total non-structural carbohydrate and total soluble sugar, were significantly increased in response to elevated $CO_2$ concentration. It has been proposed that elevated $CO_2$ concentration could extend the growing season of temperate species with increased possibility of frost damage due to early bud opening and leaf unfolding. However, our analysis showed that the increased carbohydrate concentration in bud under elevated $CO_2$ would reduce the possibility of early spring frost damage by acting as cryoprotectant.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.12-19
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• 1987

This study was carried out to investigate the effects of climatic conditions on the budding of buds and the growth of shoots of mulberry (Morus alba L.) at Suwon for the period of six years from 1978 to 1983. The results are summarized as follows. 1. The period that influenced most greatly on mulberry budding and foliating of it's buds was from late part of March to middle part of April in the district of Suwon, Korea. 2. Temperatures in soil 20cm deep during the period from late part of March to middle part of April had high correlations with budding dates. 3. It was disclosed that the budding date had high correlations with the date of bud shaped swallow-bill (r=0.9861**), date of the third leaf(r=0.97**), and date of the fifth leaf(r=0.96**), respectively. 4. The higher the average temperature of April became, the longer the length of shoots became. 5. The earlier the budding date and foliating date came, the larger the leaf yield became. However, with excessive amount of precipitation after early budding and foliating, the leaf yield was not increased in proportional. 6. The longer the growing period of the shoots became, the larger the leaf yield became.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.267-282
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• 2018

Despite the continuous development of phenology detection studies using satellite imagery, verification through comparison with the field observed data is insufficient. Especially, in the case of Korean forests patching in various forms, it is difficult to estimate the start of season (SOS) by using only satellite images due to resolution difference. To improve the accuracy of vegetation phenology estimation, this study reconstructed the large scaled forest type map (1:5,000) with MODIS pixel resolution and produced time series vegetation phenology curves from Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) derived from MODIS images. Based on the field observed data, extraction methods for the vegetation indices and SOS for Korean forests were compared and evaluated. We also analyzed the correlation between the composition ratio of forest types in each pixel and phenology extraction from the vegetation indices. When we compared NDVI and EVI with the field observed SOS data from the Korea National Arboretum, EVI was more accurate for Korean forests, and the first derivative was most suitable for extracting SOS in the phenology curve from the vegetation index. When the eight pixels neighboring the pixels of 7 broadleaved trees with field SOS data (center pixel) were compared to field SOS, the forest types of the best pixels with the highest correlation with the field data were deciduous forest by 67.9%, coniferous forest by 14.3%, and mixed forest by 7.7%, and the mean coefficient of determination ($R^2$) was 0.64. The average national SOS extracted from MODIS EVI were DOY 112.9 in 2014 at the earliest and DOY 129.1 in 2010 at the latest, which is about 0.16 days faster since 2003. In future research, it is necessary to expand the analysis of deciduous and mixed forests' SOS into the extraction of coniferous forest's SOS in order to understand the various climate and geomorphic factors. As such, comprehensive study should be carried out considering the diversity of forest ecosystems in Korea.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.275-279
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• 2009

식생지수(Vegetation Index, 이하 VI)는 위성영상의 각 밴드가 식생에 대해 나타내는 특징적 반사치를 이용하여 지피의 식생 유무와 상태를 표현하고 정량화(Quantification)가 가능하다. 본 연구는 개엽(aestivation) 전 주사된 광릉시험림 지역의 QuickBird 위성영상과 임소반도를 이용하여 수목분류간 VI의 비교를 목적으로 삼는다. VI는 식생 및 토양의 특성에 따라 많은 영향을 받게 되며 이러한 영향의 최소화를 통해서만 정확한 평가자료를 얻을 수 있기 때문에 토양부분을 제외한 수목과 상관관계가 높은 VI를 연구에 사용하였다. 그 결과 침엽수로 조림된 단순림(單純林)간의 분류는 용이하지 않았지만 개엽 전 낙엽송과 활엽수간의 분류체계에는 효과적임을 입증할 수 있었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.38-38
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• 2019

본 연구는 봄 식물계절지수와 기온지표와의 관계를 알아보기 위해 지난 9년간(2010년-2018년) 대구수목원, 팔공산, 주왕산, 가야산에 공통적으로 생육하는 소나무(Pinus densiflora), 일본잎갈나무(Larix kaempferi), 신갈나무(Quercus mongolica), 진달래(Rhododendron mucronulatum), 생강나무(Lindera obtusiloba), 당단풍나무(Acer pseudosieboldianum) 6종을 대상으로 발아, 개화, 개엽의 봄 식물계절시기의 변화 경향과 기온간의 관계를 파악하였다. 기온의 변화는 9년동안 2월보다 3~4월의 월평균기온이 증가하였으며, 지역별로 수목원과 팔공산의 평균기온이 높았다. 발아, 개화, 개엽은 수종별로 생강나무가 가장 빠르며 소나무가 가장 느렸고, 지역별로 수목원에서 가장 빨리 식물계절시기가 도래하였다. 봄 식물계절시기는 -1.267~-6.151일/9년 정도 앞당겨지고 있는 경향을 보이는데 소나무(-6.151일/9년)가 가장 크며, 진달래(-1.267일/9년)의 변화율이 가장 낮았다. 발아, 개화, 개엽에서 모두 유의한 값을 보이는 수종은 진달래와 소나무로서 이들은 1월~3월 평균기온과 상관관계를 보였다. 봄 식물계절지수(SPI)의 시계열 변화를 확인한 결과 4개 지역의 변화율이 모두 음의 값으로 식물계절 시기가 모두 빨라지고 있었다. 그 중 수목원, 팔공산 및 가야산과 같은 내륙지역일수록 변화율이 컸으며, 다소 거리가 떨어진 주왕산의 경우 변화율이 조금 낮게 나타났다.

• Journal of Sericultural and Entomological Science
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• v.32 no.2
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• pp.113-117
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• 1990

The recovery of mulberry from a late frost (April 24 to 27) was investigated for four varieties : Kaeryangppong, Cheongilppong, and Jamsang 21 in Cheongju area, Chungbuk Province. 1. Unfavourable meteorlogical conditions for recovery of mulberry followed the early late frost : lower than normal temperatures in mid-April, less sunshine in early and mid-Jay, lower temperatures and early and less precipitation in late-May, and less precipitation than normal in early June. 2. Jamsang 21 grew to the 2-3 leaf stage first, at which time Kaeryangppong and Jamsang 22 were at the 1-2 leaf stage, and Cheongilppong was at the swallow-bill shape-1 leaf stage. 3. The first leaf stage occurred on May 12, 15 days after the frost and, 19 days later in an average year. The difference lasted until the harvesting season, the 6 leaf stage. 4. Young shoot length was 50-58% of that in 1989. Kaeryangppong was the shortest at 50% and the Jamsang 21 highest at 58% of 1989 values. 5. Leaf number was 52-67% that in 1989. Kaeryangppong was the lowest at 52% and the Jamsang 21 highest at 67% of 1989 values. 6. Young shoot and leaf weight was 44-63%, and leaf weight 39-61%, compared to 1989. Kaeryangppong and Cheongilppong were the lowest, Jamsang 21 and Jamsang 22 were the highest, compared to 1989 data. 7. Young shoot length was 50-58% compared with 1989. Kaeryangppong was the lowest as 50%, the highest Jamsang 21 as 58%. 8. Number of leaf was 52-67% compared with 1989. Kearyangppong was the lowest as 52%, the highest Jamsang 21 as 67%. 9. Young shoot and leaf wight was 44-63%, and leaf weight was 39-61% compared with 1989. Kaeryangppong was the lowest, lowest, Jamsang 21 was the highest, Cheongilppong was similar with Kaeryangppong and Jamsang 22 was similar with Jamsang 21. 10. Rate of young shoot and leaf weight to total weight decreased from 75% in 1989 to 55-61% in 1990. Rate of laef weight to young shoot decreased from 72-82% to 67-71%, showed 5-10% decrease. 11. Leaf yield decreased highly in Jamsang 22 as 57% compared with 1989. Kearyangppong 61%, Jamsang 21 64%, Cheonglppong 72%. Leaf yield was 827kg/10g in Kaeryangppong, 1, 000-1, 050kg/10a in the other varieties.