• Title/Summary/Keyword: environmental dynamics

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Population Characteristics of Echinosophora koreensis (Nakai) Nakai, a Endemic Plants in Korea (한반도 특산식물 개느삼의 개체군 특성)

  • Kim, Sodam;Moon, Ae-Ra;An, Jong-Bin;Jung, Ji-Young;Park, Wan-Geun;Son, Sungwon
    • Korean Journal of Environment and Ecology
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    • v.34 no.1
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    • pp.18-26
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    • 2020
  • Echinosophora koreensis (Nakai) Nakai an endemic plant with limited distribution in some parts of the Korean Peninsula, is designated as "Endangered" species on the IUCN Red List. The species is under the threat of deterioration in nature due to various environmental changes causing loss of natural habitats. We investigated the distribution pattern and population structure of E. koreensis to serve as a basic reference for identifying the dynamics and persistence of natural populations of this species in the future. To determine the characteristics of the E. koreensis population, we laid two to three large plots sized 20m×30m on the ridgeline as the reference in Yanggu, Chuncheon, and Hongcheon and laid four to seven small quadrats sized 1m×1m on the transect. A total of 530 plots were laid, 10 each at 2m interval, to measure the number of the stems, the number of fruiting, height, and other factors. The collected distribution information was compared with the existing IUCN assessed categories by applying IUCN Red List ver 3.1 Criteria B. The average population density of the three surveyed areas was 3.47 stem/㎡; the density of each area was 3.95 stems/㎡ in Yanggu, 3.37 stems/㎡ in Chuncheon, and 2.87 stems/㎡ in Hongcheon. The number of fruiting per stem was 0.0038, indicating only 7 fruits out of 1,837 stems and that vegetative reproduction is likely to be more dominant than sexual reproduction. The distribution tendency of population density in the small plots in three surveyed areas showed that the density of E. koreensis tended to decrease toward the center of the forest with low crown openness and around the mountain ridge with high crown openness. It indicated that the quantity of light could be a very important factor for the growth of individuals of this species. The analysis of the heights of individuals present in the surveyed plots showed a range of 2.3 ~ 68.5cm and an average of 20.1cm. An analysis on the stage-structure of the E. koreensis population based on the sieve height found that the appearance frequency decreased with increasing height above 15 ~ 20cm and that the percentage of individuals lower than 10cm, which were presumed to be seedlings, was severely low, indicating a necessity of study on the population sustainability based on the monitored data. The occupied area calculated with the collected species distribution information was 200㎢, indicating the EN category according to the IUCN Red List Reference B.

Physico-Chemical Factors on the Growth of Cochlodinium polykrikoides and Nutrient Utilization (Cochlodinium polykrikoides의 성장에 미치는 물리$\cdot$화학적 요인과 영양염 이용)

  • KIM Hyung Chul;LEE Chang Ku;LEE Sam Geun;KIM Hak Gyoon;PARK Chung Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.5
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    • pp.445-456
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    • 2001
  • In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.

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An Analysis of the Comparison between the Image of the Landmarks in Daejeon (대전시 상징물과 도시 이미지에 대한 비교 분석)

  • Byeon, Jae-Sang;Kim, Dae-Soo;Lee, Jung-Soo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.2
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    • pp.53-63
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    • 2010
  • It constitutes a very important preliminary step to analyze how city image is assessed in order to determine the direction towards a desirable city image in planning on an urban landscape for future city image. This study aims to quantify the recognition and evaluation of a city image on the part of citizens, using multidimensional scaling and correspondence analysis. Furthermore, this study hopes to contribute to the quantified policy-making for improving city image by understanding how professionals and civil servants in the related field tend to recognize such image. The results from the study are as follow: 1. The image of Daejon City tends to be assessed strongly in the light of its history, dynamics, and size. While the City is recognized as new and changing in general, the civil servants consider the city as modest, and the professionals as mediocre. Therefore, the City should strive to conceive its own unique identity, which would lessen the current image of modest and mediocre. 2. Gap river, Dunsan New Town, and the Daeduk Reseach Complex turn out to be the symbolic representative venues of Daejon City, inspiring the city’s image. In contrast, Yoosung Springs, the original town, and the Expo Park do not fit the image of the City. The need to renovate these places presents itself. 3. As for the questions using “like” and “not-like”, citizens and professionals show the tendency of not liking the city’s image, whereas civil servants like it. It follows that the City needs to highlight its “modern and high-technological” image, illuminated by Dunsan New Town and Daeduk Reseach Complex. 4. An image positioning drawn from a correspondence analysis shows that the City of Daejeon can be classified as an administrative and horizontal city. As opposed to the prior simplistic analyses of city image, this study attempts to diagnose it accurately, so as to help with the gearing towards city images in the future.

The Vogue about Outwearization of Underwear in a Tendency to the Century-end (세기말 현상으로 본 속옷의 겉옷화 현상)

  • 이상례
    • Journal of the Korean Society of Costume
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    • v.35
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    • pp.325-341
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    • 1997
  • One of the noticeable trends of female wear in 1990s is the Outwearization of Underwear as it is called 'Lingerie look' This trend meaned 'Exposure Fashion' raised splendidly its head to the whole stage of fashion destrying the tradional concept having divided the fashion between outwear and underwear by Madonna an Americal populer singer showed up in front of the audience wearing the corset-dress as a stage custome. This corset-dress which can not be recognised whether it is underwear or outwear has been diffused into the mass as a fashionable trend re-gardless of any reason; therefore discrimi-nation of wear by space by far that is underwear should have the sstandard telling between private and public sector has been gradually tumbled. By the way what has propelled desigers to introduce the style continuously having the underwear motive such as outwear almost as same as underwear or underwear worn on out-wear etc. and has made it a fashion trends? How do we accept this "Ligerie look'fashion" The rearch on vogue of outwearization of underwear started by the questions above can be summarized as the followings The division between the sprit and the ma-terial-economic shrinkage by the collapse of the bubble economy in the late of 20 century and expectation for the next century doubt by changes of international politics dynamics for the next century and increasement of psycho-logical tention by the environmental destruc-tion etc, has been extended to break the sense of value down These frustration of the tra-ditional values and dissatisfaction on the pres-ent have reflected on the fashion pursuing some more sensational style to increase the ex-posure of the body. The revolution of wearing bouncing the con-servatismhas outwardly expressed underwear of the private sector. Therefore the spatial concept of wear which for the public sec-tor has been fallen into pieces and has broken the wall of the concept fixed by outwear on underwear. in addition the stage costome for the popular people like Madonna has not been limited by the specularity any more and has been assimilated with the normal wear on the street to take the distinction for away. The circumstances of the late of 20 century pursuing sensation and making sex commer-cialized have accordance with the outweari-zation of underwear. there it is on the basis of Minimalist's dogmatism has been expressed the maximization of expoure in the pubric space to popularize bra pants(knickers) as outwear. The reaction on the attribute of hiding and shanding has brought 'See-Through fashion' with the transparent materials, The contemporary doubt recalling the mem-ory of the past has sublimated corset which was an instument of toture for women into Romanticism to introduce it to fashion with the development of a new material not to be a tool of any oppression and maltretment any longer. The popularization of outwear like underwear what's more has brought high quality of underwear. There it has called for the variety of materials such as knit demin and velvet etc, and has urged the famous designers to enlarge their working boundaries to underwear designs, Besides outwearization of underwear has been popular even in the Orient which has the con-servative opinions on exposure ; so changes of the thoughts can be seen among the establish-ment generation on exposure of the body. As the more high tech information publi-cized and the more technology and media digitalized the more expression being analog the pursue for the new in fashion with vision never been seen and even though it is imprac-tical the experimental designers have drived the freedom beyond the traditional roles of the previous century. Consequently outwearization of underwear may be viewd as a trial as an expression responded the contemporary background. This trend in my opinion will have been lasted for a while by being proliperlated among lasted for a while by being proliperlated among the pub-lic who has the century-end anxiety and doubt and expectation for the next century.

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A Multi-agent System to Assess Land-use and Cover Changes Caused by Forest Management Policy Scenarios (다행위자시스템을 이용한 산림정책별 토지이용 변화와 영향 분석)

  • Park, Soojin;An, Yoo Soon;Shin, Yujin;Lee, Sooyoun;Sim, Woojin;Moon, Jiyoon;Jeong, Gwan Young;Kim, Ilkwon;Shin, Hyesop;Huh, Dongsuk;Sung, Joo Han;Park, Chan Ryul
    • Journal of the Korean Geographical Society
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    • v.50 no.3
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    • pp.255-276
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    • 2015
  • This paper presents a multi-agent system model of land-use and cover changes, which is developed and applied to the Gariwang-san and its vicinity, located in Pyeongchang and Jeongseon-gun, Gangwon province, Korea. The Land Use Dynamics Simulator (LUDAS) framework of this study is well suited for representing the spatial heterogeneity and dynamic interactions between human and natural environment, and capturing the impacts of forest-opening policy interventions to future socio-economic and natural environment changes. The model consists of four components: (1) a system of human population, (2) a system of landscape environment, (3) decision-making procedures integrating human(or household), environmental and policy information into forest land-use decisions, and (4) a set of policy scenarios that are related to the forest-opening. The results of model simulation by different combination of various forest management scenarios are assessed by the levels of household income, ecosystem service value and income inequality in the study region. As a result, the optimal scenario of forest-opening policies in the study region is to open the forest to local residential community for the purpose of recreation, considering the distinctive topographical feature. The model developed in this research is expected to contribute to a decision support system for sustainable forest management and various land-use policies in Korea.

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Analysis of Misconceptions on Oceanic Front and Fishing Ground in Secondary-School Science and Earth Science Textbooks (중등학교 과학 및 지구과학 교과서 조경 수역 및 어장에 관한 오개념 분석)

  • Park, Kyung-Ae;Lee, Jae Yon;Kang, Chang-Keun;Kim, Chang-Sin
    • Journal of the Korean earth science society
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    • v.41 no.5
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    • pp.504-519
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    • 2020
  • Oceanic fronts, which are areas where sea water with different properties meet in the ocean, play an important role in controlling weather and climate change through air-sea interactions and marine dynamics such as heat and momentum exchange and processes by which properties of sea water are mixed. Such oceanic fronts have long been described in secondary school textbooks with the term 'Jokyung water zone (JWC hereafter) or oceanic front', meaning areas where the different currents met, and were related to fishing grounds in the East Sea. However, higher education materials and marine scientists have not used this term for the past few decades; therefore, the appropriateness of the term needs to be analyzed to remove any misconceptions presented. This study analyzed 11 secondary school textbooks (5 middle school textbooks and 6 high school textbooks) based on the revised 2015 curriculum. A survey of 30 secondary school science teachers was also conducted to analyze their awareness of the problems. An analysis of the textbook contents related to the JWC and fishing grounds found several errors and misconceptions that did not correspond with scientific facts. Although the textbooks mainly uses the concept of the JWC to represent the meeting of cold and warm currents, it would be reasonable to replace it with the more comprehensive term 'oceanic front', which would indicate an area where different properties of sea water-such as its temperature, salinity, density, and velocity-interact. In the textbooks, seasonal changes in the fishing grounds are linked to seasonal changes in the North Korean Cold Current (NKCC), which moves southwards in winter and northwards in summer; this is the complete opposite of previous scientific knowledge, which describes it strengthening in summer. Fishing grounds are not limited to narrow coastal zones; they are widespread throughout the East Sea. The results of the survey of teachers demonstrated that this misconception has persisted for decades. This study emphasized the importance of using scientific knowledge to correct misconceptions related to the JWC, fishing grounds, and the NKCC and addressed the importance of transferring procedures to the curriculum. It is expected that the conclusions of this study will have an important role on textbook revision and teacher education in the future.

Water-Blooms (Green-Tide) Dynamics of Algae Alert System and Rainfall-Hydrological Effects in Daecheong Reservoir, Korea (대청호 조류경보제의 녹조현상 동태와 강우-수문학적 영향)

  • Shin, Jae-Ki;Kang, Bok-Gyoo;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.49 no.3
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    • pp.153-175
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    • 2016
  • Daecheong Reservoir has suffered eutrophication and water-blooms by blue-green algae from initial impoundment, and algae alert system (AAS) was introduced in 1997. The purpose of this study was to investigate the effect of rainfall and hydrological factors in increase or decrease variability of green-tide and prolonged AAS, studied and analyzed the current situation of AAS has been operating for 19 years (1997~2015) in Daecheong Reservoir. The total issued number of AAS was 46 times, the most frequent period in August and September were 22 times (752 days) and 16 times (431 days), respectively, it accounted for 82.6%. Many number and frequency during this period were significantly associated with rainfall, various discharge and water level. Rainfall and hydrological events are associated with the rainy season of monsoon-Changma and the typhoon, it was concentrated in June~September, total rainfall in this period accounted for 69.9% of the annual rainfall. An increase in inflows was dependent on the intensity, frequency and the amount of rainfall. Accounted for 68.4% of the total annual inflow, it was a time when the most rapidly changing hydrological variability in the reservoir. The total outflow was closely related to rainfall, and compared the distinctive characteristics of hydropower generation and watergate-spillway discharge. In addition, the upreservoir zone of Daecheong Reservoir could be vulnerable to green-tide by regulating discharge of the upstream dam. The issue of AAS was strongly related to the with and without of watergate-spillway discharge. The watergate-spillway discharge had a total of 25 times, it was maximum 17 days from July to September in the year. And the opening times and each duration of the watergate were 1~4 times and the range of 3~37 days, respectively. When the watergate opened, the issue of AAS was maintained to 13 years and the movement of water bodies and green-tide was great about five times than that of non-open, had a profound effect on prolonged AAS within reservoir. In Daecheong Reservoir, Chusori (CHU) area of the So-ok Stream was still showing serious symptoms green-tide levels in the summer, but Janggye (JAN) waters of the main reservoir was pointed out that more important. AAS will be operated by an absolutely consider the rainfall and hydrological effects around the watergate-spillway discharge. The measures of green-tide will be included in the limnological studies more suited to the characteristics of the watershed and reservoir of the our country. Finally, from now on, we will prepare the systematic management and guidelines for vulnerable zone water-blooms that are the source within the reservoir before the monsoon rather than waiting for the arrival of green-tide on the operating stations of AAS.

Understanding of Phytoplankton Community Dynamics Through Algae Bioassay Experiment During Winter Season of Jinhae bay, Korea (생물검정실험을 통한 동계 진해만 식물플랑크톤의 군집 변동 특성 파악)

  • Hyun, Bong-Gil;Shin, Kyoung-Soon;Kim, Dong-Sun;Kim, Young-Ok;Joo, Hae-Mi;Baek, Seung-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.16 no.1
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    • pp.27-38
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    • 2011
  • The distributions of phytoplankton assemblages and environmental factors in Jinhae Bay and their relationships were investigated to estimate the potential limiting nutrient for phytoplankton growth and community structure. In situ algal bioassay experiments were also conducted to assess the species-specific characteristics in phytoplankton responses under different nutrient conditions (control, N(+) and P(+) treatment). During the study periods, bacillariophyceae and cryptophyceae occupied more than 90% of total phytoplankton assemblages. Phytoplankton standing crops in the inner part of Masan Bay were higher than that of Jinhae Bay. The DIN:DIP ratio, pH and transparency showed the significant positive correlation with phytoplankton biomass. According to cluster and multidimensiolnal scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western part of Jinhae bay where cryptophyta species were dominated. The second group was distinguished from inner stations in Masan Bay. These stations showed low transpancy and high DIN:DIP ratio. The other cluster included the stations from the eastern part and central part of Jinhae Bay, which was characterized by the high DSi:DIP ratio and dominant of diatom species. Phosphorous (P) was limited in Masan Bay due to significantly increases in the phytoplankton abundances. Based on stoichiometric limitation and algal bio-assay in Jinhae Bay, nitrogen (N) was a major limiting factor for phytoplankton production. However, silicate (Si) was not considered as limiting factor, since Si/DIN and Si/P ratio and absolute concentration of nutrient did not create any potential stoichiometric limitation in the bay. This implies that high Si availability in winter season contributes favorably to the maintenances of diatom species.

Influence of the Asian Monsoon on Seasonal Fluctuations of Water Quality in a Mountainous Stream (산간 계류성 하천의 계절적 수질변동에 대한 몬순강우의 영향)

  • Shin, In-Chul;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.54-62
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    • 2005
  • The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

Analyses for Early Growth of Terminal Shoots in Persimmon (감나무 정단신초의 초기생장에 대한 분석)

  • Yoon, Young-Whang;Choi, Seong-Tae;Park, Doo-Sang;Rho, Chi-Woong;Kang, Seong-Mo
    • Horticultural Science & Technology
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    • v.30 no.4
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    • pp.385-391
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    • 2012
  • The growth of terminal shoots of persimmon (Diospyros kaki) was analyzed during the first two months from the time of bud sprout to understand the dynamics of their early growth. Field-grown, mature 'Fuyu' and 'Nishimurawase' trees were used in a three-year study at two locations in Gyeongnam province. The growth of terminal shoots was most active from late April, about 10 days after foliation, to early May, followed by a gradual decline by late May. The increase in leaf area continued unabated throughout May. The weight of a flower bud increased slowly until early May and rapidly after flowering. Although its extension growth had been ceased by late May, dry weight (DW) of a terminal shoot continued to increase almost linearly throughout May due to shoot thickening and continued growth of leaves and fruits. In late May, the leaves and the stem accounted for more than 60% and less than 20% of total DW of a shoot respectively; fruit proportion increased to 7 to 17% by then. Relative growth rate (RGR) of the terminal shoot was higher than 213 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late April, but declined to less than 63 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late May. Like the pattern of seasonal changes in RGR, net assimilation rate (NAR) of the shoots decreased from 1.9 to 2 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$ to 0.5 to 0.8 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$. An early-season 'Nishimurawase' did not differ from a late-season 'Fuyu' in RGR and NAR during the first two months of growth. The early growth of the shoots was affected mainly by the reserves redistributed from permanent organs, however, environmental conditions at the time was also involved.