Effects of Fertilizer on Growth, Carbon and Nitrogen Responses of Foliage in a Red Pine Stand

Choonsig Kim,Nam-Gyu Ju,Hye-Yeon Lee,Kwang-Soo Lee 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.1

This study was to examine growth, carbon and nitrogen responses in foliage following forest fertilization in a red pine stand. Two types of fertilizer (N:P:K=113:150:37 kg ha^-1 ; P:K=150:37 kg ha^-1) were applied on late April 2011. Growth, carbon and nitrogen responses of foliage were monitored 3 times (July, September, November) after fertilization. Morphological growth responses (dry mass, leaf area, specific leaf area) with foliage age were not significantly (P > 0.05) affected by fertilizer application, while needle dry mass and leaf area of July were significantly lower in current-year-old than in one-year-old or two-year-old needles of September or November. Carbon concentration and content in foliage was little affected by fertilizer application compared with sampling month or needle age, while the NPK fertilizer produced high nitrogen concentration and content of foliage. The results indicate that nitrogen concentration and content in foliage may serve as an indicator of the nitrogen status by fertilization in a red pine stand.

Implications of Kilpatrick's Project Method in Technology Education

Choonsig Lee 한국실과교육연구학회 2021 實科敎育硏究 Vol.27 No.4

이 연구는 먼저 전통적인 기술교육(이하 기술교육)에서의 프로젝트법은 무엇이고, Kilpatrick의 프로젝트법이 어떠한 과정을 거쳐 구안되었으며, 그 의미와 이와 관련된 논쟁을 탐색하였다. 그리고 나서 Kilpatrick의 프로젝트법이 기술교육 분야에서 새롭 게 적용되도록 한 교육적 함의에 대하여 제시하였다. 첫째, Kilpatrick은 프로젝트의 개념을 지나치게 광범위하게 정의함으로써 교수방법로서의 혼란을 가져왔으나, 기술 교육에서 다양하게 적용할 수 있는 계기를 마련해 주었다. 전통적으로 생산적이고 기 술 습득 활동과 Kilpatrick의 전심을 다한 유목적적 활동을 접목하여 다양하게 활용할 수 있게 해주었다. 둘째, 기술교육에서 전통적인 교사중심의 활동에서 학생중심의 활동으로의 전환을 가져다 주는 방법이 되었다. Kilpatrick의 프로젝트법은 기술교육의 수업에서 기존의 교과의 논리적인 측면에 부가하여 학생의 심리적인 측면을 강조한 것은 큰 전환이 되었다. 셋째, 기술교육에서의 교사의 역할을 감독자나 전수자가 아닌 조언자와 촉진자로 전환시켜 주었다. 기술교육에서 학습자들의 동기를 유발시키고 효과를 촉진하기 위하여 교사의 역할이 조언자와 촉진자가 바뀌는 계기에 프로젝트법이 기여하였다. 넷째, 기술교육에서 프로젝트법을 통해 전통적으로 선형 모형(linear model)에 따라 기술 작품을 따라하기나 모방하기에서 벗어나 학습자들이 자기주도적으로 작품을 창의성으로 만드는 것을 중시하는 혁신적인 문화를 가져다 주었다. 프로젝트 교육과 더불어 프로젝트 활동 교육을 강조함에 따라 기술교육에서의 기술습득을 자기주도 프로젝트 활동을 통해 할 수 있도록 전환되 었다. 다섯째, Kilpatrick의 프로젝트법으로 인해 전통적으로 기술교육에서의 이론과 실습의 엄격한 분리에서 벗어나 통합 모형 (univesal model)에 따른 프로젝트 활동을 하게 하는 계기가 되었다. 마지막으로, Kilpatrick의 프로젝트법은 기술교육에서의 모호한 프로젝트 수행단계를 보다 구체적으로 수행할 수 있도록 제시 해 주었다. Kilpatrick의 프로젝트법이 목적설정, 계획, 수행, 판단의 4단계를 기본으로 다양한 단계(준비, 프로젝트 선정, 정보탐 색, 설계, 제작, 평가)를 적용하여 변형할 수 있는 여지를 주었다. The purpose of this study is to explore issues related to the traditional project method and Kilpatrick's project method in technology education, and to derive educational implications for Kilpatrick's project method to be newly applied in the field of technology education. First, Kilpatrick defined the concept of a project too broadly, which caused confusion as a teaching method in technolgy education, but provided an opportunity for general use in technolgy activity classes. Second, it has traditionally been a method to bring about a shift from teacher-centered activities to student-centered activities in technolgy education. Third, the role of teachers in technolgy education has been transformed into advisors and facilitators rather than supervisors or trainers. In order to motivate learners and promote activities, the project method contributed to the opportunity to change the role of the teacher as a guide. Fourth, by applying the project method in technolgy education, it brought about a change that emphasized creativity and technology application of learners in their own initiative, away from imitating technical works. Fifth, by introducing Kilpatrick's project method, it allowed integrated project activities to break away from the traditional strict separation of theory and practice in technolgy education. Finally, Kilpatrick's project method suggested that the ambiguous project execution stage in traditional technolgy education could be carried out more specifically.

Effects of Fertilizer on Growth, Carbon and Nitrogen Responses of Foliage in a Red Pine Stand

Kim, Choonsig,Ju, Nam-Gyu,Lee, Hye-Yeon,Lee, Kwang-Soo Korean Society of Soil Science and Fertilizer 2013 한국토양비료학회지 Vol.46 No.1

This study was to examine growth, carbon and nitrogen responses in foliage following forest fertilization in a red pine stand. Two types of fertilizer (N:P:K=113:150:37 kg $ha^{-1}$; P:K=150:37 kg $ha^{-1}$) were applied on late April 2011. Growth, carbon and nitrogen responses of foliage were monitored 3 times (July, September, November) after fertilization. Morphological growth responses (dry mass, leaf area, specific leaf area) with foliage age were not significantly (P > 0.05) affected by fertilizer application, while needle dry mass and leaf area of July were significantly lower in current-year-old than in one-year-old or two-year-old needles of September or November. Carbon concentration and content in foliage was little affected by fertilizer application compared with sampling month or needle age, while the NPK fertilizer produced high nitrogen concentration and content of foliage. The results indicate that nitrogen concentration and content in foliage may serve as an indicator of the nitrogen status by fertilization in a red pine stand.

한국과 미국의 기술교과교육 기준에 대한 비교 연구

이춘식 한국기술교육학회 2001 한국기술교육학회지 Vol.1 No.2

Nowadays, many countries have been developed various types of standards in order to lift up the quality of technology education. The purpose of this study was to find a useful suggestion through comparison with the general characteristics of technology standards between Korea and United States. The results of the study were as follows; First, there are different types of technology standards those technology achievement standards and assessment standards were developed in Korea, but technology content standards were developed in United Stated. The content standards included benchmark, which are statements that provide the knowledge and abilities to meet a given standard. Second, technology achievement standards of Korea could be meant the statement of detailed teaching-learning objectives or contents based upon the curriculum that will help teachers in Technology subject-matter with practical guideline or standard in classroom. On the other hand, technology content standards and benchmarks have been designed to prescribe the content knowledge and abilities of what students should know and be able to do in order to be technologically literate. Also, a technology content standards is not a curriculum. Third, aspects of scope and characteristic of standards development, technology achievement and assessment standards of Korea will be affected the national curriculum of technology because the standards was developed according to current curriculum. But technology content standards of U.S. was created with developmentally appropriated for students in grades K-12 and it provide a basis for developing meaningful, relevant, and articulated curricula at the local, state, and provincial levels. Finally, in the development of standards, Korea technology standards, achievement and assessment standards, were developed with the short-term about one year. Then the standards have a limit in the consensus-building. But a technology content standards of U.S. was developed with the long-term about five years through the consensus-building, validation processes, and six drafts of the document.

Allometric equations and biomass expansion factors of Japanese red pine on the local level

Kim, Choonsig,Jeong, Jaeyeob,Kim, Rae-Hyun,Son, Yeong-Mo,Lee, Kyeong Hak,Kim, Jin-Seoung,Park, In-Hyeop Springer-Verlag 2011 Landscape and Ecological Engineering Vol.7 No.2

Comparison of allometric equations and biomass expansion factors for six evergreen broad-leaved trees in subtropical forests in southern Korea

Kim, Choonsig,Baek, Gyeongwon,Yoo, Byung Oh,Jung, Su Young,Lee, Kwang Soo,An, Ki Wan Informa UK (TaylorFrancis) 2019 Journal of sustainable forestry Vol.38 No.3

A multi-site approach toward assessing the effect of thinning on soil carbon contents across temperate pine, oak, and larch forests

Kim, Seongjun,Kim, Choonsig,Han, Seung Hyun,Lee, Sang-Tae,Son, Yowhan Elsevier 2018 Forest ecology and management Vol.424 No.-

<P><B>Abstract</B></P> <P>Large divergence of the post-thinning change in soil carbon contents has impaired the evaluation of the thinning effect on forest carbon storage reported in previous case studies. In this context, the present study used a multi-site approach to assess the effect of thinning on forest floor and mineral soil carbon contents. The sites included four pine (<I>Pinus densiflora</I> Sieb. et Zucc.), five oak (<I>Quercus</I> spp.), and four larch (<I>Larix kaempferi</I> (Lamb.) Carr.) forests under the temperate climate, each of which included un-thinned control, intermediate thinning (15–30% basal area reduction), and heavy thinning (30–50% basal area reduction) treatments. Forest floor and mineral soil (0–10, 10–20, and 20–30 cm depths) carbon contents were determined 0–1, 3–4, and 6–7 years after thinning. The average forest floor and mineral soil (0–30 cm) carbon contents (Mg C ha<SUP>−1</SUP>) were 6.7 and 54.1 under the control, 6.6 and 60.7 under the intermediate thinning treatment, and 6.0 and 64.7 under the heavy thinning treatment, respectively. There was a slight decrease in forest floor carbon contents but an increase in mineral soil carbon contents under the thinning treatments, although the magnitude and direction of the thinning effect were site-specific. The magnitude of the thinning effects was stronger under the heavy thinning treatment than under the intermediate thinning treatment. However, the effect of thinning was unrelated to time after thinning and forest type. Topography (altitude and slope), soil properties (soil water content, pH, and total nitrogen concentration), diameter at breast height and height of remaining trees, and the percentage of removed basal area explained approximately 45% of variance in the thinning effect, indicating that differences in the environment are important in the divergence of the thinning effect on soil carbon contents across multiple sites. Our results suggest that designing thinning practices to foster forest carbon sequestration should consider the contribution of thinning intensity and environmental conditions to variation in the thinning effect on soil carbon contents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The thinning effect on soil carbon contents differed in magnitude and direction among sites. </LI> <LI> Changes in soil carbon contents were larger under relatively heavy thinning intensity. </LI> <LI> Time after thinning and forest type did not affect the thinning effect on soil carbon contents. </LI> <LI> Topography and soil property contributed to variation in the thinning effect over sites. </LI> </UL> </P>

Carbon and nitrogen dynamics in a <i>Pinus densiflora</i> forest with low and high stand densities

Noh, Nam Jin,Kim, Choonsig,Bae, Sang Won,Lee, Woo Kyun,Yoon, Tae Kyung,Muraoka, Hiroyuki,Son, Yowhan Oxford University Press 2013 Journal of plant ecology Vol.6 No.5

<P><B>Aims</B></P><P>Understanding carbon (C) and nitrogen (N) dynamics and their dependence on the stand density of an even-aged, mature forest provides knowledge that is important for forest management. This study investigated the differences in ecosystem total C and N storage and flux between a low-density stand (LD) and a high-density stand (HD) and examined the effects of stand density on aboveground net primary productivity (ANPP), total belowground C allocation (TBCA) and net ecosystem production (NEP) in a naturally regenerated, 65- to 75-year-old <I>Pinus densiflora</I> S. et Z. forest.</P><P><B>Methods</B></P><P>LD (450 trees ha<SUP>−1</SUP>) and HD (842 trees ha<SUP>−1</SUP>) were established in an even-aged, mature <I>P. densiflora</I> forest in September 2006. The forest had been naturally regenerated following harvesting, and the stand density was naturally maintained without any artificial management such as thinning. The diameter at breast height (DBH ≥ 5.0cm) of all live stems within the stands was measured yearly from 2007 to 2011. To compare C and N storage and fluxes in LD and HD, C and N pools in aboveground and belowground biomass, the forest floor, coarse woody debris (CWD) and soil; soil CO<SUB>2</SUB> efflux (<I>R</I> <SUB>S</SUB>); autotrophic respiration (<I>R</I> <SUB>A</SUB>); litter production; and soil N availability were measured. Further, ANPP, TBCA and NEP were estimated from plot-based measurement data.</P><P><B>Important Findings</B></P><P>Ecosystem C (Mg C ha<SUP>−1</SUP>) and N (Mg N ha<SUP>−1</SUP>) storage was, respectively, 173.0±7.3 (mean ± SE) and 4.69±0.30 for LD and 162±11.8 and 4.08±0.18 for HD. There were no significant differences in C and N storage in the ecosystem components, except for soils, between the two stands. In contrast, there were significant differences in aboveground ANPP and TBCA between the two stands (<I>P</I> < 0.05). Litterfall, biomass increment and <I>R</I> <SUB>S</SUB> were major C flux components with values of, respectively, 3.89, 3.74 and 9.07 Mg C ha<SUP>−1</SUP> year<SUP>−1</SUP> in LD and 3.15, 2.94 and 7.06 Mg C ha<SUP>−1</SUP> year<SUP>−1</SUP> in HD. Biometric-based NEP (Mg C ha<SUP>−1</SUP> year<SUP>−1</SUP>) was 4.18 in LD and 5.50 in HD. Although the even-aged, mature <I>P. densiflora</I> forest had similar C and N allocation patterns, it showed different C and N dynamics depending on stand density. The results of the current study will be useful for elucidating the effects of stand density on C and N storage and fluxes, which are important issues in managing natural mature forest ecosystems.</P>

한국형 산림토양탄소모델(KFSC Model)을 이용한 RCP 8.5 기후변화 시나리오 하에서의 국내 소나무림 토양탄소 저장량 장기 변화 추정 연구

박찬우(Park, Chan-woo),이종열(Lee, Jongyeol),이명종(Yi, Myongjong),김춘식(Kim, Choonsig),박관수(Park, Gwan Soo),김래현(Kim, Rae Hyun),이경학(Lee, Kyeong Hak),손요환(Son, Yowhan) 한국기후변화학회 2013 한국기후변화학회지 Vol.4 No.2

Annual Variation of Soil CO₂ Efflux in a Broadleaved Deciduous Forest of the Geumsan (Mt.) Long-Term Ecological Research Site

김춘식,이임균,임종환,박병배,천정화,Kim, Choonsig,Lee, Im Kyun,Lim, Jong Hwan,Park, Byung Bae,Chun, Jung Hwa Korean Society of Agricultural and Forest Meteorol 2013 한국농림기상학회지 Vol.15 No.3

산림생태계 토양 호흡량은 지구탄소순환에 중요한 역할을 한다. 본 연구는 금산 장기생태 연구 조사지 낙엽활엽수림을 대상으로 4년 동안 토양 이산화탄소 방출량의 연 변동을 조사하였다. 금산 장기생태 연구 조사지 월별 토양 이산화탄소 방출량은 토양온도 변화와 밀접한 관계가 있었으며 토양수분함량과는 뚜렷한 경향을 보이지 않았다(P > 0.05). 동절기(1월과 2월, 2007년의 경우 1월부터 3월)를 제외한 평균 토양 이산화탄소 방출량은 2008년 0.32 g $CO_2\;m^{-2}h^{-1}$, 2009년 0.40g $CO_2\;m^{-2}h^{-1}$, 2007년 0.41g $CO_2\;m^{-2}h^{-1}$, 2010년 0.54 g $CO_2\;m^{-2}h^{-1}$ 순이었으며, 2008년의 연 평균토양온도는 $12.0^{\circ}C$로 다른 연도의 토양 온도 $13.0-13.5^{\circ}C$에 비해 유의적으로(P<0.05) 낮았다. 토양 이산화탄소 방출량과 토양 20cm 깊이의 토양온도는 지수함수 관계가 있었으며 ($R^2$ = 0.31-0.75, P < 0.05), 토양수분함량은 토양 이산화탄소 방출량과 유의적인 관계가 없었다(P > 0.05). 본 연구 결과에 따르면 금산장기생태연구 조사지 토양 이산화탄소 방출량의 연 변동은 토양수분보다는 토양온도 변화와 관계가 있었다. Soil respiration in forest ecosystems play an important role in global carbon cycle. This study was carried out to determine the annual variation of soil $CO_2$ efflux for 4 years in a broadleaved deciduous forest of the Geumsan (Mt.) Long-Term Ecological Research (GLTER) site in Southern Korea. The soil $CO_2$ efflux in the GLTER site showed annual variations with the fluctuations of annual mean soil temperature, but not with those of soil water content. The annual mean soil $CO_2$ efflux except for winter season was 0.32 g $CO_2\;m^{-2}h^{-1}$ for 2008, 0.40 g $CO_2\;m^{-2}h^{-1}$ for 2009, 0.41 g $CO_2\;m^{-2}h^{-1}$ for 2007, and 0.54 g $CO_2\;m^{-2}h^{-1}$ for 2010. The lowest soil $CO_2$ effluxin 2008 was associated with the lowest soil temperature ($2.0^{\circ}C$) in comparison with those of other years ($13.0-13.5^{\circ}C$). The exponential relationships between monthly soil $CO_2$ efflux and the corresponding soil temperature at the soil depth of 20 cm were significant ($R^2$ = 0.31-0.75, P < 0.05). The results indicate that the annual variation of soil $CO_2$ efflux was attributed to the variations of soil temperature rather than soil water content in the GLTER site.