• Journal of Forest and Environmental Science
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• 제35권4호
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• pp.213-222
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• 2019

Climate change has been intensifying and affecting forest ecosystems. Over the years, the intensity and frequency of climate change have increased and the effects of climate change have been aggravating due to cumulative greenhouse gases such as CO₂, which has resulted in several negative consequences, drought being the main threat among all. Drought affects forest ecosystems directly and indirectly. Insufficient soil moisture, due to drought, may affect the growth of plants and soil respiration (SR), and soil temperature may increase because of desiccated soil. In addition, the mortality rate of plants and soil microorganisms increases. As a result, these effects could reduce forest productivity. Thus, in this article, we have presented various research studies on artificial drought using throughfall exclusion, and we have mainly focused on SR, which is significantly related to forest productivity. The research studies done worldwide were sorted as per the main groups of Köppen-Geiger climate classification and intensively reviewed, especially in tropical climates and temperate climates. We briefly reviewed the properties among the exclusion experiments about the temperate climate, which mostly includes Korean forests. Our review is not a proof of concept, but an assumption for adequate investigation of drought effects in the Korean forest.

• 한국산림과학회지
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• 제88권3호
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• pp.379-388
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• 1999

우리 나라에 적용할 산림용 종자 산지구분(塵地區分)의 첫 단계로 임목집단의 유전생태적 분화에 영향이 큰 연평균 온도, 극한 최저온도, 생육기간중 상대습도, 일조량, 건조지수 등 기상인자를 척도로 수평적 산지를 구분하였다. 적용한 산지구분의 개념은 전형적인 산지구분 형태인 수종별 구분법보다는 전 수종을 포함한 생태지역 개념의 산지구분법에 따랐다. 산림대를 대구분 단위로 하여 산림대별(난대, 온대남부, 온대중부, 온대북부)로 기본구역을 설정하여 유집분석을 근거로 난대 3, 온대남부 6, 온대중부 8, 온대북부 2로 총 19개의 수평적 산지로 구분하였다. 적용한 6개의 척도중 연평균 온도, 극한 최저온도, 생장일수는 산림대별로 난대에서 온대북부 방향으로 일정한 경향을 보였으며 상대습도, 일조량 및 건조지수에서는 일정한 경향을 보이지는 않았으나 산지간에는 많은 차이를 보여 이들 인자는 미세 환경인자에 민감한 것으로 나타났다. 본 연구에 의해 구분된 산지는 구획 초기단계로 잠정적인 산지로 활용하면서 금후 생물기후도, 산지시험, 유전생태 자료 등이 축적되면 보완해 나갈 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.149-149
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• 2019

Gross Primary production (GPP) and evapotranspiration (ET) are the two critical components of carbon and water cycle respectively, linking the terrestrial surface and ecosystem with the atmosphere. The ratio between GPP to ET is called ecosystem water use efficiency (EWUE) and its quantification at the forest site helps to understand the impact of climate change due to large scale anthropogenic activities such as deforestation and irrigation. This study was conducted at the FLUXNET forest site CN-Qia (2003-2005) using Community land model (CLM 5.0). We simulated carbon and water fluxes including GPP, ecosystem respiration (ER), and ET using climatic variables as forcing dataset for 30 years (1981-2010). Model results were validated with the FLUXNET tower observations. The correlation showed better performance with values of 0.65, 0.77, and 0.63 for GPP, ER, and ET, respectively. The model underestimated the results with minimum bias of -0.04, -1.67, and -0.40 for GPP, ER, and ET, respectively. Effect of climate 'CLIM' and '$CO_2$' were analyzed based on EWUE and its trend was evaluated in the study period. The positive trend of EWUE was observed in the whole period from 1981-2010, and the trend showed further increase when simulated with rising $CO_2$. The time period were divided into two parts, from 1981-2000 and from 2001 to 2010, to identify the warming effect on EWUE. The first period showed the similar increasing trend of EWUE, but the second period showed slightly decreasing trend. This might be associated with the increase in ET in the wet temperate forest site due to increase in climate warming. Water use efficiency defined by transpiration (TR) (TWUE), and inherent-TR based WUE (IT-WUE) were also discussed. This research provides the evidence to climate warming and emphasized the importance of long term planning for management of water resources and evaporative demand in irrigation, deforestation and other anthropogenic activities.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.812-820
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• 2002

An experiment was conducted on 190 progeny (winter -74; summer -59; rainy -57) of 12 Grey Giant rabbits (10 female +2 males), to assess the effect of different seasons in a year, on their reproductive, growth and productive performances along with feed efficiency, under sub-temperate Himalayan conditions. The daily meteorological attributes recorded during winter (October to March), summer (April to June) and rainy (July to September) seasons, and analysed were minimum and maximum temperature, relative humidity and rainfall. Various biological parameters recorded were doe weights at mating and kindling, litter size at birth, litter weight at birth, kit mortality, litter size at weaning, litter weight at weaning, weekly body weight up to 98 d and weaner mortality. Individual weight gains, dressing percentages, meat weights, liver weights, raw-pelt weights, processed pelt weights and processed pelt areas at slaughter on d 84 and 98, respectively were also recorded. The feed and fodder compositions and their nutritive values during different seasons were also analysed. Average ambient temperature during winter, summer and rainy seasons were $13.2{\pm}2.8$, $22.4{\pm}3.7$ and $24.8{\pm}2.3^{\circ}C$, respectively. The average relative humidity and total rainfall for winter, summer and rainy seasons were $68.9{\pm}1.5$% and $48{\pm}26.6$mm, $66.3{\pm}4.8$% and $125.6{\pm}56.8$ mm, and $77.3{\pm}1.3$% and $116.3{\pm}90.4$ mm, respectively. The weight of doe at mating and kindling, litter size at birth, litter weight at birth and litter size at weaning were comparatively higher whereas litter weight at weaning was significantly (p<0.05) higher during winter as compared to summer and rainy seasons. The kit mortality was significantly (p<0.05) higher during winter while the weaner mortality was significantly (p<0.05) higher during rainy season. At 84 d, the live weight per doe, slaughter weight, dressing percentage and liver weight were significantly (p<0.05) higher during winter than summer and rainy. Similarly, the gain in weight and meat weight at 84 and 98 d were significantly (p<0.05) higher during winter. The weight of raw pelt and processed pelt were recorded significantly (p<0.05) higher during winter while no difference in the area of processed pelts during different seasons could be observed. No difference in the biological performance could be observed between sexes in any of the seasons. Roughage analysis revealed comparatively higher crude protein percent and lower crude fibre percent during summer and rainy seasons than in winter. The roughage dry matter intake was comparatively higher during summer and rainy seasons vis-a-vis constant amount of concentrate supplied during all the three seasons. The digestibilities of dry matter was significantly (p<0.05) lower, whereas that of crude fiber, acid detergent fibre and cellulose were negative during winter. Interestingly, the feed:gain was exceedingly well during winter than in other seasons and it is concluded that it was the best season for production of rabbits under sub-temperate Himalayan conditions.

• Ocean and Polar Research
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• 제26권3호
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• pp.401-414
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• 2004

Temperature, salinity, alkalinity, pH, nutrient, chlorophyll, and iron were measured within the upper 250m water column around the Antarctic Polar Front in the Scotia Sea from late November to early December 2001. Temperature and salinity showed a rapid change across the Polar Front, and the temperature minimum layer existed only in the southern area of the Polar Front. Total $CO_2$ and nutrient concentrations were relatively high and increased rapidly with water depth in the southern area of the Polar Front, which was resulted from upwelling of the Antarctic deep water containing high concentrations of total $CO_2$ and nutrient. ${\Delta}C:{\Delta}N:{\Delat}P$ ratios measured in the norhem and southern areas of the Polar Front were 75:11.4:1 and 84:12.5:1, respectively, which were lower than the Redfield ratio. ${\Delta}Si:{\Delta}N$ ratio (3.65) measured in the southern area of the Polar Front was two times higher than that (1.95) in the northern area. These two ratios were higher than the ratio (1.0) measured in the temperate and tropical oceans. Chlorophyll concentrations were extremely high in the area of $59^{\circ}{\sim}60^{\circ}S$, which was attributed to favorable environmental conditions for phytoplankton growth in this area, such as sufficient iron, high water column stability, and high silicate concentration.

• 한국환경과학회지
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• 제12권8호
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• pp.853-860
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• 2003

Plants sequester atmospheric CO$_2$, a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pinus densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO$_2$ uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of CO$_2$ exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO$_2$ uptake per unit leaf area ranged from 1.6-6.7 mg/d㎡/h for P. densiflora and from 3.7-8.9 mg/d㎡/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO$_2$ uptake by total leaf area per tree, which subtracted the CO$_2$ release (i.e. respiration) by leaves and woody organs from the gross CO$_2$ uptake (diurnal uptake and release by leaves). Annual CO$_2$ release by leaves and woody organs accounted for 58-73％ of the gross CO$_2$ uptake across tree specimens. Annual CO$_2$ uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. densiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO$_2$ uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO$_2$ reduction of woody plants by forest type and age class.

• 한국농림기상학회지
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• 제24권4호
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• pp.256-266
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• 2022

일사량은 작물모형의 구동에 필수적인 요소지만, 일사량의 직접관측은 다른 기상자료들과 다르게 많은 인적, 물적 자원이 필요하다. 직접 일사량을 측정하는 대신 다른 기상자료를 통해 일사량을 추정하는 여러 방식이 존재하고 그중 대표적인 방법이 일조시간을 통해 일사량을 추정하는 Angstrom-Prescott 모델이다. Frere and Popov(1979)에 의해 전세계의 기후를 세 분류로 나누어 일조시간을 일사량으로 변환하는 AP 계수(AP_Frere)가 제시되었고, 국내 18개 종관기상관측소에서 30년간 관측한 일단위 일사량과 일조량 관측자료를 통해 AP계수를 경험적으로 도출한 계수(AP_Choi)가 Choi et al.(2010)에 의해 제시되었다. 본 연구에서는 2012년부터 2021년까지 일사량 관측값(S_Obs)과 AP_Frere와 AP_Choi를 통해 도출한 일사량(S_Frere, S_Choi)을 NRMSE와 t검정을 통해 분석하였고, 이를 DSSAT 작물모형에 입력모수로 사용하여 벼 품종 오대, 화성 및 추청에 대한 생육모의를 하였다. 일사량 추정 결과 일사량의 추정값과 측정값 사이에는 12%에서 22%사이의 오차가 존재하였고, 이를 3월부터 9월 사이의 생육기간에 한정하여 누적 일사량을 계산하면 오차가 줄었다. 18개의 지역중 관찰값과 생육기간의 누적 일사량은 S_Frere의 경우에 10개의 지역에서 S_Choi 보다 S_Obs와 가까웠고, 일일 일사량의 오차율을 통해 분석하였을때 S_Frere가 12개 지역에서 더 가까웠다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.269-269
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• 2022

Pre-harvest sprouting (PHS) on rice panicles is getting problematic in recent several years in Korea due to climate changes such as high temperature and more frequent typhoons during harvesting season. PHS negatively affects grain quality severely and also yield. Genetic improvement of Korean varieties (Oryza sativa ssp. japonica) through a marker assisted-backcross breeding (MAB) with the known PHS resistant genes must be one of ideal solutions. However, the final breeding products of MAB occasionally exhibit unwanted traits, especially the cross between genetically distant parents. This might be caused by linkage drag and/or presence of the gene-unlinked donor introgressions, resulting that the final products could not be released to the farmers. The major PHS resistance gene, Sdr4 (Seed dormancy 4) originated from an indica cultivar, Kasalath was selected as a donor gene. In order to avoid unexpected phenotypes in the breeding products, we performed a precision marker-based breeding (PMBB) consisting of foreground, recombinant, and background selections (FS, RS, and BS) which aim to develop 'single small introgression lines' (~100 kb introgression). Korean varieties (Ilpum and Gopum) were crossed with Kasalath. We developed Sdr4-allele specific markers for FS and a set of polymorphic flanking markers near the Sdr4 (-350kb and +420kb) for RS. To minimize linkage drag, the small introgression (< 125kb) containing Sdr4 was selected in Ilpum background (BC₂F₄) through 1^st RS with ~1,200 F₂ or BC₁F₂ plants (one side trimmed) and then 2^nd RS with ~1,000 progenies from the 1^st RS selected plants (another side trimmed). After RS, the selected lines were genotyped by using Infinium 7K SNP chip to detect other donor introgressions and the lines were backcrossed. Currently BS is on-going from the backcross-derived progenies with BS markers to remove residual introgressions. During the PMBB process, genetic effect of Sdr-4-Kasalath allele was confirmed in Ilpum and Gopum backgrounds by PHS phenotyping using the segregating BC₂F₃ or BC₁F₄ materials. The Sdr4 PMBB lines in Ilpum background (< 125kb introgression) will be valuable genetic resources to improve PHS resistance in modem popular temperate japonica varieties.

• 현장농수산연구지
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• 제20권2호
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• pp.105-114
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• 2018

본 연구는 다른 지역에 비해 일교차가 큰 철원 지역에서 재배되고 있는 양파에 친환경제제로 사용되는 아인산염을 농도별로 처리하여 생육특성과 페놀화합물 함량의 변이를 알아보기 위해 수행되었다. 그 결과 아인산염 처리 후 양파의 구무게, 너비, 폭과 당 함량에는 큰 영향을 미치지 않았다. 반면 페놀화합물에는 영향을 미쳐 아인산 500ppm을 처리했을 때 벤조산, 카페산, 쿠마린산, 캠페롤, 쿼르세틴 함량이 무처리구보다 다소 높은 함량을 보였다. 따라서 아인산염은 생육에는 큰 영향을 주지는 않았지만 물질 변화에 영향을 미쳐 물질 촉매제 역할과 수용성 인산과 칼리를 공급하여 장마기에 질소와 균형을 이룰 수 있는 방법으로도 큰 역할을 할 수 있다고 사료된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.314-314
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• 2017

Anthropogenic activities have increased the concentrations of greenhouse gases, such as $CO_2$, $CH_4$, $N_2O$, HFCs, $SF_6$, and PFCs, in the atmosphere. Among others, $N_2O$ is well known as an important greenhouse gas accounting for 7.9% of the total greenhouse effect and the effect of its emission is 310 times greater than that of $CO_2$. Agricultural $N_2O$ emissions are now thought to contribute to about 60% of the global anthropogenic $N_2O$ emission, which have been increased primarily due to fertilizer N consumption and manure management. Therefore, the reduction of $N_2O$ emissions in agriculture is being required. This study was conducted to determine the variation of $N_2O$ emissions by no-tillage (NT) and conventional tillage (CT) practices in the cultivation of soybean from the sandy loam soils under the different kinds of fertilizer treatments June through September 2016 in Cheong-ju, Republic of Korea. An experimental plot, located in the temperate climate zone, was composed of two main plots that were NT and CT, and were divided into four plots, respectively, in accordance with types of fertilizers (chemical fertilizer, liquid pig manure, hairy vetch and non-fertilizer). Among all the treatments, $N_2O$ emission was the highest in August and the lowest in June. When $N_2O$ emissions were evaluated during the growing season (June to September) in all fertilizer treatments, NT with hairy vetch treatment emitted the highest $N_2O$ emission in August, whereas, $N_2O$ emissions was the lowest in NT with non-fertilizer treatment in June, respectively (p = 0.05). Based on the cumulative amount of $N_2O$ emissions during the growing season of soybean, NT had lower $N_2O$ emission than CT by 0.01 - 0.02 kg $N_2O$, although NT had higher $N_2O$ emission than CT by 0.03 kg $N_2O$ in only the chemical fertilizer treatments. As a result, it seems that the applications of liquid pig manure and hairy vetch rather than chemical fertilizer could decrease the $N_2O$ emission in NT, compared to CT.