Aidanosagitta crassa, a key species in South Korea’s coastal waters, exhibits three morphological types: Type C with a collarette-containing trunk, Type N lacking a collarette, and an intermediate Type I. Limited research studies have been conducted on their ecological patterns, prompting this study to elucidate seasonal occurrence patterns of A. crassa types in Pyeongtaek. Field surveys at six stations in Pyeongtaek port were conducted in winter (Feb.), spring (May), summer (Aug.), and autumn (Nov.) of 2010. Water temperature and salinity were measured and zooplankton samples were collected for abundance analysis. Type C predominated in winter and autumn. Type I predominated in summer and Type N predominated in summer and autumn. Occurrence patterns were influenced by water temperature. Type C showed a negative correlation with water temperature. Type N was positively correlated with water temperature. However, Type I showed no significant correlation with water temperature. In 2013, genetic sampling using the mtCOI marker was conducted in winter and summer. Despite morphological differences, genetic analysis revealed intraspecific diversity due to seasonal environmental changes.

청주와 증평에서 채집한 섬서구메뚜기(Atractomorpha lata)의 발생과 온도(20°C, 25°C, 30°C)에 따른 령기별 발육기간, 성충수명, 산란수 및 부화율 등을 조사하였다. 섬서구메뚜기는 5월 말부터 부화약충이 나타나기 시작하여 7월말부터 성충이 출현하고 8월 중순에 성충의 밀도가 가장 높았다. 청주와 증평에서 채집된 모든 령기에 대한 야외개체의 암수 비율은 각각 0.49와 0.45로 유사하게 조사되었다. 섬서구메뚜기 암컷은 6령까 지의 약충기를 거쳐 성충이 되지만 수컷은 5령 약충기만으로 성충이 되었다. 령기별 약충의 발육기간은 온도가 높아질수록 짧았으며 암컷이 수컷보 다 모든 온도에서 더 길었다. 성충의 수명은 온도가 높아질수록 암수 모두 감소하였고 암컷과 수컷 모두 20°C에서 각각 158.9일과 127.3일로 가장 긴 기간 동안 생존하였다. 온도가 높아질수록 산란전기는 짧아졌으나, 산란수는 반대로 증가하였다. 그러나 난괴당 산란수는 온도별 큰 차이를 보이 지 않았다. 섬서구메뚜기의 알은 30°C이상에서만 부화하여 52.0% 부화율을 보였다. 본 연구결과는 섬서구메뚜기를 방제하기 위하여 발생과 발육 에 관한 기초자료로써 활용가능 할 것으로 생각된다.

We presented foundational findings regarding the occurrence and acoustic characteristics of the finless porpoise through passive acoustic and visual surveys conducted on the southern coast of Korea, specifically at Hadong Jungpyeong Port. Over a survey period spanning from July 8 to August 16, 2023, totaling 40 days, we observed peaks in the number of clicks produced by this species on July 15, July 24, August 4, August 11, and August 16. The highest count, totaling 18,924 clicks, was recorded on July 15th, while the lowest count, at 3,888 clicks, occurred on August 8th. Examining the acoustic characteristics throughout the diurnal cycle, we found that the peak activity in terms of DPM (detection positive minute for one hour), DP10M (DPM for ten minutes), and overall number of click sounds was observed between 05:00 and 08:00, with a secondary peak occurring from 17:00 to 18:00. The quietest period was noted between 23:00 and 02:00. Furthermore, there was a significant increase in the number of clicks from sunrise, with the maximum count of 21,581 clicks recorded at 6 AM. This count gradually decreased until noon, experienced a slight increase thereafter, peaked again at sunset, and then declined. The dominant frequency mode of this species was 126 kHz, with a concentration ranging from 112 to 136 kHz. The average duration of a click sound was 127 ㎲, with approximately 16 sinusoids (cycles) within each click sound and an average cycle length of approximately 7.9 ㎲. These findings from our study are anticipated to serve as foundational data for the development of a Korean pinger and acoustic warning system.

PURPOSES : High temperatures induce excessive expansion in pavements, thus causing the closure of contraction joints between expansion joints. This results in the integration of slabs within the expansion joints into a unified slab. Compressive forces are generated owing to the friction that ensues between the unified slab and lower base layer. As the integrated slab expands and exceeds the allowable width of the expansion joint, the end restraint generates an additional compressive force. The escalating force, which reaches a critical threshold, induces buckling, thus compromising stability and causing blow-up incidents, which poses a significant hazard to road users. The unpredictable nature of blow-up incidents render their accurate prediction challenging because the compressive force within the slab must be predicted and the threshold for blow-up occurrence must be determined. METHODS : In this study, a GWNU blow-up model was developed to predict both the compressive force and period of blow-up incidents in jointed concrete pavements. The climate conditions, pavement structure, materials, and expansion joints were considered in this model. In the first stage of the model, the time at which the integrated slab expanded and surpassed the allowable width of the expansion joint was determined, and the compressive force was calculated. Subsequently, the compressive force within the integrated slab, considering both the end restraints and friction, was predicted. A large-scale blow-up test was performed to measure the blow-up force based on changes in the geometric imperfections. The measured blow-up force was adopted as the blow-up occurrence threshold, and the point at which the predicted compressive force within the slab exceeded the blow-up force was identified as the blow-up occurrence time. RESULTS : Using the GWNU blow-up model, the blow-up occurrence on the Seohean Expressway in Korea is predicted in the presence or absence of the alkali-silica reaction (ASR). Analysis is conducted using the expansion joint spacing and width as variables. As the expansion joint spacing increases, blow-up occurs sooner, and as the width increases, only the expansion joint life decreases. When applying an expansion joint spacing of 300 m and a width of 100 mm under an ASR with 99.9% TTPG reliability, the sum of the expansion joint life and blow-up occurrence time is 16 years. CONCLUSIONS : In the case of jointed concrete pavements where ASR occurred, installing an expansion joint spacing of 300 m and a width of 100 mm does not satisfy the design life of 20 years, and the expansion joint width minimally affect the blow-up occurrence time. To prevent blow-up incidents, a spacing of less than 300 m for the expansion joint is recommended. Based on the analysis results, the blow-up occurrence time and location can be predicted from the characteristics of the installed expansion joint, through which blow-up incidents can be prevented via preliminary maintenance.

Hypochaeris radicata, native to Europe and Eurasia, is a perennial plant of the Asteraceae family. In Korea, H. radicata was reported in 1992, mainly in Jeju Island, and gradually spreading to the inland. It overwinters in the form of a rosette and blooms yellow flowers from May to June. H. radicata propagates by seeds and rhizomes. The germination temperature of the seed is 15/20°C (day/night), and the rhizome forms a new plant at a depth of 2-3 cm in the soil. The roots of H. radicata secrete allelochemicals that inhibit the development of other plants. Some use it as a salad or forage substitute but to a limited extent. However, extensive research on ampicillin contained in H. radicata has been conducted, and its anticancer and anti-inflammatory effects have been recognized. There are only a few methods to manage H. radicata both culturally and physically. In orchards, soil treatments such as oxyfluorfen and diclobenil, or nonselective foliar treatments such as glufosinate-ammonium and glyphosate are used. Notably, there are no known biological control agents.

In 2022, the Korean Ministry of Environment designated Parthenium hysterophorus as an ecosystem-disturbing plant. The purpose of this study was to present a management plan for P. hysterophorus considering its distribution, morphological, physiological, and ecological characteristics, and to introduce various control techniques. P. hysterophorus is native to Central America and occurs in about 45 countries worldwide. However, in Korea, it only grows in some areas of Tongyeong and Changwon, Gyeongsangnam Province. P. hysterophorus is an annual plant and spreads by seeds, moves between countries in the process of importing and/or exporting agricultural seeds, and spreads by agricultural machinery and vehicles after introduction. P. hysterophorus releases parthenin, an allelochemical that suppresses the occurrence of the surrounding vegetation, from its stems and roots. In addition, P. hysterophorus causes damage to humans and livestock through various allergens. P. hysterophorus can be controlled by physical methods, such as cutting its stems or pulling roots, and by treatment with non-selective herbicides, such as glyphosate. Many biological control research studies have been conducted and, unfortunately, there is no a practical solution so far.

Paspalum distichum and P. distichum var. indutum are perennial weeds of the family Poaceae that prefer moist environments such as waterfronts and waterways. The origin of both species is North America. P. distichum is distributed all over the world. However, P. distichum var. indutum occurs only in the United States, Japan, and Korea. For this reason, in many countries, P. distichum and P. distichum var. indutum are classified as the same species. In other words, P. distichum var. indutum is a different ecological type of P. distichum. Both species can reproduce and spread mainly by rhizome fragments rather than seeds. This rhizome has a characteristic that it does not germinate if it is buried in the ground with depth of more than 3 cm. As a management method for P. distichum and P. distichum var. indutum in agricultural lands (paddy fields), it is effective to combine cultural control and chemical control methods. In other words, combining deep plowing and harrowing can suppress the budding of water sparrow that has invaded paddy fields or fallow paddy fields. After that, these two species that germinate can be controlled by spraying soil treatment herbicides such as butachlor and thiobencarb or foliar treatment herbicides such as cyhalofop-butyl and fenoxaprop-pethyl.

Lactuca scariola L. is one of ecosystem-disturbance plants that grow everywhere such as roadsides, grasslands, railroads, banks, and fields. L. scariola usually occurs in autumn. It overwinters in rosette form. It flowers and produces seeds in early summer of the next year. Seeds of L. scariola can germinate immediately without dormancy when the temperature is over 20°C. Due to endogenous bacteria in seeds of L. scariola, it has a strong drought tolerance. Thus, it can grow well on roadsides. L. scariola should be controlled as it can result in 60-80% of soybean yield loss at densities above 50 plants m-2. It is advisable to remove L. scariola as it competes with native plants by acting as a pioneer to other ecosystem-disturbance plants. Among various control methods, chemical control is the most effective method that is widely used. Soil treatment with herbicides such as oxyfluorfen EC and pendimethalin EC can inhibit the development of L. scariola. Foliar treatment herbicides glyphosate and glufosinateammonium are widely used. L. scariola is resistant to 2,4-D, dicamba, and MCPA among foliar treatment herbicides. Thus, it is recommended to apply herbicides with different modes of action.

우리나라의 수산 양식의 대부분이 이루어지는 연안과 내만에 최근 빈번한 고수온 현상으로 매년 막대한 양식 피해가 발생하고 있다. 2018년~2021년의 최근 4년간의 7월은 이례적인 고수온, 장마, 태풍 등에 의해 1990년 이후 수온의 연별 변동성이 1994년~1997년에 이 어 두 번째로 크게 나타났다. 동·서·남해의 대표적인 고수온 양식피해 우심해역(천수만, 가막만, 구룡포)에 대한 열속과 열수지 분석을 통 해 여름철 천수만과 가막만의 고수온 발생은 주로 대기로부터 해수면을 통한 열유입에 의한 것임을 확인하였다. 벌크식으로 계산한 순열 속과 수온변화로부터 계산한 해양 열 저장률로부터 4년간(2018년~2021년)의 7월 평균 해양 열 수송률을 추산한 결과, 서산 창리는 순열속 의 13.5 %, 여수 신월은 순열속의 62.3 %가 외부로 유출되는 것으로 계산되었다, 구룡포 하정은 순열속의 22.2 %가 평균적으로 외부로 유출 되는 것으로 평가되었으나, 냉수대 발생 유무에 따라 연도별로 해양 열 수송률이 순열속의 -174.5 %에서 132.5 %까지 큰 차이를 보였다.

우리나라 산불 발생에 관한 시계열적 특성은 다음과 같다. 1960년부터 2019년까지 연도별 산불 발생빈도는 약 16.6년을 주기를, 2003년부터 2019년까지 산불 발생빈도는 약 11.3개월의 주기를 갖는 것으로 확인되었고, 연도별, 월별 시계열은 안정된 경향을 보여 증가 혹은 감소하는 추세를 확인할 수는 없었다(P<0.05). 지역별 산불 발생 현황을 확인한 결과 경상북도에서 산불이 가장 많이 발생한 것으로 나타났고, 산불피해 면적은 강원도가 가장 넓은 특징을 보였다. 또한, 지역별 시계열적 주기성은 산불 발생빈도가 높은 순으로 FFT-Power가 높은 경향을 보였으나 공통적으로 약 11~12개월 사이의 주기를 갖는 것을 확인할 수 있었다. 또한, 요일별로 산불 발생빈도를 확인한 결과 요일별로 산불 발생빈도가 뚜렷하게 다르다는 결과를 얻을 수 있었다(P<0.001). 따라서 산불 발생빈도는 기상 현상 등 자연과학적인 요소와 함께 인문사회적인 요소 모두와 높은 관계에 있었다.

서리를 받은 ‘갑주백목’ 감의 피해 양상과 엽 피해율(0%, 11-30%, 31-60%, 61-90%, 91-100%)에 따른 과실의 피해 정도와 생리적 특성을 분석하였다. 서리를 받은 ‘갑주백목’ 감의 외관은 기부의 꽃받침 주위가 흑갈색으로 변색되는 증상을 보였다. 피해 증상은 과피보다 과육에서 더 잘 관찰되었는데 피해가 심한 과실은 과피에는 피해가 관찰되지 않는 적도부와 정부 가까이의 과육 조직에서도 갈변이 나타났다. 엽 피해율 30% 이하에서는 피해 과실이 관찰되지 않았으며, 엽 피해율 31-60%에서는 18.2%, 61-90%에서는 37.4%, 91-100%에서는 83.6%의 과실 피해가 발생되었다. 엽 피해가 심할수록 과실의 호흡속도는 증가하는 경향을 보였다. 호흡속도는 피해가 나타나지 않은 과실 보다는 피해가 나타난 과실에서 그리고 피해가 나타나지 않은 과육 조직 보다는 피해가 나타난 과육 조직에서 더 높았다. 이에 반해 전해질 용출율은 일관된 경향을 보이지 않았는데 이는 타닌이 전해질과 결합하거나 세포막의 투과성에 영향을 미친 특이한 결과로 생각된다. 경도와 Hunter L 값은 과실의 피해 정도가 심할수록 감소하는 경향을 보였다. 서리 받을 당시에는 피해가 나타나지 않았던 과실을 -1.3±0.5℃에서 110일간 저장했을 때 피해가 발생되었으며, 엽 피해가 심할수록 저장 중 피해과 발생도 높았다.

가막만 북서내만해역에서 매년 여름 발생하는 빈산소수괴는 해양환경에 악영향을 미쳐왔다. 따라서, 본 연구는 빈산소수괴 발 생시기의 집중적인 현장조사 결과를 바탕으로 다중회귀분석(MRA)을 이용하여 빈산소수괴의 종합적인 발생 메커니즘을 밝혀내고, 그 주 요인에 따른 빈산소수괴 관리방안의 방향성을 모색하였다. 그 결과, 2017년 첫 빈산소수괴는 6월 26일에 발생하였으며, 기상 조건에 의한 수온약층의 형성과 퇴적된 유기물의 영향으로 형성되었다. 이어 7월 12일에는 강우량의 증가에 의한 염분약층의 형성으로, 조사 시기 중 빈산소수괴가 수직 및 수평적으로 가장 크게 확장되었다. 그리고, 8월 8일에는 소량의 강우로 빈산소수괴가 크게 약화되었으며, 이때 주 요인은 Chlorophyll-a 농도 증가(식물플랑크톤 증식)과 퇴적된 유기물이었다. 그리고, 약 1주일 후인 8월 16일에는 많은 강우량에 기인한 매우 안정된 염분약층과 Chlorophyll-a 농도 증가(식물플랑크톤 증식)에 의해 크게 확장된 빈산소수괴가 재발생하였다. 이후 9월 13일의 빈산 소수괴 소멸시기에서는 빈산소수괴가 해저 면을 따라 얕게 확장되었으며, 퇴적된 유기물에 의해 주로 영향을 받은 것으로 나타났다. 이는 빈산소수괴 관리를 위해서는 퇴적된 유기물의 개선뿐만 아니라 성층의 완화 기술이 필요함을 암시하였다.

젠트리피케이션이란 용어가 처음 사용된 이후 도시지리 분야에서 지속적인 연구가 이어지고 있다. 그 과정에서 이 현상의 개념과 접근법 등이 변화하였으며, 최근 우리나라에서도 사회적·학문적으로 큰 주목을 받고 있다. 하지만, 젠트리피케이션 현상은 시간과 장소에 따라 다른 특징을 보인다. 해외의 젠트리피케이션 연구는 주로 Global North라 일컫는 선진국의 쇠퇴한 도시내부의 재생에 초점을 두었다. 즉, 해외 연구의 사례를 우리나라에 일방적으로 적용하기는 어렵다. 따라서, 이 연구의 목적은 서울시 젠트리피케이션의 발생 특징과 설명 요인을 계량적으로 도출하는데 있다. 이를 위해, 첫째, 젠트리피케이션의 개념 변화 과정과 선행연구를 이론적으로 고찰하였다. 둘째, 서울시 젠트리피케이션의 발생 특징을 공간분포 측면에서 고찰하였다. 셋째, 조작적으로 정의된 종속변수인 젠트리피케이션 지수에 대해 인구, 교통, 경제 측면의 독립변수를 다중회귀시켰다. 분석 결과, 서울시 젠트리피 케이션은 상업 젠트리피케이션의 맥락에서 주로 발생된다는 것을 규명하였다.

국내에서 재배하는 주요 핵과류(복숭아, 자두, 매실, 체리)에 발생하는 깍지벌레는 뽕나무깍지벌레(Pseudaulacaspis pentagona), 말채나무공깍지벌레(Lecanium corni), 무화과깍지벌레(Coccus hesperidum), 가루깍지벌레류(Pseudococcus sp.) 4종이 발견되었으나, 뽕나무깍지 벌레는 2017년에 총 113과원 중 103과원(발생과원율 91.2%), 2018년에는 77과원 중 64과원(발생과원율 83.1%) 모든 핵과류에서 가장 많이 발생하여 우점종으로 확인되었다. 2017년도에는 5월 상순부터 부화를 시작하여 암컷성충 1마리가 평균 75.5개(47∼159개)의 알을 낳으며 모든 알이 부화하는데 약 19일이 소요되었으며 5월 20일경에 월동성충의 모든 알이 부화하였다. 그러나, 2018년에는 4월 하순부터 부화를 시작하여 (부화율 72%) 부화유충(1령)으로 이동 후 5월 중순부터 고착유충(2~3령), 6월 중순부터 2세대 성충이 활동하기 시작하였다. 부화유충기(1령)에 약제 살포를 하면 살충율이 100.0%이었으나, 고착유충기(2~3령)에는 살충율은 2.7%에 불과하였다. 부화약충기를 제외한 모든 단계에서 몸체가 밀납깍지로 덮여 있어 약제를 살포하여도 직접 접촉되지 않아 치사율이 낮았다. 따라서 반드시 부화약충기에 약제를 살포하여야 방제효과를 높일 수 있다.

Forest insect pests monitoring provides essential information for forest management against their outbreaks. Long-term monitoring data for forest insect pests have been collected by National Institute of Forest Science at national level since 1968. Forest insect pests for long-term monitoring include pine needle gall midge, black pine bast scale, fall webworm, pine moth, spotted lanternfly, etc. The monitoring data were analyzed effect of meteorological factors on the outbreaks of sporadic forest insect pests. Our results showed that meteorological factors can influenced on outbreak of forest insects. The species including Lepidoptera has more occurred when fall and winter temperature were relatively high during the period, suggesting that their outbreaks depends on mortality rate during winter diapause. In Diptera, species abundance was positively related with amount of precipitation in spring but negatively related with summer temperature. The species belong to Hymenoptera was also more abundant when spring temperature was relatively warm. These results can provide useful information for predict potential forest insect pests from climate change.

This study was conducted to investigate the temperature and accumulated temperature of Lentinula edodes strains from primordial occurrence to fruit body maturity. The experimental strains were Sanjo 108 (high temperature type), Sanjo 302 (middle temperature type) and Sanjo 502 (low temperature type). When the Sanjo 108 and Sanjo 302 occurred, the daily mean temperature inside the L. edodes inoculated logs was 17.9 ~ 20.5 °C, which was lower than air temperature by 0.7 ~ 1.15 °C. When the Sanjo 502 occurred, the daily mean temperature inside the L. edodes inoculated logs was 3.6 ~ 16.6 °C, which was lower than air temperature by 0.1 ~ 0.7 °C. The difference between the maximum and the minimum temperature when the fruit body occurred was 4.4 °C inside the inoculated logs and 6.9 °C in the air temperature in Sanjo 108 and Sanjo 302, and in Sanjo 502 was 5.5 °C inside the inoculated logs and 9.1 °C in the air temperature. The number of days from primordial occurrence to fruit body maturity in Sanjo 108, Sanjo 302 and Sanjo 502 was 3.9 days, 5.1 days and 10.6 days, and accumulated temperatures of these strains were 104.9 °C, 129.2 °C and 141.4 °C, respectively. The number of days and accumulation temperatures were 518 days and 8,361 °C in Sanjo 108, 444 days and 6,475 °C in Sanjo 302, and 560 days 9,263 °C in Sanjo 502.

We analyzed the variation in occurrence time and intensity of attacks by the rice stem borer (Chilo suppressalis Walker) on several crops. We found similar occurrence patterns of C. suppressalis in different crops. Overwintering larvae showed no difference in pupal period and weight compared to the non-overwintering ones. However, the larval period was reduced to 19.1 days in Miscanthus field, in contrast to that in the paddy fields. Efficiency of the emergence trap was confirmed to be greater than that of the delta trap for capturing C. suppressalis adults. It is necessary to adjust the control period because of the advancement in occurring time of C. suppressalis in recent years. The larvae of C. suppressalis experience favorable environmental conditions for overwintering in Miscanthus fields. The results of this study provide important inputs for the development of environment-friendly control methods.

The occurrence pattern of lepidopteran adults in a paddy-upland rotation field and an organic upland field for 8 maize and 7 sorghum varieties was surveyed from May 8 to September 27, 2016. In addition, their damage ratio and the invasive pores by Ostrinia furnacalis larvae as well as harvest yields were monitored. The density of the lepidopteran adults in two fields showed similar pattern, although a little different pattern in Heliothis assulta. The damage ratio of maize and sorghum varieties by O. furnacalis at harvest periods was depended on both varieties and cultivated environments. A middle negative linear correlation was observed in damage ratios vs yields, the number of invasive pores vs yields, and the number of larvae in corn ears vs yields, but there was not a specific correlation between the damage ratio vs the number of invasive pores. These results may be useful for the establishment of a management strategy to control oriental corn borer in paddy-upland rotation or organic upland fields for maize and sorghum.