• 한국조류학회지
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• 제25권2호
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• pp.87-93
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• 2018

시화호 환경변화에 따른 흰뺨검둥오리의 개체수 변화를 확인하기 위해 2008년 1월부터 2014년 12월까지 매월 1회씩 조사하였다. 흰뺨검둥오리의 평균 개체수는 12,204개체이었고 점차적으로 감소하는 경향을 보였다. 변동지수(Fi)는 2010년에 2.16로 가장 높았다. 개체군 변화경향은 겨울철은 급격한 감소, 가을철과 봄철에는 보통감소, 여름철은 보통 증가경향을 보였다. 주요 서식지로는 북측간척지, 방수제, 탄도수로, 인공습지 이었다. 기온과의 상관관계는 봄, 여름, 가을은 음의 상관관계를 보였고, 겨울은 양의 상관관계를 보였다. 간척지 환경변화에 따라 흰뺨검둥오리의 군집에 영향을 미치고 있어 본 연구와 같은 자료를 토대로 효과적인 관리방안이 필요하다.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.104-116
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• 2019

Background: The composition of wild bird populations in temperate zones greatly varies depending on phenological changes rather than other environmental factors. Particularly, wild birds appearing in wetlands fluctuate greatly due to the crossover of species arriving for breeding during the summer and for wintering. Therefore, to understand the changes to species composition related to phenology, we conducted this basic analysis of populations to further the cause of the protection of wetland-dependent wild birds. Methods: It is wrong to simply divide a wild bird population investigation into seasons. This study identifies species composition and indicator species that change along with seasons. Wetlands to be surveyed are protected by natural monuments and wetland inventory and are in a state close to nature. In order to identify as many species as possible in wetlands, a survey was conducted in both shallow and deep wetlands. The water depth varied in these areas, ranging from 0.2 to 2.0 m, allowing for both dabbling and diving ducks to inhabit the area. Surveys were conducted using line-transect and distance sampling methods and were conducted at intervals of 2 weeks. The survey was conducted under the following three categories: the eco-tone and emergent zone, the submergent zone, and the water surface. The survey was conducted along a wetland boundary by observing wild birds. A PC-ord program was used for clustering, and the SAS program was used to analyze the changes in species composition. The data strongly indicates that day length is the main factor for seasonal migration periods, despite the fact that climate change and increasing temperatures are often discussed. Results and conclusions: The indicator species for determining seasons include migrant birds such as Ardea cinerea, Alcedo atthis, Anas penelope, and Poiceps ruficollis, as well as resident birds such as Streptopelia orientalis and Emberiza elegans. Importantly, increases in local individual counts of these species may also serve as indicators. The survey results of seasonal fluctuations in temperate zones shows that spring (April to June), summer (July to September), autumn (October), and winter (November to March) are clearly distinguishable, even though spring and summer seasons tend to overlap, leading to the conclusion that additional research could more clearly identify fluctuation patterns in species composition and abundance in the study area.

• 환경생물
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• 제24권2호
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• pp.201-211
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• 2006

울돌목 수로에서 요각류 35개 분류군을 포함하여 총 55개 동물플랑크톤이 출현하였다. 연안종은 계절적인 종천이를 보였으며, 난류 외양성 종은 전 조사 시기에서 출현하였다. 분류군 수는 창조 시 저조에서 고조로 갈수록 증가하며 낙조 시 고조에서 저조로 갈수록 감소하였다. 따라서 울돌목 해역은 연중 외해수 영향에 따른 외양종의 유입으로 동물플랑크톤 종조성에 영향을 받는다. 전체 동물플랑크톤 현존량은 $104\sim2,717indiv.m^{-3}$의 범위를 나타내며 2003년 8월에 가장 높고 2004년 2월에 가장 낮았다. 조석주기에 따른 현존량 변화에서 11월과 2월에 시간적 변이성이 크고 불규칙적인데 반해 8월과 4월에는 비교적 규칙적인 변화 추세를 나타냈다. 8월과 4월에는 창조 및 낙조에서 조류가 가장 강한 시간에는 낮은 출현 개체수가 나타났으며, 조류가 약해질수록 개체수가 증가하여 고조 및 저조에서 개체수가 높은 특징을 보였다. Paracalanus indicus, Cirripedia nauplii, Acartia hongi등을 포함한 대부분의 우점종은 창조보다 낙조에서 평균 개체수가 대략 2배 정도 높았다. 그러나 창조 및 낙조 내에서도 개체수의 변이가 크게 나타났으며 조석주기에 따른 수온, 염분, 그리고 엽록소 a등 환경변화가 작았다. 따라서 울돌목 해역에서는 강한 조류와 지형적인 조류 속도 차에 의해 형성된 와류 등이 개체군 확산, 이동 그리고 손실에 영향을 미쳐 시간적으로 복잡하고 불규칙한 동물플랑크톤 군집을 보인다.

• 환경생물
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• 제24권4호
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• pp.372-379
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• 2006

Noctiluca scintillans의 시간적 변동과 생태학적 특성을 파악하기 위해 N. scintillans의 현존량과 수리-생물학적 요인에 대한 조사가 1999년 1월부터 2000년 12월까지 인천 연안에서 수행되었다. N. scintillans는 수온 $10.3{\sim}21.5^{\circ}C$ 범위를 보인 춘계 및 추계에 출현 개체수가 높았으며 동계 및 하계에 낮았다. 동계에는 $4.5^{\circ}C$이하 수온에서 출현이 제한되는 것으로 보이며 하계에는 고온과 높은 강우량에 따른 급격한 염분 감소가 제한요인으로 판단된다. 교차 상관분석에서 엽록소 a 농도는 N. scintillans 개체수와 10일 시간 지연에서 유의한 상관관계를 나타냈다. 이는 식물플랑크톤이 N. scintillans 개체군 증가에 중요한 요인이 될 수 있음을 암시한다. 춘계에 전체 개체수의 $2.9{\sim}21.1%$의 N. scintillans에서 요각류 특히 Acartia hongi 알이 관찰되었다. 이는 동일 시기에 A. hongi가 생산해낸 알의 $1.2\sim49.5%$에 해당하는 것이다. 따라서 N. scintillans는 인천 연안에서 A. hongi의 초기 성장 단계의 개체군 크기에 영향을 미칠 것으로 추측된다.

• 생태와환경
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• 제50권3호
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• pp.337-354
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• 2017

남조류 Aphanizomenon속 개체군은 국내외에 널리 분포하고, 독소와 이취물질을 생산함으로써 유해조류로 잘 알려져 있어 육수생태학 분야에서 많은 관심을 갖게 된 분류군 중 하나에 속한다. 본 연구는 보령호에서 동계에 수위가 급격히 강하되면서 Aphanizomenon의 출현빈도, 강도 및 기간이 커지게 되어 이에 대한 시공간적 특성을 수문기상(1998년~2017년) 육수 (2010년~2017년)학의 관점으로 상호 비교하였다. 국내에서 Aphanizomenon은 고온기에 주로 번성하였으며, 저온기에 출현은 총 5회로서 드물었다. 보령호에서 저온기(12월~2월)에 유해조류 Aphanizomenon이 관찰된 것은 2014년부터이었고, 그 후 2017년에 최대값 $2,160cells\;mL^{-1}$를 기록하였다. 그리고 $>1,000cells\;mL^{-1}$를 초과하는 기간은 약 3개월을 넘기기도 하였다. 이것은 다름 아닌 저수온기 ($<10^{\circ}C$)에 비정상적인 수위 강하와 관련성이 컸다. 동계에 수위 강하는 유해조류의 발아 및 발생을 촉진 또는 증폭시킬 수 있는 잠재적 특성을 가지고 있었다. 따라서 후속 수질 생태학적 영향(예, 조류독소 및 이취물질)도 면밀하게 고려되어야 할 필요성이 있었다.

• Journal of Microbiology
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• 제42권4호
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• pp.278-284
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• 2004

Changes in the soil bacterial community of a coniferous forest were analyzed to assess microbial responses to wildfire. Soil samples were collected from three different depths in lightly and severely burned areas, as well as a nearby unburned control area. Direct bacterial counts ranged from $3.3­22.6\times10^8\;cells/(g{\cdot}soil).$ In surface soil, direct bacterial counts of unburned soil exhibited a great degree of fluctuation. Those in lightly burned soil changed less, but no significant variation was observed in the severely burned soil. The fluctuations of direct bacterial count were less in the middle and deep soil lay­ers. The structure of the bacterial community was analyzed via the fluorescent in situ hybridization method. The number of bacteria detected with the eubacteria-targeted probe out of the direct bacterial count varied from $30.3\;to\;84.7\%,$ and these ratios were generally higher in the burned soils than in the unburned control soils. In the surface unburned soil, the ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ Cytoph­aga-Flavobacterium group, and other eubacteria groups to total eubacteria were 9.9, 10.6, 15.5, 9.0, and $55.0\%,$ respectively, and these ratios were relatively stable. The ratios of $\alpha,\;\beta\;and\;gamma-proteobacteria,$ and Cytophaga-Flavobacterium group to total eubacteria increased immediately after the wildfire, and the other eubacterial proportions decreased in the surface and middle layer soils. By way of contrast, the composition of the 5 groups of eubacteria in the subsurface soil exhibited no significant fluctuations dur­ing the entire period. The total bacterial population and bacterial community structure disturbed by wildfire soon began to recover, and original levels seemed to be restored 3 months after the wildfire.

• 한국어류학회지
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• 제17권4호
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• pp.264-270
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• 2005

2004년 4월부터 10월까지 충주호 내의 3개 지점에서 어류상을 조사하였다. 채집된 어류는 모두 12과 32종이었고, 우점종은 H. labeo로 전체 개체수 비는 23.2%였으며 아우점종은 E. erythropterus (12.1%), 다음으로는 S. scherzeri (9.2%), P. esocinus (8.6%) 순으로 우세하였다. 한반도 고유종은 A. yamatsutae 등 6과 9종이었고 전체 종 수에 대한 구성비는 28.1%였다. 단양수역은 10과 28종이 출현하였고, 제천수역은 6과 17종이었으며 두 지역의 우점종은 H. labeo이었다. 충주수역은 6과 15종이 출현하였으며 우점종은 E. erythropterus이었다. 우점도는 충주수역이 0.670으로 가장 높았고, 종 다양도는 단양수역이 2.442로 가장 높았다. 생체량은 5월에 가장 많았고, 단양수역이 다른 수역에 비해 월등히 많았다. H. labeo를 비롯한 생체량이 많은 종들의 개체군 변동을 주시할 필요가 있다.

• The Korean Journal of Ecology
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• 제20권5호
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• pp.347-354
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• 1997

Seasonal fluctuations in density of soil-inhabiting Pseudoscorpions at the Piagol, Mt. Chiri were assessed on the basis of 4,984 individuals collected from March 1993 to February 1995. They encompassed 2 families, 6 genera and 11 species. Species composition and abundance were as follows: Allochthonius buanensis 47.0%, Microcreagris sp. 2. 20.7%, Microcreagris pygmaea 12.9%, Microcreagris japonica 9.8%, Pararoncus japonicus 3.7%, Mundochthonius minusculus 3.2%, Parobisium longipalpus 1.2%, Microbisium pygmaeum 1.0%, Allochthonius coreanus 0.2%, Microcreagris sp. 1 0.2%, and Parobisium robustiella 0.1%. Diversity index (H') decreased and dominance index (C) increased at the height of 1,200 m. The heights of 500 m. The heights of 500 m and 600 m were dominated heavily by A. buanensis and abundance of M. japonical and Microcreagris sp. 2 was also comparatively high and H' was high in March and April, low in August and September. in case of May, Jun., Jul., Oct., Nov., Dec., Jan. 1993, and Feb. 1994, H' stayed at a relatively constant level. A total of 4,984 individuals including 1,170 protonymphs (23.5%), 1,251 deutonymphs (25.1%), 533 tritonymphs (10.7%), and 2,030 adults (40.7%) was collected from the study sites. Sex ratio of the Pseudoscorpions was approximately 1 female : 1.1 male.

• Ocean and Polar Research
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• 제23권4호
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• pp.425-431
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• 2001

From an ecological point of view, the western part of the Atlantic sector is one of the most productive areas in the Southern Ocean. Antarctic krill (Euphausia superba) and krill-dependent predators such as fish, seals, and birds are abundant there, and most krill fisheries have operated in this area since 1970s. The hottest issues for the proper management of krill resources nowadays are to determine total biomass in this area, and to identify environmental forces controlling stock fluctuation. This paper reviews and collates information on ongoing oceanographic activities in the Antarctic Peninsula region concerning these issues. To delineate the status and function of Antarctic krill population in Antarctic marine ecosystems, multinational researches along the Antarctic Peninsula area have been developing recently. Four member states of CCAMLR (Japan, Russia, UK, and USA) had conducted acoustic surveys in January-February 2000 (socalled CCAMLR-2000 survey), and krill standing stock at 120 kHz was estimated to be 44.29 million metric tonnes in the western Atlantic sector of the Southern Ocean. On the other hand, the Southern Ocean GLOBEC (SO-GLOBEC) Programme has prepared a serial winter survey to examine the factors that govern krill survivorship and distribution in relation to shelf circulation processes. Ship-based surveys using ice-breakers are being conducted by three nations (Germany, UK, and USA) around the Marguerite Bay during the austral fall and winter 2001 and 2002. In addition to these two large-scale surveys, some CCAMLR members have carried out joint oceanographic surveys near the South Shetland Islands to detect ecosystem changes since 1994. Especially from December 1999 to February 2000, in conjunction with CCAMLR-2000 survey, four nations (Japan, Korea, Peru, and USA) conducted acoustic surveys to produce time-series information on krill distribution and biomass near the South Shetland areas. Though the aims of each program and the approach to solve the scientific questions were different each other, the results from each program fill the gaps between programs. Further cooperation and exchange in these activities could be beneficial to each program.

• 산업경영시스템학회지
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• 제40권1호
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• pp.65-78
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• 2017

Even though cars have a good effect on modern society, traffic accidents do not. There are traffic laws that define the regulations and aim to reduce accidents from happening; nevertheless, it is hard to determine all accident causes such as road and traffic conditions, and human related factors. If a traffic accident occurs, the traffic law classifies it as 'Negligence of Safe Driving' for cases that are not defined by specific regulations. Meanwhile, as Korea is already growing rapidly elderly population with more than 65 years, so are the number of traffic accidents caused by this group. Therefore, we studied predictive and comparative analysis of the number of traffic accidents caused by 'Negligence of Safe Driving' by dividing it into two groups : All-ages and Elderly. In this paper, we used empirical monthly data from 2007 to 2015 collected by TAAS (Traffic Accident Analysis System), identified the most suitable ARIMA forecasting model by using the four steps of the Box-Jenkins method : Identification, Estimation, Diagnostics, Forecasting. The results of this study indicate that ARIMA $(1, 1, 0)(0, 1, 1)_{12}$ is the most suitable forecasting model in the group of All-ages; and ARIMA $(0, 1, 1)(0, 1, 1)_{12}$ is the most suitable in the group of Elderly. Then, with this fitted model, we forecasted the number of traffic accidents for 2 years of both groups. There is no large fluctuation in the group of All-ages, but the group of Elderly shows a gradual increase trend. Finally, we compared two groups in terms of the forecast, suggested a countermeasure plan to reduce traffic accidents for both groups.