• The Korean Journal of Ecology
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• 제18권4호
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• pp.441-449
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• 1995

The abundance of coarse woody debris (CWD) has been hypothesized to increase niche for forest dwelling insectivores, concentration of nutrients, and the diversity of invertebrates. However, no abjective assessment based on replication in the field has yet been done. this study was carried out to test the relationships between invertebrate availability and the abundance of four insectivores (Sorex trowbridgii, S. vagrans, S. monticolus and Neurotrichus gibbsii) in western Washington, USA. Pitfall traps were used to determine abundance and diversity of invertebrates. Abundance of insectivores was not different between habitats except for S. vagrans which was more abundant in habitats with low amounts of CWD than in habitats with high amounts of CWD. Simpson’s diversity index computed for invertebrates did not differ between habitats. There were no significant relationships between the diversity indices of invertebrates and the abundance of shrews. Shrew abundance and the Coleoperan beetles also did not show any significant relationship. The results suggested insectivores might select a wide range of prey items in addition to surface-active invertebrates.

• Journal of Ecology and Environment
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• 제35권3호
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• pp.189-194
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• 2012

Coarse woody debris (CWD) is generally considered dead woody material in various stages of forest decomposition and has been hypothesized to be an important habitat feature for mammals in forests of the Pacific Northwest, USA. Sherman and pitfall trapping were conducted for 2 years on three paired sites with low and high amounts of CWD. Deer mice was the dominant species with a total capture of 605 (45.6%). Four species of insectivores were captured, including Sorex moncicolus, S. trowbridgii, S. vagrans, and Neurotrichus gibbsii. A Poisson regression model was used to test whether 11 CWD variables could predict insectivore captures. The volume of logs and mean decay were important variables for deer mice use of CWD. Mean distance from pieces of CWD to the capture point was significantly related to the total number of captures of trowbridge shrew (Sorex trowbridgii) and all insectivore species. Vagrant shrews (Sorex vagrans) were significantly associated with log volume. Retaining large size CWD should be part of a management plan for ground-dwelling insectivores in forests to secure their biodiversity.

• Parasites, Hosts and Diseases
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• 제53권6호
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• pp.737-743
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• 2015

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.

• Parasites, Hosts and Diseases
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• 제48권3호
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• pp.237-243
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• 2010

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. pal pale (15.7%), Neotrombicula tam/yai (14.3%), L. orientate (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticutum (0.8%), while the remaining 3 species, L subintennedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpate (21.4), were observed during the spring season.

• 환경생물
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• 제31권4호
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• pp.478-485
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• 2013

본 연구는 팔당호로 유입되는 경안천 하류구간에서 2010년에 집중강우 전(6월) 후(10월)로 구분하여 어류현장조사 및 생태특성을 분석하였다. 현장조사는 조사지점의 특성에 따라 일각망과 투망을 이용하였으며, 섭식특성은 종별 위내용물 분석을 통해 실시하였다. 현장조사결과, 총 5과 17종 970개체가 출현하였으며, 잉어과가 가장 많은 종(12종)이 출현하였고, 블루길(38%)과 피라미(24%)가 주요 우점종으로 나타났다. 외래도입어종은 3종 423개체로 44%의 높은 상대풍부도를 보이는 것으로 나타난 반면, 한국고유종은 4종 98개체로 10%의 상대풍부도를 보였다. 생태지표특성 중 내성도 분석에 따르면, 내성종의 상대풍부도가 97%로 단연 우세하게 나타났으며, 민감종은 1종이 출현하였다. 영양단계 분석에 따르면, 블루길의 우점현상에 의해 충식종의 상대풍부도가 44%로 가장 높게 나타났다. 주요종에 대한 섭식특성은, 우점종으로 나타난 블루길이 치어, 수서곤충, 저서성무척추동물, 동물플랑크톤, 깔따구류(유충), 수초 등을 다양하게 섭식하여, 육식/충식성으로 판단되었으며, 아우점종인 피라미는 지각류가 섭식량의 90% 초과하는 비율을 차지하고 있었다. 향후 본 연구에 안정동위원소 분석을 병행한다면 종별 먹이망 내 정확한 위치파악이 가능할 것으로 사료되었다.

• Parasites, Hosts and Diseases
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• 제45권2호
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• pp.157-161
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• 2007

A total of 1,496 rodents and insectivores were live-trapped at Yeoncheon-gun (n = 351), Paju-shi (804), and Pocheon-gun (343), Gyeonggi-do (Province), and examined for intestinal helminths, including Neodiplostomum seoulense, seasonally from December 2004 to September 2005. Six species of rodents, including Apodemus agrarius (1,366), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutus (6), and Cricetulus triton (3), and 1 species of insectivores Crocidura lasiura (54) were collected. A total of 321 adult N. seoulense were collected from 19 (1.4%) A. agrarius. The worm burden ranged from 1 to 101 per A. agrarius (mean; 16.9). No N. seoulense was observed in other rodent or insectivore species examined. The infection rate during autumn (4.5%) was higher than those during spring (0.8%), summer (0.8%), and winter (0.5%). The average number of N. seoulense in infected A. agrarius was the highest in spring (66.0 specimens), followed by autumn (15.2), winter (4.5), and summer (3.3). This study first confirms that A. agrarius is a natural definitive host for N. seoulense, and demonstrates that the infection rates and intensities vary seasonally and geographically.

• Journal of Ecology and Environment
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• 제41권3호
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• pp.54-65
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• 2017

Background: "Igune," a traditional agricultural landscape in the Tohoku region of Japan, is characterized by small-scale artificial woodlots surrounding a farmer's house that are interspersed with paddy fields. During the rapid economic growth of Japan over recent decades, some igune woodlots have been abandoned or logged. Biodiversity conservation is an important issue worldwide, and traditional agricultural landscapes are of particular interest. To elucidate the role of igune landscapes in conserving biodiversity, we examined the effects of environmental factors on avian communities. Results: The study was conducted in the suburban areas of Oshu and Hanamaki cities, Iwate Prefecture, Japan, at eight sites that varied in the density and area of igune woodlots within the landscape. Bird surveys were conducted from the middle to late breeding season, and several environmental factors of the igune landscape were also measured. The results of canonical correspondence analysis indicated that the characteristics of avian communities were mainly determined by the total forested area in the landscape. Increased total forested area and shrubs layer of igune woodlots did not cause a reduction in number of bird species of any habitat and foraging types, while increased both in species number and abundance of insectivores and forest species. The number of raptor species increased in igune sites without shrubs. Conclusions: Our results suggest that maintaining igune landscapes may enhance avian diversity within this landscape, although the effects of shrubs within igune varied; developed bush communities increased the evenness of the avian community, whereas some raptor species preferred an open forest understory.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.53-58
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• 2002

To better understand the reservoir host range and distribution of hantaviruses in small mammal populations in Korea, a serological survey was conducted on 1,375 wild rodents and 62 insectivores captured in seven provinces during the six-year period, 1995 to 2000. As determined by the indirect immunofluorescent antibody (IFA) test, 90 ($13.1\%$) of 685 Apodemus agrarius, 47 ($13.6\%$) of 345 Apodemus peninsulae, and 4 ($6.5\%$) of 62 Crocidura laciura were seropositive against the Hantaan virus, while 38 ($13.5\%$) of 282 Eothenomys regulus were seropositive against the Puumala virus. Serological evidence for hantavirus infection was not found in 50 Microtus fortis, six Micromys minutus, six Mus musculus, and one Cricetulus triton. Our serological data indicate that hemorrhagic fever with renal syndrome (HFRS)-related hantaviruses are widely distributed in indigenous rodents in Korea. Particularly noteworthy was the high seropositivity rates among Apodemus peninsulae and Eothenomys regulus captured in certain mountainous regions, suggesting that HFRS may be under-reported among nearby residents or among individuals who might visit such areas for recreational or occupational purposes.

• Journal of Ecology and Environment
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• 제40권2호
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• pp.107-119
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• 2016

Background: Previous studies on the biological integrity on habitat and landuse patterns demonstrated ecological stream health in the view of regional or macrohabitat scale, thus ignored the mesoscale habitat patterns of pool, riffle, and runs in the stream health analysis. The objective of this study was to analyze influences on the mesohabitat structures of pool, riffle, and run reaches on the fish guilds and biological integrity in Geum-River Watershed. Results: The mesohabitat structures of pool, riffle, and run reaches influenced the ecological stream health along with some close relations on the fish trophic and tolerance guilds. The mesoscale components altered chemical water quality such as nutrients (TN, TP) and BOD and these, then, determined the primary productions, based on the sestonic chlorophyll-a. The riffle-reach had good chemical conditions, but the pool-reach had nutrient enrichments. The riffle-reach had a predominance of insectivores, while the pool-reach has a predominance of omnivores. Also, the riffle-reach had high proportions of sensitive fish and insectivore fish, and the pool-reach had high proportions of tolerant species in the community composition. The intermediate fish species in tolerance and omnivorous fish species in the food linkage dominated the community in the watershed, and the sensitive and insectivorous fishes decreased rapidly with a degradation of the water quality. All the habitat patterns were largely determined by the land-use patterns in the watershed. Conclusions: Trophic guilds and tolerance guilds of fish were determined by land-use pattern and these determined the stream health, based on the Index of Biological Integrity. This study remarks the necessity to include additional variables to consider information provided by mesohabitats and land-use distributions within the selected stream stretch. Overall, our data suggest that land-use pattern and mesohabitat distribution are important factors to be considered for the trophic and tolerance fish compositions and chemical gradients as well as ecological stream health in the watershed.

• 생태와환경
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• 제43권4호
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• pp.503-512
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• 2010

This study was conducted to evaluate fish fauna, species composition, and various guilds against stream orders along with analysis of fish community structure and diversity in Geum River watershed from 2005 to 2007. The total number of fish collected was 4,216 representing 12 families with 56 species. Zacco platypus was the most abundant fish species with 26% in relative abundance (RA). Korean endemic species were 24 species including Zacco koreanus, Microphysogobio yaluensis, Gobiobotia nakdongensis, and Iksookimia koreensis, etc. We also collected endangered fish species such as G. nakdongensis, Liobagrus obesus, and Pseudopungtungia nigra, etc., and their new distribution sites were found in the survey, providing some sites of the fish conservation and protection. Fish tolerance and trophic guilds analysis showed that the proportion of sensitive species, intermediate species, and tolerant species were 33.4%, 29.3%, and 37.3%, respectively and omnivores and insectivores were 48.1 % and 38.4%, respectively. Analysis of site-base study indicated that tolerant species and omnivore species were high in some polluted tributary streams (i.e., Gap and Miho stream) and sensitive and insectivore species were low. In the functional relations, expressed as simple linear regression equations, of stream order on fish metric attributes, showed that the number of species and the number of individuals increased as the stream order increases. This phenomenon was explained by greater availability of stable water volume, rich food, and higher physical habitat capacity. Such guild compositions and stream order characteristics of the river influenced the community structures, based on species diversity, dominance and evenness index in the study. This study may be used as important data in the future for comparisons of fish fauna and compositions before and after two weir (dam) constructions in the middle of Geum River by the government.