• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.117-129
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• 2010

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the physical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect and species compositions were selected for the study. Physical properties of soil i.e., soil colour, soil texture (per cent of sand, silt and clay), moisture content, water holding capacity, porosity, bulk density (gm/$cm^3$) and void ratio were analyzed for three different depths viz., (i) 'upper' (0-10 cm), (ii) 'middle' (11-30 cm) and (iii) 'lower' (31-60 cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover ($Gha^{-1}$), stem density ($Nha^{-1}$), tree species richness, Simpson concentration of dominance and Shannon-Wiener diversity index were also calculated for each forest type. This study also provides the comparisons between the results of physical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand.

• 한국잡초학회지
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• 제4권1호
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• pp.11-18
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• 1984

기계이앙답(機械移秧沓)과 손이앙답간(移秧沓間)의 잡초발생(雜草發生) 생태차이(生態差異)를 구명(究明)하여 효과적(效果的)인 방제체계(防除體系)를 확립(確立)하기 위(爲)하여 이앙답(移秧沓)에 많이 사용(史要)되고 있는 butachlor, thiobencarb, oxadiazon 등 11종(種)의 제초제(除草劑)를 공시(公試)하여 1983년(年) 영남작물(嶺南作物) 시험장(試驗場) 수도포장중(水稻圃場中)에서 1년생잡초(年生雜草)와 다년생(多年生) 잡초(雜草)가 우점된 포장(圃場)에서 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 이앙방법(移秧方法)(기계이앙(機械移秧), 손이앙(移秧))에 따른 잡초발생량(雜草發生量)은 벼를 재배(栽培)하지 않은 자연방임구(自然放任區)가 $m^2$당(當) 잡초수(雜草數)가 8326 본(本) 건물중(建物重)이, 1643g으로 가장 많았고 다음은 기계이앙구(機械移秧區), 손이앙구(移秧區) 순(順)이었으며 벼재배(栽培)에 의(依)한 잡초발생(雜草發生) 억제효과(抑制效果)는 기계이앙구(機械移秧區),가 50%, 손이앙구(移秧區)가 55%이었다. 2. Simpson지수(指數)와 군락우점도(群落優點度)(Community dominance)는 손이앙(移秧)을 함으로써 군락우점도(群落優點度)는 점차 특정(特定) 초종(草種) 즉 올챙고랭이 쪽으로 치우치는 경향이었다. 3. 잡초발생량(雜草發生量)과 벼수량(收量)과의 관계(關係)는 지수함수적인(指數函數的)인 관계(關係)를 보였으며, $m^2$당(當) 잡초건물량(雜草建物量)이 300g일 때 벼수량(數量) 감소(減少)정도는 손이앙구(移秧區)가 26%, 기계이앙구(機械移秧區)가 32%였으며, 잡초발생수(雜草發生數)에 따른 벼수량감소(數量減少)는 기게이앙구(機械移秧區)와 손이앙구간(移秧區間)에 별차이(差異)가 없었다. 4. 무제초(無除草) 방임구(放任區)에서 잡초발생(雜草發生)에 의(依)한 벼수량감소(收量減少)는 기계이앙답(機械移秧沓)이 41%, 손이앙답(移秧沓)이 33%로써 벼수량감소율(收量減少率)이 기계이앙답((機械移秧沓)에서 7% 더높았다. 5. 공시(供試)된 제초제중(除草劑中)에서 이앙방법간(移秧方法間) 잡초발생량차이(雜草發生量差異)가 가장 적었던 제초제(除草劑)는 butachlor(E.C)와 CG 113/oxadiazo이었고 이앙방법간(移秧方法間)에 잡초발생(雜草發生)에 의(依)한 감소율(減少率)은 제초제(除草劑) 종류(種類)에 따라 다소 차이(差異)는 있으나 뚜렷한 경향은 없었다.

• Journal of Microbiology
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• 제44권1호
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• pp.106-112
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• 2006

In this study, the genetic diversities of multi-resistant Salmonella typhimurium (ST) isolates were analyzed via the application of both pulsed field gel electrophoresis (PFGE) and Polymerase chain reaction (PCR) analysis methods, using 6 kinds of primers (REP, ERIC, SERE, BOX, P-1254 and OPB-17). And their discriminative abilities (DA) were also compared in order to determine the most effective and reliable analysis method. 118 S. typhimurium isolates, cultured from diverse animals and human patients in Korea beginning in 1993, were analyzed and subjected to a comparison of Simpson's index of diversity (SID), using both PFGE and PCR methods. PFGE by XbaI enzyme digestion allowed for discrimination into 9 pulsotypes, with high SID values (0.991) on the genomic DNA level. This shows that PFGE is a very discriminative genotypic tool, and also that multiple clones of S. typhimurium isolates had existed in domestic animals and humans in Korea since 1993. However, we could ultimately not to trace the definitive sources or animal reservoirs of specific S. typhimurium isolates examined in this study. Depending on the SID values, the combined method (7 kinds of method) was found to be the most discriminative method, followed by (in order) SERE-PCR, REP-PCR, ERIC-PCR, PFGE & OPB-17 (RAPD), P-1254 (RAPD), and BOX-PCR at the $80\%$ clone cut-off value. This finding suggests that the REP-PCR method (which utilizes 4 primer types) may be an alternative tool to PFGE for the genotyping of S. typhimurium isolates, with comparable cost, time, and labor requirement. The establishment of a highly reliable and discriminatory method for epidemiologic analysis is considered necessary in order for researchers to trace the sources of specific pathogens and, consequently, to control and prevent the spread of epidemic S. typhimurium isolates to humans.

• 한국잡초학회지
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• 제16권4호
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• pp.259-263
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• 1996

1. 충남지역 시설채소재배지에서 발생한 잡초는 약 30여종이었으며 구슬갓냉이, 둑새풀, 별꽃, 쇠비름, 바랭이, 명아주 등이 전반적으로 우점도가 높은 것으로 나타났다. 2. 충남지역의 서북부 해안지역에서는 별꽃, 쇠비름, 둑새풀, 서남부 해안지역에서는 구슬갓냉이, 바랭이, 별꽃, 내륙북부지역에서는 구슬갓냉이, 둑새풀. 바랭이, 내륙남부지역에서는 구슬갓냉이, 둑새풀, 쇠비름 순으로 높은 우점도를 나타냈다. 3. 충남지역의 배추포장에서는 별꽃, 구슬갓냉이, 쇠비름, 무포장에서는 구슬갓냉이, 털비름, 별꽃 등, 오이포장에서는 털비름, 별꽃, 바랭이 등, 파포장에서는 구슬갓냉이, 쇠비름 등이 높은 우점도를 나다냈다.

• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.67-73
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• 2007

The present study compared the microbial diversity and activity during the application of various bioremediation processes to crude oil-contaminated soil. Five different treatments, including natural attenuation (NA), biostimulation (BS), biosurfactant addition (BE), bioaugmentation (BA), and a combined treatment (CT) of biostimulation, biosurfactant addition, and bioaugmentation, were used to analyze the degradation rate and microbial communities. After 120 days, the level of remaining hydrocarbons after all the treatments was similar, however, the highest rate (k) of total petroleum hydrocarbon (TPH) degradation was observed with the CT treatment (P<0.05). The total bacterial counts increased during the first 2 weeks with all the treatments, and then remained stable. The bacterial communities and alkane monooxygenase gene fragment, alkB, were compared by denaturing gradient gel electrophoresis (DGGE). The DGGE analyses of the BA and CT treatments, which included Nocardia sp. H17-1, revealed a simple dominant population structure, compared with the other treatments. The Shannon-Weaver diversity index (H') and Simpson dominance index (D), calculated from the DGGE profiles using 16S rDNA, showed considerable qualitative differences in the community structure before and after the bioremediation treatment as well as between treatment conditions.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.309-316
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• 2008

To develop a monitoring method for soil microbial communities in rice paddy fields, we used terminal restriction fragment length polymorphism (T-RFLP) to compare soil bacterial community structure in rice paddy fields experiencing different management practices: organic practices, conventional practices without a winter barley rotation, and conventional practices with a winter barley rotation. Restriction fragment length profiles from soils farmed using organic practices showed very different patterns from those from conventional practices with and without barley rotation. In principal component analyses, restriction fragment profiles in organic practice samples were clearly separated from those in conventional practice samples, while principal component analysis did not show a clear separation for soils farmed using conventional practices with and without barley rotation. The cluster analysis showed that the bacterial species compositions of soils under organic practices were significantly different from those under conventional practices at the 95% level, but soils under conventional practice with and without barley rotation did not significantly differ. Although the loadings from principal component analyses and the Ribosomal DNA Project II databases suggested candidate species important for soils under organic farming practices, it was very difficult to get detailed bacterial species information from terminal restriction fragment length polymorphism. Rank-abundance diagrams and diversity indices showed that restriction fragment peaks under organic farming showed high Pielou's Evenness Index and the reciprocal of Simpson Index suggesting high bacterial diversity in organically farmed soils.

• Mycobiology
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• 제45권3호
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• pp.160-171
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• 2017

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.

• 생명과학회지
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• 제26권12호
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• pp.1446-1457
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• 2016

이 논문은 무제치늪에서 채집한 기장대풀(Isachne globosa Kuntze), 솔방울고랭이(Scirpus karuisawensis Makino), 이삭귀개(Utricularia racemosa Wall.), 좀개수염(Eriocaulon decemflorum Maxim.)등 4종의 식물 뿌리에서 서식하는 내생곰팡이의 분포 및 다양성을 확인하기 위해 조사하였다. 총 226 균주가 분리되었고, 3문(Phyla), 7강(Class), 10목(Order), 22과(Family), 31(genera)속으로 분리되었다. 내생진균에서 가장 많이 분리된 속은 Acephala (19.9%), Tolypocladium (16.3%), Neopestalotiopsis (11.5%), Perenniporia (7.1%) 순으로 확인하였다. 다양성지수 분석에 있어서, 이삭귀개(Ur)가 다른 식물 종에 비해 종 풍부도 (Menhinick's index = 2.37), (Margalef's index = 4.46)와, 종 균등도 (Simpson's index diversity = 0.91), 그리고 종 다양성(Shannon's indx = 2.57)로 높게 나왔다. 이러한 분석 결과를 봤을 때, 이삭귀개(Ur)에서 내생진균이 가장 다양하게 서식할 수 있는 것으로 보여진다.

• Journal of Forest and Environmental Science
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• 제35권3호
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• pp.159-172
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• 2019

Madhupur National Park (MNP) is one of the last remaining patches of old-growth natural Sal forest left in Bangladesh where the forest is tropical moist deciduous type. A study was revealed to assess the tree species diversity and composition in this area. For determining tree species the study was conducted through extensive random quadrat survey methods with $20m{\times}20m$ sized plots. Results of the study indicated that there were 139 tree species belonging to 100 genera and 40 families. The quadrat survey assessed the basal area, stem density, diversity indices and importance value index of the tree species having ${\geq}5cm$ D.B.H (Diameter at Brest Height). The basal area and stem density of the tree species were $20.689{\pm}1.08m^2/ha$ and $1412.93{\pm}64.27stem\;ha^{-1}$ while, diversity indices, i.e. Shannon-Wiener's diversity, Simpson's evenness, Margalef's species richness and Pielou's dominance indices indicated poor diversity in comparison to that of other PAs (Protected Areas) in South-Eastern region of Bangladesh. The structural composition based on height and D.B.H through reverse-J shaped curve indicated higher regeneration and recruitment but removal of trees of large growth classes. Sal (Shorea robusta) was the most dominant tree species that accounts 75% of the total tree individuals in the natural forest patches. However, some associates of Sal, i.e. Bhutum (Hymenodictyon orixensis), Gadila (Careya arborea), and Kusum (Schleichera oleosa) etc. were seemed to be rare in MNP.

• Mycobiology
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• 제46권2호
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• pp.85-91
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• 2018

Endophytic fungi strains (n = 81) were isolated from the leaves, barks, and fruits of Camellia oleifera from Hunan province (China) to delineate their species composition and potential as biological control agents of C. oleifera anthracnose. The fungi were identified by morphological and phylogenetic analyses. Fungal colonization rates of the leaves, barks, and fruits were 58.02, 27.16, and 14.81%, respectively. The isolates were identified as 14 genera, belonging to two subdivisions, Deuteromycotina and Ascomycotina; 87.65% of all isolates belonged to Deuteromycotina. The dominant species, occurring with a high relative frequency, were Pestalotiopsis sp. (14.81%), Penicillium sp. (14.81%), and Fusarium sp. (12.35%). The Simpson's and Shannon's diversity indices revealed the highest species diversity in the leaves, followed by the barks and fruits. The similarity index for the leaves versus barks comparison was the highest, indicating that the number of endophytic fungal species shared by the leaves and barks was higher than barks and fruits or leaves and fruits. Based on the results of dual culture experiments, only five strains exhibited antifungal activity against C. oleifera anthracnose pathogen, with isolate ty-64 (Oidium sp.) generating the broadest inhibition zones. Our results indicate that the endophytes associated with C. oleifera could be employed as natural agents controlling C. oleifera anthracnose.