• Title/Summary/Keyword: Simpson's Index

Search Result 64, Processing Time 0.018 seconds

The Study of Forest Vegetation in Cryptomeria japonica D. Don Plantations (삼나무 인공조림(人工造林) 임분(林分)의 식생(植生)에 관한 연구(研究))

  • Lee, Jyung Seok
    • Journal of Korean Society of Forest Science
    • /
    • v.69 no.1
    • /
    • pp.42-50
    • /
    • 1985
  • The vegetation of common Cryptomeria (Cryptomeria japonica D. Don) stands planted in Chonnam- province was investigated to obtain the fundamental informations for evaluation of suitable site and the improvement of managing method of the Cryptomeria stands in this region. The results investigated were summarized as follows; 1) The growth condition of common Cryptomeria planted 21-25-year-old stands was similar that of same species growing in Akidaken-district in Japan, while the growth condition of 51-58-year-old stands was not so good as that of Japanese. 2) Total number of plant species was 256. The number of floristic composition varied in the range of 42-99- species, which should be mere than those of Japanese. 3) The investigated sites were located in temperate southern part and in subtropic northern part of Korean peninsular. The types of understory vegetation were classified from I to IV class. 4) From the results of high max. possible diversity (H' max), and dominance (1-J') and from the low simple dominance (${\lambda}$) and evenness (J'), It could be concluded that vegetation was relatively in evenness. 5) From the low percent similarity, the specificity among the stands could be evaluated as considerable. 6) After the index of Morista, the 8th stand in Chang sung showed the generalized vegetation, while the 12th stand in Chang hung showed the specialized vegetation. 7) From the low values of Sneath-Sokal distance, the similarity among the stands investigated appeared very high.

  • PDF

Combinations of Paraquat and Oxyfluorfen for Control of Orchard Weeds (과수원(果樹園) 제초(除草)를 위한 Paraquat 와 Oxyfluorfen 조합처리(組合處理) 효과(效果)에 관한 연구(硏究))

  • Kwon, S.L.;Guh, J.O.;Cho, Y.W.
    • Korean Journal of Weed Science
    • /
    • v.3 no.2
    • /
    • pp.208-222
    • /
    • 1983
  • To control ideally the weeds in orchards and systematize the utility of herbicides, the mixing effect of oxyfluorfen and paraquat was evaluated. Combinations of oxyfluorfen with paraquat were increased the control efficacies at any treatment without giving damage to fruit trees and appeared a synergism. The control effects were reduced from 80-90% to 40-60% as the time advanced. However, the relative synergistic index was higher at 60 days after treatment in preemergence treatment and at 90 days after treatment in early and late postemergence treatment, respectively. Also the index was relatively higher at lower dosage of both herbicides.

  • PDF

Comparative Analysis of Gut Microbiota among Broiler Chickens, Pigs, and Cattle through Next-generation Sequencing (차세대염기서열 분석을 이용한 소, 돼지, 닭의 장내 미생물 군집 분석 및 비교)

  • Jeong, Ho Jin;Ha, Gwangsu;Shin, Su-Jin;Jeong, Su-Ji;Ryu, Myeong Seon;Yang, Hee-Jong;Jeong, Do-Youn
    • Journal of Life Science
    • /
    • v.31 no.12
    • /
    • pp.1079-1087
    • /
    • 2021
  • To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

Ecological Traits of Weed Flora with Different Soil Moisture in Remodeled Paddy Field of Nakdong River (낙동강 리모델링 농경지 수분함량별 잡초발생 특성 분석)

  • Hwang, Jae-Bok;Yun, Eul-Soo;Jung, Ki-Yeol;Park, Chang-Young;Choi, Young-Dae;Jeon, Seong-Ho;Oh, In-Seok
    • Weed & Turfgrass Science
    • /
    • v.2 no.1
    • /
    • pp.8-14
    • /
    • 2013
  • Collection of weeds were done in 3 remodeled paddy fields located in different districts with different soil moisture conditions such as Samolpo district (14.6%), Gimhae (9.8%) and Chilhyun (5.6%). Remodeled paddy fields composed of 62 plant species belonging to 23 families. Among 23 families, Compositae was the largest family with 11 species belonged to (17.7%) followed by Poaceae with 9 species (14.5%), Leguminosae with 8 species (12.9%), Cyperaceae with 7 species (11.3%), and Polygonaceae with 5 species (8.1%). Summed dominance ratio of each species based on number, coverage, frequency, and plant height in Samolpo district was Echinochloa oryzoides (100%) > Cyperus difformis (9.0%) > Bidens frondosa (5.3%) > Panicum dichotomiflorum (4.8%) > Eclipta prostrata (4.4%). In Gimhae; Digitaria ciliaris (100%) > Panicum dichotomiflorum (49.4%) > Echinochloa oryzoides (48.8%) > Persicaria hydropiper (27.1%) > Chenopodium ficifolium (10.2%), and in Chilhyun were Panicum dichotomiflorum (90.8%) > Digitaria ciliaris (66.7%) > Cyperus iria (8.6%) > Bidens frondosa (7.6%). Total dry weight of weeds recorded was 535.4 g $m^{-2}$, 316.1 g $m^{-2}$ and 346.2 g $m^{-2}$ in Samolpo, Gimhae and Chilhyun districts, respectively. Simpson's index was calculated to 0.09~0.28, which showed that weed occurrence in remodeled paddy fields with different soil moistures varied.