Improvement of association-analysis classification by Braun-Blanquet technique

Bothalia ◽  
1974 ◽  
Vol 11 (3) ◽  
pp. 365-367 ◽  
Author(s):  
B. J. Coetzee
Keyword(s):  
Association Analysis ◽  
Plant Communities ◽  
Nature Reserve ◽  
Inverse Association ◽  
Nodal Analysis ◽  
Association Analyses ◽  
Table Method ◽  
Group Relationships

Normal association-analysis was carried out on data collected in the Jack Scott Nature Reserve in the Central Bankenveld of the Transvaal. As the method was found inadequate for obtaining optimal definition and arrangement of plant communities, it was supplemented by the Braun-Blanquet Table Method, which served as a substitute for inverse and nodal analyses. This led to a better understanding of the vegetation of the Reserve. Because association-analysis is strictly hierarchical, presentation of inter-group relationships and interpretation of vegetation-habitat relationships are limited. It is argued that the monothetic character of normal and inverse association-analyses is a further limitation and although this is com­pensated for by nodal-analysis, valuable information is discarded as peripheral in the latter process.

scholarly journals The application of association analysis for phytosociological interpretation of plant communities in Las Piwnicki Nature Reserve near Toruń

2015 ◽  
Vol 44 (2) ◽  
pp. 155-164
Author(s):  
A. Nienartowicz
Keyword(s):  
Statistical Methods ◽  
Association Analysis ◽  
Plant Communities ◽  
Nature Reserve ◽  
Herb Layer ◽  
Numerical Classification ◽  
Habitat Conditions ◽  
Classification Technique

The paper contains the results of analysis of the herb layer carried out under different habitat conditions of two forest associations. Camparative studies of the floristic content and an analysis of the homogeneity of the herb layer were conducted with the use of objective statistical methods and a numerical classification technique.

Classification of woody-shrub vegetation of the forest-steppe complex of Privolzhskaya Upland

2009 ◽  
pp. 27-53
Author(s):  
A. Yu. Kudryavtsev
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Dominant Species ◽  
Large Scale ◽  
Nature Reserve ◽  
Vegetation Mapping ◽  
Vegetation Classification ◽  
Forest Steppe ◽  
Mapping Data

Diversity of plant communities in the nature reserve “Privolzhskaya Forest-Steppe”, Ostrovtsovsky area, is analyzed on the basis of the large-scale vegetation mapping data from 2000. The plant community classi­fication based on the Russian ecologic-phytocoenotic approach is carried out. 12 plant formations and 21 associations are distinguished according to dominant species and a combination of ecologic-phytocoenotic groups of species. A list of vegetation classification units as well as the characteristics of theshrub and woody communities are given in this paper.

Hierarchical mixed-model expedites genome-wide longitudinal association analysis

2021 ◽  
Author(s):  
Ying Zhang ◽  
Yuxin Song ◽  
Jin Gao ◽  
Hengyu Zhang ◽  
Ning Yang ◽  
...  
Keyword(s):  
Association Analysis ◽  
Mixed Model ◽  
Repeated Measurements ◽  
Random Regression ◽  
Association Analyses ◽  
Genome Wide ◽  
Random Regression Model ◽  
A Genome ◽  
Longitudinal Association ◽  
Poultry Data

AbstractA hierarchical random regression model (Hi-RRM) was extended into a genome-wide association analysis for longitudinal data, which significantly reduced the dimensionality of repeated measurements. The Hi-RRM first modeled the phenotypic trajectory of each individual using a RRM and then associated phenotypic regressions with genetic markers using a multivariate mixed model (mvLMM). By spectral decomposition of genomic relationship and regression covariance matrices, the mvLMM was transformed into a multiple linear regression, which improved computing efficiency while implementing mvLMM associations in efficient mixed-model association expedited (EMMAX). Compared with the existing RRM-based association analyses, the statistical utility of Hi-RRM was demonstrated by simulation experiments. The method proposed here was also applied to find the quantitative trait nucleotides controlling the growth pattern of egg weights in poultry data.

scholarly journals Vegetation of the Witbank Nature Reserve and its importance for conservation of threatened Rocky Highveld Grassland

Koedoe ◽  
1997 ◽  
Vol 40 (2) ◽  
Author(s):  
C.M. Smit ◽  
G.J. Bredenkamp ◽  
N. Van Rooyen ◽  
A.E. Van Wyk ◽  
J.M. Combrinck
Keyword(s):  
Soil Moisture ◽  
Plant Communities ◽  
Nature Reserve ◽  
Soil Depth ◽  
Floristic Composition ◽  
Diversity Indices ◽  
Moisture Gradient ◽  
Negative Effects ◽  
Soil Moisture Gradient ◽  
Great Escarpment

A vegetation survey of the Witbank Nature Reserve, comprising 847 hectares, was conducted. Phytosociological data were used to identify plant communities, as well as to determine alpha and beta diversities. Eleven plant communities were recognised, two of these are subdivided into sub- communities, resulting in 14 vegetation units. These communities represent four main vegetation types, namely grassland, woodland, wetland and disturbed vegetation. Grassland communities have the highest plant diversity and wetland vegetation the lowest. Floristic composition indicates that the vegetation of the Rocky Highveld Grassland has affinities to the grassland and savanna biomes and also to the Afromontane vegetation of the Great Escarpment. An ordination scatter diagram shows the distribution of the 14 plant communities or sub-communities along a soil moisture gradient, as well as along a soil depth/surface rock gradient. The sequence of communities along the soil moisture gradient is used for calculating beta-diversity indices. It is concluded that the relatively small size of the Witbank Nature Reserve is unlikely to have significant negative effects on the phytodiversity of the various plant communities. This nature reserve is therefore of considerable importance in conserving a representative sample of the Rocky Highveld Grassland.

scholarly journals The vegetation of the southern Langeberg, Cape Province. 2. The plant communities of the Marloth Nature Reserve

Bothalia ◽  
1993 ◽  
Vol 23 (1) ◽  
pp. 153-174 ◽  
Author(s):  
D. J. Mcdonald
Keyword(s):  
South Africa ◽  
Plant Communities ◽  
Nature Reserve ◽  
Hierarchical Classification ◽  
Forest Patches ◽  
Afromontane Forest ◽  
Lower South ◽  
Mature Stands

The Marloth Nature Reserve, encompassing the mountain catchments of the southern Langeberg immediately above Swellendam, Cape Province. South Africa, is described. The vegetation of the reserve was sampled along a transect representing the variation in plant communities over the range from the lower south to the lower north slopes. Eighty-three sample sites were subjectively located in mature stands of fynbos vegetation (10 years old). The relev£ data were initially classified using TWINSPAN and then refined by Braun-Blanquet (BB) phytosociological procedures. The Afromontane Forest patches which occur mainly on the lower south slopes were not sampled but are briefly discussed. The fynbos plant communities are described, based on tables, and a hierarchical classification is proposed.

A synecological account of the Suikerbosrand Nature Reserve. II. The phytosociology of the Ventersdorp Geological System

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 199-216 ◽  
Author(s):  
G. J. Bredenkamp ◽  
G. K. Theron
Keyword(s):  
Plant Communities ◽  
Soil Texture ◽  
Nature Reserve ◽  
Surface Soil ◽  
Soil Depth ◽  
Soil Surface ◽  
Habitat Features ◽  
Species Groups

The vegetation of the Ventersdorp Geological System of the Suikerbosrand Nature Reserve is analysed and classified according to the Braun-Blanquet method. Descriptions of the plant communities include description of habitat features, the identification of differentiating species groups as well as the listing of prominent and less conspicuous species for the tree, shrub and herbaceous layers. The habitat features that are associated with differences in vegetation include altitude, aspect, slope, rockiness of soil surface, soil depth and soil texture.

Polymorphism detection of porcine PSMC3, PSMC6 and PSMD3 genes and their association with partial growth, carcass traits, meat quality and immune traits

2005 ◽  
Vol 85 (4) ◽  
pp. 475-480 ◽  
Author(s):  
Y. F. Wang ◽  
J. Yang ◽  
M. Yu ◽  
B. Liu ◽  
B. Fan ◽  
...  
Keyword(s):  
Association Analysis ◽  
Antigen Processing ◽  
Polymorphic Site ◽  
Single Nucleotide ◽  
Atpase Subunit ◽  
Association Analyses ◽  
Pcr Rflp ◽  
Immune Traits ◽  
Antigen Processing And Presentation ◽  
Proteasome 26S

PSMC3, PSMC6 and PSMD3 genes encode the proteasome 26S ATPase subunit 3, subunit 6 and the non-ATPase subunit 3, respectively, and exert the function in antigen processing and presentation. So these three genes were considered as the candidate genes that have the effect on porcine production and immune traits in this study. Genetic variations of these three genes were investigated and the single nucleotide polymorphism-based (SNPs-based) association analyses were studied initially. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) revealed that there is a MvaI polymorphic site in intron3 of PSMC3 gene and a MboI polymorphic site within intron 5 of PSMC6 gene, as well as a RsaI polymorphic site within exon 10 of the PSMD3 gene. χ2 analysis presented that allele frequencies differed among four breeds (Meishan, Erhualian, Qingping pig and Duroc) at PSMC3 and PSMD3 loci (P < 0.01). Association analysis showed that the PSMC3 gene has an effect on average backfat thickness (P < 0.01), total erythrocytes (P < 0.01) and hematocrit (P < 0.01), and there is a significant association between the PSMD3 genotypes and the mean corpuscular volume. PSMC6 has no effect on the production and immune traits we studied. Key words: Porcine, PSMC3, PSMC6, PSMD3, polymorphism, association analysis

scholarly journals Copy Number Variation of the PIGY Gene in Sheep and Its Association Analysis with Growth Traits

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 688 ◽  
Author(s):  
Ziting Feng ◽  
Xinyu Li ◽  
Jie Cheng ◽  
Rui Jiang ◽  
Ruolan Huang ◽  
...  
Keyword(s):  
Copy Number Variation ◽  
Association Analysis ◽  
Copy Number ◽  
Growth Traits ◽  
Gansu Province ◽  
Genomic Variation ◽  
Association Analyses ◽  
Qinghai Province ◽  
Real Time Quantitative Pcr ◽  
Number Variation

Copy number variation (CNV) is a type of genomic variation with an important effect on animal phenotype. We found that the PIGY gene contains a 3600 bp copy number variation (CNV) region located in chromosome 6 of sheep (Oar_v4.0 36,121,601–36,125,200 bp). This region overlaps with multiple quantitative trait loci related to phenotypes like muscle density and carcass weight. Therefore, in this study, the copy number variation of the PIGY gene was screened in three Chinese sheep breeds, namely, Chaka sheep (CKS, May of 2018, Wulan County, Qinghai Province, China), Hu sheep (HS, May of 2015, Mengjin County, Henan Province, China), and small-tailed Han sheep (STHS, May of 2016, Yongjing, Gansu Province, China). Association analyses were performed on the presence of CNV and sheep body size traits. We used real-time quantitative PCR (qPCR) to detect the CNV for association analysis. According to the results, the loss-type CNV was more common than other types in the three breeds (global average: loss = 61.5%, normal = 17.5%, and gain = 21.0%). The association analysis also showed significant effects of the PIGY gene CNV on body weight, chest circumference, and circumference of the cannon bone of sheep. Sheep with gain-type CNV had better growth traits than those with other types. The results indicate a clear relationship between the PIGY gene CNV and growth traits of sheep, suggesting the use of CNV as a new molecular breeding marker.

Geographical Elements in the Flora of Victoria

1976 ◽  
Vol 24 (2) ◽  
pp. 249 ◽  
Author(s):  
PB Bridgewater
Keyword(s):  
Plant Communities ◽  
Vascular Plants ◽  
Distribution Data ◽  
Inverse Association ◽  
Central Victoria ◽  
South Central ◽  
Southern Half ◽  
Species Groups ◽  
Geographical Elements ◽  
Very High

Distribution data for vascular plants in Victoria were recorded on grid squares of 1° latitude by 1.5° longitude. Data for six angiosperm families (Cyperaceae, Liliaceae, Chenopodiaceae, Rhamnaceae, Rutaceae and Myrtaceae) were analysed by the techniques of normal and inverse association analysis. Analyses of the data produced a series of species groups with similar geographical ranges (elements). These elements may be broadly divided into eastern and western groups, with two exceptions-one extending over the southern half of the State and the other occupying the coastal fringe. Geographical elements are helpful in defining the range of plant communities, as well as suggesting hypotheses as to the origins of floras. South central Victoria is seen to be a junction for species of both the eastern and western groups of elements, which may explain the very high number of species recorded from the Melbourne region.

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