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The analysis of vegetationenvironment relationships by canonical correspondence analysis
, 1987
"... Canonical correspondence analysis (CCA) is introduced as a multivariate extension of weighted averaging ordination, which is a simple method for arranging species along environmental variables. CCA constructs those linear combinations of environmental variables, along which the distributions of the ..."
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Canonical correspondence analysis (CCA) is introduced as a multivariate extension of weighted averaging ordination, which is a simple method for arranging species along environmental variables. CCA constructs those linear combinations of environmental variables, along which the distributions of the species are maximally separated. The eigenvalues produced by CCA measure this separation. As its name suggests, CCA is also a correspondence analysis technique, but one in which the ordination axes are constrained to be linear combinations of environmental variables. The ordination diagram generated by CCA visualizes not only a pattern of community variation (as in standard ordination) but also the main features of the distributions of species along the environmental variables. Applications demonstrate that CCA can be used both for detecting speciesenvironment relations, and for investigating specific questions about the response of species to environmental variables. Questions in community ecology that have typically been studied by 'indirect ' gradient analysis (i.e. ordination followed by external interpretation of the axes) can now be answered more directly by CCA.
An analysis and synthesis of multiple correspondence analysis, optimal scaling, dual scaling, homogeneity analysis and other methods for quantifying categorical multivariate data
 Psychometrika
, 1985
"... We discuss a variety of methods for quantifying categorical multivariate data. These methods have been proposed in many different countries, by many different authors, under many different names. In the first major section of the paper we analyze the many different methods and show that they all lea ..."
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We discuss a variety of methods for quantifying categorical multivariate data. These methods have been proposed in many different countries, by many different authors, under many different names. In the first major section of the paper we analyze the many different methods and show that they all lead to the same equations for analyzing the same data. In the second major section of the paper we introduce the notion of a duality diagram, and use this diagram to synthesize the many superficially different methods into a single method. Key words: multiple correspondence analysis, optimal scaling, dual scaling, homogeneity analysis, categorical multivariate data. This paper has two major sections. In the first section we discuss a variety of apparently different data analysis methods and show that they all lead to the same equations for analyzing the same data. In the second section we use the notion of a duality diagram to systematize and organize the relationships between these superficially different meth
Canonical community ordination. Part I: Basic theory and linear methods. Ecoscience
 Ecoscience
, 1994
"... 1 Canonical community ordination comprises a collection of methods that relate species assemblages to their environment, in both observational studies and designed experiments. Canonical ordination differs from ordination sensu stricto in that species and environment data are analyzed simultaneously ..."
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1 Canonical community ordination comprises a collection of methods that relate species assemblages to their environment, in both observational studies and designed experiments. Canonical ordination differs from ordination sensu stricto in that species and environment data are analyzed simultaneously. Part I reviews the theory in a nonmathematical way with emphasis on new insights for the interpretation of ordination diagrams. The interpretation depends on the ordination method used to create the diagram. After the basic theory, Part I is focused on the ordination diagrams in linear methods of canonical community ordination, in particular principal components analysis, redundancy analysis and canonical correlation analysis. Special attention is devoted to the display of qualitative environmental variables. Key words: principal components analysis, redundancy analysis, canonical correlation analysis, biplot, ordination diagram, speciesenvironment relations. 2
Biocenoses of Collembola in atlantic temperate grasswoodland ecosystems
 Pedobiologia
, 1993
"... Summary. Samples (679) from various forest sites in the atlantic temperate region (lowlands in the northern half of France) have been studied. Their Collembolan species composition (145 species, with only 43 rare species) was analysed by Benzecri's correspondence analysis, a multivariate method ..."
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Summary. Samples (679) from various forest sites in the atlantic temperate region (lowlands in the northern half of France) have been studied. Their Collembolan species composition (145 species, with only 43 rare species) was analysed by Benzecri's correspondence analysis, a multivariate method. Five groups of species, each associated with a given habitat, were determined: above the ground surface a distinction is evident between light species (open sites), hygrophilic species (moist forest sites) and corticolous species (dry forest sites); edaphic species may be divided into acidophilic species (mor, moder and acid mull humus) and neutroacidocline species (earthworm mull). A depth gradient may be traced from edaphic to atmobiotic species in both forest and open sites. As a conclusion, it is apparent that vegetation in itself does not directly influence Collembola but may effect them indirectly through humus formation.
Continuous Track Analysis: A New Phylogenetic and Biogeographic Method. Systematic Biology 44
, 1995
"... Abstract.—Continuous track analysis (CTA) can depict reticulate evolutionary patterns in phylogenetics and biogeography. A reticulate connection implies convergence, hybridization, or introgression in an evolutionary graph of taxa and implies dispersal in an evolutionary graph of biogeographic are ..."
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Cited by 13 (0 self)
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Abstract.—Continuous track analysis (CTA) can depict reticulate evolutionary patterns in phylogenetics and biogeography. A reticulate connection implies convergence, hybridization, or introgression in an evolutionary graph of taxa and implies dispersal in an evolutionary graph of biogeographic areas. CTA finds graphs that (1) have a minimal number of connections and (2) imply that most character states or taxa have distributions or tracks across taxa or areas (objects) that are continuous, i.e., can be traced across the connections among the objects including that state without traveling through any other objects. Continuous tracks imply either that character states in phylogenies have unique evolutionary origins or that taxa in biogeographic analyses are monophyletic. Relatively simple graphs usually cannot imply completely continuous tracks. Therefore, CTA graphs seek to minimize the number of track fragments, which are locally continuous parts of a track; tracks with more than one fragment are discontinuous. Minimizing fragments is the same as minimizing characterstate transitions only if there are no reticulations. Because hypothetical ancestors do little to reduce the number of fragments, CTA tends to place known taxa or areas at internal nodes. A heuristic algorithm analogous to tree bisectionreconnection is used to find highly parsimonious CTA graphs. In phylogenetic analyses, CTA employs a special com
Weighted averaging partial least squares regression (WAPLS): an improved method for reconstructing environmental variables from species assemblages. Hydrobiologia
, 1993
"... methods for speciesenvironment calibration. Chapter 25 in: Multivariate Environmental ..."
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methods for speciesenvironment calibration. Chapter 25 in: Multivariate Environmental
oro.open.ac.uk Quantification of Uncertainties in Fossil Leaf Paleoaltimetry Does Leaf Size Matter?
"... and other research outputs Quantification of uncertainties in fossil leaf aleoaltimetry: does leaf size matter? Journal Article ..."
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and other research outputs Quantification of uncertainties in fossil leaf aleoaltimetry: does leaf size matter? Journal Article
Metric Scaling Graphical Representation of Categorical Data
 Penn State University
, 1995
"... : Metric Scaling is a wellknown method to represent a finite set with respect to a given Euclidean distance matrix. Several methods to represent rows and columns of a twoway contingency table are available: Correspondence Analysis, Dual Scaling, Canonical Coordinates, etc. We show that metric s ..."
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: Metric Scaling is a wellknown method to represent a finite set with respect to a given Euclidean distance matrix. Several methods to represent rows and columns of a twoway contingency table are available: Correspondence Analysis, Dual Scaling, Canonical Coordinates, etc. We show that metric scaling provides a similar representation by using Hellinger or Rao distances together with Gower's addapoint formula and discuss its relationship with the other approaches. The present approach suggests an alternative to Multiple Correspondence Analysis for multivariate categorical data. Keywords: Categorical data; Correspondence Analysis; Distances between observations; Multidimensional scaling; Biplot. AMS Subject Classification: 62H25, 62H20, 6209. 1 Introduction The statistical methodology dealing with categorical data currently has an increasing interest. Under the name Correspondence Analysis (CA), the data analyst recognizes a method of graphical representation of categorical ...