Abstract:
We present a statistical method called STATICO that can be
used to analyze series of pairs of ecological tables. The objective of
this method is to find the stable part in the dynamics of the
relationships between the species and their environment. The treated
data are a sequence of pairs of ecological tables. Each pair is made of
a species abundance table (species in columns) and an environmental
variables table (variables in columns). The sampling sites (in rows)
must be the same for the two tables of one pair, but they may be
different among the pairs. The environmental variables must be the same
in all the environmental tables, and the list of species must be the
same in all the species tables too, although some species may be absent
from some tables (the corresponding columns will contain all zeroes).
From a statistical point of view, STATICO is a multitable analysis
(partial triadic analysis) performed on the series of cross-tables
resulting from the co-inertia analysis of each pair of tables. A small
ecological example data set is analyzed and the results are discussed
to show how this method can be used to extract the stable part of
species-environment relationships. All computations and graphical
displays can be performed with a free software available on Internet.
Key words :
Series of paired ecological tables, three-way table, STATICO, STATIS,
partial triadic analysis, interstructure, compromise, co-inertia analysis,
canonical correspondence analysis, redundancy analysis, ADE-4.