Community Analysis Package
This menu allows you to (1) assign individual samples to different groups, (2)
undertake an Analysis of Similarity (
) and (3) Identify those species
which most contribute to the similarity (or dissimilarity) between samples
Why does CAP allows you to assign samples to groups? You might for example
allocate a series of samples to polluted and control groups or in a benthic study to
different physical conditions such as mud, sand and gravel substrates. In another
type of study you might want to define as a group all samples that held a species
of particular interest.
By allocating samples to groups you can show the different groups in ordination
plots and other graphs.
For example, in the Powerfish example dataset supplied with CAP the species of
fish caught on different power station intakes the stations are grouped as
estuarine and marine. If a PCA is run on these data the two groups can be clearly
seen to cluster around different positions within the ordination space.
Once samples have been placed into groups you can test if the similarity of
samples within each group is greater than the similarity that would occur by
random chance using
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