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ECOM II

Sample Score and Species Score tabs. Generally you will be far more interested in

the plot of the results which is viewed from the Ordination Plot tab is shown below.

This is a plot of the 1st and 2nd canonical axes, which we have shown above are the

only statistically significant axes. Thus, there is not much point in examining the

other axes.

The lengths and positions of the arrows provide information about the relationship

between the environmental variables and the derived axes. Arrows that are parallel to

an axis (e.g. moisture and axis 1) indicate a correlation, the length of the arrow tells

us about the strength of that correlation. Thus, pasture is related to axis 1 but not as

strongly as moisture. Neither of these is related to axis 2.

The above plot is rather confusing and cluttered because we have plotted the

environmental vectors or centroids, the site (sample) scores and the species

(dependent variable) scores all on the same graph. Further, all the labels have been

included. The 

graph plotting options

 allow many variations to be plotted to make the

output clearer.

The position of the sites indicates their status with respect to the environmental

variables. Thus site 19 has a negative score on axis 2 and axis 2 has a high manure

component. This indicates that we would predict there has been little manuring on

site 19.

In similar fashion the positions of the species indicates their response to particular

environmental variables. For example Potpal, Elepal and Ranfla are associated with

moist sites.

Copyright 2004  PISCES Conservation Ltd