1. From: McCune, B. & J. B. Grace. 2002. Analysis of Ecological Communities. MjM Software Design, Gleneden Beach, Oregon http://www.pcord.comhttp://www.pcord.com Tables, Figures, and Equations

2. Figure 15.1. Comparison of ordination of sample units in species space before and after varimax rotation. Dots represent sample units. The vectors show correlations of species with the ordination space. Note the improved alignment of the vectors with the ordination axes in the rotated ordination. The vectors are calculated with the PC-ORD method (Ch. 13).

3. Figure 15.2. Rotation of ordinations to align patterns from separate ordinations. In Ordination 1, the point cloud has been rotated to maximize the loading of Variable 1 onto Axis 1. In Ordination 2, the same dominant trends were found but at an angle to those found in Ordination 1. Therefore, Ordination 2 can be rotated through an angle (indicated by arrow) so that it too aligns Variable 1 with Axis 1. In Ordination 3, the configuration is not only at an angle to Ordination 1, but it is also a mirror image of it. To align Ordination 3 with Ordination 1, Axes 1 and 2 are first rotated to align Axis 1 with Variable 1 (Step 1). In Step 2, the ordination is rotated by 180o in the plane of Axis 2 and 3, such that both Variables 1 and 2 are now similar in orientation to Ordination 1.