In a 1981
PDC in Wilton, NH (and probably in the Designer's Manual somewhere, I haven't raised the funds for that brick yet), Ol'
Bill Mollison said (my italics):
Diversity isn't involved so much with the number of elements
in a system as it is with the number of functional connections
between these elements. Diversity is not the number
of things, but the number of ways in which things work.
(Source on page 7)
In this recent TED
video, Dave Troy maps big data to show the connections between people in different cities. This is systems science stuff. What's interesting, as
permaculture people, is that even in cities (huge human near-monocultures with some canines and felines) there are specific elements (ideas, people) that form functional relationships, and others that don't.
What I take away from this is the importance of remembering that diversity isn't just a lot of different elements, but elements that work together, or work for other elements. I really like Holzer's seed
bucket mix and dispersal method that helps you to observe those relationships (or lack thereof) as they evolve.