What is meant by increase in information embodied in the system?
Table 1 on the next page (p. 36) lists a number of properties for each of the three "growth forms".

For information, properties include:  


Life history types
Diversity (taxonomic &amp; ecological)
Body size
Stability


I have to admit that some of these properties doesn't really make sense to me under these headings (at least from the common use of these terms). However, I suspect that they are used in a very specific sense that might make sense if you read the entire book. And systems ecology isn't really my thing.

Note also that exergy (which is used in relation to these three growth forms in the book) is a term borrowed from thermodynamics (ie physics), and it describes potential/available work. Exergy is also negatively related to entropy, so when exergy decreases, entropy increases. Since higher entropy is related to disorder, the opposite goes for exergy, so high exergy means a higher amount of order (within the system), which can be translated into "structural information". I suspect that this is the form of information that the book is referring to, as one of the "growth forms".