[EAS]Ecosystems on the Brink?

[pjk]

Subject:   Ecosystems on the Brink?

Nonlinearities, as engineers well know, are what make a lot of
engineering interesting, providing changes of state in systems that
provide recognition (logic) thresholds, memory, learning and many
other important system attributes.

http://www.sciencedaily.com/releases/2001/10/011011065827.htm
http://www.nature.com/nature/links/011011/011011-3.html

A major review article in Nature, and a news article about it, tell us
that ecosystems can be gradually pushed beyond their realm of
equilibration, into sudden catastrophic shifts, a most unwelcome
change of state. 
Apart from raising concern about what 'margins of safety' might be
assumed for ecosystems, it also raises the interesting question
whether it is more effective to improve an ecosystem's ability to
maintain its stability (making it more 'robust,' as engineer's would
say) vs. the more traditional practice of controlling the impact of
destabilizing disturbances ('sheltering' it, as it were). The
proposition of 'ruggedizing' ecosystems should be approached with
some humility, I would think. --PJK