As fundamental changes in ecological–economic
systems can involve a loss of function and productivity
seen from a human perspective, a central research
question concerns the ability of systems to absorb stress
or shock without losing their self-organization. This
ability is called the resilience of the system (in the sense
of Holling, 1973, 1986), and in principle, it can be
measured by the severity of shock that can be absorbed
before the system flips to another stability domain. One
of the most important factors influencing the resilience
of a system is the diversity of organisms constituting
the system.