Is maximizing resilience compatible with established ecological goal functions?
N. P. Kristensen, A. Gabric, R. Braddock, R. Cropp (2003)
Keywords: Concordance, Emergent properties, Resilience, Thermodynamic goal functions
Abstract
Cropp and Gabric [Ecosystem adaptation: do ecosystems maximise
resilience? Ecology. In press] used a simple
phytoplanktonzooplanktonnutrient model and a genetic algorithm
to determine the parameter values that would maximize the
value of certain goal functions. These goal functions were to
maximize biomass, maximize flux, maximize flux to biomass
ratio, and maximize resilience. It was found that maximizing
goal functions maximized resilience. The objective of this
study was to investigate whether the Cropp and Gabric
[Ecosystem adaptation: do ecosystems maximise resilience?
Ecology. In press] result was indicative of a general
ecosystem principle, or peculiar to the model and parameter
ranges used. This study successfully replicated the Cropp and
Gabric [Ecosystem adaptation: do ecosystems maximise
resilience? Ecology. In press] experiment for a number of
different model types, however, a different interpretation of
the results is made. A new metric, concordance, was devised to
describe the agreement between goal functions. It was found
that resilience has the highest concordance of all goal
functions trialled, for most model types. This implies that
resilience offers a compromise between the established
ecological goal functions. The parameter value range used is
found to affect the parameter versus goal function
relationships. Local maxima and minima affected the
relationship between parameters and goal functions, and
between goal functions.
Ecological Modelling 169: 61--71.