When an ecological network is expressed as a series ofenergy flows and transformation steps where the transformation steps are represented as Lindeman efficiencies, the resulting UEVs represent trophic convergence and a measure of the amount ofsolar energy required to produce each level in the hierarchy. As such, they play the role ofefficiency indicators. This is true for systems selected under maximum power constraints and is therefore true in healthy ecosystems. However, in an ecosystem stressed by excess outside pressure, relationships among components are likely to change: some components may disappear, others may emerge, and the whole hierarchy may be altered. The efficiency of given processes within the system may therefore change and due to a simplified structure of the system, some patterns of hierarchical control of higher to lower levels may diminish or disappear. All in all, these changes will translate into different values of the UEVs, the variations of which become clear measures of lost or decreased system integrity.
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