Compartment Stock-and-Flow Models Revisited: DaD-Unstable Pine Forest Svicobia.ns Need a New Stability Concept

Revisiting stock-and-flow models is motivated by a recent publication that reported on the stability analysis in the simplest stock-and-flow diagram for a Sphagnum-type pine forest and indicated inconsistences in certain empirical data. To address the question of whether this discouraging result was due to oversimplifying the model, I examine here a diagram consisting of five compartments and apply the Svicobian notion in couple with its DaD-stability. The method of this analysis proves unexpectedly the same as that to certify the sign stability of a real n×n matrix and it does prove the pine forest Svicobian to be DaD-unstable. This instability entails quite definite conclusions for both the theory of compartment models and the practice of their applications.