Ascendency as an ecological indicator in the nitrogen flow of the Neuse River Estuary, North Carolina, USA

Abstract

Ascendency, a holistic measure of a system’s aggregate activity and flow distribution, is employed to evaluate sixteen seasonal models of nitrogen flow in the Neuse River Estuary. The results and methods are contrasted with ascendency’s typical use with carbon food web models. Ascendency (A), developmental capacity (C), A/C ratio, total system throughput, average mutual information, overheads, and Finn’s cycling index values for the Neuse are reported. The use of the A/C ratio, rather than ascendency alone, for ecosystem comparisons is supported as found in other recent studies. An indicator ratio (Ag+d) is presented as an alternative to ascendency for short-term analysis, distinguishing between increases in ascendency via growth (g) and development (d), and increases coupled with information loss. Focusing on ascendency as an ecological indicator, an attempt is made to use ascendency theory to inform ecological managers while employing the Neuse River Estuary’s nitrogen flow to inform ascendency theory.