Abundance-Biomass Comparison curves

ABC curves plot abundance and biomass k-dominance lines on the same plot, and are interpreted in the literature as indicating an undisturbed community if the biomass curve is above the abundance curve, gross disturbance if the abundance curve lies above the biomass and moderate disturbance if the two largely intersect. This is based on the observation that for climax communities of soft-sediment macrobenthos the biomass dominants are large-bodied but do not dominate abundance, and are the more susceptible species to impact, whereas gross disturbance, especially from organic enrichment, leads to abundance dominance by a few, small-bodied opportunist species. (A very different example is given by Smith WH & Rissler LJ, 2010, Restor Ecol 18, 195-204, who show that ABC curves for herpetofauna track succession after forest fires).

Restore the full set of samples for Linnhe macrofauna abundance by Select>All (and Edit>Clear Highlight if you wish, though the latter is unnecessary since all routines – with the exception of Pre-treatment>Transform (individual) – operate on the current selection, not the highlights). The eleven ABC plots, one for each sample (year), are generated by a single run of Analyse>Dominance Plot, and placed in a multi-plot. The active sheet must be the abundance matrix and the Linnhe macrofauna biomass matrix must be available in the workspace as the secondary sheet.