The Little Bubbler Spring – near Blanche Cup and The Bubbler in Wabma Kadarbu Mound Springs Conservation Park – has shown some interesting vegetation trends over the past two decades or so.

The vegetation of the Little Bubbler has been monitored since the mid-1980s and had an almost pure stand of bore-drain sedge, Cyperus laevigatus, until the early 2000s. At that time, reeds (Phragmites) established at the spring vent, very likely as a result of seed transported to the spring on the boots of monitoring personnel. Subsequent colonisation of the spring vent by Phragmites was slow. The next significant perturbation of the spring occurred from 2016, when cattle from neighbouring Stuart Creek pastoral lease breached boundary fencing and had a major impact on the Little Bubbler and other springs nearby.

Since 2018, cattle pressure on the Little Bubbler has eased and there has been an interesting sequence in the recovery of spring vegetation. Although the spring vent was dominated by Phragmites at the time of cattle impact, the bore-drain sedge, C. laevigatus, was the first to recolonise the vent. Only after the sedge had stabilised the vent area did the Phragmites once again exert itself and, as at August 2023, it now dominates the spring vent. This is shown in the accompanying sequence of photographs.

A similar trend has been seen at Bopeechee Spring, on Finniss Springs, where horses rather than cattle have had major impact. The underlying factors are not clear but it is apparent that at least in these two cases – where a spring with both Cyperus laevigatus and Phragmites is impacted by grazing herbivores – it is the Cyperus that recovers first with regrowth of Phragmites occurring as a secondary process. Care should be taken not to over-generalise this phenomenon but it has occurred at Little Bubbler and Bopeechee.