Regrowth or dispersal? Recovery of a freshwater red alga following disturbance at the patch scale

Abstract

Disturbance is an important factor in species coexistence. Disturbance models require knowledge about whether disturbed patches must be colonized anew from dispersal or whether species left behind can dominate, hence altering recovery trajectories of patches. The red, filamentous alga Audouinella hermannii Roth is a common macroalgal species present at sites in the Steavenson River, a stony, upland stream in south-eastern Australia. We conducted an experiment in which we contrasted the recovery trajectory of the alga on overturned rocks compared with those that were not overturned, and for rocks that had remnants of the alga left behind compared with others where the alga was scrubbed off co..