Post‐disturbance evolution of a prograded foredune barrier during a sustained dynamic restoration project—the role of wind speed, wind direction and vegetation

Abstract Disturbed (de‐vegetated) coastal dunes can follow divergent evolutionary pathways, evolving to one of a range possible morphologies in response spatial and temporal variations windiness (i.e. the speed direction competent winds) or vegetation cover magnitude rate loss). Here we examine influence these factors on evolution two adjacent barriers during sustained dune restoration programme, at Doughboy Bay, Aotearoa/New Zealand. We document shift from stable prograded foredune barrier mobile state over 15‐year period. The patterns sedimentation across reflect alongshore incident wind direction. Changes resulted an gradient speed, with little decline recorded towards more sheltered sections almost total loss centre bay. Subsequent changes continued gradients direction, increase associated relatively coast no change exposed parts barriers. Finally, localized sediment accumulation both is strongly presence dune‐building species. This case demonstrates post‐disturbance development. propose three‐stage conceptual model consistent existing biogeomorphic disturbance models: (1) initial ‘reaction’ phase, characterized by high topographic change; (2) ‘activation’ low rapid rates (3) ‘stabilization’ increasing stability. Dune interventions this type would clearly benefit analysis conditions prior commencement careful consideration where how reintroduce native sand‐binding