Data from: Loss of spatial structure after temporary herbivore absence in a high-productivity reed marsh. Journal of Applied Ecology.Here, we experimentally tested how the release from grazing by greylag geese (Anser anser) affects spatial vegetation structure in a highly productive, brackish marsh in which dense reed (Phragmites australis) stands and bare roosting areas co-exist. Next, we assessed the resilience of the change in vegetation patterning by re-introducing the geese after a two-year exclosure period. The experiment was conducted on the West-Frisian barrier island of Schiermonnikoog in the years 2014 to 2017. The full methodology can be found in the linked paper.This dataset contains the vegetation biomass and surface elevation along transects in our experimental plots over the three-year experimental period.