The experiment was established in 2007 in the high marsh and consisted of four blocks of 12 m x 8 m. The blocks differed in surface-elevation change during the experiment. Each block was subdivided into 24 plots of 1 m x 1 m. The original elevation of all plots in relation to the German ordnance datum (NHN) was assessed at the start of the experiment. Plots within the blocks were randomly assigned to one of the three N-fertilisation treatments.Within each plot we planted five randomly chosen individuals of Elymus. After four years of treatment, the vegetation composition and cover was recorded in all plots and aboveground biomass was collected.

Supplement to: Nolte, Stefanie; Wanner, Antonia; Stock, Martin; Jensen, Kai (2019): Elymus athericus encroachment in Wadden Sea salt marshes is driven by surface‐elevation change. Applied Vegetation Science, 22(3), 454-464