Salt marsh plant community development in a metacommunity experiment in the Wadden Sea

Shallow tidal coasts are characterized by shifting tidal flats and
emerging or eroding islands above the high tide line. Salt marsh
vegetation colonizing new habitats distant from existing marshes are an
ideal model to investigate metacommunity theory. We installed a set of 12
experimental salt marsh islands made from metal cages on a tidal flat in
the German Wadden Sea to study the assembly of salt marsh communities in a
metacommunity context. Experimental plots at the same elevation were
established within the adjacent salt marsh on the island of Spiekeroog.
For both experimental islands and salt marsh enclosed plots, the same
three elevational levels were realized while creating bare patches open
for colonization and vegetated patches with a defined transplanted
community. We followed the plant community assembly from the initial setup
in September 2014 until August 2023, when the experimental setup was
dismantled. The dataset includes vegetation data surveyed for two squares
of 1 x 1 m within the 2 x 2 m experimental plots that were randomly
assigned at the start of the experiment for permanent non-destructive
surveys. Plant species presence/absence was recorded for each 10 x 10 cm
area within 0.9 x 0.9 m quadrants placed at the center of the plot. Our
data highlights spatially and temporally explicit metacommunity dynamics
that should be considered in salt marsh plant community assembly and
disassembly. Details of the experimental setup are published in Balke et
al. 2017.