Table 1. Sampling sites of coastal Salix repens communities used in this study.

Site	Code	Geological district, habitat	Latitude, longitude	pH	OTUs
Goeree: Middelduinen	R-G1	Renodunal, wet	51.827238; 3.943405	6.01	971
Goeree: Westduinen	R-G2	Renodunal, wet	51.810850; 3.861609	6.73	934
Wassenaar: Meijendel 1	R-M1	Renodunal, dry	52.137439; 4.341960	7.3	691
Wassenaar: Meijendel 2	R-M2	Renodunal, dry	52.142707; 4.333034	7.42	790
Haarlem-Bentveld: Amsterdamse Waterleidingduinen 1	R-H1	Renodunal, wet	52.338001; 4.531978	7.11	727
Haarlem-Bentveld: Amsterdamse Waterleidingduinen 2	R-H2	Renodunal, dry	52.337312; 4.533910	6.56	660
Callantsoog: Zwanenwater 1	W-Z1	Wadden, dry	52.822073; 4.709229	5.71	867
Callantsoog: Zwanenwater 2	W-Z2	Wadden, wet	52.821516; 4.708264	5.32	762
Terschelling: Groene Strand	W-T1	Wadden, wet	53.364741; 5.201769	6.39	718
Terschelling: West aan Zee	W-T2	Wadden, dry	53.398326; 5.269489	5.78	804

Code, geological district, habitat type (wet dune slack vs. dry dune side and top), geographic coordinates, soil pH, number of quality-filtered sequences and the number of 97% ITS2 sequence similarity OTUs are displayed for each site.