This README file describes the 21 attribute fields in the dataset accompanying the above publication. The notation ‘ntr’ and ‘na’ in the dataset means ‘nothing to report’ and ‘not available’, respectively. Field name Description id unique identifier for each field observation. site unique site name. transect_num transect number at a given site. plot_num plot number along a given transect. X longitude coordinates in degrees (WGS 84 coordinate system, EPSG 4326). Y latitude coordinates in degrees (WGS 84 coordinate system, EPSG 4326). GPS_acc accuracy of geographical coordinates (in m). ‘dep’ indicates that the plot was georeferenced using aerial photographs due to field-accessibility issues (e.g. ledge, swamp). HGM hydrogeomorphic type from Brinson (1993), expressed in five categories: ‘riverine or estuarine fringe’, ‘depressional’, ‘slope’, ‘lacustrine fringe’, ‘flat’. Brinson, M., 1993. A Hydrogeomorphic Classification for Wetlands (Wetlands Research Program Technical Report No. WRP-DE-4). US Army Corps of Engineers. habitat_code Code of habitat type according to the EUNIS classification system (Davies et al. 2004). ‘INV’ indicates that vegetation entirely consists of invasive plant species. Davies, C.E., Moss, D., Hill, M.O., 2004. EUNIS habitat classification revised 2004. Rep. Eur. Environ. Agency-Eur. Top. Cent. Nat. Prot. Biodivers. 127–143. habitat_name Name of habitat type according to the EUNIS classification system. habitat_min_radius minimum radius of the vegetation patch (in m). soil_depth depth of the soil profile (in cm). soil_redox_depth depth of occurrence of redox features that covered 5% or more of the soil aggregates (in cm). soil_redox_thickness thickness of redox features that covered 5% or more of the soil aggregates (in cm). soil_reduced_depth depth of the occurrence of soil horizons with a reduced matrix that covered 95% or more of the soil aggregates (in cm). soil_reduced_thick soil_ness thickness of soil horizons with a reduced matrix that covered 95% or more of the soil aggregates (in cm). soil_histic_depth depth of the occurrence of histic features in the soil profile (in cm). soil_histic_thickness thickness of histic features in the soil profile (in cm). soil_organic_thickness thickness of the organo-mineral horizon in the soil profile (in cm). soil_moist_0_50 soil moisture at a depth of 0-50 cm. Expressed in ordinal categories: ‘1_dry’, ‘2_fresh’, ‘3_moist’, ‘4_damp’ or ‘5_ waterlogged’. soil_moist_50_120 soil moisture at a depth of 50-120 cm. Expressed in ordinal categories: ‘1_dry’, ‘2_fresh’, ‘3_moist’, ‘4_damp’ or ‘5_ waterlogged’.