Fig. 1. Plot of the results from the two first factors in the principal component analysis (PCA) and factor analyses. TP_%, relative total phosphorus retention; TP_SL, specific total phosphorus load; TP_SR, specific total phosphorus retention; TP_CI, inlet total phosphorus concentration; TP_CO, outlet total phosphorus concentration; q, specific runoff from catchment; HLR, hydraulic loading rate; DRP, dissolved reactive phosphorus; A_w to A_c ratio, wetland surface area to catchment area ratio; age, years from construction of wetland; k, first-order removal rate constant.