DNA)**                                                                                                                                                                                                             BS                                   Water           ND                                          \>00             0.00                                            0.00                                              0                −0.00   BSM                                  Water           ND                                          \>00             0.00                                            0.00                                              0                −0.00   BS                                   Sediment        ND                                          \>0              0.00                                            na                                                na               na   BSM                                  Sediment        ND                                          \>0              ND                                              na                                                na               na   BSM                                  Vegetation      ND                                          \>00             0.00                                            0.00                                              0                −0.00  *BS, mesocosm without vegetation; BSM, mesocosm with vegetation; N~nat~, background count before spike; t~bac~, time required for target counts to reach the background level; 