EVALUATION OF THE ECOLOGICAL STATUS AND DIVERSITY OF MACROPHYTES OF DRAINAGE DITCHES THREATENED BY A PESTICIDE TOMB

The research was aimed at determining whether a pesticide tomb affects the ecological status of drainage ditches located in its vicinity as well as how it affects the diversity of the flora of the ditches and in which direction its effect on the surrounding environment is. In addition, the results of the study are a contribution to a comparative analysis of methods for macrophyte evaluation of watercourses used in Poland and to identify the possibilities of their application in investigations of artificial watercourses under the pressure of pesticides. Values of indices of the hydromorphological evaluation (HQA, HMS) were similar for all drainage ditches examined. This points to a negligible effect of the pesticide tomb on the hydromorphological characteristics of the analyzed watercourses. The pesticide tomb was found to affect the ecological status and floral diversity of the drainage ditches. The lowest values of macrophyte and diversity indices were recorded in the first and the second watercourse, whereas higher ones were in the third watercourse. Changes in the indices of ecological status and those of floral diversity observed in the watercourses examined show that the effect of the pesticide tomb on the surrounding ecosystem is consistent with topographic features and proceeds in a north-easterly direction. Both methods of the macrophyte evaluation of the ecological status of watercourses (MTR, MIR) yield different numeric values, yet their results are comparable in terms of the tendency of changes in the ecological status of the analyzed watercourses. In both methods, the highest rank was reported for the third watercourse. The MTR index diversifies the examined watercourses to a smaller extent than the MIR index. The MIR method is better under conditions of lowland Poland for the evaluation of the ecological status of artificial watercourses, as it enables stronger diversification of the ecological status of the watercourses examined due to a higher number of indicatory species.