Macrophytes in the assessment of river ecological condition on the example of Pszczynka River (Silesian Upland)

The Water Framework Directive introduced an ecological approach to the assessment and classification of waters. The part of the assessmentare macrophyte - based methods used in the evaluation of the ecologicalcondition of rivers in respect of biodiversity. The Macrophyte Method for River Assessment has been used in Poland since 2007 and provides us with an information about ecological state of the rivers. Presented analyses were aimed to describe macrophyte development in the sandylowland type of river in the Silesian Upland. The assessment was made for lowland Pszczynka River (45.8 km total length, total catchment area 368.3 km2), which is a left-bank tributary of Vistula River. At the selected 10 research sections of the river (100 m each) the composition of macrophytes and abiotic conditions of the river were described. The paper presents the results of preliminary assessment of ecological condition of Pszczynka River on the background sources of substances discharged to the riveralongits course. Macrophyte Index for Rivers (MIR) was calculated based on the results of the research - river bed surface coverage by the particular plant species. The MIR limit values were used to determine the class of water quality in the examined river. Overall, the ecological status of Pszczynka River was rated as moderate and its water classified as Class III of water quality.