This paper presents the ecological risk factors related to the watercourses regulation and maintenance works on the small and medium-sized lowland water-courses found in Lower Silesia. These factors include: occurrences related to the execution of regulation and maintenance works, which have an impact on the eco-logical condition of the watercourses, probability of these occurrences and their consequences in the form of adverse ecological changes in the river beds. Based on the observed responses of aquatic vascular plants species to the technical inter-ference on a watercourse's bed, a detailed assessment of one of these factors - ecological changes in the watercourse's bed was made. Field studies were con-ducted during 2007-2008 on 44 sections of various unregulated, conserved and regulated watercourses. Research included identifying the species of aquatic macrophytes found in the streambed as well as determining the degree of cover-age.The field studies showed, that the regulation and maintenance works had an adverse impact on the aquatic plant species composition. In most cases species removed during the technical interference did not regenerate. In some transformed study sections the plant species abundant was lower than on the unregulated tran-sects. Only in rare cases the plant species abundant in the compared study sec-tions was ...
The following study presents an assessment of the influence of fascine and stone scarp`s reinforcement on the quantitative and qualitative composition of vascular water plants. The analysis was based on field results obtained between 2007 and 2008, and 2011-2012. The research was performed in four small and medium lowland watercourses located in Lower Silesia were 16 study sections were established. These sections varied in the material used for scarps` reinforcement. The field research included identification of vascular water plants occurrence in the river bed and determination of the degree of their bottom coverage. These factors served as the basis for Shannon-Wiener biodiversity index calculation. Jaccard`s species similarity index was used for the assessment of similarities among water plants communities in different study sections. Conducted research indicates that the choice of the scarp`s reinforcement has an impact on analyzed plant indexes and it does not undergo any changes re-lated to time. However, positive indexes change has been reported in water plants communities. ...
