IMPACT ASSESSMENT OF LITTORAL VEGETATION CONDITIONS OF BASIN OF VESELÍ SYSTEM ALTER GRAVEL - SAND EXTRACTION

The sand-pits which were formed especially in the floodplain of the Lužnice River since the 1950s, curretly constitute important landscape elements of the Třeboň Basin. My bachelor thesis is focused on the assessment of the littorla vegetation of sand-pits of Veselí system. Field investigations were carried out from beginning foe July till mid-Septamber 2006 on the Veselí systém, which includes five snad-pit lakes. Seventy-four phytosociological relevés were places along the shores of all lakes in order to document the littoral vegetation as well as main environmental paramentrs and the extent of anthropogenic influence. A total of 137 plant species, of which 115 herbs and 22 trees and shrubs, were recorded on these relevés. The records included two stronngly endangered species: Lysimachia thyrsiflora and Lycopodiella inundata. The biotopes hosted 51 wetland species and 20 ruderal species