An overview of aquatic vegetation in Serbia

Abstract

The majority of aquatic vegetation studies in the Middle Danube Basin (Serbia) were done independently during the last two decades, including data from small areas, which resulted in several classification solutions. The main purpose of this paper was to develop a numerical classification of the aquatic vegetation in Serbia, without fitting the vegetation groups into the existing phytocoenological classification scheme. Datasets of (i) surface and subsurface vegetation of free-floating duckweeds, ferns, liverworts and bladderworts, and (ii) vegetation of free-floating hydrocharids, submerged occasionally anchored ceratophyllids and rooted aquatic vegetation were compiled from phytocoenological releves (974). In order to fill the geographical and methodological gaps of these datasets, additional data matrix (iii) was compiled from sample quadrats (1055), collected during the aquatic vegetation season (summer months) of 2009, 2010 and 2011 at 31 lakes in Serbia. The datasets were analyzed using SYN-TAX 5.1 program, by non-metric hierarchical clustering OrdClAn and the Goodman-Kruskal's gamma resemblance coefficient. The cluster analysis revealed 28 aquatic vegetation groups (VG), of which three have been recognized as new vegetation units for the area of study: VG dominated by Vallisneria spiralis and Potamogeton perfoliatus, VG characterized by Polygonum amphibium and VG with Paspalum paspaloides as a constant. Geographical ranges and constant, diagnostic and dominant species of vegetation groups were determined.